HomeMy WebLinkAboutCommittee of the Whole - 08 Sep 2025 - Agenda - Pdf
CITY OF RENTON
AGENDA - Committee of the Whole Meeting
6:00 PM - Monday, September 8, 2025
7th Floor Conferencing Center
1. KING COUNTY REGIONAL HAZARD MITIGATION PLAN AND RENTON
ANNEX ADOPTION
a) DRAFT Resolution
b) Exhibit A: King County Regional Hazard Mitigation Plan
c) Exhibit B: City of Renton Plan Annex
2. COUNCIL INTRODUCTION TO UPDATED AGENDA BILL SOFTWARE
1
CITY OF RENTON, WASHINGTON
RESOLUTION NO. _______
A RESOLUTION OF THE CITY OF RENTON, WASHINGTON, ADOPTING THE 2025-
2030 KING COUNTY REGIONAL HAZARD MITIGTION PLAN AND AUTHORIZING
THE CITY’S ANNEX THERETO, AND ADOPTING THE CITY OF RENTON PLAN
ANNEX.
WHEREAS, the City and the surrounding areas are subject to a wide range of natural and
anthropogenic hazards, including floods, winter storms, earthquakes, landslides, hazardous
material spills and more; and
WHEREAS, in 2020, a partnership between King County and over sixty (60) different
entities, including the City of Renton, schools, fire districts, utilities and other special purpose
districts created the King County Regional Hazard Mitigation Plan (“the Plan”); and
WHEREAS, the Plan, and City’s annex to the Plan, was adopted by the City Council on July
13, 2020; and
WHEREAS, Federal rules require the Plan to be updated every five years; and
WHEREAS, FEMA has announced its pending approval of the draft 2025-2030 King County
Regional Hazard Mitigation Plan (“the 2025-2030 Plan”) and King County plans to formally adopt
the 2025-2030 Plan by September 2025; and
WHEREAS, it is necessary for City Council to adopt the 2025-2030 Plan and authorize the
City of Renton’s annex thereto, and adopt the City of Renton’s Plan Annex;
NOW, THEREFORE, THE CITY COUNCIL OF THE CITY OF RENTON, WASHINGTON, DO
RESOLVE AS FOLLOWS:
AGENDA ITEM #1. a)
RESOLUTION NO. _______
2
SECTION I. The City Council adopts the 2025-2030 Plan, attached hereto as Exhibit A, in
anticipation of adoption by the King County Council in September 2025.
SECTION II. The City Council adopts the City of Renton Plan Annex to the 2025-2030 Plan,
attached hereto as Exhibit B.
PASSED BY THE CITY COUNCIL this day of , 2025.
______________________________
Jason A. Seth, City Clerk
APPROVED BY THE MAYOR this day of , 2025.
______________________________
Armondo Pavone, Mayor
Approved as to form:
Shane Moloney, City Attorney
RES-EM: 25RES023: 8.6.2025
AGENDA ITEM #1. a)
King
County
Regional
Hazard
Mitigation
Plan
2025 - 2030
EXHIBIT A
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Executive Summary
i
Acknowledgements
The King County Office of Emergency Management extends its sincere gratitude to our local, state,
and national partners, non-governmental organizations, community members, and dedicated staff
whose expertise, experience, and support were instrumental in the development of this plan. All
contributions, big and small, are greatly appreciated.
Program Leads
Mercedes Stroeve, King County Hazard Mitigation Planner
Andrew Matthews, King County Emergency Management Coordinator
County Agency
Brendan McCluskey, Director OEM
Nicole Johnson, Risk Reductions Manager OEM
Celia Taylor, Planning & Finance Manager OEM
Sheri Badger, Public Information Officer OEM
Alli Ferreri, Wildfire Planning Coordinator OEM
Andrew Dixon, Dam Safety Coordinator OEM
Edan Edmonson, Prevention Coordinator OEM
Lexi Swanson, Homeland Security Coordinator OEM
Nathan Emory, Extreme Weather Coordinator OEM
Tom Sharp, LEPC Manager OEM
Sunita Hall, Zone-1 Liaison OEM
Sally Calengor, Zone-3 Liaison OEM
Audrey Hoen, Cyber Security Fellow OEM
Alexis Mee, Preparedness Fellow OEM
Keara Ryan, Preparedness Specialist OEM
Ken Zweig, Program Manager, DNRP
Laura Hendrix, Floodplain Management Program
Manager DNRP
Katy Vanderpool Program Manager, DNRP
Mike Lasecki, Rural Forest Health Coordinator KCD
Stephan Carr, Assistant CISO KCIT
Jamie Emert, Emergency Preparedness Planning and
Partnerships Manager PHSKC
Lara Whitely-Binder, Climate Preparedness Specialist
EOC
Cecelia Hayes, Equity and Social Justice Program
Manager DES
Sean Catanese, Risk Management
Addison Houston, Climate Adaptation Strategist PHSKC
State Agency
Doug Larm, WSFC
Maximilian Dixon, Earthquake Program Manager EMD
Kate Mickelson, Landslide Hazards Program Manager
DNR
Megan Anderson, Earthquake Geologist and
Geophysicist DNR
Josh Halofsky, Natural Resource Scientist DNR
National Agency
Dennis D’A mico, Forecast Director NWAC
Reid Wolcott, Meteorologist NWS
Brent Bower, Senior Service Hydrologist NWS
Jurisdictions & Special Districts
Cat Robinson, Emergency Coordinator EFR
Diane Pottinger, District Manager NCWD
Jared Schneider, Issaquah Emergency Manager
Deborah Needham, Renton Emergency Manager
Will Lugo, SeaTac Emergency Manager
Colby Cavanaugh, Bothell Emergency Manager
Lisa Figueroa, Redmond Emergency Manager
Ryan Zavala, Shoreline Emergency Manager
Non-Government Organization
Matt Rogers, Research Scientist UW CIG
Dave Cook, Principal Geologist Aspect Consulting
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Executive Summary
ii
Executive Summary
The King County Regional Hazard Mitigation Plan (RHMP) 2025-2030 serves as a strategic blueprint to
safeguard the community and its assets from potential nature and human-induced hazards. In
compliance with the Federal Emergency Management Agency (FEMA) and the Washington State
Emergency Management Division (EMD) regulations, the plan ensures King County remains eligible for
critical hazard mitigation funding and other resources.
The plan’s overarching goal is to create a framework that reduces the impact and susceptibility of the
identified hazards on people, property, and the environment, prioritizing historically underserved
communities. To achieve this goal, the Core Planning Team worked to foster collaboration across local,
state, and federal agencies, community organizations, and private sector partners. Collaboration is at the
heart of this plan, working in partnership to identify and assess potential hazards and their impacts,
determine high-risk areas and populations, integrate hazard mitigation into land use planning, and
develop strategies to minimize risk.
Equity is a cornerstone of the King County Regional Hazard Mitigation Plan, ensuring that mitigation
efforts prioritize those most vulnerable to the impacts of hazards. This includes focusing on communities
that are historically underserved, such as low-income households, elderly residents, and individuals with
disabilities. By recognizing the unique challenges faced by these populations, the plan strives to reduce
disparities in risk exposure and access to resources.
Through comprehensive research, analysis, and collaboration, a set of targeted mitigation strategies has
been developed, incorporating both structural and non-structural measures. Structural actions, such as
retrofitting buildings and infrastructure, are complemented by non-structural approaches like land use
planning and community engagement. Key mitigation actions identified include the development and
implementation of floodplain management plans, improvements to emergency response capabilities,
and the promotion of green infrastructure solutions to manage stormwater and reduce flood risks.
The significance of the 2025-2030 King County RHMP cannot be overstated. By identifying and
addressing the region's most pressing hazards, the plan aims to protect lives and property, reduce the
risk of injury, loss of life, and property damage, and enhance community resilience. This includes
strengthening infrastructure, strengthening emergency response capabilities, and fostering social
cohesion, ensuring that communities can better withstand, prepare, and recover from disasters.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Executive Summary
iii
Table of Contents
Executive Summary ............................................................................................................................ ii
Chapter 1: Introduction ................................................................................................................... 1-1
1.1 Mitigation Goal and Priorities .......................................................................................................... 1-1
1.2 Revisions from 2020 Edition ............................................................................................................ 1-2
1.3 Plan Guide ........................................................................................................................................ 1-3
1.4 EMAP Standards ............................................................................................................................... 1-4
Chapter 2: Planning Process ............................................................................................................ 2-1
2.1 Partner Engagement and Collaboration .......................................................................................... 2-1
2.2 Planning Steps .................................................................................................................................. 2-5
2.3 Jurisdiction Annex Process .............................................................................................................. 2-6
2.4 Timeline .......................................................................................................................................... 2-10
2.5 Outreach and Engagement ............................................................................................................ 2-13
2.5 Plan Integration .............................................................................................................................. 2-19
Chapter 3: Community Profile ......................................................................................................... 3-1
3.1 Geography ........................................................................................................................................ 3-1
3.2 Climate ............................................................................................................................................. 3-2
3.3 History .............................................................................................................................................. 3-2
3.4 Population ........................................................................................................................................ 3-3
3.5 Economy ........................................................................................................................................... 3-9
3.6 Development Trends ...................................................................................................................... 3-10
Chapter 4: Risk Assessment Overview .............................................................................................. 4-1
4.1 Overview .......................................................................................................................................... 4-1
4.2 Methodology .................................................................................................................................... 4-3
4.3 Risk Assessment Results ................................................................................................................... 4-8
4.4 GIS Data ............................................................................................................................................ 4-9
4.5 Jurisdiction-Specific Risk Assessments ........................................................................................... 4-11
Chapter 5: Avalanche ...................................................................................................................... 5-1
5.1 Hazard Description ........................................................................................................................... 5-2
5.2 Location ............................................................................................................................................ 5-3
5.3 Magnitude ........................................................................................................................................ 5-5
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2025 King County Regional Hazard Mitigation Plan
Executive Summary
iv
5.4 Previous Occurrences ....................................................................................................................... 5-6
5.5 Probability of Future Occurrences ................................................................................................... 5-8
5.6 Climate Change Considerations ....................................................................................................... 5-9
5.7 Impact Assessment .......................................................................................................................... 5-9
5.8 Vulnerability Assessment ............................................................................................................... 5-11
Chapter 6: Civil Disorder .................................................................................................................. 6-1
6.1 Hazard Description ........................................................................................................................... 6-2
6.2 Location ............................................................................................................................................ 6-4
6.3 Magnitude ........................................................................................................................................ 6-4
6.4 Previous Occurrences ....................................................................................................................... 6-7
6.5 Probability of Future Occurrences ................................................................................................... 6-8
6.6 Climate Change Considerations ....................................................................................................... 6-9
6.7 Impact Assessment ........................................................................................................................ 6-10
6.8 Vulnerability Assessment ............................................................................................................... 6-12
Chapter 7: Cyber Incidents .............................................................................................................. 7-1
7.1 Hazard Description ........................................................................................................................... 7-2
7.2 Location ............................................................................................................................................ 7-4
7.3 Magnitude ...................................................................................................................................... 7-10
7.4 Previous Occurrences ..................................................................................................................... 7-11
7.5 Probability of Future Occurrences ................................................................................................. 7-14
7.6 Climate Change Considerations ..................................................................................................... 7-15
7.7 Impact Assessment ........................................................................................................................ 7-15
7.8 Vulnerability Assessment ............................................................................................................... 7-18
Chapter 8: Dam Failure .................................................................................................................... 8-1
8.1 Hazard Description ........................................................................................................................... 8-2
8.2 Location ............................................................................................................................................ 8-5
8.3 Magnitude ........................................................................................................................................ 8-9
8.4 Previous Occurrences ....................................................................................................................... 8-9
8.5 Probability of Future Occurrences ................................................................................................. 8-11
8.6 Climate Change Considerations ..................................................................................................... 8-11
8.7 Impact Assessment ........................................................................................................................ 8-12
8.8 Vulnerability Assessment ............................................................................................................... 8-15
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Executive Summary
v
Chapter 9: Earthquake ..................................................................................................................... 9-1
9.1 Hazard Description ........................................................................................................................... 9-2
9.2 Location ............................................................................................................................................ 9-3
9.3 Magnitude ........................................................................................................................................ 9-5
9.4 Previous Occurrences ....................................................................................................................... 9-9
9.5 Probability of Future Occurrences ................................................................................................. 9-11
9.6 Impact Assessment ........................................................................................................................ 9-12
9.7 Vulnerability Assessment ............................................................................................................... 9-19
Chapter 10: Flood .......................................................................................................................... 10-1
10.1 Hazard Description ....................................................................................................................... 10-2
10.2 Location ........................................................................................................................................ 10-4
10.3 Magnitude .................................................................................................................................... 10-7
10.4 Previous Occurrences ................................................................................................................... 10-9
10.5 Probability of Future Occurrences ............................................................................................. 10-12
10.6 Climate Change Considerations ................................................................................................. 10-13
10.7 Impact Assessment .................................................................................................................... 10-13
10.8 Vulnerability Assessment ........................................................................................................... 10-18
Chapter 11: Hazardous Materials ................................................................................................... 11-1
11.1 Hazard Description ....................................................................................................................... 11-2
11.2 Location ........................................................................................................................................ 11-3
11.3 Magnitude .................................................................................................................................... 11-6
11.4 Previous Occurrences ................................................................................................................... 11-7
11.5 Probability of Future Occurrences ............................................................................................. 11-10
11.6 Climate Change Considerations ................................................................................................. 11-10
11.7 Impact Assessment .................................................................................................................... 11-10
11.8 Vulnerability Assessment ........................................................................................................... 11-13
Chapter 12: Health Incidents ......................................................................................................... 12-1
12.1 Hazard Description ....................................................................................................................... 12-2
12.2 Location ........................................................................................................................................ 12-3
12.3 Magnitude .................................................................................................................................... 12-5
12.4 Previous Occurrences ................................................................................................................... 12-7
12.5 Probability of Future Occurrences ............................................................................................... 12-9
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Executive Summary
vi
12.6 Climate Change Considerations ................................................................................................. 12-10
12.7 Impact Assessment .................................................................................................................... 12-10
12.8 Vulnerability Assessment ........................................................................................................... 12-12
Chapter 13: Landslide .................................................................................................................... 13-1
13.1 Hazard Description ....................................................................................................................... 13-2
13.2 Location ........................................................................................................................................ 13-5
13.3 Magnitude .................................................................................................................................... 13-7
13.4 Previous Occurrences ................................................................................................................... 13-9
13.5 Probability of Future Occurrences ............................................................................................. 13-11
13.6 Climate Change Considerations ................................................................................................. 13-11
13.7 Impact Assessment .................................................................................................................... 13-12
13.8 Vulnerability Assessment ........................................................................................................... 13-15
Chapter 14: Severe Weather .......................................................................................................... 14-1
14.1 Hazard Description ....................................................................................................................... 14-2
14.2 Location ........................................................................................................................................ 14-2
14.3 Magnitude .................................................................................................................................... 14-5
14.4 Previous Occurrences ................................................................................................................... 14-9
14.5 Probability of Future Occurrences ............................................................................................. 14-11
14.6 Climate Change Considerations ................................................................................................. 14-12
14.7 Impact Assessment .................................................................................................................... 14-13
14.8 Vulnerability Assessment ........................................................................................................... 14-18
Chapter 15: Terrorism .................................................................................................................... 15-1
15.1 Hazard Description ....................................................................................................................... 15-2
15.2 Location ........................................................................................................................................ 15-4
15.3 Magnitude .................................................................................................................................... 15-5
15.4 Previous Occurrences ................................................................................................................... 15-7
15.5 Probability of Future Occurrences ............................................................................................. 15-10
15.6 Impact Assessment .................................................................................................................... 15-10
15.7 Vulnerability Assessment ........................................................................................................... 15-12
Chapter 16: Tsunami ..................................................................................................................... 16-1
16.1 Hazard Description ....................................................................................................................... 16-2
16.2 Location ........................................................................................................................................ 16-3
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Executive Summary
vii
16.3 Magnitude .................................................................................................................................... 16-6
16.4 Previous Occurrences ................................................................................................................... 16-6
16.5 Probability of Future Occurrences ............................................................................................... 16-8
16.6 Impact Assessment ...................................................................................................................... 16-9
16.7 Vulnerability Assessment ........................................................................................................... 16-11
Chapter 17: Volcano ...................................................................................................................... 17-1
17.1 Hazard Description ....................................................................................................................... 17-2
17.2 Location ........................................................................................................................................ 17-3
17.3 Magnitude .................................................................................................................................... 17-5
17.4 Previous Occurrences ................................................................................................................... 17-7
17.5 Probability of Future Occurrences ............................................................................................... 17-8
17.6 Climate Change Considerations ................................................................................................... 17-9
17.7 Impact Assessment ...................................................................................................................... 17-9
17.8 Vulnerability Assessment ........................................................................................................... 17-12
Chapter 18: Wildfire ...................................................................................................................... 18-1
18.1 Hazard Description ....................................................................................................................... 18-2
18.2 Location ........................................................................................................................................ 18-4
18.3 Magnitude .................................................................................................................................... 18-6
18.4 Previous Occurrences ................................................................................................................. 18-10
18.5 Probability of Future Occurrences ............................................................................................. 18-12
18.6 Climate Change Considerations ................................................................................................. 18-12
18.7 Impact Assessment .................................................................................................................... 18-12
18.8 Vulnerability Assessment ........................................................................................................... 18-16
Chapter 19: Capabilities ................................................................................................................ 19-1
19.1 Plan, Policies, & Ordinances ......................................................................................................... 19-2
19.2 Programs .................................................................................................................................... 19-10
19.3 Staffing & Departments ............................................................................................................. 19-19
19.4 Potential Funding Sources ......................................................................................................... 19-24
Chapter 20: Mitigation Strategies .................................................................................................. 20-1
20.1 Mitigation Plan Goal..................................................................................................................... 20-2
20.2 Mitigation Plan Strategies ........................................................................................................... 20-2
20.3 Mitigation Plan Actions ................................................................................................................ 20-3
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Executive Summary
viii
20.4 Prioritizing Mitigation Strategies ................................................................................................. 20-3
20.5 Crosswalk with the Strategic Climate Action Plan ....................................................................... 20-7
20.6 Mitigation Strategy 2020 Status Updates .................................................................................... 20-8
20.7 Mitigation Strategies 2025 ......................................................................................................... 20-16
Chapter 21: Plan Maintenance ....................................................................................................... 21-1
21.1 Monitoring and Updating ............................................................................................................. 21-1
21.2 Integrating into Existing Planning Mechanisms ........................................................................... 21-2
21.2 Continued Public Involvement ..................................................................................................... 21-3
Chapter 22: Plan Adoption ............................................................................................................ 22-1
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 1: Introduction
1-1
Chapter 1: Introduction
Mitigation planning is a vital strategic tool for reducing risk and enhancing community resilience to
hazard events. It provides a platform for local partners to collaborate, assess potential risks, and
build integrated mitigation strategies for risk reduction. The 2025 King County Regional Hazard
Mitigation Plan explores the intersection of mitigation with prevention, protection, response, and
recovery.
Hazard mitigation, a core mission within emergency management, goes beyond life safety by
emphasizing that disaster impacts are not inevitable. While incidents will occur, their consequences
are not predetermined. Through targeted investments in critical areas, we can strengthen the most
vulnerable aspects of our community, enhancing resilience, and reducing the severity of future
disasters.
The 2025 King County Regional Hazard Mitigation Plan complies with FEMA’s local mitigation
planning requirements outlined in Title 44, Part 201 of the Code of Federal Regulations (44 CFR 201)
incorporating the latest policy updates that took effect in April 2025. The plan reassesses the risks
and vulnerabilities associated with eight natural hazards and seven human-caused hazards,
developing actionable strategies to mitigate these risks.
Serving as a base plan for all of King County, the plan also includes annexes from 50 jurisdictions,
schools, and special districts, each contributing their specific analyses and mitigation actions
tailored to their needs.
1.1 Mitigation Goal and Priorities
The goal of the 2025 King County Regional Hazard Mitigation Plan is to create a framework that
reduces the impact and susceptibility of the identified hazards on people, property, and the
environment, prioritizing historically underserved communities. This framework takes into account
King County’s 15 Determinants of Equity and Social Justice. These population-level indicators help
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 1: Introduction
1-2
planners to better understand disparities and opportunities to make a difference across the
communities we serve.
1.2 Revisions from 2020 Edition
When updating the 2020 RHMP, several key revisions and improvements have been made to
enhance the plan's effectiveness and alignment with contemporary needs and requirements . The
2020 plan was fully rewritten and reformatted to comply with FEMA’s 2022 updated local
mitigation planning requirements. This includes the incorporation of new subsections addressing
climate change considerations, and ensuring the plan accounts for the evolving impacts of climate
change on hazards and vulnerability.
The risk assessments have been refocused to better support emergency managers, who are the
primary audience of the plan. This shift ensures that the risk assessments are more directly relevant
to the people responsible for preparedness and operations related to the hazards in King County.
With advancements in science and technology since the development of the original plan, the 2025
edition benefits from newly available data and tools. These improvements enable a more detailed
and accurate risk assessment, providing better insight into the County’s hazard exposure and
vulnerabilities. The methodology for ranking hazards has been refined to incorporate criteria from
the Emergency Management Accreditation Program (EMAP). This enhanced scoring approach offers
a more robust evaluation of hazards, better reflecting the County’s risk landscape.
The 2025 plan places a stronger emphasis on equity and social justice, integrating these
considerations into the understanding of risk and vulnerability. The County worked with various
departments to identify vulnerable populations and include relevant data in a way that is
operationally meaningful, ensuring that mitigation strategies address and reduce risks to these
populations. Additionally, a community profile was introduced to this update, offering a deeper
understanding of King County’s demographics. This addition allows the plan to better identify and
understand vulnerable populations in the region, ensuring that mitigation strategies can be tailored
to meet the needs of these groups.
In anticipation of a significant increase in federal grants for natural hazard mitigation through the
Disaster Recovery Reform Act, the plan includes a strategy to identify projects and project
champions. This revision emphasizes capacity-building among planning partners and County
agencies to better identify vulnerabilities, craft mitigation strategies, communicate the benefits of
projects, and pursue funding opportunities effectively.
These revisions ensure that the 2025 Regional Hazard Mitigation Plan is more comprehensive, up-
to-date, and aligned with local, regional, and federal priorities, while addressing the unique needs
of vulnerable populations and the evolving risks posed by climate change.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 1: Introduction
1-3
1.3 Plan Guide
The base plan satisfies all requirements for King County plus many of the planning requirements for
local planning partners. The plan is organized as follows.
Planning ProcessChapter 2
•The planning process section corresponds to Element A in the FEMA Mitigation Plan
Review Guide and includes information on the planning process such as public outreach,
meetings, and the planning timeline.
Community ProfileChapter 3
•The community profile provides a detailed overview of King County's demographics,
including population data, economic conditions, and historical context. It also highlights
development trends, helping to identify potential vulnerabilities.
Risk AssessmentsChapter 4-18
•The risk assessment chapters include profiles of each profiled natural and human-caused
hazard. These profiles are brief and are designed to provide an overview to emergency
managers and other users of this plan. This section meets the requirements of Element B
in the FEMA Mitigation Plan Review Guide.
Capabilities AssessmentChapter 19
•The capabilities chapter meets requirements associated with coordinating the hazard
mitigation program with other entities as well as information on available funding.
Mitigation StrategiesChapter 20
•Hazard mitigation strategies are the key deliverable of this plan and include information
on how strategies are identified, developed, and prioritized. This section meets the
requirements in Element C of the FEMA Mitigation Plan Review Guide.
Plan MaintenanceChapter 21
•The plan maintenance chapter outlines a framework for monitoring, evaluating, and
updating the plan at regular intervals to ensure its relevance and accuracy throughout the
5-year period. Additionally, it provides a structured approach for tracking the progress and
effectiveness of mitigation strategies.
Plan AdoptionChapter 22
•The plan adoption chapter outlines the formal approval of the hazard mitigation plan by
the King County Council, affirming the King County’s and annex jurisdiction's commitment
to the outlined goals and actions.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 1: Introduction
1-4
1.4 EMAP Standards
The Emergency Management Accreditation Program (EMAP) is a national, standards-based
assessment and accreditation process for emergency management programs. In the context of
hazard mitigation, EMAP ensures the RHMP takes into account all the phases of emergency and
disaster management: mitigation, protection, prevention, response, and recovery. These phases are
addressed in the impact (or consequence) and vulnerability assessments, which are essential for
evaluating hazards risk to various community components.
Each identified hazard includes a detailed quantitative summary of its overall impact, vulnerability,
and risk on the respective chapter cover page, along with a qualitative summary provided at the
end of the chapter. The RHMP narrative is tailored to local emergency managers , the primary
audience, and emphasizes collaboration by involving them in the planning, implementation, and
ongoing maintenance of the plan.
EMAP
Section 2022 Standard Location in Plan
4.1 Hazard Identification, Risk Assessment, and Consequence Analysis
4.1.1 The Emergency Management Program identifies the natural and human-caused hazards
that potentially impact the jurisdiction using multiple sources. The Emergency
Management Program assesses the risk and vulnerability of the following:
(1) people; Located in each hazard
profile Chapters 5
through 18 both on the
chapter cover page and
under the section title
Vulnerability Assessment.
Definitions are found in
Chapter 4, Section 2.
(2) property;
(3) the environment; and
(4) its own operations from these hazards.
4.1.2 The Emergency Management Program conducts a consequence analysis for the hazards
identified in Standard 4.1.1 to consider the impact on the following:
(1) public; Located in each hazard
profile Chapters 5
through 18 both on the
chapter cover page and
under the section title
(2) responders;
(3) continuity of operations, including continued delivery of
services;
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 1: Introduction
1-5
(4) property, facilities, and infrastructure;
Impact Assessment.
Definitions are found in
Chapter 4, Section 2.
(5) environment;
(6) the economic condition of the jurisdiction; and
(7) public confidence in the jurisdiction’s governance.
4.1.3 The Emergency Management Program has a maintenance process for its Hazard
Identification, and Risk Assessment (HIRA) identified in Standard 4.1.1, and the
Consequence Analysis (CA) identified in Standard 4.1.2, including a method and
schedule for evaluation and revision.
Maintenance Process (HIRA) Maintenance process for
HIRA and CA, including
evaluation and revision,
are located in Chapter 21,
Section 1.
Maintenance Process (CA)
Method and schedule evaluation
Method and schedule for revision
4.2 Hazard Mitigation
4.2.1 The Emergency Management Program has a plan to implement mitigation projects and
sets priorities based upon loss reduction. The plan:
(1) is based on the natural and human-caused hazards
identified in Standard 4.1.1 and the risk and consequences
of those hazards;
Located in Chapter 4,
Section 1.
(2) is developed through formal planning processes
involving Emergency Management
Located in Chapter 2,
Sections 1 and 2.
4.2.2 The Emergency Management Program documents project ranking based upon the
greatest opportunity for loss reduction and documents how specific mitigation actions
contribute to overall risk reduction.
Priority Process Located in Chapter 20,
Section 4.
Mitigation Actions Located in Chapter 20,
Section 7.
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2025 King County Regional Hazard Mitigation Plan
Chapter 1: Introduction
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4.2.3 The Emergency Management Program utilizes a process to monitor the overall progress
of the mitigation activities and documents completed initiatives and their resulting
reduction or limitation of hazard impact on the jurisdiction.
Emergency Management
Program monitoring is
addressed in Chapter 21,
Section 1.
4.2.4 The Emergency Management Program, consistent with the scope of the mitigation
program, does the following:
(1) identifies ongoing mitigation opportunities and tracks
repetitive loss;
Mitigation program
tracking and technical
assistance is addressed in
Chapter 21, Section 1. (2) provides technical assistance in implementing
mitigation codes and ordinances; and
(3) participates in jurisdictional and multi-jurisdictional
mitigation efforts.
Multi-jurisdictional
mitigation is addressed in
Chapter 21, Section 2.
4.2.5 The Emergency Management Program has a maintenance process for the plan
identified in Standard 4.2.1, including a method and schedule for evaluation and
revision.
Maintenance process for
the plan, including
evaluation and revision,
are located in Chapter 21,
Section 1.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 2: Planning Process
2-1
Chapter 2: Planning Process
The King County 2025 Regional Hazard Mitigation Plan (RHMP) follows the established planning
guidelines of the Office of Emergency Management (OEM). This approach adheres to the standards
of the Emergency Management Accreditation Program (EMAP) and FEMA’s Comprehensive
Preparedness Guide (CPG). The planning process embraced a whole-community approach,
collaborating with a multiagency multijurisdictional steering committee. Consulting with subject
matter experts through targeted focus groups, and actively engaged vulnerable communities
through listening sessions to ensure comprehensive and inclusive input. Cities, tribes, special
purpose districts, and school districts were invited to participate in this plan update. These
jurisdictions and entities are critical to effective implementation of multi-jurisdictional mitigation
projects.
2.1 Partner Engagement and Collaboration
Core Planning Team
The Core Planning Team, composed of key members from the King County Office of Emergency
Management, played a pivotal role in guiding both the internal county process and supporting the
planning efforts of individual cities. Their responsibilities included coordinating outreach activities,
developing and reviewing plan drafts, contributing to the risk assessment, formulating mitigation
goals and strategies, and overseeing the submission of the plan for local adoption.
Steering Committee
The Steering Committee, overseen by the Core Planning Team, is made up of different King County
departments and representatives from participating jurisdictions and special districts including
community planners, emergency managers, and subject matter experts. The committee supervised
the writing of the plan and was consulted for final decisions made by the Core Planning Team.
Individual departments developed their own strategies internally and then socialized the strategies
with the other county participants.
Table 2-1 Planning Team Members
Name Organization Title
Core Planning Team
Andrew Matthews King County Emergency
Management
Hazard Mitigation Program
Coordinator
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 2: Planning Process
2-2
Nicole Johnson King County Emergency
Management
Senior Program Manager
Mercedes Stroeve King County Emergency
Management
Hazard Mitigation Planner
Steering Committee Members
Addison Houston KC Public Health Climate Adaptation Strategist
Cat Robinson Eastside Fire and Rescue Emergency Coordinator
Cecelia Hayes King County Department of
Executive Services
Equity and Social Justice Program
Manager
Colby Cavanaugh City of Bothell Emergency Manager
Deborah Neeham City of Renton Emergency Manager
Diane Pottinger North City Water District District Manager
Edan Edmunson King County Emergency
Management
Dam Safety Coordinator
Jared Schneider City of Issaquah Emergency Manager
Lara Whitely-Binder King County Department of
Natural Resources and Parks
Climate Preparedness Specialist
Laura Hendrix King County Department of
Natural Resources and Parks
Floodplain Management Program
Manager
Lisa Figueroa City of Redmond Emergency Manager
Meisha Roberton Riverview School District Assistant Superintendent Business
Program Manager
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 2: Planning Process
2-3
Sally Calengor King County Emergency
Management
Zone 3
Nathan Emory King County Emergency
Management
Extreme Weather Coordinator
Ryan Zavala City of Shoreline Emergency Manager
Sean Catanese King County Risk Management Risk Management
Sheri Badger King County Emergency
Management
Recovery Program Manager
Sunita Hall King County Emergency
Management
Zone 1
Will Lugo City of SeaTac Emergency Manager
The steering committee convened monthly to assess the progress of the core planning team and
provide strategic guidance on critical decisions regarding the direction of the planning efforts. These
meetings were held in-person at the King County Office of Emergency Management, with a virtual
option also available to ensure broad participation.
Table 2-2 Steering Committee Meetings
DATE SUMMARY
Feb 2024 Introductions
Create outline for 2024/2025 update process; Review the new FEMA guidance and
how it will affect the plan; Discuss other County wide plans we can incorporate;
Begin creation of annex template.
Mar 2024 Public outreach strategy
Strategize public outreach approach; Identify subject matter experts for risk
assessment; Review Annex template; Examine example HMPs (i.e. Thurston County
RHMP).
Apr 2024 Equity and social justice (part 1)
Address how the RHMP will factor in equity in the planning and implantation;
Review the Equity in Response Planning Tool; Update the Equity Matrix for scoring
strategies; identify potential new partners and/or opportunities for collaboration.
May 2024 Equity and social justice (part 2)
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 2: Planning Process
2-4
Continue to discuss how the RHMP will factor in equity in the planning and
implantation; Continue to update the Equity Matrix for scoring strategies; Finalize
outreach event schedule and locations.
June 2024 Plan goals, priorities, and strategy (part 1)
Establish plan goals, priorities, and strategy prioritization method; Provide update
on current risk profiles; Review public outreach survey flyer and questions.
July 2024 Plan goals, priorities, and strategy (part 2)
Confirm RHMP goal, priorities, and strategy prioritization method.
Aug 2024 Risk assessment
Review risk assessment matrix; organize risk assessment workshop identifying
speakers; Create invite list of subject matter experts.
Oct 2024 Impact and vulnerability assessment
Recap the risk assessment workshop; Identify plans and studies to incorporate into
the risk assessments; Identify impacts and vulnerabilities.
Nov 2024 Mitigation strategies
Review King County capabilities for mitigation efforts (i.e. policies, programs, staff,
collaborations); Review previous mitigation strategies; Brainstorm new mitigation
action opportunities.
Jan 2025 Review draft base plan
‘Subject Matter Experts’ Engagement
This region has benefitted significantly over the years from the partnerships and collaboration to
address all the phases in emergency management (prevention, mitigation, preparedness, response,
and recovery). The following discipline partners were sources of subject matter experts and/or the
channels to share information and engage in emergency management planning efforts.
• King County Fire Chiefs Association
• King County Police Chiefs Association
• King County Office of Emergency Management
• Zone 1, 3 & 5 Emergency Managers
• Washington Association of Water & Sewer Districts
• Puget Sound Educational Service District
• King County Emergency Management Advisory Committee & Subcommittees
• King County partner agencies (Department of Natural Resources and Parks (DNRP),
Public Health (PHSKC), Facilities Management Division (FMD), Executive Climate Office
(ECO))
• Washington State departments (Emergency Management Division, Department of
Natural Resources, Washington Geological Survey, Fusion Center, Department of
Transportation)
• Federal agencies (National Oceanic and Atmospheric Administration (NOAA), National
Weather Service (NWS), Northwest Avalanche Center (NWAC))
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 2: Planning Process
2-5
All subject matter experts, partners, and participating jurisdictions and special districts were directly
invited to partake in the steering committee and be involved in the planning process.
2.2 Planning Steps
The hazard mitigation planning process is a systematic approach to identifying, assessing, and
reducing the risks posed by natural and human-made hazards to a community. It is an essential part
of building resilience, ensuring that future disaster impacts are minimized through strategic
planning and collaboration. This process is divided into four distinct phases, each of which
contributes to the development of a comprehensive mitigation plan.
Plan Coordination
The planning process begins with initial coordination and the establishment of a structured
framework for development. This phase involves gathering key stakeholders and creating a
foundation for the plan's development.
• Initial Coordination: Organizing the Core Planning Team and Steering Committee to help
establish goals and planning process. The core planning team outlines the steps, timelines,
and resources necessary to complete the mitigation plan. The steering committee,
consisting of representatives from key agencies and local officials, oversees and guides the
planning process.
• Partner Development: Identify and engage partners who will contribute to the process.
These partners include local government agencies, non-governmental organizations (NGOs),
community groups, and other entities with a vested interest in hazard mitigation.
• Develop Outreach Strategy: An outreach strategy is developed to engage the public and
stakeholders through various channels. This may include meetings, social media,
newsletters, and more. This includes a public survey to gather feedback from residents
about their perceptions of hazards, mitigation needs, and priorities.
Assess Risk
Once the coordination phase is complete, the next step is to assess the hazards and risks that the
community faces. This phase focuses on identifying and analyzing potential threats and their
impacts.
• Risk Assessment Methodology: Identifies the natural and human-made hazards that may
affect King County. This includes developing criteria for evaluating the severity, likelihood,
and potential impacts of each hazard. This process helps ensure that all risks are adequately
considered and prioritized. This is done by evaluating a comprehensive list of local, state,
and federal data (see Chapter 4: Risk Assessment Overview).
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 2: Planning Process
2-6
• Capability Assessment: Evaluates the community's current capacity to respond to and
manage the identified risks. This includes reviewing existing mitigation measures, resources,
and expertise (see Chapter 19: Capabilities).
Mitigation Strategy
This phase focuses on developing strategies to reduce the identified risks. It is about determining
actions that align with our goals, and establishing how the plan will be maintained.
• Mitigation Strategy: Craft detailed mitigation strategies in that align with the goal to reduce
the impact and susceptibility of the identified hazards on people, property, and the
environment, prioritizing historically underserved communities.
• Identify Plan Maintenance: Outline how the plan will be maintained and updated over time.
This includes establishing a process for monitoring progress, updating risk data, and revising
the plan as necessary.
Review & Adoption
The final phase of the hazard mitigation planning process involves reviewing and formalizing the
plan, ensuring it meets regulatory requirements, and gaining official approval.
• State Review: The draft plan is submitted to the Washington Emergency Management
Department (EMD) for review. The state ensures that the plan meets all applicable state
regulations and is consistent with state hazard mitigation goals.
• FEMA Review: After state approval, the Federal Emergency Management Agency (FEMA)
reviews the plan to ensure it meets federal standards and requirements for hazard
mitigation planning.
• Public Comment Period: Following FEMA approval, the plan is made available to the public
for 30-days to review and provide further input or concerns before the final plan is
approved.
• Council Approval: The plan is submitted to King County Council for final approval. Once the
governing body approve, the plan is officially adopted and becomes a living document that
guides ongoing hazard mitigation efforts.
2.3 Jurisdiction Annex Process
KCOEM invited incorporated municipalities, Tribes, school districts, special districts, and other
stakeholders to participate in the RHMP planning process. There are 29 participating jurisdictions
and 21 special districts.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 2: Planning Process
2-7
Jurisdictions
Beaux Arts Village
Bothell
Burien
Carnation
Clyde Hill
Covington
Des Moines
Duvall
Federal Way
Hunts Point
Issaquah
Kenmore
Kent
Kirkland
Lake Forest Park
Maple Valley
Mercer Island
Newcastle
North Bend
Redmond
Renton
Sammamish
SeaTac
Shoreline
Skykomish
Snoqualmie
Tukwila
Woodinville
Special Districts
Cedar River Water & Sewer
District
Coal Creak Utility District
Covington Water District
King County Water District #19
(KCWD 19)
King County Water District #20
(KCWD 20)
King County Water District #90
(KCWD 90)
King County Water District
#125 (KCWD 125)
Midway Sewer District
North City Water District
Northeast Sammamish Sewer
and Water District
Renton School District
Riverview School District
Sammamish Plateau Water
District
South King County Fire and
Rescue
Shoreline School District
Seattle Housing Authority
Skyway Water and Sewer
District
Soos Creek Water and Sewer
District
Valley Regional Fire Authority
Vashon Island Fire and Rescue
Woodinville Water District
Individual jurisdictions and special districts participating in a multi-jurisdictional plan must meet the
mitigation planning requirements, adopt the plan and provide documentation to FEMA through
Washington State Emergency Management Department (EMD). Once the agency receives the
jurisdiction’s adoption, FEMA will issue an approval letter for the jurisdiction.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 2: Planning Process
2-8
Each jurisdiction that chose to participate in the planning process and development of the plan was
required to meet plan participation requirements defined at the first planning meeting. Those that
were not able to participate in KCOEM’s planning meetings had organized their own planning
processes and have noted those meetings in their annex. The Core Planning Team hosted meetings
for different phases of the planning process and presented at emergency management meetings in
order to meet participants “where they’re at” to provide updates on the planning process and
gather input. Opportunities for participation include:
•Kickoff Meeting: First meeting to discuss the update of the RHMP and learn about FEMA’s
updated planning policy guide.
•Steering Committee Meetings: 9 total meetings providing committee members opportunity
to contribute to the shaping of the planning process.
•Annex Workshops: 6 total workshops for participating jurisdictions and special districts to
go through FEMA requirements for their RHMP annex.
•Risk Assessment Workshops: Review data on each of the identified hazards presented by
subject matter experts and offering input on impacts and vulnerabilities.
•Quarterly Emergency Management (EM) Meeting: Review findings from the Risk
Assessment Workshop and offering additional input on impacts and vulnerabilities.
•Zone Meeting Presentation: Discuss local, county, and state tools that help mitigate hazard
risks and identify gaps in capabilities.
•Co-Host Tabling Events: Help to organize a community outreach event to discuss local and
regional hazard risks.
Table 2-3 Jurisdictions and special districts participation in RHMP planning process
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Bothell 1 1 1 1 4
Burien 1 1 2
Carnation 1 1 2
Clyde Hill 1 1
Covington 1 1 1 1 4
Des Moines 1 1 1 1 4
Duvall 1 1 1 3
Federal Way 1 2 1 1 1 6
Hunts Point 0
Issaquah 8 1 9
Kenmore 1 1
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 2: Planning Process
2-9
Jurisdiction Ki
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Lake Forest Park 0
Maple Valley 1 1 2
Mercer Island
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Newcastle 1 2 3
North Bend 0
Redmond 1 4 1 6
Renton 8 2 1 1 12
Sammamish 0
SeaTac 1 5 1 1 1 1 10
Shoreline 1 7 3 1 12
Skykomish 0
Snoqualmie 0
Tukwila 1 1 1 3
Woodinville 1 1
Cedar River Water & Sewer District 1 4 5
Coal Creak Utility District 1 1 2
Covington Water District 1 1 2
King County Water District #19 (Vashon) 0
King County Water District #20 (Burien) 0
King County Water District #90 (East
Renton)
2 2
King County Water District #125 (Tukwila) 1 1 2
Midway Sewer District 3 3
North City Water District 5 2 1 8
Northeast Sammamish Sewer and Water
District
1 1 2
Renton School District 0
Riverview School District 1 1 2
Sammamish Plateau Water District 1 2 3
Shoreline School District 0
Seattle Housing Authority 1 1
Skyway Water and Sewer District 1 2 5 1 9
Soos Creek Water and Sewer District 1 4 5
South King County Fire and Rescue 0
1
1
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 2: Planning Process
2-10
Jurisdiction Ki
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Vashon Island Fire and Rescue 0
Woodinville Water District 1 2 3
Grand Total 23 42 53 8 7 7 2
Individual jurisdiction annexes were developed in partnership with King County, but with separate
internal steering committees. The members of each jurisdiction’s steering committee are
documented in each annex.
Jurisdictions may join the regional hazard mitigation plan at any time by submitting a letter of intent
to King County Emergency Management and completing the planning process and plan template.
Each plan can be unique, and jurisdictions may do more than what is required in the template;
however, this template is designed to help walk communities through the planning process in an
accessible way. King County staff will provide technical assistance to planning partners, whenever
possible.
The Core Planning Team hosted regular workshops for participating jurisdictions and special
districts to go through FEMA requirements for their RHMP annex. These workshops were held on
June 7th, June 14th, June 20th, July 11th, July 19th, and July 25th. There were over 50 attendees for the
combined six workshops. Further support was offered to those seeking to apply for grant funding
for their mitigation strategies.
Following the submission of the base plan in October 2025, King County will begin a second stage of
outreach targeting those jurisdictions who missed the original submission deadline and those who
were not previously involved. Among the second group, school districts will be proactively engaged
and offered assistance in developing annexes to the hazard mitigation plan.
2.4 Timeline
The following timeline outlines key events and milestones for King County in the Regional Hazard
Mitigation Plan Update. The planning process officially began in December 2023 and workshop,
open to all planning partners. Following the kickoff, the Core Planning Team successfully facilitated
9 steering committee meetings, 6 planning workshops for jurisdictions annexing onto the plan, and
engaged with over 60 subject matter experts to ensure a comprehensive and collaborative
approach to the plan’s development.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 2: Planning Process
2-11
Table 2-4 Plan update timeline
PLANNING ACTIVITY DATE SUMMARY ATTENDEES
Plan Kickoff Dec 2023
Conduct a kickoff meeting for
the planning process, including
discussions of expectations and
the project timeline.
Designated county,
city, and special district
staff who are leading
local plan updates
Steering
Committee
Meeting Kickoff Feb 2024
Outline proposed planning
process and timeline and
approve plan and plan annex
templates. Steering committee
Outreach
Strategy Meeting Feb 2024
Meet with staff to identify
outreach strategy KCOEM staff
Steering
Committee
Meeting Mar 2024
Identify public outreach sites
and strategy Steering committee
Steering
Committee
Meeting Apr 2024
Integrating equity and social
justice into the mitigation plan. Steering committee
Steering
Committee
Meeting May 2024
Integrating equity and social
justice into the mitigation plan. Steering committee
Annex Workshop June 2024
Hosted 3 workshops the month
of June to review the planning
process and help local partners
on mitigation planning
questions
local jurisdiction
partners
EMCC Meeting June 2024
Mitigation strategy meeting
discussions and identify points
of contact in each agency County departments
Steering
Committee
Meeting June 2024
Establish plan goals, priorities,
and strategy prioritization
method Steering committee
Annex Workshop July 2024
Hosted 3 workshops the month
of July to review the planning
local jurisdiction
partners
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 2: Planning Process
2-12
process and help local partners
on mitigation planning
questions
Steering
Committee
Meeting July 2024
Establish plan goals, priorities,
and strategy prioritization
method Steering committee
Wildfire Strategy
and Community
Preparedness
Discussion July 2024
Discuss planning process,
community outreach, funding
opportunities, and mitigation
strategies
Residents of North
Bend, KC community
members, local
partners
Hazard Mitigation
Workshop July 2024
Work through the entire
strategy development process
from risk identification to
mitigation projects.
County and local
partners
Steering
Committee
Meeting Aug 2024 Review mitigation capabilities Steering committee
Mitigation
Funding
Workshop Aug 2024
Work through process of
developing a successful hazard
mitigation grant application
County and local
partners
Risk Assessment
Workshop Sept 2024
Review risk and vulnerability
assessments Subject matter experts
Steering
Committee
Meeting Oct 2024
Review base plan and King
County mitigation strategies Steering committee
County
Departments
Strategy
Coordination Nov 2024
Meet with King County
departments to go over all the
mitigation strategies, eliminate
gaps, and ensure consistent
priorities.
County departments,
including OEM, FMD,
DNRP, PHSKC, KCIT,
DES.
Steering
Committee
Meeting Nov 2024 Review draft base plan Steering committee
Mitigation
Strategy
Meetings Dec 2024
Meet with internal planning
partners (county departments)
DNRP, PHSKC, ECO,
FMD
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 2: Planning Process
2-13
to develop mitigation
strategies.
Steering
Committee
Meeting Jan 2025 Review draft base plan Steering committee
Submit to WA
EMD and FEMA Feb 2024
Submit full mitigation plan to
FEMA for review Planning Team
Plan Adoption Sept 2025
King County Council vote to
approve plan King County Council
Plan Approval Oct 2025 FEMA plan approval FEMA Region 10
2.5 Outreach and Engagement
King County Office of Emergency Management (KCOEM) led an extensive public outreach campaign
to gain public input for the RHMP. KCOEM uses public input to help prioritize which strategies listed
in this plan should be implemented. The campaign included partnering with jurisdictions and
community-based organizations to engage the public both through an online public survey and in-
person tabling events.
2.5.1 Public Survey
The online survey was run from June 2024 to November 2024. It conducted on the platform
“PublicInput” and saw a total 135 participants from all over the county. The top hazards listed were
earthquake, extreme weather, and wildfire (including smoke impacts). To maximize outreach, the
survey was promoted through the King County Emergency Blog and Department of Executive
Services newsletters, advertised on the KCOEM Instagram page, and featured on the King County
website banner. Additionally, printed copies of the survey were distributed at tabling events,
community meetings, and shared with partners, jurisdictions, and entities involved in the planning
process.
Survey questions include:
1. Where do you live?
2. What top three hazards are you most concerned about?
3. If your city had $1,000,000 to make your community safer from disasters, what would you
spend it on?
4. If your city had $10,000 to make your community safer from disasters, what would you
spend it on?
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 2: Planning Process
2-14
Figure 2-1 King County hazard survey flyer
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 2: Planning Process
2-15
Figure 2-2 King County public survey results on top hazard concerns
In addition, on September 19, 2024, KCEOM conducted its semiannual Alert King County test and
survey to opt in members of the Alert King County System. One of the survey questions asked
participants, “What are the top three King County Hazards you are most concerned about?” The
survey saw 1194 responses and the top three hazards were: 1. Earthquake 2. Extreme Weather and
3. Cyber Incident.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 2: Planning Process
2-16
Figure 2-3 Alert King County survey results on hazard concerns
2.5.2 Tabling events
Figure 2-4 Public outreach tabling event in Kent, WA
KCOEM attended 34
community events across the
county with approximately
3000 attendees (see Table
2-4).
At the events, we presented
the survey using an
interactive poster (see Figure
2-5). Attendees were invited
to place dotted stickers on
the locations where they live
and on the hazards they
were most concerned about.
We also provided sticky
notes for participants to
write down actions they’d
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 2: Planning Process
2-17
like to see taken to mitigate these hazards. For children, we offered a spinning wheel featuring
trivia questions on hazards and emergency preparedness to engage them in a fun and educational
way.
These tabling events received input from over 700 community members in total, requesting
information on which hazards they are most concerned about in their communities. Wildfire
emerged as a top hazard in the more rural areas of North Bend and Black Diamond, whereas
earthquake was the top hazard in the more urban areas of Seattle, Tukwila, and Des Moines.
Community members in Redmond cited cyber incident as their top concern.
Many residents also shared personal stories of past events that left them vulnerable. For example,
during snow and ice storms, Skyway residents often find themselves unable to travel due to the
area’s hilly terrain. This isolation is compounded by limited resources including the community only
having one grocery store on the hilltop and one bus line that runs through the area. This makes
access to food and services challenging, particularly during severe weather events.
Table 2-5 Public outreach tabling events, May 2024 – November 2024
Date Event Jurisdiction Attendees
May 4, 2024 Pacific Islander Cultural Festival Seattle 80-100
May 8, 2024 Skyway Public Library Resource Fair Skyway 20
May 10, 2024 Auburn Valley Cities Resource Fair Tabling Auburn 35
May 20, 2024 Chinese Cultural Festival Seattle 150-200
May 29, 2024 Wildland Fire and Touch a Truck Black Diamond 200
June 6, 2024 White Center Heights STEAM Carnival White Center 80-100
June 15, 2024 Skykomish Tunnel Days Skykomish 25
July 27, 2024 Community Resource Fair Kent 60
July 30, 2024 Legislative Branch Picnic Redmond 60
July 30, 2024 Des Moines Block Party Des Moines 30
July 31, 2024 Marymoor - Movies in the Park/Go Green
Night
Redmond 50
August 6, 2024 National Night Out Carnation 55
August 6, 2024 National Night Out Milton 100
August 14, 2024 Akin Children's Resource and Back to
School
Kent 250
August 17, 2024 Skyway Health and Safety Fair Skyway 40
August 17, 2024 Redmond Ridge Summer Festival Redmond 150
August 26, 2024 Covington Wildfire Town Hall Covington 70
September 12,
2024
Uwajimaya Seattle Seattle 60
September 13,
2024
Uwajimaya Renton Renton 100
September 14,
2024
Sammamish Emergency Preparedness Fair Sammamish 70
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 2: Planning Process
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September 14,
2024
NEMCo Preparedness Fair Lake Forest Park 70
September 14,
2024
Maple Valley fire open house Maple Valley 115
September 21,
2024
Love Train Community Block Party Skyway 40
September 21,
2024
China Town Night Market Seattle 100
September 26,
2024
Uwajimaya Bellevue Bellevue 150
September 28,
2024
Carnation Be Dam Ready Evacuation Drill Carnation 15
September 28,
2014
Maple Valley Emergency Preparedness Fair Maple Valley 150
October 9, 2024 Highline College Resource Fair Des Moines 200
October 11, 2024 Mother Africa Health and Wellness Fair Kent 100
October 27, 2024 Skyway Farmers Market Skyway 35
November 4, 2024 Muckleshoot Casino Resort Safety and
Benefits Fair
Muckleshoot 200
November 13,
2024
Liberty Square Community Resource Fair Renton 20
November 21,
2024
City of Carnation Open House Carnation 10
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
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Figure 2-5 Tabling event poster for public engagement
2.5.3 Continued Outreach
King County and its partner cities already maintains substantial public outreach capabilities,
focusing on personal preparedness and education. Information on ongoing progress in
implementing the hazard mitigation plan will be integrated into public outreach efforts. In the
vertical integration of risk-reduction activities from personal to local to state and federal, it is
important that the public understand how its activities support, and are supported by, larger-scale
efforts.
The Core Planning Team will also continue to work with media and other agency partners to
publicize mitigation success stories and help explain how we are safeguarding communities from
the risk of hazard events. When possible, public tours of successfully completed mitigation projects
will be organized to allow community members to see successful mitigation in action.
2.6 Plan Integration
When plans and planning processes are more integrated, it is possible to achieve greater impact
through clearer definition, smarter investment, partnerships, and innovation. Successful integration
requires coordination between planning efforts and, especially, cross-participation in planning
processes. The goals of plan integration are to:
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• Ensure consistency with jurisdiction priorities across all planning processes
• Leverage opportunities to further multi-benefit initiatives that are supported by multiple
planning processes
• Achieve common measures of success for outcomes
The hazard mitigation plan can benefit from integration with planning processes that:
• Prioritize and invest in infrastructure
• Regulate development
• Set strategic direction for programs
To other planning processes, the hazard mitigation plan brings risk and vulnerability information to
help prioritize projects and set development standards or regulations. The mitigation plan also
comes with potential funding for investments in cost-effective risk-reduction projects. On the other
hand, the mitigation plan depends on other plans and processes to implement many strategies.
Since the mitigation plan is not itself a regulatory or budgetary document, strategies identified in
the mitigation plan are often best implemented through those processes or programs.
The Core Planning Team leveraged a number of existing and ongoing planning processes and other
documents, integrating data and strategies from state, regional, and county plans. This approach
ensures alignment of priorities, synchronization of actions, and reduction of silos across
jurisdictions. By coordinating hazard mitigation efforts at the regional and county levels, it is
possible to address widespread hazards more effectively. Furthermore, by identifying common
goals, there can be joint funding initiatives, sharing of resources, and coordinated efforts in
implementing mitigation strategies. More information can be found in the Program Capabilities
chapter of this plan.
• 2024 King County Comprehensive Plan
• 2024 King County Flood Management Plan
• Public Health - Seattle & King County 2024-2029 Strategic Plan
• 2023 Washington State Enhanced Hazard Mitigation Plan
• 2023 Hazardous Materials Response Plan
• Puget Sound Regional Council’s Vision 2050
• 2022 KC Wildfire Risk Reduction Strategy
• 2022 Washington Geological Survey:
• 2022 Washington Geological Survey: Tsunami Inundation, Current Speeds, and Arrival Times
Simulated from a Large Seattle Fault Earthquake Scenario
• 2020 King County Strategic Climate Action Plan (SCAP)
• 2020-2025 KC Clean Water Healthy Habitat Strategic Plan
• 2019 King County Dam Inventory from the Washington State Department of Ecology
• 2017 Dam Safety Gap Analysis Report
• King County Equity and Social Justice Strategic Plan, 2016-2022
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• 2016 Mapping of Potential Landslide Hazards along the River Corridors of King County,
Washington
Furthermore, the RHMP will help inform plans and strategies put together by KCOEM including
Prevention Protection Plan, Response Plan, Recovery Plan, and the Comprehensive Emergency
Management Plan (CEMP).
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Chapter 3: Community Profile
3.1 Geography
King County is located in western Washington, bordered by Snohomish County to the north, Pierce
County to the south, and Kittitas County to the east. Its topography is incredibly varied, ranging
from sea level along the Puget Sound in the west to mountain peaks approaching 8,000 feet in the
Cascade Range to the east.
The county’s human geography reflects this natural diversity, with densely populated urban areas
along Puget Sound, suburban neighborhoods east of Lake Washington, rural communities to the
southeast, and remote towns nestled in the Cascade foothills. King County is home to 39 cities and
towns, and two tribal nations Muckleshoot and Snoqualmie Tribe.
Seattle, the county seat, is Washington state's largest city and serves as the cultural and economic
hub of the region. King County is both the most populous county in the state and the most densely
populated, ranking 12th largest in the nation.
Figure 3-1 King County geography
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3.2 Climate
The Puget Sound and Cascade Range plays a key role in shaping its climate. The region is heavily
influenced by maritime atmospheric conditions, with the mountains acting as natural barriers
trapping in moisture. As moist air is forced upward by the Cascades, it cools and condenses, leading
to heavy precipitation on the windward side of the mountains. In addition to its natural climate
influences, the region is home to numerous urban centers and transportation networks that feature
impermeable surfaces, which contribute to the urban heat island effect.
3.3 History
King County is a part of a larger area that has been the traditional aboriginal territory of the Coast
Salish peoples, who continue to live around the Salish Sea in what is now Washington State and the
Canadian province of British Columbia. These sovereign tribal nations enrich the region through
environmental stewardship, cultural heritage, and economic development.1
Before European-American settlers arrived, the region’s economy and culture were sustained by
the Coast Salish peoples through practices like hunting, freshwater and saltwater fishing, and
gathering plants for food and medicine. Waterways served as the primary means of transportation,
fostering interconnectedness and commerce.
European-American settlement of the area now known as King County began in the 1840s. Natural
resources – especially timber – played a major role in King County’s early history. Maritime trade
spurred the development and growth of Seattle, which was established in 1869. Seattle became an
important stopping point for those hoping to prospect for gold in Alaska and the Yukon Territory at
the close of the 19th century.2
In the 20th century, communities in King County were profoundly shaped by discriminatory
practices, particularly in housing and employment. All minority groups in Seattle faced various
forms of discrimination, including geographic segregation, inequitable access to jobs, and housing
discrimination. Seattle’s redlining practices, in particular, exacerbated racial and economic
1 Metropolitan King County Council, “King County Comprehensive Plan” (December 2024):
https://kingcounty.gov/en/dept/council/governance-leadership/county-council/useful-links/comprehensive-
plan/2024
2 Anneliese Vance-Sherman, Ph.D., “King County profile” Washington Employment Security Department (May
2022): p 1,
https://esd.wa.gov/media/pdf/952/king20county20profile202022pdf/download?inline#:~:text=The%20county's%
20median%20household%20income,the%20state%20at%209.8%20percent.
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segregation, leaving neighborhoods like the Central District to suffer long-term disinvestment,
declining property values, and substandard housing quality.3
The legacy of redlining continues to shape the built environment and ongoing inequalities in the
region. Communities of color still face limited access to critical resources like education, healthcare,
and job opportunities. Additionally, these neighborhoods often experience heightened exposure to
environmental hazards, such as flooding, pollution, and the impacts of earthquakes.
3.4 Population
Table 3-1 2023 King County Demographics4
King County’s population has increased by
approximately 17 percent from 2010 to
2023. Since 2020, the population has grown
by an average of 1,675 people annually, or
0.1%, a significant slowdown compared to
the 1.1% average annual increase from
2017 to 2020. The slowdown in population
growth is primarily due to fewer people are
being born in King County than before, and
more people have been leaving the area
than moving in.
Most of King County's residents are of
working age, with the largest share of
residents (17 percent) being 30 to 39 years
old. Approximately 20 percent (449,242) of
King County's population is 17 years old or
younger. Unincorporated King County
residents are older on average than King
County residents.
The per capita income in King County
exceeds $72,000, while the median household income is over $120,000. Income distribution is
varied, with 20% of the population earning less than $50,000, 22% earning between $50,000 and
$100,000, 29% earning between $100,000 and $200,000, and 29% earning over $200,000. While
the data shows King County to be overall affluence, a significant portion of low-income households
3 City of Seattle, “Redlining in Seattle” Seattle Municipal Archives (n.d.):
https://www.seattle.gov/cityarchives/exhibits-and-education/online-exhibits/redlining-in-seattle
4 US Census Bureau, “DP02: Selected Social Characteristics”, “DP03: Selected Economic Characteristics”, DP04:
Selected Housing Characteristics”, “DP05: ACS Demographic and Housing Estimates” American Community Survey
(2023)
King County King County
Estimate
Total population 2,271,380
Under 5 years 5.0%
Median age (years) 37.7
Under 18 years 19.1%
65 years and over 14.5%
Male 50.6%
Female 49.4%
Owner-occupied 55.6%
Renter-occupied 44.4%
Gross Rent Median (dollars) $ 2,043
Average household size 2.35
Median household income
(dollars)
$120,824
Per capita income (dollars) $72,488
High school graduate or higher 94.1%
Bachelor's degree or higher 58.3%
Employed 67.8%
Unemployment 3.0%
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face substantial housing challenges. In 2023, 70% of low-income households in King County spent
more than 30% of their income on housing.5 This financial strain makes it difficult for these
households to afford other essential needs, such as food, healthcare, and transportation.
Figure 3-2 2020 US Decennial Census, King County Race and ethnicity Data
Figure 3-2 shows King County’s 2020
Decennial Census data on race and
ethnicity. Between 2010 and 2020, King
County saw significant increases in
racial diversity, particularly large growth
in the Asian (60 percent) and
Hispanic/Latino community (41
percent). Communities that saw a
decline in population include White (1.6
percent) and American Indian/Alaskan
Native population (8.7 percent). It’s
important to note that U.S. Census has
historically faced challenges when it
comes to accurately capturing Native
American populations, especially those
living on reservations.
Vulnerable Populations and Population-Based Vulnerability
Population vulnerability (or social vulnerability) measures factors that theoretically increase the
likelihood of a population to suffer more losses during disasters or recover more slowly after being
impacted. There is a growing body of work on this kind of vulnerability; however, how the data is
reported can obscure the root causes of vulnerability when converted into an index or score.
Knowing the root causes of vulnerability and how those vulnerabilities contribute to losses during
disasters is critical for hazard mitigation professionals since each cause may require a unique
strategy to address. For example, if the vulnerability results from language differences, then this
can be addressed with robust translation and outreach services.
Communities that consider population-based vulnerability and social justice, often do it as an
overlay – examining the impacts of a proposed project on vulnerable populations, for example,
after the project has already been prioritized or mapping the location of vulnerable populations in
accordance with some composite score and institutionally-defined definition of vulnerability. It is
5 King County, “Regional Affordable Housing Dashboard” (November 2024):
https://kingcounty.gov/en/dept/dchs/human-social-services/housing-homeless-services/affordable-housing-
committee/regional-affordable-housing-dashboard
White
54%
Black, African American
6%
American
Indian, Alaska
Native
0%
Asian
20%
Native
Hawaiian,
Pacific Islander
1%
Other Race
1%
Two or More Races
7%
Hispanic, Latino
11%
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unclear if mapping alone, if awareness alone, has had much impact on where the bulk of resources
are directed.
For this analysis, we examine the best available data of factors that have been found to lead to
increased losses or recovery times following hazard events. This is to establish areas with different
kinds of heightened vulnerability. We then overlay data on race, ethnicity, and income. This is to
establish where equity may be a concern, where causes of vulnerability overlap with historically
underrepresented minority populations.
Determinants of Population Vulnerability
Factors that were identified through research and by the planning team as critical determinants of
vulnerability. However, Good data at the appropriate scale was not available for all the below
factors. Maps of a selection of these factors, along with priority hazard areas, follow the list of
variables.
Population factors
(population-based
measures)
•Home Ownership Status
•Age
•Unemployment, Income
•Wealth, Access and
Functional
Needs/Disability
•Dependence on public
transportation
•Language other than
English spoken at home
•No health insurance
•Hazard insurance
coverage
•Minimum wage
employment/service
sector employment,
•Families with dependents
•Living in poverty
•Crime rate
•Years of schooling
completed
Accessibility &
capital factors
(access/infrastructure
meaures/ social capital)
•Access to services
•Quality of public
facilities
•Access to phone +
internet
•Average age of
housing
•Average commute
time/distance to work
•Per capita government
spending
•Neighborhood
engagement
Meta-factors
(Determinants of equity)
•Race, ethnicity
•Age
•Income
•Immigrant, refugee
status
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The following maps are gathered from FEMA’s Resilience Analysis and Planning Tool (RAPT) with
quantitative insight from the 2023 US Census American Community Survey 1-Year estimates. They
illustrate several of the above variables associated with greater hazard risk along with high hazard
areas and non-white populations. This is just a selection of potential variables and illustrates how
high-hazard areas, factors associated with hazard risk, and communities of color or with higher
rates of disability may overlap. The highest population-risk areas in King County tend to be areas
south of Seattle in the Green River Valley. These areas also are areas with the highest hazard risk.
Investments that target critical public infrastructure and support structures in these communities
would likely have the best cost-benefit ratio. Investments in these areas would have the added
benefit of also promoting more equitable access to high-quality infrastructure and services for
populations historically underserved by public investment.
People with access and functional
needs/disabilities 10.5%
Concentrated populations in Kent, Algona,
Pacific, Renton, Shoreline, and Kenmore. These
individuals may require additional support in
areas such as mobility, communication, or daily
living activities.
Limited English 11%
Residing primarily in Bellevue, Newcastle,
Renton, Federal Way, Burien, and Seattle.
Limited English proficiency can affect
individuals’ ability to access essential services
such as healthcare, education, and
employment opportunities. This population
includes immigrants, refugees, and non-native
English speakers who may face language
barriers in navigating day-to-day life,
emphasizing the need for culturally competent
services and language assistance programs in
these areas.
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No high school diploma
Trend is shown in south Seattle, Tukwila,
SeaTac, Des Moines, Algona, and Auburn. This
demographic often faces greater barriers to
employment and economic mobility. Lack of a
high school diploma can limit access to better-
paying jobs and higher education
opportunities, contributing to socioeconomic
disparities in these communities.
Don’t own a vehicle 11.9%
Higher concentration in Seattle, Renton, Kent,
and Auburn. While the city of Seattle has a
robust transit network, cities such as Renton,
Kent, and Auburn are more limited and would
require connections to the Sound Transit Light
Rail, or train stations (connecting to Sound
transit buses or the Sounder commuter rail) to
better connect to the region. Lack of vehicle
ownership can limit access to job
opportunities, healthcare, education, and
essential services, particularly in areas with
limited public transportation options.
Below the poverty line
8.8% of individuals, 10.8% of children under 18
years old, 5.1% of families are living below the
poverty line. Those facing these economic
challenges experience a higher cost burden
which can limit their access to education,
healthcare, housing and food security.
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No health insurance coverage 4.9%
Primarily reported with people who reside in
South King County, lack of health insurance can
result in individuals delaying or avoiding
necessary medical care, which may lead to
worsened health outcomes and higher costs in
the long term.
Unemployment 3%
Seen in communities such as Vashon,
Skykomish, and Redmond. This can be the
result of a lack of diverse work opportunities.
Unemployment can pose several risks to
individuals, families, and communities. These
risks extend beyond financial instability and can
have long-term effects on health, mental well-
being, and overall societal outcomes.
The results from this analysis will be used to promote more effective, equitable disaster mitigation,
response, and recovery by identifying key vulnerabilities and areas that may require additional
investment. This analysis will also help identify areas where public infrastructure is older or less
resilient, or where hazard risk is greater, so that additional investments can be targeted in those
areas.
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3.5 Economy
Figure 3-3 2023 US Census data, King County Industries
Throughout the 1990s, the county
underwent extraordinary gains in
employment, population and
wages. Despite the county’s
increasing cost of living, especially
in housing, the high-tech job boom
lured well-educated newcomers to
the area; a pattern that has
continued to the present day. King
County continues to hold a strong
national reputation as a hub for
information technology
development.6
King County is culturally diverse
and aims to be a place where
people from a variety of
backgrounds can feel at home. The
geographic orientation of King
County on the Pacific Rim and the
presence of an active natural deep-
water port reinforce strong
economic ties to East Asian
markets. In 2008, King County
nonfarm employment reached a
peak in excess of 1.2 million jobs before joining the rest of the nation in recession. Job growth was
strong and stable from 2010 to 2019. Total nonfarm employment in King County climbed to nearly
1.47 million over the long economic expansion. The pandemic-induced recession of 2020
interrupted the long arc of local employment growth. From February to April 2020, total nonfarm
employment plummeted by about 166,600 jobs – more than 11.0 percent. Total employment since
April 2020 has shown remarkable recovery, with a great deal of variation by industry. Total
employment continues to expand. As of March 2022 (preliminary), businesses located in King
County collectively supplied nearly 1.46 million jobs – about 10,000 shy of pre-pandemic levels. King
County is characterized by a diverse economy. Major industry sectors in King County supplying
6 Anneliese Vance-Sherman, Ph.D., “King County profile” Washington Employment Security Department (May
2022): p 2,
https://esd.wa.gov/media/pdf/952/king20county20profile202022pdf/download?inline#:~:text=The%20county's%
20median%20household%20income,the%20state%20at%209.8%20percent.
Management,
Business, Science,
and Arts
59%
Service
13%
Sales and
Office
15%
Natural Resources,
Construction, and
Maintenance
5%
Production, Transportation,
and Material Moving
8%
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more than 100,000 estimated jobs in 2021 include professional and business services, education
and health services, retail trade, government, information, and leisure and hospitality.
Prior to the pandemic-induced recession of 2020, King County was well-situated, with long-term
growth observed in all major industry sectors. The COVID-19 pandemic disrupted all industries at a
local level, with employment patterns varying substantially from one industry to the next. Leisure
and hospitality lost the largest number of jobs of any sector (65,100 jobs from February to May, not
seasonally adjusted). As of March 2022, this set of industries was still down 44,000 jobs or about 30
percent. At the other end of the continuum, industries such as information and professional and
business services, maintained or even expanded employment levels, even early on, insulated by the
ability to establish telecommuting arrangements for their workforces. King County’s information
sector added 700 jobs during the initial months of the pandemic. As of March 2022, employment in
the information sector was 15,500 above the level observed in March 2020. Comparing March 2022
against March 2020, the following industries have fully recovered or expanded total employment:
professional and business services (up 15,600 jobs), information (up 15,500 jobs) retail trade (up
9,000 jobs), financial activities (up 4,000 jobs), and construction (up 1,400 jobs).
Referencing the same time frame, the following industries have yet to recover the number of jobs
lost in the pandemic recession: leisure and hospitality (down 19,400 jobs), manufacturing (down
9,900 jobs), government (down 9,200 jobs), other services (down 8,600), wholesale trade (down
3,700 jobs), transportation, education and health services (down 2,800 jobs), and warehousing and
utilities (down 1,400 jobs).
3.6 Development Trends
Over the past decade, King County saw steady population growth, particularly in Seattle and its
surrounding cities including Bothell, Kent, Renton, Shoreline, Lynnwood, Redmond, SeaTac. The
demand for housing close to transit hubs, job centers, and amenities spurred the construction of
high-rise apartments and condominiums in downtown Seattle and other urban areas. The
Washington State Office of Financial Management projects that King County's population will grow
by 24.6%, reaching 2,887,137 people by 2044. In contrast, the population of unincorporated King
County is expected to grow more slowly, increasing by 7.3% to 266,301 people by 2044.
As demand for housing increased, King County also faced challenges with affordability. Housing
prices surged, especially in Seattle, due to high demand, limited supply, and low interest rates.
Many residents moved further out from the city center, due to rising costs in Seattle, leading to
increased development in suburban areas like Bothell, Renton, Shoreline, and Kent. There was a
notable shift toward suburban apartments, townhomes, and single-family homes that catered to
those seeking more affordable living options. To accommodate the housing needs of both current
and future residents, King County is required by the Growth Management Act and the Countywide
Planning Policies to plan for housing that serves a range of income levels, from moderate to
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extremely low-income households. This includes provisions for emergency housing, shelters, and
permanent supportive housing. By 2044, urban unincorporated King County will need an additional
5,412 housing units, along with 1,034 new emergency housing beds to meet short-term housing
needs.7
The 2024 King County Comprehensive Plan Maintaining the urban growth boundaries and
developing within this area. The plan focuses on maintaining urban growth boundaries and
encouraging development within these areas. Zoning updates will expand middle housing options,
such as duplexes and triplexes, and offer increased incentives for affordable housing. It will also
address temporary farmworker housing needs. Environmental protections are part of the plan, with
policies aimed at promoting green energy, climate action, and improving infrastructure resilience
against flooding and wildfires.
7 Metropolitan King County Council, “King County Comprehensive Plan” (December 2024):
https://kingcounty.gov/en/dept/council/governance-leadership/county-council/useful-links/comprehensive-
plan/2024
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Chapter 4: Risk Assessment
Overview
4.1 Overview
The King County Regional Hazard Mitigation Plan identifies 14 hazards, including 8 natural hazards
and 6 human-induced threats. The list of hazards was developed through an examination of the
previous RHMP, local hazard mitigation plans, and hazard events in the last five years. The list was
cross referenced with FEMA’s National Risk Index (NRI), a tool that assesses natural hazards and
community risk factors. Based on insights from these sources and recent trends in hazard events,
we retained the same list of hazards from the 2020 plan.
Natural Hazards Human-Induced Hazards
Avalanche
Earthquake
Civil
Disturbance
Cyber
Incident
Dam
Failure
Hazardous
Materials
Health
Incidents
Terrorism
Flood
Landslide
Severe Weather
Flood
Volcano
Wildfire
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A risk assessment was conducted with subject matter experts for each hazard. Risk assessment is
the process of measuring the potential loss of life, personal injury, economic injury, and property
damage resulting from hazards.
Risk profile structure
• Description: This section provides clear, concise definitions of the specific hazard being
assessed. It includes scientific and technical terms related to the hazard and its
characteristics, ensuring a shared understanding for all stakeholders involved.
• Location: This section identifies and outlines geographical regions that are particularly
vulnerable to the hazard. It highlights areas that are more likely to experience higher levels
of risk based on historical data, topography, weather patterns, and other relevant factors.
• Magnitude: This defines the scale of the hazard’s potential effects. For example, in the case
of an earthquake, magnitude might be measured by the Richter scale, or in a flood, it could
be measured by the depth of inundation or the amount of rainfall. This provides a basis for
understanding how severe the hazard could be in terms of its physical, economic, and social
impact.
• Previous Occurrences: This section provides a historical record of previous occurrences of
the hazard in the area. It includes dates, locations, and the severity of past events, offering
valuable insights into the frequency and extent of the hazard, as well as the impacts on
people, property, and infrastructure.
• Probability of Future Occurrences: This section forecasts the likelihood of the hazard
occurring in the future. It may include statistical probabilities based on historical data,
trends, and modeling.
• Climate Change Considerations: This section examines how climate change might influence
the frequency, intensity, or characteristics of the hazard.
• Impact Assessment: This section evaluates the specific consequences of the hazard on
various sectors, using a structured table format.
• Vulnerability Assessment: This section outlines the vulnerabilities in different sectors. It
identifies which groups or resources are most at risk and why. Stats and Specifics on What Is
at Risk: Specific data, such as population demographics, infrastructure condition, or
environmental features, are included here.
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4.2 Methodology
Table 4-1 Hazard risk assessment methodology
The Core Planning Team
developed a risk matrix to assess
hazards, their impacts on county
assets, and the vulnerabilities of
these assets across various
dimensions (see Table 4-1). The
purpose of this risk assessment is
to identify which hazards pose the
greatest risk and which areas and
assets are most vulnerable. The
matrix incorporates Emergency
Management Accreditation
Program (EMAP) standards to
quantify the hazard impacts on
county assets and assess their
vulnerability. It provides a
snapshot of each hazard’s impact
and is complemented with
qualitative insight to guide
mitigation action. It contains key
details to enable emergency
managers to plan for and
responding to disasters effectively.
The matrix is broken up into three
categories that equate to total risk.
Risk depends on all three factors:
the hazard that can cause damage,
exposure to the hazard and the
vulnerability of the exposed
population. Risk is the estimated
impact that a hazard would have
on people, services, facilities, and
structures in a community. It
refers to the likelihood of a hazard
event resulting in an adverse
condition that causes injury or
damage.
HAZARD RISK ASSESSMENT
Risk = Hazard (Severity) x Impact (Exposure) x Vulnerability
(Susceptibility)
Location
Ha
z
a
r
d
Probability
Extent/Magnitude
Public
Im
p
a
c
t
Responders
Continuity of Operations (COO)
Property, Facilities, and Infrastructure (PFI)
Environment
Economy
Public Confidence in Governance (PCG)
Vulnerable Population
Vu
l
n
e
r
a
b
i
l
i
t
y
Property
Environment
Operations
People
Ri
s
k
Property
Environment
Operations
Overall Risk
Measurement
1 Low
2 Moderate
3 High
4 Very High
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4.2.1 Hazard Assessment
A hazard is an act or phenomenon that has the potential to produce harm or other undesirable
consequences to a person or thing. Hazards exist with or without the presence of people and land
development. Earthquakes, hurricanes, tornadoes, and other geological and meteorological events
have been occurring for a very long time, and the natural environment adapted to their impacts.
Hazard identification is the process of identifying hazards that threaten a given area. The likelihood
and severity of the 14 hazards were measured in the following ways.
• Location – The percentage of the people and property within the planning area impacted by
the event, and the degree to which they are impacted.
LOCATION
1 - Negligible 2 - Limited 3 – Critical 4 - Catastrophic
Less than 10% - Few if
any injuries or illness.
Minor quality of life
lost with little or no
property damage. Brief
interruption of
essential facilities and
services for less than
four hours.
10-24% - minor injuries
and illness. Minor,
short term property
damage that does not
threaten structural
stability. Shutdown of
essential facilities and
services for 4 to 24
hours.
25-49% - Serious injury
and illness. Major or
long-term property
damage, that threatens
structural stability.
Shutdown of essential
facilities and services
for 24 to 72 hours.
More than 50% -
Multiple deaths.
Property destroyed or
damaged beyond
repair. Complete
shutdown of essential
facilities and services
for 3 days or more.
• Probability – Probability of a hazard event occurring in the future was assessed based on
the number of times the hazard event occurred divided by the period of record. If the
hazard lacked a definitive historical record, the probability was assessed qualitatively based
on regional history and other contributing factors.
PROBABILITY
1 - Unlikely 2 - Possible 3 – Likely 4 - Highly Likely
Less than 1%
probability in the next
100 years.
Between 1% and 10%
probability in the next
year, or at least one
chance in the next 100
years.
between 10% and
100% probability in the
next year, or at least
one chance in the next
10 years.
Greater than 1 event
per year (frequency
greater than 1).
• Extent/Magnitude – Magnitude measures the strength of a hazard event. It was calculated
for each hazard using available property damage data using the following equation:
Property Damage / Number of Incidents) / $ of Building Stock Exposure = Magnitude. In
some cases, the HAZUS model provided specific people/dollar impact data. For other
hazards, a GIS exposure analysis was conducted.
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EXTENT/MAGNITUDE
1 - Negligible 2 - Limited 3 – Critical 4 - Catastrophic
Less than 5% - Very
minor impact to
people, property,
economy, and
continuity of
government at 90%.
6-24% - Injuries or
illnesses minor in
nature, with only slight
property damage and
minimal loss associated
with economic impact;
continuity of
government only
slightly impacted, with
80% functionality.
25-49% - Injuries result
in some permanent
disability; 25-49% of
the population
impacted; moderate
property damage;
moderate impact to
economy, with loss of
revenue and facility
impact; government at
50% operational
capacity with service
disruption more than
one week, but less
than a month.
More than 50% -
Injuries and illness
resulting in permanent
disability and death to
more than 50% of the
population; severe
property damage
greater than 50%;
economy significantly
impacted as a result of
loss of buildings,
content, inventory;
government
significantly impacted;
limited services
provided, with
disruption anticipated
to last beyond one
month.
4.2.2 Impact Assessment
The impact assessment examines seven key types of county assets located with a hazard area,
incorporating both asset exposure and event magnitude to determine the overall impact. These
assets are identified by the Emergency Management Accreditation Program (EMAP) consequence
analysis for the hazards specified in Standard 4.1.1.
• Public: The impact on public health and safety is gauged by the number of people exposed
and the magnitude of the hazard. A low-impact scenario involves minimal health and safety
concerns, leading to minor inconveniences or temporary disruptions. In contrast, a very
high-impact event can cause extensive health issues, significant fatalities, and severe public
safety disruptions, potentially overwhelming healthcare systems and necessitating
extensive emergency responses.
• Responders: The impact on emergency services - including fire, police, and EMS – is
determined by the number of emergency requests and the magnitude of the event, which
influences response times and resource allocation. A low impact would involve minor delays
or disruptions with manageable resource demands. In a very high impact scenario,
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responders face severe delays, overwhelming resource demands, and may struggle to
provide adequate emergency services.
• Continuity of Operations (COO): This includes the operational stability of King County
government functions, assessing disruptions and their effects on essential services and
processes. A low impact involves minor disruptions with manageable effects on essential
services and processes. A very high impact entails severe and widespread disruptions,
potentially leading to a complete breakdown in essential services and prolonged recovery
periods.
• Property, Facilities, and Infrastructure (PFI): The impact on private property includes
damage to housing, critical infrastructure, roadways, and utilities. Low impact means
minimal damage or inconvenience to property with little long-term effect. Very high impact
results in severe and widespread damage to properties and infrastructure, causing
significant financial losses and prolonged recovery.
• Environment: Hazards can affect natural resources, including wildlife, vegetation, and
ecosystems, leading to changes in landscapes, waterways, and environmental systems. A
low impact involves minor environmental changes with negligible effects on wildlife and
natural systems. A very high impact indicates severe and widespread environmental
destruction with long-term effects on natural resources, wildlife, and ecosystems, requiring
substantial recovery and restoration efforts.
• Economy: Economic impacts encompass disruptions to business operations and economic
assets, affecting overall financial stability. A low impact entails minimal disruption to
business operations and economic assets with minor financial effects. Very high impact
signifies severe and widespread economic disruption with major financial losses, potentially
leading to long-term economic instability and extended recovery periods.
• Public Confidence in Governance (PCG): The perception of government effectiveness during
and after a hazard event can influence public trust and confidence in emergency
preparedness and response efforts. A low impact involves minor concerns about
government response with little effect on overall public trust. A very high impact entails a
severe loss of public confidence and trust in government, potentially leading to widespread
criticism and long-term reputational damage.
4.2.3 Vulnerability Assessment
Vulnerability is susceptibility to physical injury, harm, damage, or economic loss. It depends on an
asset’s construction, contents, and economic value of its functions. Vulnerability assessment
provides the extent of injury and damages that may result from a hazard event of a given intensity
in a given area.
The Emergency Management Program identifies the natural and human-caused hazards that
potentially impact the jurisdiction using multiple sources. The Emergency Management Program
assesses the risk and vulnerability of the following:
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• Vulnerable Populations: Communities limit to preparing and preventing impact to a hazard
event.
• Property: Properties limit to withstanding and maintaining integrity to a hazard event.
• Environment: Environments limitation to preventing degradation during and following a
disaster.
• Operations: lifelines that have limited capacity and resources to properly respond to a
hazard event.
4.2.4 Risk Calculation
When calculating risk, we’re looking at most likely scenario accounting for currently capabilities and
regulations (reference chapter 19 for capabilities).
People
To assess the total risk to people, we consider hazard assessments, potential impacts on individuals,
responders, and the economy, as well as the concentration of vulnerable populations who have
limited ability to prepare for or respond to a hazard event.
Property
In evaluating the total risk to property, we consider hazard assessments, the potential impacts on
buildings, facilities, infrastructure, the environment, and the economy. Additionally, we assess the
ability of properties to withstand and maintain structural integrity during and after a hazard event.
Environment
When assessing the risk to the environment, we account for hazard assessments, potential
environmental impacts, and economic consequences. We also evaluate the environment's capacity
to prevent degradation during and after a disaster.
Operations
To determine the total risk to operations, we consider hazard assessments, the impact on the
continuity of government functions, the economy, and public confidence in the government. We
also assess the vulnerability of critical operations, such as lifeline services, which may have limited
capacity and resources to respond effectively to a hazard event.
Overall Risk
The overall risk is determined by combining the risks to people, property, environment, and
operations.
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4.3 Risk Assessment Results
Table 4-2 King County risk assessment results
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4.4 GIS Data
Geographic Information System (GIS) data was taken from a variety of King County, Washington
State, and federal sources. The data was sourced via King County GIS, including layers owned by
both GIS and by other entities. Some of the GIS data analyzed in completing this risk assessment
include:
Title Description Source
Active Faults Known active faults in the Puget
Sound region
WA State Department of Natural
Resources (DNR)
Wastewater
Systems
King County wastewater treatment
and conveyance systems
King County Department of Natural
Resources and Parks Water Treatment
Division (DNRP)
Water Supply
Facilities
Seattle water supply facilities and
conveyance systems. These are
used to supply Seattle as well as
many cities.
City of Seattle Public Utilities
Bridges King County-maintained bridges King County Roads
Rail Routes All rail routes, including BNSF and
Sound Transit
King County GIS
Transit Routes Metro transit routes King County Metro
Arterials Arterial streets King County Roads
Levees and
Revetments
County-maintained flood protection
structures.
DNRP, King County Flood Control
District
BPA
Transmission
Lines
Bonneville Power Administration
power transmission systems
Bonneville Power Administration
Historic
Buildings
Designated historic buildings King County GIS
Schools School facilities King County GIS
Government
Buildings
King County government buildings King County GIS, Facilities
Management Division
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Hospitals and
Medic Units
Hospitals and medic unit locations King County GIS
Pharmacies Pharmacy locations King County GIS
First Responder
Facilities
Locations of fire, police, and EMS King County GIS
City Boundaries City jurisdictional boundaries King County GIS
Rivers and Lakes Waterbodies King County GIS
Building Address
Points
Building address points and age King County Assessor
Building Age Building address points and age King County Assessor
Volcanic Hazard
Areas
Lahar, lava flow, and lahar sediment
areas
WA DNR, U.S. Geological Survey
Landslide Hazard
Areas
Lidar-based landslide inventory
mapping
WA DNR
Preliminary 100-
year Floodplain
1% annual chance, special flood
hazard area as mapped by FEMA.
Will take effect as the regulatory
floodplain in 2020.
FEMA, King County Flood Control
District
Floodways The regulatory areas including the
channel and adjacent land areas
that must be preserved in order to
discharge the base flood without
increasing the water surface
elevation by more than a
designated height.
FEMA, King County Flood Control
District
Liquefaction
Potential
Areas of NEHRP soil classes D, E, and
F.
WA DNR
Landslide Buffer
Areas
Buffers of 50 feet around known
landslide areas.
King County GIS
Statewide Roads State and federal highways King County GIS
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This and any additional data can be viewed on the ArcGIS online hazard map called the King County
Equity in Response and Planning Tool.
4.5 Jurisdiction-Specific Risk Assessments
In addition to this countywide risk assessment, each participating jurisdiction completed a risk
assessment focusing on the priority hazards, vulnerabilities, and consequences. These assessments
are contained in each planning partner annex. These assessments will have much more detail about
Health Insurance
Coverage
Individuals with health insurance, by
Census Tract
US Census, American Community
Survey (ACS)
Travel Time to
Work
Travel time to work on average by
Census Tract
US Census, ACS
Means of
Transportation
to Work
Means of transportation to work, by
percent, by Census Tract
US Census, ACS
Race Self-identified race US Census, ACS
Ethnicity Self-identified ethnicity US Census, ACS
Income Income (range) US Census, ACS
Languages Languages other than English
spoken at home
US Census, ACS
Disability Status Counts of disabled persons King County GIS
Education Educational attainment by years, by
Census Tract
US Census, ACS
Tenure Housing tenure (ownership) status King County GIS
HAZUS for
earthquake
(Seattle Fault,
Cascadia
Subduction
Zone)
HAZUS runs for Seattle Fault 7.1 and
Cascadia Subduction Zone 9.0
scenarios
FEMA RiskMAP
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individual jurisdiction risks and should supplement the wider lens of the risk profiles contained in
the base plan.
To complete their assessments, jurisdictions were provided with GIS data and an ArcGIS online map
containing relevant data on hazards and impacts. The data is the same as that used in the base plan
risk assessments, but jurisdictions were asked to focus on impacts specific to their assets and
boundaries. Jurisdictions assessed risk in two ways.
• First, jurisdictions looked at hazards that could impact them, how susceptible/vulnerable
they are to those hazards, and the consequences/impacts of a hazard event. The task was to
develop “risk elevator pitches” that summarize the key elements of hazard risk in a way
accessible to elected officials and the public.
• Second, jurisdictions were asked to consider an asset-based approach, looking at their
priority assets, the hazards that threaten those assets, and the consequences of losing the
asset. All jurisdictions were encouraged to complete this process, but only special purpose
districts were required to complete it. The goal of this approach was to identify assets that
needed mitigation.
In developing their risk assessments, jurisdictions held internal meetings to select the list of hazards
that would be included and to assess the relative risk of each hazard. Most used a high-medium-low
approach for impact, where high impact is a debilitating event, and moderate impacts are serious
events that disrupt operations for multiple days. For those that also considered probability
separately from the base plan, a high probability event is likely to occur on an annual basis. These
jurisdiction-specific risk assessments are not designed to be exhaustive but should give a much
clearer picture of risk and vulnerability than is normally available from countywide assessments.
AGENDA ITEM #1. b)
Risk Assessment
Scoring
1 Location
Ha
z
a
r
d
2 Probability
2 Magnitude
1 Public
Im
p
a
c
t
1 Responders
1 COP
1 PFI
1 Environment
1 Economy
1 PCG
1 People
Vu
l
n
e
r
a
b
i
l
i
t
y
1 Property
1 Environment
1 Operations
1 People
Ri
s
k
1 Property
1 Environment
1 Operations
Low Overall Risk
PC: WADOT
Chapter 5Avalanche
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Chapter 5 Avalanche
5.1 Hazard Description
Avalanche hazards in the Pacific Northwest are most common during the winter and spring in the
Cascade and Olympic Mountain Ranges. They occur when a mass of snow slides, flows, or tumbles
down a slope. The slopes range between 30 to 45 degrees and have enough snow depth to cover
anchors such as rocks and small trees. Avalanches may also release on slopes steeper than 45
degrees, where snow may accumulate, and occasionally on low-angle slopes under ideal wet snow
conditions. Avalanche forecasters use nine categories to describe the current avalanche problem.
These include two primary types of avalanches:
• Loose snow avalanche: an avalanche that releases from a single point and entrains
cohesionless snow as it fans downhill.
• Slab avalanche: a cohesive layer of snow that avalanches. Slab avalanches account for the
large majority of avalanche accidents because their failures propagate across the slope and
around the victim, making them harder to escape than a point-release avalanche. Slabs
form as snow settles and becomes denser or winds load or add cohesion to snow.
• Roof avalanche: an avalanche that falls from the roof of a man-made structure. Roof
avalanches commonly slide on the roof’s surface, thus involving the entire existing
snowpack. Roof avalanches most commonly occur during warming periods after substantial
snow has accumulated. Accidents involve unsuspecting residents, or snow removal and
maintenance workers.
Additional categories include qualification to the age and depth of the snowpack's weak layer, the
formation type, and a few specific types, such as cornices.
Common factors that contribute to avalanche danger include old snow depth, old snow surface,
new snow depth, new snow type, snow density, snow fall intensity, precipitation intensity,
settlement, wind direction and wind speed, temperature, subsurface snow crystal structure, and
tidal effect.1 Research done at Snoqualmie Pass indicates that most natural avalanches occur within
one hour after the onset of rain over a weakened snow pack. Large amounts of new snow
accumulation also increases avalanche risk, especially when coupled with wide temperature swings.
These events, whether natural or human-triggered, pose risks to recreationalists, ski area
operations, and travelers on highways.
1 Scott M Kruse, “Avalanche Evaluation Check List” Avalanche Review vol. 8, No 4 (February 1990)
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5.2 Location
Avalanche events occur at two mountainous locations in King County: Stevens Pass in the northeast
along US Highway 2 and Snoqualmie Pass on the county’s central-eastern boarder along Interstate
90. Snoqualmie and Stevens Pass are significant transportation routes, particularly for commercial
traffic connecting the Ports of Tacoma and Seattle to Eastern Washington and the northern tier of
the US. They are also the closest ski areas and snow parks to the greater Seattle area.
Snoqualmie Pass spans 3,022 feet of the I-90 roadway and receives an average annual snowfall of
294 inches. The typical daily traffic volume on I-90 is around 28,000 vehicles, with approximately
5,600 of those being freight.2 In the event of an avalanche, significant disruptions to east-west
travel are anticipated. Figure 5-1 shows in orange common avalanche paths, and in grey infrequent
avalanche paths. It also highlights projects, bridges, and viaducts that could be disrupted.
Figure 5-1 Snoqualmie Pass
2 WSDOT, “Avalanche control” WSDOT Operations & Services (n.a.): https://wsdot.wa.gov/travel/operations-
services/avalanche-control
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Stevens Pass spans 4,061 feet of the highway and receives an average annual snowfall of 338
inches. The typical daily traffic volume over Stevens Pass is approximately 4,500 vehicles, with
about 450 of those being freight. Figure 5-2 highlights the avalanche paths in red, with the
Wellington Avalanche, marked in yellow, which remains the deadliest avalanche in U.S. history. This
tragic event occurred in 1910, claiming the lives of 96 people.
Figure 5-2 Stevens Pass
Both maps indicate that most avalanches occur in remote areas away from the ski resorts. The
primary risks are posed to backcountry recreationalists and travelers along the transportation
corridors.
The popular backcountry areas around Stevens and Snoqualmie passes involve complex terrain
where avalanche fatalities occur with relative frequency. These areas draw in snowshoeing, alpine
and cross-country skiing, snowmobiles, and winter hikers and campers. While many people who
engaged in snow sports in these areas are highly experienced enthusiasts; even with safety
equipment, they may trigger or fall victim to avalanches. The Snoqualmie Pass backcountry area has
more complex terrain with more elevation difference between top and bottom of surrounding
mountains than Stevens Pass. Based on the terrain, Snoqualmie Pass backcountry has larger
avalanche paths capable of producing larger and more destructive avalanches than Stevens Pass.
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Several stretches of Interstate 90 and Highway 2 in King County are vulnerable to avalanches
between October and April each year, depending on snowpacks and weather conditions. In the
event that these transportation corridors are closed down due to an avalanche, I-84 in Oregon or air
travel are the only practical ways to travel between Spokane and Seattle. These closures can have a
significant economic impact, particularly due to delays in freight transportation. To address these
risks, the Washington State Department of Transportation (WSDOT) has established specialized
avalanche crews that play a vital role in monitoring and mitigating avalanche hazards, ensuring the
safety and efficiency of travel.
5.3 Magnitude
Each year, avalanches in Washington State cause an average of one to three fatalities. Thousands of
avalanches occur in the Cascades during the winter season, though most are triggered naturally and
have no human impact. In King County, the primary avalanche risk arises from severe winter storms
between October and May, when Pacific storms frequently affect the region.
Figure 5-3 North American Public Avalanche Danger Scale
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Avalanches are measured using the North American Public Avalanche Danger Scale, which
measures the likelihood of both natural and human-triggered avalanches, as well as their size and
distribution. Figure 5-3 shows the scale ranges from 1 (low danger) to 5 (extreme danger).
Both Stevens and Snoqualmie Pass areas experience all levels of avalanche danger as well as
human-triggered and natural avalanches in their surrounding backcountry terrain. However,
Snoqualmie Pass has more highway and parking capacity than Stevens Pass. There is no definitive
source on backcountry use, however, known parking capacity, proximity to population centers, and
the number of avalanche observations publicly submitted to Northwest Avalanche Center per zone
suggest more backcountry users visit the Snoqualmie Pass corridor over the course of the season.
The most frequent impact from avalanches is from pass closures, especially along Snoqualmie Pass
on I-90. In particularly severe events, Snoqualmie, Stevens, and White Passes may close for days,
cutting the state in half. The other routes that cross the cascades, such as US 20, SR 410, and SR 14,
are closed throughout the winter and are not suitable for large traffic volumes or commercial
traffic. Impacts on transportation through mountain passes result in travel delays with local to
regional economic effects. Avalanche risk reduction occurs on these corridors throughout the spring
as WSDOT clears the road for summer operations.
In addition to the roadway risk, two of the state's three cross-state railways pass through the
Cascades. These railroads travel along a route similar to the major highways and are similarly
susceptible to avalanche danger. Significant snowfall and avalanche danger can disrupt rail freight
traffic across the state, with substantial economic impacts.
5.4 Previous Occurrences
The Northwest Avalanche Center has reported on avalanche incidents that presented a risk of
human injury or fatality, excluding those avalanches that occurred without resulting in significant
impact. There was a total of 14 injuries and 13 fatalities across the region. Specifically, Stevens Pass
experienced 3 injuries and 2 fatalities, while Snoqualmie reported 11 injuries and 11 fatalities.
Regarding the reported danger levels for each event, 68% were classified as moderate risk, and 26%
were classified as considerable. The number of reported avalanche incidents have also show to
decline over this period.
While there is more frequent reporting of avalanche activity in Snoqualmie Pass, the avalanche
terrain around Stevens Pass is more than capable of producing avalanches large enough to bury,
injure or kill a person, and has over the years. In fact, the most significant avalanche event in
Washington State, and the deadliest in US history, occurred in 1910 near Stevens Pass. Two trains
carrying passengers were hit by an avalanche killing 96 people.
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Table 5-1 Significant Avalanches in King County, 2001-20243
DATE PASS SIZE FATALITIES AND INJURIES
1910 (Historic
Maximum)
Stevens Pass (railway) n/a 96 Fatalities
April 9, 2010 Snoqualmie Pass D2 - Moderate 2 Injuries
April 10, 2010 Snoqualmie Pass D3 - Considerable 1 Injury
February 1, 2011 Snoqualmie Pass D2 - Moderate 1 Fatality
March 23, 2011 Snoqualmie Pass D1 - Low None
March 27, 2011 Stevens Pass n/a 1 Fatality
April 3, 2011 Stevens Pass n/a 1 Injury
April 6, 2011 Snoqualmie Pass D2 - Moderate 3 Injuries
January 1, 2012 Snoqualmie Pass n/a None
January 21, 2012 Snoqualmie Pass n/a None
February 19,2012 Snoqualmie Pass D2 - Moderate 1 Fatality
February 19, 2012 Stevens Pass n/a 1 Fatality
January 15, 2013 Snoqualmie Pass n/a 1 Injury
April 13, 2013 Snoqualmie Pass (two
locations)
n/a 2 Fatalities
April 13, 2013 Stevens Pass n/a None
January 4, 2014 Snoqualmie Pass n/a None
February 11, 2014 Stevens Pass D3 - Considerable 2 Injuries
February 22, 2014 Snoqualmie Pass n/a None
March 22, 2014 Snoqualmie Pass D3 - Considerable 1 Fatality
3 NWAC “Northwest Avalanche Accident Summaries” Northwest Avalanche Center (December 2024)
https://www.nwac.us/accidents/accident-reports/
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April 27, 2014 Snoqualmie Pass D2 - Moderate 1 Injury
December 6, 2015 Stevens Pass D2 - Moderate None
December 17, 2015 Snoqualmie Pass D3 - Considerable 1 Injury
December 19, 2015 Snoqualmie Pass D3 - Considerable 1 Fatality
December 31, 2015 Snoqualmie Pass D1/D2 –
Low/Moderate
1 Fatality
March 4, 2017 Snoqualmie Pass D2 - Moderate 1 Injury
March 5, 2017 Stevens Pass n/a None
April 11, 2017 Snoqualmie Pass D2 - Moderate 1 Fatality
February 18, 2018 Snoqualmie Pass D2 - Moderate None
February 25, 2018 Snoqualmie Pass (two
locations)
D2 - Moderate 3 Fatalities
February 16, 2019 Stevens Pass n/a None
February 16, 2020 Stevens Pass n/a None
January 31, 2021 Snoqualmie Pass D2 – Moderate 1 Injury
February 7, 2021 Stevens Pass n/a None
February 12, 2023 Stevens Pass n/a None
March 5 2024 Stevens Pass D2 - Moderate None
5.5 Probability of Future Occurrences
The overall frequency of avalanche events is likely to decrease due to the changing climate. As
snow cover diminishes at lower elevations, the potential areas for avalanches to occur are reduced.
However, at higher elevations where snowfall remains abundant, avalanche events may increase in
intensity. Many factors contribute to avalanche formation and release, though the most significant
involves the bond between snow layers and loading from new snow or rain. The Pacific Northwest
has a maritime snow climate, and most avalanche activity is directly related to precipitation events,
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either snow or rain. Rapid changes in temperature, especially at or near the freezing point, further
contribute to avalanche release.
5.6 Climate Change Considerations
Research pertaining to climate change impact on avalanche activity in this region is currectly
limited. However, climate change is expected to lead to a significant decrease in snowpack in
Washington, with projections indicating a reduction of up to 70% by 2080 compared to 2006
levels.4
Avalanche frequency and type relative to elevation and location will likely change over time due to
the impacts of climate change. Initial research on the impacts of climate change and avalanches
suggest we may see fewer lower elevation avalanches due to reduced snowpack. Depending on
how the climate warms in our region, we may see fewer avalanches associated with colder weather
(persistent slabs) and more wet snow avalanches.
5.7 Impact Assessment
Public Avalanche conditions can cause closure of ski areas like: Alpental, Hyak
(Summit East), Ski Acres (Summit Central), and Stevens Pass. The
recreational skiers and the people who are seasonally employed can be
impacted when these conditions close ski areas. People who ski “out of
bounds” take exceptional risks in locations where avalanche control
does not maintain safe conditions and search and rescue operations
may be hampered.
Pass closures may inconvenience people by causing them to either take
commercial flights between eastern and western Washington or cause
them to take wide routes around the mountain area through the
Columbia Gorge between Washington and Oregon.
There are no major populations in King County that are exposed to
avalanche terrain. The King County community closest to avalanche
country is Skykomish. It has not experienced an avalanche in recent
memory.
4 Washington Emergency Management Division (EMD), “Avalanche” Washington State Enhanced Hazard
Mitigation Plan (2023): p. 28, https://mil.wa.gov/asset/651ec296d76a9/2023_WA_SEHMP_final_20231004.pdf
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Responders When avalanches bury or injure skiers and backcountry hikers, the King
County Sheriff’s Office Search and Rescue team(s) may be deployed
along with trained volunteers and specially trained volunteer K-9 units
like BARK (Backcountry Avalanche Rescue K-9). Most search missions
occur in or around the off-trail perimeter of ski areas like Snoqualmie
Acres, Hyak, Alpental, and Steven’s Pass. Buried skiers are often
severely injured or may be killed from their injuries or suffocation
under large amounts of snow in areas difficult to reach.
Continuity of
Operations
Avalanche areas are remote to most King County operations. Where
avalanches may occur, King County Sheriff’s Office Search and Rescue,
Ski patrols, and volunteers may be involved. This may include BARK, a
group that provides K-9 search capability for avalanche victims. Support
may also be required from the aviation unit of the King County Sheriff’s
Office and from Emergency Medical Service units.
Support personnel for avalanche control are provided by Washington
State Department of Transportation.
Property, Facilities,
and Infrastructure
Property
Property exposed to avalanches include seasonal vacation homes and
ski resort operations.
Facilities
There are no known healthcare facilities or systems exposed to
avalanches.
Infrastructure
Critical infrastructure that may be impacted includes the BNSF railway
(also used by Amtrak) and the east west highways, US 2 (Stevens Pass)
and I-90 (Snoqualmie Pass). Chinook Pass usually closes from October
through May.
Environment Avalanches are natural events, but they can have significant
environmental impacts, including the destruction of wildlife, trees, and
the alteration of the landscape. These events can reshape terrain and
disrupt ecosystems. To mitigate the effects of avalanches on both
infrastructure and the environment, several upcoming infrastructure
projects along I-90 in Snoqualmie Pass are being proposed including the
installation of avalanche chutes. These chutes are designed to redirect
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snowfall away from the I-90 animal crossing overpass, which serves as
a vital north-south habitat connector for wildlife.
Economy Closure of ski areas from avalanche danger usually lasts only a short
time. While revenue to one or more ski areas may be reduced, no long-
term economic impacts can be expected from avalanche issues.
Heavy snows and avalanche danger may close Stevens and/or
Snoqualmie Pass for extended periods. These pass closures can impede
transportation of goods between eastern/western Washington, impact
the Port of Seattle and port/countries around the/Pacific Rim.
Avalanche closure of King County passes may cause motorists and
truckers to reroute through Interstate 84 in Portland.
In 2024, WSDOT completed an “Estimated Road User Cost of
Snoqualmie Pass Closure”, using the volumes of traffic in the winter
months to determine an average total hourly cost of delays based on
weekday/weekend calculations. For weekdays, the average hourly cost
of a delay is $52,743, while for a weekend, the average hourly cost of a
delay is $67,576.5
Public Confidence in
Governance
The public at risk has a good understanding of the risks from avalanche.
Warnings are regularly posted and announced to skiers and back
country hikers during the winter months.
5.8 Vulnerability Assessment
Vulnerable
populations
Snowmobilers, hikers, and skiers in back-country and off-trail
environments are at the highest risk from avalanche. Search and
Rescue regularly travel on search missions for missing recreationists,
putting them at risk from avalanche as well.
Property Several homes in the Alpental Valley have been directly affected by
avalanches. Snow fences installed in 1999 mitigate the hazard.
Avalanche professionals' ongoing monitoring and evaluation contribute
to the risk evaluation.
5 WSDOT, Snoqualmie Winter Operations Study (December 2024): p. 6,
https://wsdot.wa.gov/sites/default/files/2024-12/Snoqualmie-Winter-Operations-Study-December2024.pdf
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Environment Avalanches are a natural disturbance that can both harm and benefit
ecosystems. Next to Snoqualmie Pass is the wildlife crossing overpass
that provide a critical north-south connection for elk, deer, coyotes,
and cougars.
Operations I-90 and US-2 are the most vulnerable routes to avalanche. Disruptions
to both are common during the winter, though most are for a short
duration. A long-duration disruption could have significant economic
consequences.
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PC: Dean Rutz
Chapter 6Civil Disorder
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Chapter 6: Civil Disorder
6.1 Hazard Description
The United State Constitution, in accordance with the stipulations of ratification from the Colonies,
adopted the first 10 amendments collectively known as the Bill of Rights, laying out the initial
protected rights under the Constitution guaranteed to all citizens of the United States. The First
being the protected right to peacefully assemble. This right has been entrenched in the very fabric
of the United States even before the country as we know it existed. However, as we evolved as a
nation, complex social, political, and economic problems began to arise. Almost in tandem, the
effectiveness of this right began to come into question with many movements, leveraging changing
tactics and technology, finding other forms of assembly more effective at affecting change either
for or against the status quo. With the evolution of the protest many social and political scientist
began to identify the different forms of protests, collectively known as Civil Unrest, and laws were
written to both protect public order and further define the right to protest under the 1st
Amendment.
Table 6-1 Hierarchy of civil unrest
Name Description
Peaceful Protests Under the 1st Amendment, the right to “protest” is defined as “the right of
the people peaceably to assemble.” However, laws have evolved that
govern this right clarifying that assemblies which are not peaceful are
generally not protected under the law. The laws that deal with disruptive
conduct are generally grouped into offenses that disturb the public peace.
They range from misdemeanors, such as blocking sidewalks or challenging
another to fight, to felonies, such as looting and rioting. 1
Civil Disobedience Promoted by nationalist movements in Africa and India, the Civil Rights
movement in the U.S., and labor and anti-war movements in many
countries, Civil Disobedience is typically equated with protests or non-
violent resistance. Civil Disobedience, in contrast, is a “public, nonviolent,
conscientious yet political act contrary to law, usually aimed at bringing
about a change of the law or government policy; limited to instances of
substantial and clear injustice and must occur only after the legal means
of redress have proved futile.”2
1 Revised Code of Washington Title 9A.
2 US Department of Justice, “Theory of Civil Disobedience” NCJRS Virtual Library (1989):
https://www.ojp.gov/ncjrs/virtual-library/abstracts/theory-civil-disobedience-civil-disobedience-p-125-149-1989-
paul
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Civil Disorder Defined under Title 18 of the United States Code § 232 (1) Civil Disorder is
“any public disturbance involving acts of violence by assemblages of three
or more persons, which causes an immediate danger of or results in
damage or injury to the property or person of any other individual.” 18
U.S. Code § 231 outlines what is considered “disorder,” including the use,
application or making of any firearm, or explosive or incendiary device, or
technique capable of causing injury or death to persons; transports or
manufactures for transportation in commerce any firearm, or explosive or
incendiary device, knowing or having reason to know or intending that the
same will be used unlawfully in furtherance of a civil disorder; commit any
act to obstruct, impede, or interfere with any fireman or law enforcement
officer lawfully engaged in the lawful performance of official duties
incident to and during the commission of a civil disorder. In this context,
any disobedience in which participants turn violent and antagonistic
toward public safety and civil authority is illegal.3
Similarly, Washington state law defines civil disorder as “any public
disturbance involving acts of violence that is intended to cause an
immediate danger of, or to result in, significant injury to property or the
person of any other individual.” Further, under the Revised Code of
Washington 9A.48.120, a person is guilty of civil disorder training if “he or
she teaches or demonstrates to any other person the use, application, or
making of any device or technique capable of causing significant bodily
injury or death to persons, knowing, or having reason to know or
intending that same will be unlawfully employed for use in, or in
furtherance of, a civil disorder.”
Causation
Civil disorder can arise from a variety of circumstances and encompasses a wide range of civil
actions, from peaceful demonstrations to more disruptive or violent forms of unrest. The intensity
of these disturbances often correlates with the level of public dissatisfaction or protest.
Examples of civil disorder include, but are not limited to, violent protests, roadblocks, riots, acts of
sabotage, and various forms of criminal behavior. Such disturbances can pose serious risks,
becoming increasingly chaotic and difficult to control.
3 Office of the Law Revision Council. “Ch. 12: Civil Disorders” 18 USC (1968):
https://uscode.house.gov/view.xhtml?path=/prelim@title18/part1/chapter12&edition=prelim.
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One group often associated with civil disorder is the "Black Bloc." This tactic, employed by certain
anarchist factions, involves a group of individuals dressing uniformly in black clothing to create the
illusion of a cohesive and unified force, which is meant to promote solidarity for a particular cause.
This strategy is especially challenging for law enforcement, as it makes it nearly impossible to
distinguish one participant from another, providing anonymity while facilitating coordinated
criminal acts.
Additionally, the presence of law enforcement often escalates tensions during these events. Rather
than deterring violence, their intervention can sometimes heighten aggression and provoke further
unrest.
The political climate surrounding civil disorder is constantly shifting, with changes in leadership,
policies, and public sentiment contributing to the volatile nature of these disturbances.
6.2 Location
While demonstrations and protests can occur throughout King County, civil disorder is more likely
to occur in specific areas, particularly in Seattle, which serves as the county's political and cultural
hub. These civil actions often involve free speech rights in public places and do not evolve into
chaos and violence. Civil disorder is often seen at government buildings, military bases, schools,
universities, city council meetings, as they represent centers of power and decision-making.
Additionally, areas like state and city parks, as well as the downtown core, are prime locations for
civil unrest due to their visibility and accessibility to large groups.
Sites that are attractive for political rallies should be viewed as potential locations for the epicenter
of civil disorder events. Disruption of critical infrastructure may occur during very severe civil
disorder events. Public services such as water, power, communication, and transportation may be
temporarily unavailable.
6.3 Magnitude
In King County, civil disorder can emerge from a series of escalating events, each building upon the
next. It often begins as peaceful protest or civil disobedience, where individuals express their
grievances within the bounds of the law. However, when external factors—such as the presence of
anarchists, police violence, or broader social unrest—intervene, these peaceful demonstrations can
transform into civil disturbances and, in extreme cases, civil disorder. The impact of such events can
be far-reaching, affecting not only the immediate community but also the larger social and political
landscape. Understanding the escalation of civil disturbances into full-scale civil disorder requires a
look at the different phases and levels of conflict—from peaceful protesting to violence and
property damage.
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Phases of Protest and Escalation
Protests typically start as peaceful demonstrations, where individuals or groups gather to voice
their concerns on a particular issue. In King County, these types of events are often seen as
essential elements of civic expression. People may gather in public spaces to peacefully advocate
for causes such as racial justice, environmental protection, or workers' rights. The aim is to engage
in civil disobedience, challenging laws or actions perceived as unjust, without resorting to violence
or property destruction.
However, not all protests remain peaceful. As tensions rise, peaceful demonstrations can escalate
into civil disturbances. Civil disturbances often involve acts of resistance that push the boundaries
of legal protest. This might include blocking roads, disrupting business operations, or engaging in
minor property damage. While these actions may be disruptive, they are usually aimed at drawing
attention to the issue at hand without the intent to incite widespread violence. In this phase, there
may still be some level of public support or sympathy, as the demonstration is seen as a legitimate
expression of discontent, albeit one that has exceeded acceptable behavior.
In the worst-case scenario, civil disturbances can escalate into civil disorder. Civil disorder
represents the highest level of escalation, where protests turn violent and cause significant
disruption to public order. This stage can be triggered by a variety of factors, including the actions
of provocateurs or groups seeking to exploit the unrest for their own agendas4. The presence of
anarchists, especially those utilizing tactics like the "Black Bloc," can turn an otherwise peaceful
protest into a violent event. The Black Bloc strategy involves groups of anarchists dressing in all
black, often with masks, to conceal their identities and present a unified front. This anonymity
allows them to engage in criminal activities, such as vandalism, arson, or violent confrontations with
law enforcement, without immediate identification or accountability.
The 1999 World Trade Organization (WTO) protests in Seattle serve as a clear example of civil
disorder. Initially organized as a peaceful demonstration against the WTO’s policies, the protests
quickly escalated into violent confrontations. Anarchists, employing Black Bloc tactics, vandalized
businesses, looted stores, and engaged in violent clashes with police. The event led to over 600
arrests, widespread property damage, and millions of dollars in losses for local businesses.5 The
city’s cost of managing the situation ballooned, with emergency services, repairs, and security
efforts costing far more than anticipated. This event marked a significant turning point in the way
law enforcement responded to large-scale protests, with authorities becoming more adept at
identifying the potential for escalation and monitoring certain groups for signs of trouble.
4 Kory Flowers, “Understanding the Black Block” Police: The Law Enforcement Magazine. (January 30, 2015):
https://www.policemag.com/341767/understanding-the-black-bloc.
5 Sean Rossman, “G-20 summit protests: What is a Black Bloc?” USA Today. (February 2, 2017):
https://www.usatoday.com/story/news/nation-now/2017/02/02/what-black-bloc/97393870/.
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Triggers and Tensions
Civil disorder can be triggered by a variety of factors, often stemming from a combination of social,
political, and economic issues. Police violence is a common catalyst for such events. For example,
the 2009 police shooting of Oscar Grant in Oakland, California, led to widespread unrest, which
echoed in cities across the country, including Seattle.6 Similarly, in King County, the 2008 video of a
King County deputy assaulting a teenage girl in a holding cell became a flashpoint for public
outrage. In 2010, activists in Seattle organized a "March Against Police Brutality," drawing attention
to systemic violence and misconduct. Protests like these can lead to cycles of unrest, where each
new demonstration builds upon the emotional intensity of previous events.7
Protests often create a feedback loop, where the actions and outcomes of one protest can inspire
and fuel subsequent protests. This cycle occurs because protests are not just reactions to
immediate events but are deeply rooted in emotional and social responses to perceived injustice or
systemic problems. When one protest takes place, it sets off a chain reaction that can influence the
actions and emotional environment of future demonstrations.
When protests escalate into civil disorder, the presence of anarchist groups like Black Bloc often
plays a pivotal role. These groups operate as accelerants, transforming protests into more violent
confrontations. Law enforcement now carefully monitors these groups during peaceful protests,
noting any signs of aggression or unlawful behavior. As soon as such elements appear, the situation
can rapidly deteriorate, creating a volatile environment where clashes are inevitable. These
heightened police presence can, in turn, provoke further unrest, exacerbating tensions and leading
to a dangerous feedback loop.
The ultimate severity of any civil disorder event will depend on the magnitude of the event and its
location. The more widespread an event is, the greater the likelihood of excessive injury, loss of life
and property damage. Additional factors, such as the ability of law enforcement to contain the
event, are also critical in minimizing damages.
6 Associated Press, “Ex-BART Officer Johannes Mehserle Released From Jail” KPIX CBS SF Bay Area. (June 13, 2011)
https://sanfrancisco.cbslocal.com/2011/06/13/ex-bart-officer-johannes-mehserle-released-from-prison/.
7 J Seattle, “Protest against police brutality starts at Seattle Central” Capitol Hill Seattle Blog. (April 9, 2010)
https://www.capitolhillseattle.com/2010/04/protest-against-police-brutality-starts-at-seattle-central/.
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6.4 Previous Occurrences
Date Location Cause Description
Nov 1999 Seattle, WA –
World Trade
Organization
Anti-
globalization
An example of a worst-case scenario was the
1999 Seattle World Trade Organization rioting
which significantly impacted the City and led to
numerous injuries and arrests. The rioting
raised Seattle's cost of handling the conference
to $9 million from an earlier estimated city cost
of $6 million surpassing worst-case projections.
In addition, downtown Seattle businesses lost
an estimated $20 million in property damage
and lost sales during the WTO conference.8
Feb 27,
2001
Seattle, WA –
Pioneer Square
Unknown During a Mardi Gras celebrations, there were
numerous random attacks including reports of
widespread brawling, vandalism, and weapons
being brandished. Damage to local businesses
exceeded $100,000. About 70 people were
reported injured. Several women were sexually
assaulted. One man, Kris Kime, died of injuries
sustained during an attempt to assist a woman
being brutalized.9
May 2013 Seattle, WA May Day A 2013 May Day protest in downtown Seattle
turned violent with police responding to
demonstrators throwing rocks, bottles, metal
pipes, fireworks -- and even a skateboard. The
clashes left eight officers with injuries, and
police reporting the arrests of 17 people on
various offenses including property destruction
and assault. During the clashes, police deployed
flash-bang grenades and tackled unruly
protesters to the ground.10
May 2016 Seattle, WA May Day In 2016 May Day protest in Seattle a peaceful
march turned violent when protesters lit
8 CBC News,” WTO protests hit Seattle in the pocketbook” (January 6, 2000):
https://www.cbc.ca/news/world/wto-protests-hit-seattle-in-the-pocketbook-1.245428.
9 Lynsi Burton, “Looking back: Mardi Gras riots of 2001” The Seattle Times. (February 16, 2015):
https://www.seattlepi.com/seattlenews/article/Looking-back-Mardi-Gras-riots-of-2001-6084162.php.
10 Amanda Watts, Lindy Royce-Bartlett. “17 arrested as Seattle May Day protests turn violent” CNN. (May 2, 2013)
https://www.cnn.com/2013/05/01/us/seattle-may-day-protests/index.html.
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fireworks and threw rocks and Molotov
cocktails at police. Nine people were arrested
and five officers were injured in the clashes.
January
2017
Seattle, WA –
University of
Washington
Politics In January 2017 at University of Washington,
demonstrators and counter-demonstrators
gathered as a politically conservative
commentator was scheduled to speak. Violent
protests took place on campus and a person
was shot.
June 2020 Chaz/Chop
Seattle Zone
Police
Brutality
In the wake of George Floyd protests, some
demonstrators took over a portion of the
Capitol Hill neighborhood, establishing the
CHOP/CHAZ (Capitol Hill Organized
Protest/Capitol Hill Autonomous Zone). This
area became a flashpoint for further clashes,
with occasional violence, shootings, and
confrontations between police and activists.
6.5 Probability of Future Occurrences
There is a significant likelihood of future civil disorder in King County. Like many urban centers
across the U.S., King County is grappling with growing political discontent driven by ideological
divides over social policies, economic priorities, and individual rights. These divisions are further
intensified by a political realignment that has funneled differing viewpoints into two increasingly
polarized parties. This polarization is compounded by longstanding tensions between certain
communities, particularly communities of color, and local law enforcement, which continue to fuel
distrust and demands for reform.
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Figure 6-1 Political Polarization in the American Public 11
Moreover, the rapid spread of information and organization via social media platforms, especially
TikTok, amplifies these tensions. Social media enables quick mobilization and the viral
dissemination of events, making it easier to organize protests and quickly escalate unrest. As these
factors converge, the risk of civil disorder in King County is likely to increase.
6.6 Climate Change Considerations
The effects of climate change have shown to amplify civil unrest by exacerbating existing economic,
social, and political instabilities. Urban areas, particularly those with limited greenspaces that are
susceptible to climate-related phenomena like the urban heat island effect, are more prone to
increased communal frustration and conflicts. The intensifying effects of climate change, such as
extreme weather events, resource scarcity, and rising costs of living, intersect with social
inequalities, creating a volatile environment where vulnerable communities are disproportionately
affected. This intersectionality between social issues and climate change heightens tensions, fueling
civil unrest as people confront both environmental and systemic challenges simultaneously. Figure
11 Michael Dimock, Carroll Doherty, Jocelyn Kiley, Russ Oates, “Political Polarization in the American Public” Pew
Research Center (June 2014): p. 6, https://www.pewresearch.org/wp-content/uploads/sites/4/2014/06/6-12-
2014-Political-Polarization-Release.pdf
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6-2 takes the city of Los Angeles as a case study and plots the point estimates for the temperature-
crime relationship. The assessment concluded that heat acts as a driver crime, namely that occurs
within the same day.
Figure 6-2 Impact of Daily Temperature on Crime Rates in Los Angeles 12
6.7 Impact Assessment
Public All King County residents can be impacted, though those who live or work in
downtown areas tend to be more exposed and impacted by civil disorder
incidents.
Responders Responders are often on the front line of events. Responders can be targeted,
causing injury to personnel, damage to facilities, and the loss of equipment.
Responders are often injured during major incidents and, even when events are
brought under control, may be seen as an enemy of the community causing
long-term trust issues.
Continuity of
Operations
Major incidents can bring government services to a standstill. In King County,
with both City of Seattle and King County offices are in the same area, along with
12 Kilian Heilmann, Matthew Kahn, Cheng Keat Tang, “The urban crime and heat gradient in high and low poverty
areas” Journal of Public Economics (May 2021): p. 17
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court facilities. A major incident in this area would prevent employees from
getting to work or home. Furthermore, government buildings are often targeted
and can be damaged or destroyed.
Property,
Facilities,
Infrastructure
Property
Much of the impact from civil disorder is to property, secondary only to
economic impacts. During the World Trade Organization protests in 2000, over
$20 million in damage was recorded by businesses and $9 million in costs to the
city.
Facilities
Health systems can be overwhelmed by civil disorder incidents, such as when
large numbers of demonstrators are brought to the hospital due to exposure to
tear gas or due to clashes with counter-demonstrators or with police.
Infrastructure
• Energy: Pipelines carrying oil are a potential target for demonstrators. Oil
trains have been targeted frequently in Washington; however, these protests
do not tend to turn violent.
• Water/Wastewater: Water systems are rarely the primary target of a
demonstration and may only be peripherally impacted.
• Transportation: One of the largest impacts from a major incident is
disruption to transportation. Transit facilities and assets like busses may be
destroyed. Roads can be closed for hours or days.
• Communications: Communication systems are redundant and are unlikely to
be severely impacted by a civil disorder incident.
Environment Civil Disorder will have a minimum impact on the environment; unless, hazard
material facilities such as petroleum, chemical, and recycling are targeted in
arson fires or vandalism. The impact on the environment in such cases could be
significant.
Economy Economic impacts caused by loss of business, destruction of businesses, and
business interruption can exceed the property damage dollar figures by a factor
of two or more. Lost sales and uninsured losses can permanently destroy many
businesses. Areas can also become perceived as unsafe or unwelcoming for
business, further hurting the economy.
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Public
Confidence in
Governance
Major incidents can cause long-term damage to public confidence in the
jurisdiction or, especially, public safety elements of jurisdiction governance. This
can cause either alienation or, when response is proactive, help rebuild
confidence and trust. To best preserve and grow confidence, a jurisdiction must
respond quickly and effectively but without excessive force. The general public
expects a quick restoration of order and protection of property while activists
may demand accountability from officials and safety for peaceful demonstrators.
6.8 Vulnerability Assessment
Vulnerable
populations
Certain population groups are more vulnerable during civil disorder
event either because they are the target of civil discord, or because of
social, economic, or physical circumstances.
Communities of color
People of color, particularly Black, Indigenous, and Latino communities,
are historically targeted by civil disorder events. While rare in our
region, the United States has a long history of racially-motivated riots
that burn and destroy minority-owned businesses and homes.
Immigrant communities
Immigrant and refugee populations are often already marginalized and
may face heightened vulnerability during civil disorder due to language
barriers, lack of familiarity with local legal systems, or fear of
interaction with law enforcement due to potential immigration status
concerns.
People experiencing homelessness
In times of civil unrest, people experiencing homelessness are more
likely to be exposed to violence, police crackdowns, or displacement
from encampments, making it even harder to access basic necessities
like food, shelter, or healthcare. Moreover, homeless individuals may
have nowhere to go when public services, shelters, or transportation
networks are disrupted.
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Woman and gender minorities
Women may face increased risks of sexual violence, exploitation, or
harassment in chaotic or unsafe environments, while gender minorities
may face added discrimination, marginalization, or violence.
Essential workers
Workers in essential services, such as healthcare, public transportation,
utilities, and law enforcement, are particularly vulnerable during civil
disorder events due to their proximity to the unrest. These workers
may face risks of violence or aggression, especially if they are seen as
part of the system that protesters are targeting.
Property Businesses in high traffic areas of Seattle would be vulnerable to
property damage from civil disorder. Property that would be targeted
in this situation includes banks, financial institutions, government
buildings, retail chains, and monuments.
Environment During civil disorder events, acts of arson and the destruction of
properties—such as vehicles, buildings, and businesses—can result in
the release of harmful pollutants into the air. Fires release smoke, soot,
and toxic chemicals like carbon monoxide, particulate matter, and
volatile organic compounds (VOCs) that can severely impact air quality
and public health. In urban areas, these pollutants may be
concentrated, exacerbating pollution levels in already affected regions.
Operations Government Facilities
Civil disorder incidents often target government organizations or visible
images of the government such as police vehicles, city halls, or court
facilities.
Businesses
Businesses such as banks, businesses in downtown areas or along
transportation routes, and other commercial establishments are often
targeted during looting or may be targeted for political or racist
reasons such as ownership by an immigrant group in the case of anti-
immigration riots or because they are associated with an industry being
targeted by the manifestation (banks, abortion clinics, oil company
offices, etc.).
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Chapter 7CyberIncidents
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Chapter 7: Cyber Incidents
7.1 Hazard Description
Information technology has become deeply integrated into how we conduct everyday life. In the
context of government, technology plays a crucial role in delivering essential public services, such as
healthcare, public transportation, law enforcement, citizen engagement, public utilities, and
managing tax and ratepayer systems. A cyber incident can have a profound and disruptive effect on
these technologies, jeopardizing local governments' ability to provide critical services and maintain
daily operations.
A cyber incident is defined by the Department of Homeland Security (DHS) in the 2024 National
Cyber Incident Response Plan as “an event occurring on or conducted through a computer network
that actually or imminently jeopardizes the confidentiality, integrity or availability of computers,
information on communication systems or networks, physical or virtual infrastructure controlled by
computers or information systems, or information resident thereon. A cyber incident may include a
vulnerability in an information system, system security procedures, internal controls, or
implementation that could be exploited by a threat source.”1 This definition is further elaborated in
U.S. Code, Title 44, Section 3542.
Figure 7-1 CIA triad model2
Confidentiality: preserving authorized restrictions on
information access and disclosure, including means for
protecting personal privacy and proprietary information.
Integrity: guarding against improper information
modification or destruction and ensuring information
non-repudiation and authenticity.
• Data Integrity (DI): The property that data has not
been altered in an unauthorized manner. DI covers data
in storage, during processing, and while in transit.
• System Integrity (SI): The quality that a system has
when it performs its intended function in an unimpaired
manner, free from unauthorized manipulation of the
system, whether intentional or accidental.
Availability: Ensuring timely and reliable access to and use of information.
1 Department of Homeland Security, National Cyber Incident Response Plan Draft, (December 2024): p. 5,
https://www.cisa.gov/sites/default/files/2024-12/NCIRP%20Update%20Public%20Comment%20Draft%20508c.pdf
2 Debbie Walkowski, “What is the CIA Triad?” F5 Labs (2019): https://www.f5.com/labs/learning-center/what-is-
the-cia-triad
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Cyber incidents can be categorized as (1) malicious attacks, (2) human errors and system glitches, or
(3) environmental hazards.
Malicious attacks
Cyber incidents based on actors with malicious intent can be driven by criminal motives for profit,
extortion, and theft or to damage, destroy or interfere with infrastructure systems. Organizations
worldwide experience malicious attacks on a daily basis. Most of the attacks are unstructured with
little to no organization behind them such as a phishing attack or malware hidden in a downloaded
file. Attacks are carried out with tools aiming to take advantage of well-known flaws and are often
detected by security tools such as antivirus programs before they cause harm. However, an
undetected attack can cause significant harm to an organization before it’s detected and fully
contained. More sophisticated attacks with a specific target are less common, harder to detect and
take longer to contain. These attacks are more likely to have a catastrophic impact on an
organization causing disruptions over some or all of the network. Over the last few years attackers
have been targeting organizations using sophisticated ransomware, which encrypts the
organizations’ data and demands a ransom to decrypt it. Other attacks include cyber
terrorism(aiming to cause sufficient destruction or disruption) to generate fear or undermine
entities such as an organization, a region, a sector or a country.
Human error and system glitches
Cyber incidents due to human errors and system glitches can occur because of negligence, lack of
implemented policies and/or process, unclear roles and responsibilities, insufficient training,
misconfigurations etc. Such incidents are often identified and contained faster than disruptions
caused by malicious actors. Human errors and system glitches can expose confidential data,
decrease availability and put data integrity at risk.
Environmental hazards
Data centers, physical IT infrastructure and hardware are vulnerable to other hazards such as
earthquakes, flooding, fires, and extreme weather that result in long lasting power outages. In the
event of such hazards it is likely that the disruption to information technology will slow down the
recovery time of critical communication systems, essential services and hardware. This can cause a
variety of cyber incidents including loss of data and system availability and communications.
Unshielded electronic and electrical equipment is sensitive to electromagnetic pulses (EMP) and
geomagnetic disturbances (GMD). An EMP is an intense burst of electromagnetic energy resulting
nuclear explosion in the atmosphere whereas a GMD is a temporary disturbance of the Earth’s
magnetosphere caused by a solar wind shock or cloud of magnetic field that interacts with Earth’s
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magnetic field.3 Whether caused by man or nature, EMP and GMD events can temporarily affect or
permanently damage electronic equipment. Solar storms that affect electronic equipment are rare
but have occurred in the past, impacting GPS satellite systems and signals sent to ground-based
receivers.
7.2 Location
The cyber threat “landscape” is constantly evolving due to advances in technology, the growing
motivation of attackers, and the expansion of attack “surfaces” across digital ecosystems. Wherever
information technologies exist and are used, cyber incidents can occur. The nature of a cyber-
incident differs from other types of hazards because it is inherently driven by online actions and
targets digital systems, but it can also result in significant physical impacts. For instance,
cyberattacks can disrupt critical infrastructure, manufacturing processes, or even cause breaches in
physical security. As the digital landscape expands and technology becomes more integrated into
daily operations, cyber incidents increasingly have the potential to affect both virtual and physical
environments. The primary avenues of attack, or virtual locations of threat, include cloud-based,
phishing, third party breaches, ransomware, and insider threats.
Cloud-Based
Regardless of where data is stored, it is always susceptible to breaches. However, some storage
environments are more vulnerable and costly to breach than others. A significant number of
breaches involve data that is distributed across multiple environments, including public clouds,
private clouds, and on-premises systems. As organizations continuously evolve their data
management strategies, they often fail to account for shadow data —data that’s unmanaged and
likely invisible to the IT department. This shadow data typically arises when employees use
unauthorized applications or upload files to unsanctioned cloud storage locations without the
organization's knowledge. In fact, approximately 40% of all data breaches are linked to data spread
across multiple environments, highlighting the complexity of managing data security in hybrid and
multi-cloud architectures.
3 Department of Homeland Security, Electromagnetic Pulse (EMP)/Geomagnetic Disturbance (GMD) (December
2023): https://www.dhs.gov/science-and-technology/electromagnetic-pulse-empgeomagnetic-disturbance
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Figure 7-2 IBM data storage type for reported data breaches, 2024
Phishing
Phishing is a social engineering tactic that is used to persuade individuals to provide sensitive
information and/or take action through seemingly trustworthy communications, such as through
impersonations of financial institutions, IT departments, or government agencies. Phishing attacks
are usually untargeted and come in the form of an email. According to the IBM, employee training
continues to be an essential element in cyber defense strategies, specifically for detecting and
stopping phishing attacks.4
Third Party Breaches
Technology vendors that provide technical, software, and healthcare services are particularly
vulnerable to third-party breaches.5 Hackers frequently exploit weaknesses in software or
4 IBM, Cost of a Data Breach Report (2024): p. 23
5 Black Kite, Third Party Breach Report (2023): p. 7, https://blackkite.com/wp-content/uploads/2023/01/third-
party-breach-report-2023.pdf
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manipulate code to gain unauthorized access. However, many organizations place undue trust in
the security of the software and services they rely on, often neglecting to conduct thorough checks
for vulnerabilities within their digital supply chain. In 2022, industries such as healthcare, finance,
and government, which are heavily reliant on technology vendors, were particularly impacted by
these kinds of attacks.
This type of breach occurred in 2020 for the Washington State Employment Service Department
(ESD). The breach was traced back to Accellion, a technology provider that facilitated file transfers.
At the time, many individuals were applying for unemployment benefits due to the COVID-19
pandemic, increasing the volume of sensitive data being processed. As a result, personal
information of approximately 1.6 million individuals was compromised, and the ESD faced a
staggering loss of $600 million due to fraudulent unemployment claims.6
Ransomware
Ransomware is a type of malicious software (malware) designed to deny access to a computer
system or data until the victim pays a ransom. Ransomware attacks saw a significant resurgence in
early 2023, with high-profile incidents affecting organizations worldwide. The United States was the
most targeted country, accounting for 43% of all attacks, followed by the UK (5.7%) and Germany
6 Kurt Schlosser, “Data breach exposes 1.6 million Washington state residents who filed unemployment claims in
2020” Geekwire February 2021): https://www.geekwire.com/2021/data-breach-exposes-1-6-million-washington-
state-residents-filed-unemployment-claims-2020/
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(4.4%). Among industries, manufacturing (19.5%), professional, scientific, and technical services
(15.3%), and educational services (6.1%) were the most frequently targeted.
Manufacturing and professional service companies are often prime targets due to the valuable
intellectual property and sensitive data they store, making them attractive to cybercriminals looking
for high-value ransoms. Educational institutions, on the other hand, tend to hold large volumes of
personal data, including information on students, staff, and research, which makes them lucrative
targets for ransomware groups.
Insider Threats
While external threats often dominate discussions, insider threats, whether malicious or
inadvertent, pose significant risks. Insiders could include employees, contractors, or
partners/collaborators who have access to critical systems. While malicious insider attacks make up
only 7% of breaches, they are often the highest cost for response and recovery averaging 4.99
million dollars.
Others
While cloud-based attacks, phishing, third-party vulnerabilities, ransomware, and insider threats are
some of the most common avenues for cyberattacks, they are not the only vectors that entities
should consider when planning their defenses. Table 7-1 offers a comprehensive list of various
cyber threat vectors and their subtypes, including different types of malware, network and
database interception, password and access control breaches, social engineering tactics, and
physical/infrastructure-related threats.
Table 7-1 Cyber threat vectors used for malicious attacks
Cyber Threat Vector Definition
Malware Types
Advanced Persistent
Threat (APT)
An attack in which the attacker gains access to a network and
remains undetected. APT attacks are designed to steal data instead
of cause damage.
Backdoor An undocumented way of gaining access to a computer system. This
is a security risk.
Drive-by Downloads Malware is downloaded unknowingly by the victims when they visit
an infected site.
Malware Software or firmware intended to perform an unauthorized process
that will have an adverse impact on the confidentiality, integrity, or
availability of an information system. Examples include:
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• Adware: A form of software that displays advertising content
in a manner that is potentially unexpected and unwanted by
users, which may also include various user-tracking functions
(similar to spyware).
• Malvertising: Malware downloaded when the victim clicks on
an affected ad.
• Ransomware: Malware that locks a person’s keyboard or
computer to prevent them from accessing data until a ransom is
paid, usually in Bitcoin. A popular variation of this is ransom
crypto ware, which corrupts files using a private key that only
the attacker possesses.
• Spyware: Software that allows others to gain private
information about a user, without that person’s knowledge or
consent, such as passwords, credit card numbers, social security
numbers, or account information.
• Trojan horses: A computer program that appears to have a
useful function, but also has a hidden and potentially malicious
function that evades security mechanisms.
• Virus: A program or code that attaches itself to a legitimate,
executable program, and then reproduces itself when that
program is run.
• Worms: A self-contained program (or set of programs) that is
able to spread copies of itself to other computer systems,
usually through network connections of email attachments.
Structured Query
Language injection (SQLi)
Attackers use malicious SQL code for backend database manipulation
to access information that was not intended to be displayed.
Zero-day exploit An attack which occurs the same day a vulnerability is discovered in
the software. The vulnerability is exploited by the attacker before it
can be fixed by a patch or a permanent solution.
Network and Data Interception
Denial-of-Service Attack
(DoS)
Attacks that focus on disrupting service to a network in which
attackers send high volumes of data until the network becomes
overloaded and can no longer function.
Man-in-the-Middle
(MITM)
MITM attacks mirror victims and endpoints for online information
exchange. In this type of attack, the MITM communicates with the
victim who believes they are interacting with the legitimate endpoint
website. The MITM is also communicating with the actual endpoint
website by impersonating the victim. As the process goes through,
the MITM obtains entered and received information from both the
victim and endpoint
Pharming Arranging for a website’s traffic to be redirected to a different,
fraudulent site, either through a vulnerability in an agency’s server
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software or through the use of malware on a user’s computer
system.
Password and Access Control
Password Attacks Third party attempts to crack a user’s password and subsequently
gain access to a system. Password attacks do not typically require
malware, but rather stem from software applications on the
attacker’s system. These applications may use a variety of methods
to gain access, including generating large numbers of generated
guesses, or dictionary attacks, in which passwords are systematically
tested against all of the words in a dictionary. Due to users reusing
the same password for different systems a password attack targeting
an unrelated system can give the attacker access to a more sought-
after system.
Spoofing Attempting to gain access to a system by posing as an authorized
user, synonymous with impersonating, masquerading, or mimicking.
Attempting to fool a network user into believing that a particular site
was reached, when actually the user has been led to a false site that
has been designed to appear authentic, usually for the purpose of
gaining valuable information, tricking the user into downloading
harmful software, or providing funds to the threat actors.
Social Engineering
Social Engineering In the context of cyber-security, this refers to an effort to
psychologically manipulate a person, especially through
misrepresentation or deception, to gain access to information.
Methods of social engineering include:
• Phishing: Malicious email messages that ask users to click a link
or download a program. Phishing attacks may appear as
legitimate emails from trusted third parties.
• Spear Phishing: A form of phishing that targets a specific
individual, company, or agency, usually relying on an
accumulation of information to make subsequent ruses more
effective when further probing the target, until a successful
security breach finally becomes possible.
Physical and Infrastructure
Physical damage Intentional or unintentional damage to physical infrastructure such
as data centers, hardware, or power grids.
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7.3 Magnitude
Cyber incidents put both financial resources and sensitive information at risk. The financial impact
includes costs related to downtime, remediation efforts to repair damaged systems, expert
consultations, and potential ransom payments. Data loss or compromise also poses a significant
threat, particularly for entities handling sensitive information such as Personally Identifiable
Information (PII) or Personal Health Information (PHI). The County, for example, manages a wide
range of public, sensitive, and confidential data, some of which is regulated by federal law, the
Revised Code of Washington, and global compliance standards. Unauthorized, unintentional, or
unanticipated disclosure of confidential data could lead to identity theft, financial loss for
individuals, operational disruptions for businesses, legal action, and reputational damage for the
County.
The magnitude of a cyber incident is further influenced by the duration of the event and the ability
to detect and respond to it in a timely manner. Having the ability to preempt the incident and
activate a well-known and effective incident response plan is also critical in reducing the duration of
the event. It could take weeks, months, or even years to fully recover from a cyberattack. According
to IBM’s 2024 Cost of a Data Breach Report, the average time it takes a business to identify a data
breach is 194 days. The average time it takes to fully contain a breach, after it has been identified, is
64 days.7
Scenarios
Smaller cyber incidents may have minimal impact, such as a minor configuration error discovered
early, or a stolen encrypted laptop without sensitive data. These types of incidents, while
disruptive, are often recoverable without significant consequences for the County’s operations. On
the other hand, a large-scale cyber incident, such as a ransomware attack that encrypts all or most
of the County's data, can have catastrophic effects. This could lead to the loss of critical operational
capabilities, economic damage, reputational harm, and even health and safety risks for the
individuals living, working, or visiting the region. The County’s essential services, which are crucial
for public health, safety, and legal compliance, can be severely disrupted if they are unavailable for
0-72 hours after the initial attack.
A prolonged disruption to these essential services can have devastating consequences for the
region. The County's essential functions, which are critical to supporting life, health, and safety,
include services that must meet specific legal requirements. The loss of critical system availability,
functionality, and operational effectiveness can hinder productivity and impact the performance of
individuals supporting County operations. In cases where hardware, networks, servers, or backup
systems are damaged by other hazards or malicious actions, recovery delays can be further
7 IBM, Cost of a Data Breach Report (2024): p. 10
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compounded. Moreover, if unauthorized changes are made to IT systems or data—either
intentionally or accidentally—system and data integrity may be compromised. If such integrity
issues are not addressed, continued use of contaminated systems or corrupted data can lead to
inaccurate decisions, fraud, or further operational risks.
Vendors
The County also relies on SCADA (Supervisory Control and Data Acquisition) systems, which are
used to control infrastructure and facility processes, including wastewater treatment and airport
operations. Cyber incidents targeting these critical systems could have severe consequences,
including environmental, health, safety, and financial risks for the region.
Not all IT systems utilized by the County are managed internally; the County also relies on third-
party vendors and partners who may be exposed to cyber threats. Disruptions within these external
organizations can also affect the County’s operations, underscoring the importance of securing the
entire ecosystem of stakeholders to minimize cyber risk.
Cyber Resiliency
As cyber threats evolve, entities must continually update their security posture. Due to the
complexity of the cyber threat landscape, a comprehensive, multi-layered approach to defense is
essential. Cyber defense can be broken down into five phases: (1) identification, (2) protection, (3)
detection, (4) response, and (5) recovery strategies. To mitigate the risk of cyber incidents, it is
crucial to manage threats and vulnerabilities by investing in network protection and malware
detection, developing incident response plans and exercises, providing employee training, and
establishing backup systems.
The Cybersecurity and Infrastructure Security Agency (CISA) is the Nation’s risk advisor, partnering
with industry and government to understand and manage risk to our Nation’s critical infrastructure.
They coordinate security and resilience efforts using trusted partnerships across the private and
public sections and deliver technical assistance and assessments to federal stakeholder as well as to
infrastructure owners and operators nationwide. Their CISA Resource Hub offers a range of
cybersecurity assessments that evaluate operational resilience, cyber security practices,
organizational management of external dependencies, and other key elements of a robust and
resilient cyber framework.
7.4 Previous Occurrences
Cyber incidents occur daily across the globe. The quantity of information being stolen by malicious
attackers, destroyed or exposed as a result of a human error, or made unavailable due to a system
glitch is growing each year. King County is the recipient of a constant variety of attacks ranging from
scans for weaknesses in our defenses, malware, phishing, and internet-based attacks, as well as
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insider threats. In recent years, we have seen a rise ransomware. Table 7-2 comprises local, state,
national, and international events and exemplifies consequences of cyber-incidents.
Table 7-2 Notable cyber-attack events, 2014 – 2024
Year Location/Affiliation Vector Description
2014 Washington State Human error Washington State experienced a six hour long
911 system outage due to human error.
2014 United States Malicious
insider threat
280,000 AT&T accounts were breached by
insiders who accessed user information with
malicious intent.
2015 United States Third-party
breach
The Office of Personnel Management (OPM)
experienced a malicious attack resulting in over
20 million compromised personnel records.
2016 United States Third-party
breach
The US Special Counsel Robert S. Mueller, III
investigated Russia’s interference in the 2016
presidential election. Known as the Mueller
Report, the investigation states Russians hacked
into the Democratic National Committee and
released documentation through the media
organization WikiLeaks.8
2017 Global Hazard A geomagnetic storm affected power grids and
radios.
2017 University of
Washington
Human error The University of Washington suffered a HIPAA
data breach exposing the information of nearly 1
million patients due to human error.
2019 Washington State Ransomware The City of Sammamish was targeted by a
ransomware attack that shut down many of the
city’s online services, requiring the city manager
to declare an emergency and request support
from law enforcement and King County IT, as
well as hire a tech company to help resolve the
crisis.
8 Special Council Robert S. Muller III, Report On The Investigation Into Russian Interference In The 2016 Presidential
Election, v. I of II (March 2019): p. 1, https://www.justice.gov/archives/sco/file/1373816/dl?inline=
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2020 WA Employment
Security Department
(ESD)
Third-party
breach
Personal information of more than 1.6 million
people who filed for unemployment claims
through ESD was compromised in 2020. The
Office of the Washington State Auditor
attributed the breach on a third-party software
provider named Accellion, whose services are
used to transmit computer files. The state
Employment Security Department (ESD) lost
$600 million to fraudulent unemployment
claims.9
2023 Pierce College District Human error Personal data belonging to more than 155,000
former Pierce College students and staff was
leaked on the dark web after a cyber attack. It
was the third-largest data breach in Washington
state that year.10
2024 City of Newcastle, WA Ransomware The City of Newcastle had fallen victim to a
ransomware attack orchestrated by the
cybercriminal group RansomHub. The attackers
have claimed possession of the city's confidential
data and threatened to publish or sell the stolen
data if the city did not respond to their
demands.11
2024 Port of Seattle Ransomware The Port of Seattle isolated its critical systems
after the port identified system outages
consistent with a cyberattack. The investigation
determined that the unauthorized actor was
able to gain access to certain parts of its
computer systems and was able to encrypt
access to some data. As the port refused to pay
the ransom, it is feared that the attacker may
post allegedly stolen data on the dark web.12
9 Kurt Schlosser, “Data breach exposes 1.6 million Washington state residents who filed unemployment claims in
2020” Geekwire February 2021): https://www.geekwire.com/2021/data-breach-exposes-1-6-million-washington-
state-residents-filed-unemployment-claims-2020/
10 Shea Johnson, “Pierce College cyberattack exposed 155,000 people’s data. Is the district at fault?” The News
Tribune (November 2023): https://www.thenewstribune.com/news/local/article281698368.html
11 Halcyon, RansomHub Ransomware Attack Threatens City of Newcastle, Washington’s Data Security (July 2024)
https://www.halcyon.ai/attacks/ransomhub-ransomware-attack-threatens-city-of-newcastle-washingtons-data-
security
12 Syed Rakin Rahman, “Port of Seattle shares details of a cyberattack” Port Technology International (September
2024): https://www.porttechnology.org/news/port-of-seattle-shares-details-of-a-cyberattack/
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2024 Seattle Public Library Ransomware The Seattle Public Library’s experienced a
ransomware attack that took down their
systems, internet, public computers, and library
catalog at all 27 locations throughout the city.13
2024 Highline School
District
Ransomware School district within Seattle, WA identified a
form of ransomware on their network which
shutdown their systems. A third-party
cybersecurity forensic specialist and launched an
investigation which is ongoing.14
7.5 Probability of Future Occurrences
Unlike natural hazards, cyber threats cannot be predicted at regular intervals. However, as our
digital reliance increases so will vulnerabilities that can be exploited by threat actors. In mitigating
these vulnerabilities, organizations are faced with choices regarding response to ransomware
threats. Best practices dictate not paying ransomware attackers the sums of money they request.
This is thought to decrease the risk of future occurrences by potentially removing financial gain as a
viable option for the target.
With increased digital reliance comes increased and evolving technological advancements. Artificial
Intelligence makes its way into daily operations for many organizations. While AI can decrease the
gap of necessary skilled professionals in cybersecurity and increase efficiency in the detection and
response process, it can also decrease the barrier to entry for attackers. Language models make
producing phishing messages simple for threat actors.15 Inputting sensitive data into AI models can
also pose a risk to organizations as how this data is used and reused by AI models is not well
accounted for. Due diligence is needed to ensure companies providing AI services have adequate
protection for the data inputted into their models. This may contribute to frequency of cyber threat
occurrences in the future.
13 Keely Quinlan, “Seattle Public Library ransomware attack to cost $1M, officials say” Statescoop (September
2024): https://statescoop.com/ransomware-attack-seattle-public-library-2024/
14 Highline Public Schools, “Incident FAQS” Departments/Communications (2024):
https://www.highlineschools.org/departments/communications/incident-faqs
15 IBM, Cost of a Data Breach Report (2024): p. 6
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7.6 Climate Change Considerations
Artificial Intelligence impacts to carbon emissions and water usage make it a contributor to climate
change. As natural disasters, storms, and hazards increase in frequency, vulnerabilities in critical
infrastructure impacted by these hazards also increase.
7.7 Impact Assessment
Public Anyone who is present in King County during a cyber-incident can be
impacted. Impact on residents may include: delayed services such as
transportation, impaired or cancelled healthcare services, decreased
or no availability of public services, information, and financial loss
and exposed or lost information.
Responders Emergency responders may not be able to access their mission
critical system, and therefore experience delays or performance
issues. If data confidentiality is lost the public may lose their trust in
the response organization and system. If data integrity is lost it may
put patients and first responders at risk. King County may
experience a prolonged incident response if the disruption is long
lasting, complex and exhausting internal resources.
Continuity of Operations Minor cyber incidents which are identified early and are recoverable
may have some impact on daily operations before being fully
contained but won’t lead to significant loss of operations. A
significant incident impacting one or more functions and businesses
can severely affect the County’s capability to perform critical
operations. However, not all daily operations are critical. The County
has defined its essential services, which need to become operational
within 0-72 hours after disruption to ensure the organizations
capability to maintain critical healthcare, safety, legal and regulatory
needs.
In the event of a cyber-incident which render a non-critical service
unavailable the County may lose revenue, experience loss of
productivity and risks losing data over time.
Property, Facilities, and
Infrastructure
Property
Cyber incidents can cause physical damage if property such as
facilities, devices, infrastructure, or end consumers are affected by
the disruption. An incident including utilities, life support devices,
transportation or telecommunications may lead to extensive
property damages.
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Facilities
Last years’ cyber incidents including ransomware attacks, distributed
denial of service attacks, system glitches and human error in
healthcare systems all demonstrate that cyber incidents are capable
of triggering emergencies that impact patient care and public health.
If an agency cannot access its own EHR, patient care could be
delayed or hindered. Furthermore, if other critical healthcare related
systems and devices can’t be accessed or data integrity can’t be
guaranteed, patient safety will be at risk.
Infrastructure
• Energy – Information technology has a direct dependency to
energy. A hazard impacting the power system can therefore have a
secondary effect on the County and lead to a cyber-incident due to
loss of power to devices rendering systems and data unavailable,
loss of power to cooling systems which can cause overheating and
fires in server rooms and data centers. Critical infrastructure has
backup generators. Ensuring fuel delivery during long lasting power
outages for the generators is critical.
A cyber incident impacting King County and no other organization
should not have an effect on the energy system.
• Water/Wastewater – Both water and wastewater facilities and
infrastructure are vulnerable to cyber incidents on their SCADA
systems, which can result in the release of hazardous material and
system malfunctions. Such scenarios can result in environmental
impact and create health and safety risks in the region.
• Transportation – Transportation systems are vulnerable to attacks
on their SCADA systems, which may result in trains and vehicles
not operating as planned, airport functionality issues, delays, and
cancellations which can result in a secondary economic impact in
the region due to loss of productive if people can’t access public
transportation to and from work.
• Communications – The County relies on different types of
technology-based communications methods such as its website,
VOIP and email to conduct its daily operations. A cyber incident
impacting the VOIP or email system would quickly result in a loss
of productivity, a negative consumer experience and could
potentially halter or delay some of the County’s operations.
Environment The loss of control or availability of the County’s SCADA systems
could potentially impact the environment in the region if, for
example, it causes the release of hazardous materials or improper
disposal of wastewater.
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Economy The financial impact of a cyber-incident ranges from little or minimal
to significant depending upon duration, scale, affected systems,
devices and users. A significant, extended cyber incident affecting
most or all of the County’s operations would likely impact the local
and possibly regional economy for some time. An incident of that
magnitude would likely create significant, potentially long-term or
ongoing challenges to the County's ability to fund essential services
and activities related to Executive priorities.
Organizations who experience cyber incidents which leads to data
breaches of sensitive or confidential information can be subjects to
legal fines and financial penalties if, for example, Personal
Healthcare Information (PHI) is lost or exposed or personal
identifiable information including social security numbers, credit
card information or driver’s license information is breached.
Organizations who fail to meet regulatory and contractual
obligations due to a cyber-incident may have significant cost for
legal fees, settlements, and fines.
Public Confidence in
Governance
Recent cyber-incidents involving government agencies such as the
ransomware attack on the City of Atlanta shows that such large-
scale disruption generate National media interest; third party
actions; jeopardizes perceptions of effective operations, Executive
priorities, and public confidence.
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7.8 Vulnerability Assessment
Vulnerable Populations Individuals who have a direct dependency on King County for health
and safety reasons are vulnerable to cyber incidents impacting their
needed services. Other vulnerable populations include individuals
and organizations who depend on an income from the County if
payments can’t be processed, who are dependent on critical public
services or County provided transportation.
Property Critical SCADA Systems
Industrial control systems which are used to control infrastructure
and facility-based processes such as wastewater treatment and
airports.
Environment If SCADA systems were to become compromised, ecosystems could
become vulnerable to the release of hazardous material. This
impacts waterways, soil, and vegetation.
Operations Facilities such as data centers and incident response facilities.
The County has identified a number of essential services which are
critical to support life, health, safety and legal requirements in the
region.
Although separate communication systems can be utilized in the
event of a severe incident the County still relies on its
communications systems for daily operations.
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Chapter 8Dam Failure
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Chapter 8: Dam Failure
8.1 Hazard Description
Dam failure is an uncontrolled, often times, rapid release of water from an impoundment.1 The
impact of failure varies on factors such as impoundment size, steepness, land use downstream of
the dam, and speed of failure. For larger dams, failure is characterized by a flood wave with high
velocities. Smaller dams may only raise water levels slightly and slowly. The result of a dam failure
can result in loss of life, property, infrastructure damage, public health impacts, safe drinking water,
and environmental degradation within the inundation zone, but may have secondary effects on
populations outside of the flooded area.
King County has 127 dams that serve in a variety of ways, agriculture, hydroelectric power
generation, flood control, and recreation. All but eleven of these dams are embankment-type dams.
Contrary to the popular images of dams like the Hoover dam, these dams are smaller and are
typically made of a mixture of compacted materials such as soil, clay, and rock. A semi-pervious
outer covering with a dense impervious core gives embankment dams their ability to resist seepage
and water pressure. The other dams are made of concrete.
Dams fail for a variety of reasons, but the four most common are:2
• Overtopping, 34% - caused by the reservoir reaching capacity and water spilling over the
top of a dam.
• Foundation defects, 30% - caused by settlement and slope instability.
• Piping and seepage, 20% - when water travels through the dam and causes internal erosion.
• Conduits and valves, 10% - Piping of embankment material into the conduit through joints
or cracks.
3
1 Tetra Tech. 2017. King County Dam Safety Emergency Planning Gap Analysis Report. Page 10.
2 Washington State Department of Ecology – Water Resource Program – Dam Safety Office. Accessed 8/28/2019.
https://ecology.wa.gov/Water-Shorelines/Water-supply/Dams/Emergency-planning-response/Incidents-failures.
3 Washington State Department of Ecology – Water Resource Program – Dam Safety Office. 2018. Status of High
and Significant Hazard Dams. Page 6.
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Causation
Dam failure events are infrequent and may coincide with other events, such as earthquakes,
landslides, excessive rainfall, wildfires, lahars and snowmelt. The average age of dams in King
County is 47. As infrastructure ages, increased spending is needed to maintain its integrity.
Following is a selection of events that may cause a dam to fail.
Table 8-1 Causation of dam failure by hazard events
Causation Description
Earthquake4 Earthquakes can result in damage or failure of a dam. Earthquake effects
on dams mainly depend on dam types. For example, the 2011 Tohoku
Earthquake damaged 48 dams, causing one embankment type dam to
fail 5. Safety concerns for embankment dams subjected to earthquakes
involve either the loss of stability due to a loss of strength of the
embankment and foundation materials or deformations such as
slumping, settlement, cracking and planer or rotational slope failures.
Dams are engineered to withstand the Maximum Considered
Earthquake, but older dams may have been engineered before we fully
understood the earthquake risk in the region.
Climate Change6 While dam failure probabilities are low. The chance of flooding
associated with changes of dam operation in response to weather
patterns is higher. Dam designs and operations are developed in part
from hydrographs and historical records. If weather patterns experience
significant changes over time due to the impacts of climate change, the
dam design and operations may no longer be valid for the changed
condition. Release rates and impound thresholds may have to be
changed. This would result in increased discharges downstream, thus
increasing the probability and severity of flooding.
Landslides 7 The integrity of a dam or reservoir can be affected by a landslide if they
fail or move. Landslides can be triggered by heavy rainfall, snowmelt,
reservoir drawdown, or earthquakes. Landslides can occur upstream in
the reservoir, in a canyon downstream of a dam, or within the abutment
of a dam. A landslide into the reservoir can generate a wave large
enough to overtop a dam. Sloshing back and forth in the reservoir can
4 KUOW. Seattle’s Faults: Maps that Highlight Our Shaky Ground. Accessed 8/29/19.
http://archive.kuow.org/post/seattles-faults-maps-highlight-our-shaky-ground
5 International Commission on Large Dams. 2013. The 2011 Tohoku Earthquake and Dams. Page 9.
6 Climate Impacts Group - University of Washington. 2018. New Projections of Changing Heavy Precipitation in King
County. Page 40.
7 Washington State Department of Natural Resources. Geological Portal Information. Accessed 8/28/2019.
https://geologyportal.dnr.wa.gov/#natural_hazards
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result in multiple waves overtopping the dam. If the waves are large
enough, there could be downstream consequences just from a wave
overtopping the dam even if it doesn’t fail. If enough large waves overtop
an embankment dam or a concrete dam with erodible abutments, a
failure could potentially result 8. Some dams in the County have been
built abutting a landslide. Often, these are ancient landslides that have
stopped moving or are moving very slowly. However, if a landslide moves
far enough, it can crack the core of an embankment dam, resulting in
pathways for internal erosion to initiate, or disrupting the abutment
support of a dam, resulting in failure.9
Wildfires 10 Many of the County’s highest hazard dams lie within wildfire-prone
areas. Wildfires can damage dams, such as Eightmile dam near
Leavenworth, directly by burning the surface of the dam or spillway and
damaging other facilities at the dam. But the main threat from wildfires is
how the surrounding watershed behaves. Heavy rains in a burned area
can create:
• More and faster runoff from rainfall events, especially high-intensity
storms.
• Large amounts of sediment, which may reduce storage capacity in a
reservoir.
• Debris flows (mudslides) or downed timber, which may obstruct
access to the dam.
• Debris flows from hill slopes near spillways, which may obstruct
spillways.
• More floating debris (dead trees, branches, sticks) in a reservoir,
which may obstruct spillways11
8 U.S Department of the Interior: Bureau of Reclamation. 2015. Risk Management: H-2 Landslide Risks. Page 1.
9 Quartz. 2015. The World’s Biggest Hydro Power Project May Be Causing Giant Landslides in China.
https://qz.com/436880/the-worlds-biggest-hydropower-project-may-be-causing-giant-landslides-in-china/
10 NW News Network. 2019. Eightmile Dam Near Leavenworth Has New Spillway, Is Being Monitored.
https://www.nwnewsnetwork.org/post/eightmile-dam-near-leavenworth-has-new-spillway-being-monitored
11 Washington State Department of Ecology - Water Resources Program - Dam Safety Office. 2015. Focus on Dams
and Wildfires. Page 1.
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Additionally, new development, outside of the 100-year flood plain, continues in dam inundation
zones, meaning the population-at-risk from dam failure will continue to rise. Below shows
development outside of the floodplain, but within a dam failure inundation area.
8.2 Location
There are a total of 127 dams located within King County, with an additional 20 dams situated
outside, though their inundation zones extend into the county. Figure 1-1 illustrates all identified
dams in the county, color-coded from dark blue to light blue. The darker blue shades represent
higher hazard classifications, while the lighter blue indicates lower hazard classifications. The six
dams marked with circles are classified as "Significant Dams" due to their potential impact, if they
were to fail.
Green River 2009
Green River 2012
100-Year Floodplain
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Figure 8-2 Dams in King County
Howard A Hanson
Howard Hanson, constructed in 1961, is a federally owned and operated dam by the United States
Army Corps of Engineers. Its primary purpose is to provide flood control in the winter and fish
enhancement in the summer. It dramatically reduced the amount of flooding that the Green River
Valley experienced before its construction.
The right abutment of the dam is the toe of a large landslide. Seepage problems can occur for dams
built into landslides. As mentioned previously, landslide activity can pose a serious risk to dams.
Many mitigation actions have been taken to reduce risk at the dam, such as a gravel blanket and
additional vertical and horizontal drains in the drainage tunnel have all drastically improved the
safety of the dam. If preventative actions are not taken, internal erosion could fail the dam.
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South Fork Tolt Dam
The South Fork Tolt Dam is owned and operated by the City of Seattle. It is a hydroelectric dam that
also provides drinking water for 30% of 1.3 million people across the greater Seattle area. South
Fork Tolt Dam is a large embankment type dam, equipped with a morning glory spillway.
The Tolt dam has known landslide hazards below the dam, and above the reservoir. If a slide were
to occur below the dam, the slide may create a dam of its own. Engineers would need to evaluate
what action should be taken. The Tolt Dam would have to lower the amount of flow downstream
why the risk is being assessed. Additionally, if a slide were to occur in the reservoir, an overtopping
wave may be generated that could cause the dam to fail or send a flood wave downstream.
Mud Mountain Dam
Mud Mountain Dam is a United States Army Corps of Engineer owned and operated dam on the
White River. Its primary purpose is to provide flood control for nearly 400,000 residents in King and
Pierce Counties. Typically, there isn’t a reservoir being impounded by the dam. During heavy rains
or times of snowmelt, engineers will impound the water and slowly release it downstream to avoid
flooding residents.
The White River is a glacial river fed by Mt. Rainier. This leaves the possibility that a lahar, triggered
by an earthquake, volcanic activity, or heavy rains could cause a debris flow that would block the
intake structure on the dam. Such an event would decrease the storage capacity of the reservoir
and cause flows to travel over the spillway. The loss in flood control capabilities on the White River
would leave the Green, White, and Puyallup River Valleys susceptible to flooding.
Culmback Dam
Situated in Snohomish County, but inundating a portion of the King County’s Lower Snoqualmie
Valley, the Culmback Dam is owned and operated by Snohomish Public Utility District One.
Culmback offers hydroelectric power generation, flood control, drinking water, and recreational
benefits to the region.
Culmback Dam’s morning glory spillway is designed to maintain adequate levels of freeboard in
maximum probable flood events. Changes in hydrology affect the amount of water a dam would
need to convey downstream to keep it from failing. Culmback Dam’s watershed lies within a
densely forested area that slows the speed in which water enters the reservoir, prevents sediment
from entering the reservoir, and prevents debris flows. A wildfire around the dam would increase
the hydrologic strain on the dam. An increased flow could be compensated with larger releases
from the dam but would result in flooding of the Town of Sultan. If not, enough water could be
discharged, an overtopping scenario at the dam would prove very dangerous.
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Lake Tapps
Lake Tapps is a reservoir that sits in Pierce County made up of a system of dikes. If particular dikes
were to fail, they would inundate Auburn and portions of the Green and White River Valley. Lake
Tapps was built by Puget Sound Energy in 1911 and ran a hydroelectric program until 2004. Lake
Tapps was purchased by Cascade Water Alliance in 2009 who currently owns and operates the
reservoir. Its primary function is to provide drinking water to a group of contracting King County
cities and water districts.
In addition to providing drinking water, Lake Tapps is also a residential community, many of whom
use the Lake for recreational purposes. While residents are instructed to stay off the dikes, there is
no physical security to keep individuals from accessing the structure. Many dikes have publicly
accessible roads. Acts of terrorism or sabotage could pose a serious threat to the integrity of the
levees.
Madsen Creek Flow and Water Control Pond
Madsen Creek Pond is a King County-owned dam. Constructed in 2008, its primary purpose is to
provide flood control in extreme rainfall events. There is oftentimes no impoundment behind the
dam in Summer months when there isn’t consistent rainfall.
Madsen Creek Pond is designed to store runoff from a 100-year 24-hour storm and still maintain
freeboard necessary to prevent flooding downstream. While the dam is comparatively very young
as climate patterns become more unpredictable, Madsen Creek Pond and other dams may need to
be retrofitted to accommodate the change in probable maximum precipitation. If actions were not
taken to adjust to the new hydrology, chances of failure from an overtopping situation or an
uncontrolled release would become higher.
Cedar Falls Project Masonry Dam
While there have been fewer failures of concrete dams than earthen dams in general12, this doesn’t
mean that failure is unrealistic. The Masonry dam sits near the Rattlesnake Mountain Fault. While
concrete dams have escaped failure in earthquake scenarios, minor damage has been observed.
The Masonry Dam would need to be assessed for damage after an earthquake for cracking or other
deficiencies in the structure or supporting structures. If deficiencies are noted, action must be taken
to ensure that the dam doesn’t fail. Earthquakes can also trigger landslides around the dam. Finally,
large earthquakes can devastate communities, created a resource-scarce environment, potentially
making it more difficult to find resources.
12 Association of State Dam Safety Officials. 1989. Failure of Concrete Dams. Page 4.
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8.3 Magnitude
The impact of a dam failure depends on factors such as the size of the impoundment, the steepness
of the terrain, downstream land use, and the speed of failure. For larger dams, failure typically
results in a fast-moving flood wave with high velocities. In contrast, smaller dams may only cause a
gradual rise in water levels. The consequences of a dam failure can include loss of life, property
damage, destruction of infrastructure, public health risks, contamination of drinking water, and
environmental harm within the inundation zone. Additionally, there may be secondary effects on
communities and ecosystems outside the flooded area.
While there are 127 dams in King County, there are 21 other dams situated in neighboring counties
that impact the County if they were to fail. Out of the 147 total dams, 94 threaten human life.
Table 8-2 Dam hazard classification
Hazard Class Number
1A = High – Greater than 300 lives at risk 10
1B = High – 31 to 300 lives at risk 18
1C = High – 7 to 30 lives at risk 42
2* = Significant – 1 to 6 lives at risk 17
2D = Significant – 1 to 6 lives at risk 7
2E = Significant – Environmental or economic impact 3
3 = Low – No lives at risk 50
* Legacy classification, parsing all 2's into 2D's and 2E's 13
the KCOEM Dam Safety program consists of creating response plans for high hazard dams in the
community, educating at-risk populations of the threat of dam failure, and connecting poor
condition dams to resources that are available for repair or removal of the dam. The King County
Emergency Management Dam Safety Officer works closely with Washington State Department of
Ecology’s Dam and Wells Manager to share information and create a regional effort to heighten
dam safety in the County. The information on dams in the hazard profile are from the State
Department of Ecology’s Inventory of Dams. The Washington State Department of Ecology Dam
Safety Office (DSO) is the regulating body over non-federal dams that impound at least 10-acre feet
of water in the State of Washington. The DSO permits all new dam construction, inspects all high
and significant hazard dams every 5 years, and requires that all deficiencies be remedied.
8.4 Previous Occurrences
King County has high hazard 1A dams that sit on the Green, White, Cedar, and Tolt Rivers.
Additionally, Culmback dam in Snohomish County would flood parts of the Lower Snoqualmie
13 Washington State Department of Ecology - Water Resources Program - Dam Safety Office. 2019. Inventory of
Dams Report.
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Valley. The Green, White and Lower Snoqualmie Valleys are the areas of greatest concern for dam
failure. Smaller privately owned and government dams are also a concern, as they may not have
access to funding streams that other larger municipal governments do.
Four dam failure incidents have occurred in King County; they account for all lives lost due to dam
failure in Washington State:14
Table 8-3 Previous dam failure events
Date Dam Name Description
December
1918
Masonry Dam Located near North Bend, Masonry Dam had excessive
seepage, which caused a mudflow, destroyed a railroad line
and damaged the village of Eastwick; no lives lost. Now
referred to as the “Boxley Burst”.
February 1932 Eastwick RR Fill The failure was caused by a blockage in the culvert. Resulting
in the destruction of the town of Eastwick and the loss of 7
lives.
January 1997 N. Boeing Creek
Dam
Failure from damage caused by seepage resulted in water
running into an intersection and detention pond.
January 2009 Howard
Hanson Dam
Two depressions were discovered in the right abutment of
the United States Army Corps of Engineers’ Howard Hanson
Dam. While repairs were being conducted, there was a 1 in 3
chance of a 25,000 cfs release down the Green River which
would have caused significant flooding. The USACE was able
to fully fix the dam by 2011 before a substantial flood ensued.
King County and local jurisdictions spent $30 million on flood
protection that wasn’t reimbursed by FEMA.15
January 2009 Mud Mountain
Dam
Mud Mountain Dam, owned and operated by the USACE,
released a higher than usual flow down the White River
during a heavy rain event. As a result, 100 homes were
flooded. Since then, King County Flood Control District,
Washington State, and Pierce County jointly funded a levee
setback to reduce the risk of flooding and increase habitat
restoration 16.
14 Washington State Department of Ecology - Water Resources Program - Dam Safety Office. 2019. Washington
State Notable Dam Failures and Incidents.
15 Seattle Times. 2011. FEMA won’t pick up $30 million tab to prepare for flooding.
https://www.seattletimes.com/seattle-news/fema-wont-pick-up-30-million-tab-to-prepare-for-flooding/
16 King County Department of Natural Resources and Parks – Water and Land Resource Division. 2018. Lower
White River Countyline Levee Setback Project. https://www.kingcounty.gov/depts/dnrp/wlr/sections-
programs/river-floodplain-section/capital-projects/lower-white-river-countyline-a-street.aspx
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In King County, levees have a long history of damage and sediment problems resulting in costly
repairs. Notable levee damage that has occurred since 2013 includes:
• Two flood events in November 2015 and December 2015 caused widespread impacts in
King County, especially along the South Fork Skykomish River, Snoqualmie River, Tolt River,
and Green River. These events resulted in the following levee damage:
o South Fork Skykomish River – Levee armor eroded from Town of Skykomish Left
Bank Levee.
o North Fork Snoqualmie River – A total breach of the Shake Mill Left Bank Levee
occurred, but no private property or infrastructure was damaged.
o Middle Fork Snoqualmie River– Damage to the levee face of the Mason Thorson
Extension Levee.
o South Fork Snoqualmie River – Damage to the face of the Reif Road Levee.
o Tolt River – Face rock was displaced from the Girl Scout Camp and Frew levees.
o Green River – Scour and slumping along the Tukwila 205 Levee.
• A significant flood event in January – February 2020 damaged numerous flood protection
facilities along the Cedar River, Green River, and Issaquah Creek, including:
– Cedar River – Damage to the Belmondo Levee (which protects a regional fiber optic
line, a regional trail, and a state highway) and erosion and scour at the Orchard
Grove, Royal Arch, McDonald, Jan Road, and Getchman levees.
– Green River – Erosion at the Fort Dent Levee, seepage and ponding at the Desimone
and Briscoe School levees, and cracking in the crest of the McCoy Levee.
Issaquah Creek – Erosion at the State Route 18 Upstream and Downstream levees.
8.5 Probability of Future Occurrences
The likelihood of a dam failure in King County is very low. While the county’s location near the Juan
de Fuca Plate and Puget Sound Faults does lead to more frequent earthquakes than other parts of
the U.S., the risk of dam failure from seismic activity is still minimal. Many of the dams in King
County are relatively new, which reduces the chance of structural damage. Additionally, all large,
high-hazard dams in the area are closely regulated by the Federal Energy Regulatory Commission
(FERC) and other agencies. These organizations ensure that dams are properly maintained and that
operators are prepared for potential emergencies, such as flooding.
8.6 Climate Change Considerations
Climate change introduces several factors that can increase the risk of dam failure. Wildfires, for
example, can heighten the likelihood of landslides and sloughing, creating cascading hazards.
Additionally, debris runoff from fires can lead to post-fire sedimentation and siltation in
downstream dams. Warmer water temperatures, a direct result of climate change, can contribute
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to soil saturation, increasing the risk of dam seepage. The earlier spring thaw and changing
snowmelt patterns may also cause higher flow rates, placing additional stress on dams.
Heavy rainfall events can lead to erosion and scouring near dams, exacerbating runoff and
increasing water pressure, while rising temperatures lead to faster evaporation, which may weaken
dam structures over time. Both extreme heat and cold can further damage the structural integrity
of dams. Finally, the increasing frequency and intensity of precipitation events elevate the risk of
dam overtopping and complicate freeboard management, making it harder to ensure the dam's
safety in extreme weather conditions.
8.7 Impact Assessment
With all the dams in the county, only a small amount of information can be shared here due to “For
Official Use Only Designation”. Another reason is that there is a lack of in-depth study done on dam
failure impacts to King County. The best and most available estimates for dam failure
damages/impacts are from the potential high release scenario at Howard Hanson Dam in 2009.
Examples provided here relate to those studies.
Public As the Green River Valley experience drastic differences in day time/night time
population being an economic hub. The number of people that would need to
be evacuated could drastically differ from the numbers identified in the hazard
classification. An estimate in 2009 put a 25,000 cfs release from Howard Hanson
triggering an evacuation on the scale of 200,000 to 300,000 people.17
Responders Kent, Pacific, Seattle, Renton Regional Fire Authority, Valley Regional Fire
Authority, and Eastside Fire and Rescue all have fires stations within dam
inundation areas.
Auburn, Algona, Pacific, Kent, Seattle, State Patrol Crime Lab, and King County
Sherriff all have stations in dam failure inundations.
Continuity of
Operations
Auburn, Kent, Tukwila, Carnation, Pacific, and Algona all have city halls within
inundation areas. Courts, the County Elections office, King County Regional
Justice Center in Kent where Superior Courts, Adult Detention, and other county
agencies are located within dam failure inundation areas as well.
17 Seattlepi. 2019. 300,000 might have to evacuate if Green River Floods.
https://www.seattlepi.com/seattlenews/article/300-000-might-have-to-evacuate-if-Green-River-889468.php
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Property,
Facilities,
Infrastructure
Dam Name Residential Buildings
Impacted in King County
(Full Pool Failure)
Estimated Impacted in
King County (Sunny Day
Failure)*
Mud Mountain 9,992 829
Howard Hanson 8,508 2,545
South Fork Tolt 935 N/A
Lake Youngs 1,120 873
Culmback 59 N/A
Other Dams Combined
(Estimate)
N/A
N/A
18
*Sunny day failure assumes a regular pool
2009 modelling of a high release from Howard Hanson.
Structures impacted Lower
Green
In 17,000 cfs
impact area
In 25,000 cfs
impact area
Residential 3,486 1,743 1,937
Commercial 16,798 12,245 13,667
Industrial 7,839 6,549 6,644
19
Facilities
18 Tetra Tech. 2017. King County Dam Safety Emergency Planning Gap Analysis Report. Page 168.
19 FEMA Region X. 2009. HAZUS Analysis for the Green River Valley. Page 166.
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MultiCare Auburn Medical Center lies within a dam failure inundation area, but
further study is needed to fully understand the impacts on health systems from
dam failure.
Infrastructure
Infrastructure impacts vary dramatically based on the individual dam and type
of failure.
• Energy- While there are dams that generate power in the County, they
provide a relatively small amount of power. The Cedar, Snoqualmie, Twin
Falls and, Tolt projects account for only 126 max MW output 20. Power
outages may be long term in areas where there has been a failure.
• Water/Wastewater – Drinking water availability would be drastically
impacted by a failure of the Masonry, Lake Tapps, Lake Youngs, and
Howard Hanson Dams. A failure of one of the many of the reservoirs
around the County would also challenge water systems. The King County
South Treatment Plant also lies within a dam failure inundation area.
• Transportation- Rail lines (commercial and commuter), LINK Light Rail,
bus routes, numerous state highways, and numerous bridges can be
impacted by dam failure.
Environment The primary environmental impact from dam failure is natural and manmade
debris from the inundation. Silt, wood, rocks and gravel, hazardous materials,
construction debris, vehicles, dead animals may be carried by inundation waters
to locations that may be spawning areas for local fish, wetlands for birds and
reptiles, or inhabited areas that the County has invested in heavily. While
recovery and impact will vary with each inundation area.
Economy The Green River Valley is an economic powerhouse in the region. Flood damage
prevented in the valley by Howard Hanson Dam since the January 2009 flood is
estimated at $6 billion alone 21. The economic impact of a failure would
devastate the region. With large employers, such as Boeing, and economic
centers like the South Center Mall, in the Valley, a dam failure would leave the
local economy crippled. Commutes, roadways, and rail lines would all be
impacted by a high release from Howard Hanson. Unemployment may follow in
areas that experience a dam failure.
20 Bonneville Power Administration. 2018 Transmission Plan. 2018. Page 77.
21 USACE. Howard A. Hanson Dam. Accessed 8/28/2019. https://www.nws.usace.army.mil/Missions/Civil-
Works/Locks-and-Dams/Howard-Hanson-Dam/
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Public
Confidence in
Governance
A dam failure may cause the public to lose confidence in dam owners, both
public and private, to manage local dams. Depending on the success of the
response, the public may also lose confidence in first responders.
8.8 Vulnerability Assessment
Vulnerable
Populations
Dam inundation areas consist of some of the highest Limited English Proficiency
populations in the County. Spanish, Vietnamese, African Languages, and
Mandarin are all spoken in high percentages in dam inundation areas.
Auburn, Kent, and Riverview School District, as well as private schools, have
locations that are vulnerable to dam failure. Riverview school district practices an
evacuation of Carnation Elementary School and Tolt Middle School every
September in the City of Carnation. Both schools would need to be evacuated if
the South Fork Tolt Dam failed.
Preliminary studies indicate that there are at least 15 assisted living facilities
within dam inundation areas.22 Evacuation will take longer for this population
than most.
A 2019 report indicates that there 11,199 individuals experiencing homelessness
in the County.23 Alert and warning can be especially challenging for this
population as they may not be tied to a geo-coded database.
Lack of public knowledge
Most dams use a “For Official Use Only” designation on their inundation maps.
This means that inundation maps only be shared on a need-to-know basis. A lack
of public knowledge about dams, their presence in the community, and their
failure potential creates an added challenge in creating a resilient community.
Property Dam events, such as seepage, overtopping, or failure, can cause significant
damage or destruction to homes, businesses, and other property in downstream
flood areas. For this reason, it is recommended that people in these areas secure
insurance or review their current coverage to ensure they’re protected. The
extent of downstream impacts can vary depending on the size of the dam and
22 FEMA Region X. 2009. HAZUS Analysis for the Green River Valley. Page 168.
23 All Home. 2019. Seattle/King County Point-In-Time County of Persons Experiencing Homelessness.
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the specific event, but generally, low-lying areas in floodplains with dense
infrastructure are most at risk for physical damage and economic disruption.
Environment Dam incidents, particularly dam failures, can have significant negative impacts on
both downstream and upstream environments. A sudden failure often leads to
severe erosion and a rapid increase in sediment in local water sources.
Additionally, ecosystems in the area are affected by the sudden release of water
and debris. In some cases, smaller dams may contain contaminated water, which
can pose chemical or biological risks to the local environment. While these
instances are rare and typically involve small dams with limited water storage,
they still present a potential hazard. Moreover, such events can disrupt migrating
fish populations, which in turn may affect local communities that rely on fishing
as an economic resource.
Operations Small Local Government and Privately Owned Dams
These dams may not have access to funding, or have employees dedicated to
dam safety. This means that there is a higher chance that maintenance and
deficiencies go unmediated. Thus, leading to a higher chance of dam failure.
Emergency Action Plan
High and significant dams are required to have Emergency Action Plans in
Washington State. Missing EAPs and out of date EAPs pose a risk if owners are
unequipped to deal with an emergency at their dam.
Dam Standard
Any dam that is designated as “poor” or “unsatisfactory” by the Washington
State Dam Safety Office should be brought to a higher standard.
AGENDA ITEM #1. b)
Risk Assessment
Scoring
4 Location
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4 Magnitude
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4 PFI
3 Environment
4 Economy
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4 Environment
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Very High Overall Risk
PC: Elaine Thompson, The Associate Press
Chapter 9Earthquake
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Chapter 9: Earthquake
9.1 Hazard Description
Washington has the second-
highest earthquake risk in the
United States, after California.
This risk largely originates from
the Cascadia subduction zone
(CSZ) off the coast of Washington
where Juan de Fuca Plate collides
and descends beneath the North
American Plate. This tectonic
activity generates significant
stress in the earth, making the
region prone to powerful
earthquakes.
Earthquakes present the greatest regional threat in terms of potential damage, casualties,
economic disruption, and social impacts. Disruptions to essential services, including
communications, power, gas, water, and transportation infrastructure, are also inevitable. The
severity of an earthquake’s impact is driven by ground shaking and secondary impacts include
liquefaction, landslides, tsunamis, and even post-earthquake fires.
Table 9-1 Earthquake secondary hazards
Secondary Hazard Description
Ground shaking The most immediate and widespread consequence of an earthquake.
Ground shaking can also happen from foreshocks or aftershocks that can
persist for days to even decades, worsening damage and injuries. While the
shaking itself rarely causes fatalities, the resulting destruction—such as
collapsing buildings and falling debris—is a major contributor to casualties.
Liquefaction Occurs when soft, water-saturated soils lose their strength during an
earthquake and behave like a liquid. This phenomenon can severely
damage buildings and infrastructure that rely on solid ground for support,
particularly in areas with loose sedimentary soils.
Landslides Soil, rock or debris that detach and fall downslope – can be triggered by
ground shaking. Depending on where the landslide occurs, this event can
lead to additional cascading effects. For instance, in 1949 an earthquake
landslide that occurred on the Tacoma Narrows generated a tsunami.
Tsunamis A destructive movement of the ocean involving at least one ‘wave’, and
strong currents. Even a relatively ‘small’ tsunami could be devastating to
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port and maritime infrastructure within Puget Sound.1 There is evidence
that an earthquake on the Seattle fault that occurred around 923-24 CE
produced a 16-foot tsunami.
Dam failure Earthquakes can cause significant shaking that may compromise the
structural integrity of dams. If a dam is already weakened by age, poor
maintenance, or underlying geological issues, the seismic forces can cause
cracks, ruptures, or even complete failure of the dam structure. This would
result in the flooding of inundation zones.
Volcanic eruptions/
Lahar
The shaking from the earthquake can impact volcanic systems. Particularly
if a volcano is already experiencing unrest, an earthquake could induce a
landslide, the collapse of a volcanic vent, or disrupt the pressure balance
inside a volcano, leading to an eruption. An example of this is the 1980
eruption of Mount St. Helens where an earthquake triggered a landslide.
This led the volcano, which had already been at an elevated level of
activity, to violently erupt out of the north face where the landslide had
occurred.
Hazardous material
release
Earthquakes can trigger hazmat releases from a pipelines rupture,
underground fuel storage tanks fail, oil train derailment, or damage to port
facilities.
9.2 Location
The Juan de Fuca plate is moving northeastward with respect to the North American plate at a rate
of 3 to 4 centimeters per year. The boundary where these two plates converge, the Cascadia
subduction zone, lies approximately 50 miles offshore from Washington and extends nearly 700
miles from northern Vancouver Island in British Columbia to northern California. The collision of
these two tectonic plates produces three types of earthquakes: crustal (shallow) earthquakes, deep
earthquakes, and subduction zone earthquakes. The relative frequency of these events varies
across the region; for example, deep earthquakes have historically occurred more frequently in
parts of western Washington, however, it dependents on the tectonic environment and in lots of
places, shallow crustal earthquakes are more common than deep earthquakes. Subduction zone
earthquakes are rarest events in the region but pose the most significant risk.
1 Seattle Office of Emergency Management, “Tsunamis and Seiches” Seattle.gov (n.d.)
https://www.seattle.gov/emergency-management/hazards/tsunamis-and-seiches.
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Figure 9-1 Earthquake sources and past events
Subduction zone earthquakes originate from the Cascadia Subduction Zone (CSZ), located off the
coast of Washington and Oregon. These earthquakes are the largest, because they happen on such
a long fault. While they occur offshore and are distant from many communities, they still pose a
major threat. A subduction zone earthquake has the potential to reach a magnitude of 9.0 or
greater. If this occurs, it will trigger a tsunami along the entire fault line, from British Columbia to
Mendocino, California. However, even if a megathrust earthquake along the CSZ doesn’t reach a
magnitude of 9.0, a tsunami could still be generated. The ground shaking from such an event would
last several minutes, causing catastrophic regional damage from the earthquake itself and
widespread destruction from the resulting tsunami. Additionally, these earthquakes are typically
followed by numerous large aftershocks.
Deep earthquakes are the most frequent earthquakes in the Puget Sound area. They occur within
the Juan de Fuca plate as it subducts beneath the North American Plate, at depths ranging from 16
to 60 miles. Due to their depth, aftershocks are typically not felt. Deep earthquakes usually last
between 20 to 30 seconds and can reach magnitudes of 7 to 7.5 on the moment magnitude scale.
The most recent major deep earthquake in the Puget Sound region was the 6.8 magnitude Nisqually
Earthquake on February 28, 2001.
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Crustal earthquakes occur within the North American plate at depths of 18 miles or less. Typically,
they have magnitudes under 8 and last between 20 to 60 seconds. Local examples include:
• Seattle Fault, running east to west through downtown Seattle.
• Rattlesnake Mountain Fault Zone, running northwest to southeast through Fall City,
Snoqualmie, and North Bend.
Of the three types of earthquakes, the timelines and recurrence intervals for crustal events are the
least understood. In 2020, the USGS refreshed their documentation of crustal faults in Washington,
and the WGS is currently engaged in mapping faults from North Bend to the southeast edge of King
County.
Figure 9-2 2020 USGS Crustal Faults in King County, Crustal Faults
9.3 Magnitude
In earthquake science, there are two kinds of magnitude; the Moment Magnitude Scale (MW) that
measures amount of energy released when an earthquake happens, and the Earthquake Intensity
USGS Quaternary Faults
National Seismic Hazard Model
2021-2025 mapping
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Scale (or Modified Mercalli Intensity MMI) that is based on impacts to people, property, and
operations.
Moment Magnitude Scale
Washington Department of Natural Resources (WADNR) no longer uses the Richter scale, but the
Moment Magnitude Scale. It’s logarithmic, meaning for every single digit increase the moment
magnitude, you have a 32 times stronger earthquake, which translates to 32 times the amount of
energy released at the source. A magnitude 2 earthquake with be equivalent to 56 kilograms of
explosive whereas a magnitude 10 earthquake would release over 60 trillion kilograms of explosive.
Figure 9-3 Moment Magnitude Scale
Earthquake Intensity Scale
Earthquake intensity, or ground shaking, is measured by the Modified Mercalli Scale. Its intensity
depends on the original moment magnitude and the distance of where the earthquake started to
where the impacts are being assessed, and the soil type and material near the surface at the area
being shaken.
A shallowly-sourced earthquake that has relatively small magnitude, but nearer to populated areas
is potentially more damaging than a much larger magnitude earthquake that is farther away from
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populated areas. Even when an earthquake source is distant, unconsolidated soils, such as
uncompacted sands, or gravels, found in many floodplains or river valleys, amplify shaking, leading
to more potential damage.
Figure 9-4 Earthquake Intensity Scale
Liquefaction
The National Earthquake Hazard Reduction Program (NEHRP) supports map creation based on soil
characteristics to help identify locations subject to ground shaking amplification and liquefaction
during earthquakes. Areas with NEHRP soil classes D, E and F are prone to shaking amplification,
and structures in these areas experience greater damage during shaking. These soils also tend to be
more susceptible to liquefaction.
Table 9-2 NEHRP Soil Classification System
NEHRP Soil
Type
Description Mean Shear Velocity in Meters per
Second
A Hard Rock 1500
B Firm to Hard Rock 760-1500
C Dense Soil / Soft Rock 360-760
D Stiff Soil 180-360
E Soft Clay <180
F Special Study Soils (liquefiable soils,
sensitive clays, organic soils, soft clays > 36
meters thick)
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Figure 9-5 shows the level of susceptibility areas in King County area to liquefaction. Liquefaction
maps in Washington State have not been updated for some time. However, there is currently an
academic government collaborative, CRESCENT, that is working with the Washington Department
of Natural Resources to update state maps relating to ground shaking and liquefaction.
Figure 9-5 Liquefaction susceptibility in King County
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Figure 9-6 Nisqually Earthquake 2001, Impact Map
An example of an Intensity Scale map from the
Nisqually earthquake of 2001. Colors match the
scale in Figure 9-4.
This was a deep earthquake, which are the most
frequently occurring types in Washington. The map
shows only a few areas experiencing up to very
strong to severe shaking. However, the shaking
happened over a broad area. King County,
highlighted in white, saw high impacts along the
Duwamish River where there is soft surface
material. The grey band shows the area in
Washington prone to such deep-seated
earthquakes.
9.4 Previous Occurrences
Figure 9-7 Past Earthquakes in Washington
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Name Source Date Size
Nisqually Earthquake Deep – Juan de Fuca February 28, 2001 M 6.8
This earthquake, with an epicenter 10 miles northeast of Olympia in Thurston County (over 40
miles from Seattle), resulted in statewide losses exceeding $2 billion and injured 700 people,
many in King County.2 A landslide in King County generated from the 2001 Nisqually Earthquake
partially blocked the Cedar River – flooding several homes.
The 6.8 magnitude Nisqually earthquake was centered under Anderson Island in south Puget
Sound. The most extensive damage occurred along the Interstate-5 corridor, where river
sediments led to shaking amplification and liquefaction impacts. Damage was experienced in
300,000 households, many from settling foundations. Buildings built prior to 1950 located in the
south downtown area and Pioneer Square in Seattle were the most impacted; structural damage
to chimneys, walls, foundations, and nonstructural elements accounted for two-thirds of all
damage reported.3 Insured losses were recorded as $305M with $2B in losses overall. Of those
persons impacted, 21% had earthquake insurance but did not meet the deductible. 75% of retail
businesses in Seattle that were impacted closed for a period for cleanup or repairs. The average
closure was 4.8 days in Pioneer Square. Of those businesses impacted, 50% were financially
threatened with closure. Harbor Island saw 69 businesses impacted for an average of $30,900.
The Nisqually Earthquake led to a new emphasis in Washington, and King County especially, on
the importance of retrofitting historic, unreinforced masonry buildings (URMs). The loss of
historic buildings is not only costly in financial terms but can alter the social fabric of a community
and fundamentally change its feel and sense of place.
Puget Sound
Earthquake
Deep – Juan de Fuca April 1965 M 6.5
At magnitude 6.5, the earthquake killed seven people and caused $12.5 Million in damage (1965
dollars). Severe shaking was felt in Seattle and as far as Issaquah and beyond. Most damage was
in the Pioneer Square area and waterfront. Older masonry buildings were most impacted.
Damage patterns experienced in 1949 were repeated. Eight schools were closed for inspections
and repairs; two were severely damaged. Areas along the Duwamish River experienced severe
settling. Three water mains failed in Seattle.
Olympia Earthquake Deep – Juan de Fuca April 1949 M 7.1
The 7.1 magnitude earthquake was centered along the southern edge of Puget Sound. Eight
people were killed and property damage in Olympia-Tacoma-Seattle amounted to about $25
Million in 1949 dollars. In Seattle, a sixty-inch water main ruptured, a radio tower collapsed,
power lines and gas lines were broken in over 100 places. Three damaged schools needed to be
demolished and one rebuilt. Three days after the event, a landslide entering the water along the
2 EQE International, “Seattle Nisqually Washington Earthquake” (Feb 2001):
http://www.propertyrisk.com/refcentr/seattleeq.pdf
3 “Hazard Mitigation Survey Team Report, Nisqually Earthquake” Federal Emergency Management Agency and
Washington Military Department, Emergency Management Division (February 2001)
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steep bluff of the Tacoma Narrows said to have been correlated with the earthquake generated a
tsunami.
Cascadia Earthquake Subduction zone 1700 M 9.0
This earthquake, one of the largest in the history of North America, was found by combining First
Nations and Native American oral histories with tree-ring dating and other geological evidence in
North America and an “orphan tsunami” in Japan. From oral history of the Huu-ay-aht First
Nation, people were just going to sleep in the longhouses at Anacla, on Pachena Bay, [present-
day Vancouver Island] when the earthquake hit. It shook for more than half a minute, and many
of the longhouses sank into the sand [a description of liquefaction]. The tsunami that followed
had an estimated wave height of more than 50 ft (15 m) and flooded Anacla and other coastal
villages. Only 1 out of more than 600 people in Anacla survived, and in all, seven Huu-ay-aht
villages were destroyed. Only the village of Malthsit survived, since it was on high ground about
75 feet (23 m) above Pachena Bay. Several oral accounts describe a great flood on what is known
today as the Olympic Peninsula of Washington.4
Seattle Fault Crustal fault in 923-924 CE M 7.0 and 7.5
The Seattle fault runs east-west and cuts across Puget Sound, through downtown Seattle, and
across Lake Washington. Geologic evidence indicates that it ruptured in a major earthquake
(estimated magnitude 7.3) around in 923-924 CE, causing a maximum of 7 meters (~21 feet) of
offset at the surface, generating a tsunami in Puget Sound, and large block landslides into Lake
Washington. Native oral traditions from Puget Sound associate landsliding, earth-shaking, and
rushes of turbid water with a monstrous serpent called A'yahos.5
9.5 Probability of Future Occurrences
The likelihood of future earthquakes in King County is inevitable, with a 100% certainty that one will
occur eventually. However, predicting the magnitude and exact location is not possible.
Earthquakes occur at unpredictable intervals, and there are few scientifically verified early warning
signs to indicate when one might strike. Estimating the probability of a future earthquake in
Washington is challenging due to their rarity and the insufficient length of historical data needed to
establish reliable recurrence patterns. Consequently, we rely on analyzing available data to detect
potential trends that could inform planning and decision-making. However, pattern detection must
be approached with caution, as it is prone to biases (e.g., pattern recognition bias), which could
lead to misleading conclusions. Despite advanced analytical methods, earthquakes continue to defy
reliable prediction.
In 2023, the US National Seismic Hazard Model (NSHM) updated seismic hazard estimates for all 50
states based on available seismicity, fault rupture, and ground motion data. Zooming in on this
4 David Wiwchar, “Prepare for next tsunami, says chief” Raven’s Eye vl 8 Issue 9(2005): p.3,
https://www.ammsa.com/publications/ravens-eye/prepare-next-tsunami-says-chief
5 R. S. Ludwin, et al., “Serpent Spirit-power Stories along the Seattle Fault” Seismological Research Letters, V. 76,
No. 4, 426-431(July 2005)
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map, you see the King County region has from 75% to greater than 95% chance of damaging shaking
in the next hundred years.
Figure 9-8 2023 US National Seismic Hazard Model, Chance of Damaging Earthquake Shaking 6
9.6 Impact Assessment
The severity of an earthquake is different depending on the conditions under which it occurs. Also,
different sectors of the population, economy, or government will have different levels of exposure
and vulnerability that impact their susceptibility to an earthquake. This risk assessment looks at
impacts of five earthquake scenarios to a series of critical sectors. The impact data for physical
structures is generated using the Hazus-MH tool for three different Seattle Fault M7.0 scenarios, a
Tacoma Fault M 7.1 scenario, and a Cascadia M9.0 scenario. These scenarios are chosen based on
their probability and potential impact. This earthquake model also includes information on
liquefaction potential of soils and the age of buildings (as an instrument for building code levels).
This assessment considers impacts to physical and human elements of each of 11 impact areas. For
example, for health systems, the locations of key facilities identified by Public Health Seattle – King
6 Mark D. Petersen, et al., “The 2023 US 50-State National Seismic Hazard Model: Overview and implications” USGS
(December 2023): https://www.usgs.gov/publications/2023-us-50-state-national-seismic-hazard-model-overview-
and-implications#:~:text=The%20US%20National%20Seismic%20Hazard,than%20%E2%88%BC475%20or%20less
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County will be assessed against data on high hazard areas. The impacts to the health system overall,
including employees and existing patients, will also be examined.
The HAZUS scenarios used in this section were generated by the FEMA RiskMAP team for the 2018
King County Risk Report.7
Public The entire population of King County is potentially exposed to the direct and
indirect impacts from earthquakes. The degree of exposure is dependent on
many factors, including the age and construction type of residence, the soil
type homes are constructed on, the proximity to the fault, etc.
Impacts to the population are not restricted to displacement and sheltering.
People may be injured, lose their jobs, schools may be closed from their own
damages, government services may be interrupted, health facilities and care
may also be interrupted or be completely unavailable. Family members may
be separated, including children, elderly in care facilities, may be moved to
alternate facilities – and unaccounted for. Deaths of homeless and
unidentified people may require burial before family can claim their remains.
Responders First responders experience personal and professional impacts from an
earthquake. Since responders are also local residents, they will be personally
impacted by the disaster. Professionally, emergency services will be called
upon to help with life safety operations while also seeking to restore day-to-
day services.
Continuity of
Operations
Any damaging earthquake has the potential to impact delivery of essential
government services in the days, weeks, months, and even years following
the earthquake. The damages to infrastructure and residential or business
locations may curtail or even prevent government employees from reaching
their work locations or may prevent services from reaching populations in
need scattered around the county. Even after initial short-term repairs have
been made, the impact on the taxable value of properties in the county may
cause a revenue shortfall that reduces available services from budgetary
impacts. Collection of available tax revenue, the revaluation process
(including documentation), and appeals process might produce a further
burden on already stretched government obligations.
Earthquakes can damage anything at which services are provided. This may
include adult and juvenile detention facilities, wastewater treatment
facilities, solid waste disposal systems and facilities, the court system, health
7 Federal Emergency Management Agency, “King County Risk Report” (2018)
https://fortress.wa.gov/ecy/gispublic/AppResources/SEA/RiskMAP/King/KingCounty_RiskReport.pdf
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and medical institutions and clinics, fire and police stations or equipment,
public transportation, schools, and libraries.
Property,
Facilities,
Infrastructure
Property
Unreinforced masonry buildings are particularly vulnerable during an
earthquake. The Nisqually Earthquake of 2001 caused extensive damage to
such structures, as well as to those built prior to the 1949 earthquake. A
similar pattern of damage was observed in roads and bridges. In contrast,
buildings constructed after the 1949 and 1965 earthquakes, which influenced
the development and improvement of seismic building standards, showed
little to no significant damage, underscoring the effectiveness of modern
seismic building standards.
In October 2018, the Washington State Department of Archaeology and
Historic Preservation (DAHP) developed a statewide inventory of identified
and suspected unreinforced masonry (URM) buildings, excluding single-
family homes. This data was integrated into an interactive online map,
revealing 1,145 identified URM buildings within Seattle. Outside the city, King
County has over 120 suspected URM buildings, with the highest
concentrations in Bothell, Kirkland, and Redmond. Across the county, nearly
50% of buildings were constructed to pre- or low-code standards, leaving
them susceptible to moderate to high-magnitude earthquakes. These are
preliminary numbers and could go up after further assessment.
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Figure 9-10 Identified Unreinforced masonry (URM) buildings in King County 8
Figure 9-11 Suspected Unreinforced masonry (URM) buildings in King County
Facilities
Health system impacts from a major disaster include disruptions to
emergency services, community health clinics, pharmacies, and hospitals.
8 Department of Archaeology and Historic Preservation (DAHP), “Washington URM Dashboard” (2018):
https://fortress.wa.gov/com/urmasonary/urmasonary/#11/47.6469/-122.3026/775
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While new hospitals are required to meet criteria for seismic resilience and
may engage in supply-chain and patient evacuation planning, much of the
rest of the network is likely to be shut down after a disaster. This is an
especially high threat to populations needing regular medical services, such
as kidney dialysis and insulin injections (which require refrigeration). In
Hurricane Maria in 2017, Puerto Rico was left without power for months and
the majority of fatalities recorded due to the storm were from the elevated
death rate among medically-fragile populations.
To function, hospitals require significant infrastructure inputs, including
power and water that are likely to be disrupted after an earthquake. Backup
services are available; however, may be insufficient to meet the need if
infrastructure recovery takes too long.
Health system impacts therefore include large-scale disruptions to supply
chains, disruptions to ongoing care regimens for certain medically-vulnerable
populations, disruption of community care networks of pharmacies and local
clinics, loss of trained staff, and potential damage to hospitals or loss of
hospital functionality due to infrastructure damage.
Infrastructure
Energy: Dams are the primary source of electricity generation for the region
and may be impacted by a major earthquake, even if failure is relatively
unlikely. Furthermore, most generators have a maximum run time before
needing to be serviced (~500 hours for natural gas generators). Pipelines
cross the region carrying fuel and are susceptible to earthquakes. In the
event of a catastrophic earthquake, the energy infrastructure could be
impacted for months surpassing the generators capacity. Since Washington is
home to the Pacific Northwest’s only refineries, damage to this conveyance
system will have far reaching, regional consequences. A major concern for
maintaining power in facilities while the power grid is down after an
earthquake is fuel distribution. With transportation networks seriously
impacted, it will be difficult to ensure a supply of fuel is distributed to
hospitals, public facilities, and communications centers. Without this fuel,
systems are likely to fail after a few days of operation.
Water/Wastewater: Water and wastewater systems are among the most
vulnerable to an earthquake of all lifeline infrastructure. Pipelines, especially
those over NEHRP class D, E, and F soils, are vulnerable to rupture. King
County maintains a wastewater treatment system that is connected to
dozens of smaller systems and operates multiple water treatment plants.
There are also many separate water systems that operate their own
conveyance systems and reservoirs. All of these systems will be impacted.
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Transportation: Transportation lifelines are both state and local
responsibilities. According to a Regional Resiliency Assessment Program
(RRAP) report published by DHS, WSDOT has operated a seismic retrofit
program since 1991 and has been steadily retrofitting bridges through a
three-stage process of stabilizing the bridge superstructure, strengthening
single-column bridge supports, and reinforcing multi-column piers. As of
January 2025, King County has 25 out of 229 bridges in the program. At least
every two years, those bridges are inspected and recommendations are
made for their repair or replacement.
Bridges, however, are only part of the transportation puzzle. Bridge
approaches, and pavement crossing on unstable soils can be impacted. The
WSDOT Seismic Lifeline route discussed above is only considering bridges,
not pavement or approaches.
Railways are another highly-vulnerable piece of transportation infrastructure.
Tracks can become misaligned and require repair before train travel is
possible. Even in the relatively moderate 2001 Nisqually Earthquake, rail
travel was disrupted for several days.
Port facilities are seriously threatened by a major earthquake due to
liquefaction potential of port areas and tsunami threats. It is likely a major
earthquake would completely destroy port facilities, requiring years of
investment to completely recover. As with the 1995 Kobe, Japan earthquake,
port operations may never again reach pre-disaster levels.
Airports are also vulnerable to earthquakes. In the 2001 Nisqually
Earthquake, the air traffic control tower at Seattle-Tacoma International
Airport was damaged, drastically reducing takeoff and landing capacity.
Runway damage is also common as the ground shifts and would require
repair before large jets could land. While the region has a number of airports,
many of them will also be critical facilities for disaster response, medical
patient evacuation, and food and fuel deliveries.
Communications: While the public sector maintains critical radio
communications networks, the networks on which most residents depend is
privately owned. While cell towers are equipped with backup generators,
these generators may only have enough fuel for a few days of continuous
operation.
Environment Impacts to the environment from an earthquake include the creation and
disposal of large quantities of debris, releases of hazardous materials, the
disruption of environmental conservation programs, and the relaxing of
environmental program rules during the cleanup and recovery. Moving
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debris out of the area, given the disruptions to transportation infrastructure,
will be difficult.
The greatest potential for environmental damage is from hazardous
materials releases as fuel and waste pipelines rupture, underground fuel
storage tanks fail, trains, including oil trains, may derail, port facilities are
damaged by any tsunami or seiche, and other chemicals, including household
items, are spilled. The multi-source nature of materials releases, the scale of
potential releases, and the lack of resources for cleanup all complicate the
scenario.9 An example is the Northridge and Loma Prieta earthquakes, where
hundreds of gas line ruptures and pipeline breaks, and releases of ammonia,
chlorine, and sulfuric acid.10
Economy The economic risks posed by a major earthquake are wide-ranging and
multifaceted. The immediate impacts include the destruction of facilities and
inventory, as well as the loss of employees and customers. In King County,
which accounts for approximately 55% of Washington's gross domestic
product, these disruptions could be particularly severe. Although the
county’s economy is diverse and has proven resilient to various types of
disruptions, it is heavily dependent on global interconnectedness. A total loss
of critical lifeline infrastructure—such as port facilities, communication hubs,
and major highway corridors—could be devastating, particularly if these links
are not swiftly restored.
While some major companies in western Washington, like Amazon and
Microsoft, may experience less disruption due to the global reach of their
operations and the redundancy in their systems, others, like Boeing, would
face significant setbacks. The loss of essential transportation routes, such as
rail and highways crucial for material shipment, would severely impact their
production. Additionally, a large earthquake could halt or reverse King
County’s population growth, as displaced residents might lose their jobs,
struggle with uninsured housing recovery costs, and move to safer areas in
the aftermath of the disaster.
Public
Confidence in
Governance
Disasters of the magnitude we can expect from a damaging earthquake have
the potential to shake public confidence in government’s ability to maintain
law and order, provide essential services, repair or replace needed
infrastructure for employment, process building permits and inspections,
clear debris, and other needs. Restoration efforts may take longer than the
public is willing to accept. Amendments to zoning and building standards
may not be embraced by those seeking to rebuild. If rapid restoration is not
possible, the area may lose employers and the population may relocate to
9 Sengul et al., “Analysis of Hazardous Materials Releases Due to Natural Hazards in the United States” (2012)
10 Stacy Young, Lina Balluz, and Josephine Malilay, “Natural and Technologic Hazardous Material Releases During
and After Natural Disasters: A Review” Public Health Resources (2004)
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other areas of the country in search of employment, as well as housing,
schools, and services.
Earthquake hazards specifically have been the subject of significant reporting
in recent years. Articles in the Seattle Times, the New Yorker, and on local
television have argued that the Pacific Northwest is unprepared for the level
of destruction expected following a Cascadia Subduction Zone 9.0 event.11
These articles have led to both stepped-up state and local action on
earthquake preparedness and to more public awareness.
9.7 Vulnerability Assessment
Vulnerable
Populations
Vulnerable populations are more likely to suffer losses during an
earthquake and are likely to take longer to recover after. Factors
influencing likelihood of damage include living in higher hazard areas,
living in older buildings, being less likely to have emergency supplies,
and having a higher rate of persons with disabilities. Slower recovery is
exacerbated by poorer populations likelihood of not having access to
institutions leading recovery, not having insurance, not having a stable
job, wealth, or savings, being more likely to be renters who are
ineligible for many federal recovery programs, and having a lower-level
of education on average, making it more difficult to find a new job and
to navigate the complex post-disaster system.
In many catastrophic disasters, most notably Hurricane Katrina, poor
communities may never recover.
Populations without the means to care for themselves over multiple
weeks, especially those with Access and Functional Needs
The response and initial recovery following a catastrophic earthquake
will take weeks. Homebound populations, those requiring medications,
the chronically ill, or others with access and functional needs may need
to sustain themselves for an estimated two weeks in some places.
Populations without insurance, especially those without renters’
insurance or homeowner insurance earthquake riders.
According to the Office of the Insurance Commissioner, which
conducted a major earthquake insurance study in 2017, residential
earthquake coverage in western Washington is 13.8%. Commercial
coverage rates are much higher than residential, with 43.2% of
11 Kathryn Schulz, “The Really Big One,” The New Yorker (July 20, 2015)
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insurance policies having some earthquake coverage. A key finding is
that, for both residential and commercial customers, insured properties
have a much higher assessed value than uninsured properties,
indicating that it is higher-income people that are, in general,
purchasing earthquake insurance coverage.
Earthquake insurance coverage rates are a good measure of resilience
because insurance is the primary source of disaster recovery funding
after an earthquake. Low levels of insurance coverage have stymied
recovery efforts in major disasters, such as hurricanes, where hazard
coverage is not automatically included in homeowner’s policies.
Populations communicating in languages other than English
Information from responders, notifications, and other information will
likely be communicated predominately in English. Special care will need
to be taken to ensure that non-English speakers have access to relief
supplies from established points of distribution.
Property Unreinforced masonry buildings, especially those built during pre or
low-code eras (pre-1973)
Unreinforced masonry buildings (URMs) that characterize areas like
Pioneer Square in Seattle are extremely susceptible to even minor
earthquakes. Unreinforced masonry buildings are likely to collapse or
partially collapse during a major earthquake and be a leading source of
fatalities due to falling debris.
Structures, including roads and bridges, structures, built on vulnerable
soils.
Structures on less stable soils are more likely to buckle or collapse. High
risk areas cover the region and are especially common in historic river
valleys where sediment has been deposited very recently.
Public facilities built to “life safety” codes that will be unusable after a
major earthquake
Public facilities, such as city halls, schools, etc. are not required to be
built to “immediate occupancy” standards. A major earthquake would
render many of these facilities inoperable, leading to difficulties in
organizing the recovery in affected jurisdictions.
Structures and populations on or near steep slopes
Steep slopes greater than 40% grade are likely to fail in an earthquake,
unless properly stabilized by geological engineering techniques. This
likelihood increases when the ground is saturated. Buildings on or
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below these slopes will be damaged or destroyed if these slopes were
to fail.
Environment Hazmat
Hazardous materials, or Hazmat, sites dot the region and FEMA has
recognized hazardous materials as a community lifeline due to
experiences dealing with recovery after recent disasters. Hazmat
releases are likely to occur at industrial facilities, on pipelines, and
elsewhere around the region. The chemical cocktail of potential
contaminants is likely to threaten the public, responders, and the
environment, and to delay recovery in parts of the region for years.
Operations Dams, especially older, less regulated dams
Major dams in the region that provide electricity, such as the Tolt Dam
and Howard Hanson Dam, play a vital role in future recovery. It is
unlikely a total failure would occur at these dams because they are
highly regulated. However, damage to these dams from an earthquake
could require a shutdown to perform repairs before they can resume
electricity generation.
There are also many lower-priority dams that meet high-hazard
throughout King County that are not recognized by their jurisdiction. A
failure of some of these dams has the potential to cause numerous
fatalities and the inundation of property and infrastructure.
Levees, dikes, and other flood control structures
Flood control structures are usually earthen and built on highly
unstable soils. An earthquake during the winter months when these
systems are running close to capacity could cause major failures and
widespread flooding.
Rail systems
Rail systems require tracks to be perfectly aligned and will fail during an
earthquake as the ground shifts and buckles. Landslides may deposit
material on the tracks. Trains traveling at high speeds during an
earthquake have a significantly greater chance of de-railing, potentially
injuring passengers, or spilling cargo, which may cause additional
hazardous material incidents.
Port facilities
Ports are almost always built on fill and other extremely unstable soils.
Major earthquakes will damage and potentially destroy port facilities.
Any seiche or tsunami will also have a greater impact on port facilities
than inland facilities.
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Water and sewer transmission lines
Water and sewer transmission lines, especially those built of cast iron,
concrete, or wood, are vulnerable to fracturing or breaking in the event
of an earthquake. Many of these lines are being replaced with ductile
iron throughout the region. Nevertheless, most special purpose
districts undertaking this work are decades from completing it. Water
systems will likely fail throughout the region and will be difficult to
restore due to limitations in transportation capacity. Even systems able
to complete conversion to ductile iron will experience failures,
especially in areas of unstable soils.
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Risk Assessment
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High Overall Risk
Chapter 10Flood
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Chapter 10: Flood
10.1 Hazard Description
Flooding is King County’s
most persistent and
recurrent natural hazard,
impacting tens of thousands
of families and property
owners across the region.
These events have far-
reaching impacts on life
safety, economic stability,
and the overall functioning
of the county system.
Flooding occurs when
normally dry areas are
inundated by overflowing
rivers, coastal surges, or
other accumulations of surface water. King County’s diverse geography—from the Cascade
Mountains to Puget Sound—leads to various forms of flooding, each with distinct causes. The most
common types of flooding observed in King County include:
• Riverine flooding: a river or stream overflows its banks and spills into nearby low-lying areas
due to excess water flow.
• Tributary flooding: a smaller stream or river overflows its banks and spills into nearby low-
lying areas due to excess water flow. For example, Tokul Creek flows into the Snoqualmie
River and is therefore a tributary of the Snoqualmie. King County has an extensive network
of smaller tributary streams.1
• Coastal flooding: when high tides and storm surges inundate or cause damaging erosion to
normally dry areas along the marine shoreline.2 King County has 103 miles of saltwater
shoreline, including incorporated areas along the east side of Puget Sound and the
unincorporated areas of Vashon and Maury Islands. Additionally, compound flooding—
resulting from saturated soils and significant freshwater inflow—exacerbates these
conditions.
1 King County. 2024. King County Flood Management Plan. kingcounty.gov/en/dept/dnrp/nature-
recreation/environment-ecology-conservation/flood-services/flood-management-plan/about-plan source
2 FEMA. 2023. FEMA National Risk Index website, Coastal Flooding webpage. hazards.fema.gov/nri/coastal-
flooding.
Flooding along the Snoqualmie River in 2015
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• Urban flooding: Caused by stormwater runoff or overwhelmed urban storm sewer systems,
leading to localized flooding in developed areas.
Several conditions can cause flooding from too much rainfall in a river’s watershed to sustained
offshore wind driving a high tide inland, but flooding can also be caused by events such as
liquefaction of levees during an earthquake that release water the levees hold back. Causes of
flooding are listed in Table 10-1.
Table 10-1 King County Flood Causation Types
Causation Type Description
Heavy Rain Intense rainfall, typically seen in the fall and winter months, can
overwhelm rivers’ ability to carry flows in their banks and cause
inundation of the adjacent floodplains. These factors not only drive
riverine flooding, but also urban flooding issues that can overwhelm local
stormwater infrastructure.
Atmospheric Rivers Atmospheric rivers are narrow bands of concentrated moisture in the
atmosphere that transport water from the tropics to be dropped as heavy
precipitation.
Storm Surge and
King Tides
Strong winter storms combined with king tides can lead to significant
coastal flooding, damaging properties and infrastructure, as seen during
the 1982 king tide event in King County.
Sea level rise Rising sea levels in Puget Sound elevates the base sea level, increasing the
likelihood of inundation along King County coastlines during storm surge
events.
Channel Migration Rivers that significantly shift during high flow events or gradually through
erosion of streambanks. This is a prevalent feature in northwest river
systems including Green, Cedar, Tolt, Raging, and Snoqualmie River.3
Dam/Levee Failure Dam and levee failure is the uncontrolled release of impounded water
resulting in downstream flooding, affecting both life and property.
Overtopping Overtopping, often a precursor of dam failure, is water spilling over the
top of a dam. This can be the due heavy rain causing excess water or
inadequate spillway design. For instance, water can seep through levees
and cause weaknesses that lead to collapse.
3 Seattle and King Hazard Ready, n.d. Channel Migration Zones.
hazardready.org/seattle/static/img/data/flood_cmz.pdf
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Landslide Landslides can block rivers or add material, leading to mudflows and rapid
property damage, notably on the Cedar River.
Earthquake Earthen levee systems are prone to liquefaction in an earthquake. If water
is being held back, this could lead to swift flooding.
Volcanic Eruption In the event that Mt. Rainier erupts, lahars can fill river valleys and
drastically change the course of rivers, streams, and shorelines.
Tsunami Tsunamis, caused by underwater earthquakes or collapses, can generate
significant wave action and damage coastal properties in King County.
Humanmade
watershed changes
Development of impervious surfaces speeds up floodwater flow to
streams, increasing flood severity.
Climate Change Climate change is projected to intensify flooding risks through increased
rainfall, sea level rise, and other altered weather patterns affecting King
County.
The King County Flood Control District was established in 2007 to regionally manage flood hazards
and reduce risk, in partnership with the Department of Natural Resources and Parks’ River and
Floodplain Management Section. The newly updated 2024 King County Flood Management Plan
drives much of the work that both the District and King County do to reduce flood risk and manage
flood-related hazards.
10.2 Location
King County is broken up into four watersheds: Snohomish, Cedar-Sammamish, Duwamish-Green,
and Puyallup-White (shown in Figure 10-1). Within these watersheds are eight sub-basins, shown in
Figure 10-2, that host six major river systems flow through King County (South Fork Skykomish,
Snoqualmie, Sammamish, Cedar, Green and White Rivers) along with their significant tributaries
(Tolt, Raging, Miller and Greenwater rivers). Additionally, the county has other smaller tributaries
and streams, including but not limited to those with existing flood risk reduction facilities (Tokul,
Kimball, Coal (Snoqualmie), Issaquah, Fifteen Mile, and Holder creeks).4
4King County Flood Control, “About Us,” accessed October 23, 2024, kingcountyfloodcontrol.org/about-us/
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Figure 10-1 King County Watersheds
Figure 10-2 King County Sub-Basins
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A variety of factors affect how flooding occurs and its severity. One main factor for riverine flooding
is the “hydrology,” which includes how much precipitation falls, how fast it falls, how fast it reaches
the stream, and the amount of water already in the stream. The second main factor for riverine
flooding is the “hydraulics” of the watershed, which includes characteristics like the topography,
stream channel dynamics, and the overall slope of areas of the watershed.
The combination of hydrology and hydraulics plays a critical role in shaping the behavior of rivers in
King County and directly contributes to the significant flood risks the region faces. Several rivers in
King County face significant flood risks, each presenting unique challenges. The most flood-prone
areas include:
• Snoqualmie River Valley, located within the Snohomish Watershed and Snoqualmie River
sub-basin, is the most flood-prone area of King County. Flooding typically results in
inundation by deep, slow-moving floodwaters, with some areas of deep and fast flows,
especially along certain tributaries. The Upper Snoqualmie River and some of the major
tributaries are characterized by steep gradient headwater systems and some lower gradient
floodplains near the incorporated communities of North Bend and Snoqualmie. The cities of
Carnation and Duvall and the unincorporated community of Fall City all lie within the broad
Lower Snoqualmie Valley that features wide floodplains along the low gradient channel.5
• South Fork Skykomish River generates deep, fast-moving flood flows capable of severe
bank erosion. This sub-basin drains 234 square miles of mountainous terrain within King
County and includes major tributaries such as the Foss, Tye, Miller, and Beckler Rivers. The
cities of Skykomish, Baring, and Gold Bar as well as many unincorporated area
neighborhoods are located near or on the banks of the rivers and frequently experience
impacts from flooding. The basin features steep slopes in the upper portion, thus significant
runoff can result in fast major flooding. The rivers in the basin are also very prone to
channel migration.
• Cedar River that connects to the south end of Lake Washington experiences fast, erosive
flows. The basin has been heavily altered from its natural condition, with major projects
constructed including Masonry Dam and the Landsburg Diversion, both to serve as water
supply infrastructure. Along the Cedar River are many unincorporated community
neighborhoods as well as cities like Maple Valley and Renton. Naturally-occurring large
wood is a prevalent hazard in the basin.
• Issaquah Creek, located in Sammamish River Basin, can experience “flashy” flows that can
rise quickly during storms with minimal infiltration.
• Green River which becomes the Duwamish River at the Black River confluence in the city of
Tukwila, can experience fast flowing flooding in some areas and slow-moving overbank
inundation in others. The Howard Hanson Dam in the upper reaches of the Green River,
5 King County. 2024. 2024 King County Flood Management Plan. Seattle: King County Department of Natural
Resources and Parks, Water and Land Resources Division.
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built and managed by the U.S. Army Corps of Engineers, provides flood control to the highly
developed downstream areas of the river corridor.
• Duwamish River is characterized primarily by slow-moving inundation primarily driven by
precipitation as well as tidal influence from the Puget Sound.
• White River is lightly populated flowing through the Muckleshoot Indian Tribe reservation
before reaching more developed areas in the most downstream part of the river. These
developed areas face significant flood risk due to being in a depositional reach of the river.
The river carries the most significant sediment load of any river in King County, and reduced
channel capacity arising from ongoing sediment deposition is a primary flood risk in this
watershed. However, the Mud Mountain Dam has a significant effect on reducing flooding
in the basin. Additionally, water is diverted from the river to Lake Tapps.
Coastal flood hazard areas also pose potential risks to King County. There is approximately 100
miles of shoreline, about half of which is on Vashon Island in unincorporated King County and the
other half is the incorporated shoreline through the cities of Shoreline, Seattle, Burien, Des Moines,
and Federal Way. Storm surge and wave action are significant flood hazards facing development
along shorelines. Coastal erosion also is a prevalent hazard, including along the steep bluff areas
around the shoreline in King County. Many miles of shoreline are variably armored by bulkheads
and other structures. Coastal flooding will be exacerbated by sea level rise and other impacts of
climate change.
10.3 Magnitude
FEMA Special Flood Hazard Areas (SFHAs) in King County were first mapped in 1975 and last
updated in 2020. SFHAs encompass regions at risk for flooding, mudflow, or flood-related erosion.
These areas are classified based on their annual probability of occurrence, with larger flood events
generally associated with a lower likelihood of occurrence. These classifications are illustrated in
Figure 10-3.
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Figure 10-3 King County Special Flood Hazard Areas
King County’s SFHAs are broken up into the following flood zones:
• 100-Year Floodplain: areas with a 1% annual chance of flooding. FEMA floodplain
regulations and federal flood insurance are based on this flood event forms the basis for
community regulations for participating communities in the National Flood Insurance
Program. Flood zones A, AE, AH, AO, and VE are all Special Flood Hazard Areas (SFHAs) in
King County, Washington, which are areas that have a 1% chance of flooding in any given
year.
• 500-Year Floodplain: area with a 0.2% (or 1 in 500 chance) annual chance of flooding.
• Floodway: Channel of a river or other watercourse and the adjacent land areas that must be
reserved in order to discharge the base flood without cumulatively increasing the water
surface elevation more than a designated height.
Figure 10-3 shows the 100-year floodplain areas and floodways. Note that Lake Washington does
not have an identified floodplain because its water levels are controlled by the US Army Corps of
Engineers operated at Chittenden Locks in Seattle.
King County experiences a wide range of annual precipitation amounts depending on location.
Western areas including Seattle receive approximately 37 inches per year while areas along the
cascade foothills to the east can exceed 100 inches annually.
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10.4 Previous Occurrences
King County has faced 29 presidentially declared flooding disasters since 1956, resulting in millions
of dollars in property damage. Historical data indicates that minor flooding occurs every winter,
while significant flooding events happen every two to five years.
The most recent county-wide flood event occurred in between January to February 2020, when an
atmospheric river arrived in the region bringing heavy and sustained rain. The Tolt River reached
the highest flow in over 10 years and other rivers overflowed their banks causing widespread road
closures. Dams on some of King County’s major rivers captured large volumes of water that are
typically slowly released over several days to make room for the next storm. The next atmospheric
river arrived without enough time to allow for sufficient release of water from several of these
dams. The combination of prolonged rainy conditions, high river flows, saturated soils, and elevated
pools behind dams caused some areas in King County to experience the most severe flooding in
decades.
The most recent high impact coastal flooding event occurred in December 2022. King tides and
strong winds resulted in major coastal flooding with the Puget Sound water level peaking at 3.76
feet above the normal mean higher high water (MHHW) mark. Impacts were seen in numerous
locations along the marine shoreline but were especially significant in the South Park neighborhood
on the lower Duwamish River, which overtopped its banks. This lead to the evacuation of 15 to 18
homes and damage to several businesses.
The following table summarizes flood events throughout King County dating back to 1990. Data was
collected from the National Center for Environmental Information (NCEI) Storm Events Database.6
Table 10-2 NCEI Flood Related Events in King County, 1990 - 2023
Date Type of
Flood
Location Deaths/
Injuries
Property
Damage
Narrative
9/3/1996 Flood Seattle,
Bellevue
0 Unknown Urban flooding
3/1/1999 Heavy
Rain
County-
Wide
0 $5,500,000 The heavy rain, which in turn caused
flooding and mudslides, over the
winter season.
11/17/1999 Heavy
Rain
Issaquah 0 $85,000 Heavy rains led to a road being washed
out by Issaquah Creek.
6 National Oceanic and Atmospheric Administration, "Storm Events Database," accessed October 23, 2024,
www.ncdc.noaa.gov/stormevents/
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2/28/2001 Heavy
Rain
County-
Wide
0 $200,000 An earthquake triggered a mudslide
that damaged a home. The slide also
blocked the Cedar River, which then
backed up and flooded a road, forcing
its closure.
11/13/2001 Heavy
Rain
County-
Wide
- Unknown Urban flooding and mudslides
9/8/2003 Heavy
Rain
Kirkland 0 $5,000 Urban flooding
8/22/2004 Heavy
Rain
Bellevue 0 $50,000 Urban flooding
01/05/2006 Heavy
Rain
County-
Wide
0 $800,000 The Governor declared a state of
emergency after 10-day long
rainstorm, causing over 7 million in
damage, mainly to transportation
infrastructure throughout western
Washington. In King County, there
were 19 road closures from water over
the roadway. Many homes had flooded
basements or crawlspaces.
11/4/2006 Flood Snoqualmie
Falls
0 $11,100,000 Major flooding on the Tolt, Snohomish,
Skokomish, Skagit, and White rivers.
12/14/2006
Flash
Flood
Seattle 1 $750,000 The strongest reported rain and
windstorm struck producing areas of
urban and small stream flooding and
overwhelming drainage systems. In the
Madison Valley area of Seattle, heavy
rainfall produced excessive street
runoff, flooding 25 basements and
drowning one woman trapped in her
basement by rapidly rising water.
12/3/2007
Heavy
Rain
Bothell $12,000,000 Flooding occurred on the Snohomish,
Skykomish, Snoqualmie, and Issaquah
Creek. Impact was felt in Snohomish,
King, Lewis, Thurston, Mason, and
Kitsap counties.
11/12/2008 Flood Snoqualmie 0 $100,000 Major flooding caused by heavy rain on
the Snoqualmie River.
1/7/2009 Flood Snoqualmie,
Carnation,
0 $14,000,000 The cities of Snoqualmie, Carnation,
Duvall and Fall City flooded, some
residents had to be rescued, many
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Duvall, Fall
City, Pacific
homes were flooded. The Issaquah
Creek flooded some residences and
businesses. It also eroded part of the
riverbank, which caused a guest house
to fall into the creek. About 40 King
County roads were closed. In Pacific,
about 1000 people evacuated their
homes due to flooding from releases
from the Mud Mountain dam, 100 of
those homes were damaged, some
with 3 feet of water in them.
12/12/2010 Flood Covington,
North Bend,
Vashon
Island
0 $3,000,000 There was major flooding along the
Snoqualmie River. Westside Hwy on
Vashon Island was closed due to a
portion of the road sinking. Some
basements flooded as China Creek in
Newcastle, overflowed. Several roads
around North Bend and Carnation were
closed due to flooding.
1/16/2011 Flood Snoqualmie
Falls, Fall
City,
Carnation
1 $20,000 The Snoqualmie Falls golf course in Fall
City and parts of Highway 202 were
flooded after the Snoqualmie river near
Carnation reached major flood stage. A
66 year old state DOT worker was killed
when a tree fell on Highway 203 south
of Carnation, hitting him and his truck.
Several mudslides blocked roads.
9/5/2013 Heavy
Rain
Burien 0 $10,000 Rain caused flash floods and mudslides
in several locations and closed a 24-
mile section of the North Cascades
Highway for several days. Also heavy
rain caused a sinkhole which damaged
a road in Burien.
11/17/2015 Heavy
Rain
Skykomish 0 $200,000 Heavy rain swelled a creek that
undermined the foundation of a US
Hwy 2 bridge outside of Skykomish,
closing a 15-mile stretch of the
highway for about a week.
2/9/2017 Heavy
Rain
Seattle 0 $33,000,000 Heavy rainfall in the Puget Sound area
lead to high storm runoff. damaged the
West Point sewage treatment plant in
Seattle. King county dumped an
estimated 235 million gallons of
untreated wastewater - including 30
million gallons of raw sewage - into
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Puget Sound because of damage to the
plant.
1/12/2021
Flood Duvall 0 $474,000 The Snoqualmie and White Rivers
exceeded flood stage. Urban and small
stream flooding occurred as well.
Heavy rain caused some landslides.
1/7/2022
Heavy
Rain
Seattle,
Renton
1 $1,520,000 Two atmospheric river events from Jan
5 - 7 and Jan 11- 13 that resulted in
heavy rain, minor to major flooding,
and landslides. 2 flood fatalities
occurred, and possibly a third from a
landslide.
12/27/2022
Coastal
Flood
Seattle 0 Unknown Duwamish river and tidal flooding
leading to evacuation of 15-18 homes
and damage to several businesses. It
was reported that 18 homes did
sustain damage.
12/05/2023
Heavy
Rain
Seattle 0 Unknown An atmospheric river event brought
flooding, record breaking rainfall, and
record high temperatures to Western
Washington.
10.5 Probability of Future Occurrences
King County is inherently
vulnerable to flooding due to its
distinctive geography and heavy
precipitation patterns. As a result,
flooding is an annual reality for the
region. King County sees at least
minor flooding ever year in the fall
and winter and big events are
often driven by atmospheric river
narrow bands of concentrated
moisture in the atmosphere
transport water from the tropics to
be dropped as heavy precipitation
in western Washington. On
average, major floods occur every
two to five years, and projections indicate that both the frequency and severity of these events will
likely increase due to the broader impacts of climate change.
House destroyed due to channel migration along the Raging River.
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According to King County’s Flood Frequency Analysis conducted in 2016, certain areas exhibit
particularly high probabilities of severe flooding. For instance, the upper Snoqualmie River Valley
has a 22% annual probability of severe flooding, with an expected return period of approximately
4.5 years. The Tolt River faces an even higher annual probability of 38%, translating to a return
period of about 2.8 years.7
10.6 Climate Change Considerations
According to the 2023 Fifth National Climate Assessment, the northwest region in the United States
is projected to see an increase in frequency and intensity of extreme precipitation events.8 While
results will vary by location and flood interval, river flooding is expected to increase due to the
combined effects of wetter winters, more intense heavy rain events, and more winter precipitation
falling as rain rather than snow in mountain watersheds.
Sea level rise will also increase the frequency and extent of coastal flooding. Sea level in King
County is projected to rise approximately 1 to 2 feet by mid-century and 2 to 5 feet by 2100 under a
high greenhouse gas scenario. This expected increase may also exacerbate compound flooding in
coastal drainages, which could impact public health, life, and safety.
10.7 Impact Assessment
Flooding, no matter the source, causes widespread and long-lasting damage. The force of moving
floodwaters can tear homes from their foundations, sweep cars off the road, and destroy public
infrastructure. Houses and businesses damaged by flooding can take many months to repair and are
often unsuitable to live in during the repairs. Certain types of flooding can leave buildings inundated
for several days, which can further worsen property damage. Flood-damaged buildings can pose
health risks including mold, contaminated food and drinking water, and mental health stresses from
the traumatic experience.
Public Flooding can impact anyone who lives, works, or travels in or near floodplains.
There are over 50,000 people residing in designated flood hazard zones. For
those situated within the 100-year floodplain, there is a 26% likelihood of
experiencing flooding over a 30-year period, the length of a typical mortgage.
Not only can it impact people’s safety, but flooding can also have significant
financial costs. It’s estimated that one foot of water in an average size home can
7 King County. 2016. Flood Frequency Analysis of King County Rivers with an Emphasis on the January 2009 Floods.
Prepared by Curtis DeGasperi, Water and Land Resources Division. Seattle, Washington.
8 U.S. Global Change Research Program. "2023 National Climate Assessment." Accessed October 23, 2024.
nca2023.globalchange.gov/.
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cause over $50,000 in damage. Without flood insurance, this level of damage can
overwhelm a family’s finances.
Flooding also affects those who work in flood-prone areas or commute through
them. In a flood event, most deaths occur from people driving through
floodwaters and being swept away in their cars. Many farmworkers are
employed in the Snoqualmie, Sammamish, and Green River valleys that are
susceptible to river or tributary flooding.
Responders Police, firefighters, and paramedics play key roles in the response to flooding.
Police officers often help shut roads down to prevent people from driving
through floodwaters; firefighters often rescue people trapped by flooding; and
paramedics transport people hurt by flooding, often from hypothermia or other
causes. If any of these first responders’ buildings are in the 0.2% annual chance
floodplain, their ability to respond is seriously threatened.
Additionally, neighborhoods with roads that are inaccessible during flooding
pose challenges to first responders. They may not be able to drive to homes and
may require helicopters or boats to access.
Continuity of
Operations
There are few government facilities located within flood prone areas in King
County. Thus, flooding does not pose a substantial risk to the continuity of
government operations. Those within flood areas include city buildings located
in Snoqualmie, North Bend, and Carnation.
Although the facilities themselves are relatively safe, government employees
may still need to traverse flood-prone regions to reach their workplaces. This
may necessitate the development of alternative work sites to ensure continuity
of operations during flood events.
Property,
Facilities, and
Infrastructure
Properties
Flooding often results in many millions of dollars in property damage. For
families, damage to homes may mean difficult financial decisions, displacement
for weeks, and lost belongings. For business owners, flood damage may mean
lost economic output from shutdowns, destroyed inventory, and inability to pay
employees.
The National Flood Insurance Program is the primary way building owners
financially protect their property in flood prone areas. As of June 2019, flood
insurance policies cover over $2 billion worth of property throughout King
County. Many larger commercial or industrial facilities are insured through
private contracts, the value of which is not available to government agencies.
Below is the cost estimate for Repetitive Loss (RL) properties across the county,
along with a breakdown of the number of structures and their types by
jurisdiction. Jurisdictions not listed do not have any RL properties. These
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properties are defined as insurable buildings for which the National Flood
Insurance Program (NFIP) has paid two or more claims exceeding $1,000 each
within any 10-year rolling period.
Table 10-3 County-wide Damages of Repetitive Loss Properties
Table 10-4 NIFP Repetitive Loss Properties by Jurisdiction
Jurisdiction 2-4
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Auburn 1 1
Bellevue 1 1
Burien 1 1
Carnation 1 17 18
Duvall 1 4 5
Fall City 1 1 2
Issaquah 1 1 9 11
Kent 1 1 2
Maple Valley 3 3
Normandy Park 1 1
North Bend 18 18
Sammamish 1 1
Seattle 1 1 2
Skykomish 3 3
Snoqualmie 4 1 1 2 127 135
Vashon 1 1
Grand Total 6 1 4 5 189 205
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Critical Facilities
There are 498 critical facilities county-wide that could be exposed to the 1%
annual chance riverine flood event, and 26 critical facilities for a coastal flood
event. Potential damages could exceed $114 million for a 1% annual chance
riverine flood event and approach $500,000 for a 1% annual chance coastal flood
event.9
In unincorporated King County, one medical facility is located in the 1% annual
chance floodplain, and an additional four medical facilities are in the 0.2% annual
chance floodplain. No hospitals are in the 0.2% annual chance floodplain. While
these five facilities are at risk, the risk from flooding to the overall healthcare
and medical system is low.
There is concern that residents in sole-access neighborhoods, such as the lower
Snoqualmie Valley, could become isolated in a flood event and won’t be able
evacuate for medical reasons.
Infrastructure
Transportation: Flooding regularly causes impacts to our roadways and bridges,
which can cause very extensive and expensive repairs. Roads through the lower
Snoqualmie Valley are particularly susceptible to flooding and close regularly
during high water events. During these events, Valley residents can become
isolated making evacuation and access for emergency responders challenging.
Repeated roadway inundation also accelerates infrastructure deterioration and
increases lifecycle costs.
Energy systems: Most overhead powerlines are not susceptible to impacts from
flooding unless the power poles are not resistant to flooding. Buried cables
typically aren’t affected by flooding very often.
Water/Wastewater: Flooding, particularly from king tides and coastal storm
systems can damage wastewater infrastructure such as the County’s West Point
Treatment Plant. Some city wastewater treatment plants are also located in
flood prone riverine areas. Where these linear systems cross rivers, flooding can
pose issues. The Tolt Pipeline, a water supply line for Seattle, was at risk from the
Snoqualmie River migrating further toward its alignment. In 2019, a project was
completed to provide some protection from that risk.
Communications: Most communications infrastructure is not vulnerable to
flooding, with the primary exception being a regional fiber optic line that runs
under the Cedar River Trail and along State Route 169. In some locations, the
river abuts the trail, and erosion of the trail prism presents risk to this
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infrastructure. King County regularly monitors at-risk locations, and the King
County FCD has implemented several projects to ensure the continued
protection of this significant infrastructure.
Environment Flooding is a natural process and supports unique ecosystems and habitats.
Many riparian and aquatic ecosystems depend upon some amount of regular
flooding or high-water events. Various salmonid species use high water events to
seek refuge as juveniles or access more favorable habitats, which makes flooding
an important part of recovery for the endangered salmon species in Puget
Sound.
Natural floodplain functions typically result in slower-moving floodwaters with
less intense flood height peaks. When upland forest areas are logged or burned,
rain and snowmelt reach streams faster, which can cause flooding to be more
intense and push water through the floodplain more quickly.
King County often incorporates natural functions into the design of projects,
which helps reduce flood risk as well as protect and restore ecosystems.
Reconnecting rivers and coastlines to their historic floodplains through levee
setbacks, creating side channels, and removing obstructions help restore natural
functions and bring flood risk reduction benefits as well. The large Countyline
project near Auburn restored 121 acres of floodplain along the White River and
reduce flood risk for over 200 residential properties.
Economy Flooding can significantly impact industries that rely on floodplain locations such
as agriculture, aerospace, manufacturing, and distribution. In the lower
Snoqualmie valley, there are nearly 200 farms that produce a wide range of
products from dairy to herbs and row crop vegetables. The Sammamish River
valley supports a number of wineries and other small farms. And the Green River
valley hosts many large fields of row crops as well as a large County-owned farm
leased out by a diverse group of farmers. Flooding can negatively impact these
operations, particularly if it occurs before harvest or late into the spring planting
season. Farmers cannot sell food products from flood-damaged fields. Flooding,
however, also provides nutrients to the soil that supports productive agriculture.
While some agricultural sectors are dependent on natural floodplain functions,
other economic sectors have located in the floodplain over decades for other
reasons. Large warehouses in the Green River valley, many in the floodplain,
make the region one of the largest logistics hubs in the nation. But, the square
footage of warehouse and aerospace facilities means that billions of dollars are
at risk of flooding every year as well as thousands of jobs.
9 King County. 2024. King County Flood Management Plan. kingcounty.gov/en/dept/dnrp/nature-
recreation/environment-ecology-conservation/flood-services/flood-management-plan/about-plan source
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In 2007, an economic study was conducted to understanding the economic
impact of flooding. The study found that 6% of the county’s jobs are located in
floodplains and nearly 7% of the county’s wages and salaries are generated in
the floodplain ($3.7 billion). Approximately 20% of the county’s manufacturing
employment and 30% of the county’s aerospace employment are found in
floodplains. While new data have not been generated since that time, the study
found that a major flood that would shut down economic activity in floodplains
would result in at least $46 million per day in lost economic output. The figure is
likely much higher today.
Public
Confidence in
Governance
Flooding occurs frequently enough in King County that residents often turn to
the King County River & Floodplain Management Section for help and
information during flooding events. Confidence is high in the government’s
ability to respond to flooding events. The multiple iterations of the Flood
Management Plan have featured robust stakeholder involvement processes,
which has inspired confidence in King County’s ability to manage floodplains with
higher regulatory standards and other programs to keep people and property
safe from flooding.
10.8 Vulnerability Assessment
Vulnerable Population Vulnerable populations that are particularly susceptible to the long-
term impacts of flooding include low-income individuals, renters, and
people with limited English proficiency, and communities of color.
Low-Income
Low-income individuals and families are among the most affected by
flooding. The financial burden of flood damage can be overwhelming,
making recovery difficult. Without flood insurance, families may have
to deplete their savings to cover repair costs. Even with insurance,
flood-damaged homes can remain uninhabitable for months,
prolonging the disruption to their lives.
Renters
Renters are far less likely to have a flood insurance policy and may not
even be aware of their flood risk. Generally, renters are not required to
obtain such coverage, and it can often be unaffordable, especially in
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flood prone areas. Renters may also have less wealth or savings to
draw from to pay for uninsured losses.
Limited English
Those who do not speak English do not have easy access to
government resources. Most flood warning systems are in English and
much of the flood insurance, floodplain regulations, and any mitigation
programs are made up of materials in English. Flooding is a complicated
hazard to understand and accessing flood warning, flood insurance,
and other information often requires command of English,
understanding of government bureaucracy, and access to financial
resources.
BIPOC
In King County, approximately 41% of the 57,737 residents living in
mapped flood hazard areas are Black, Indigenous, and other People of
Color (BIPOC). The Green/Duwamish watershed is the only major river
watershed in King County in which more BIPOC residents (59%) than
white residents (41%) reside in mapped flood hazard areas. Other
watersheds exhibiting a high percentage of BIPOC community
members residing in flood hazard areas include the Sammamish (43%),
Cedar (36%), and White River watersheds (38%).10
Property The exposure analysis determined that approximately $11.9 billion of
structural value for the general building stock is at risk to the 1% annual
chance riverine flood event, and approximately $15.3 billion to the
0.2% annual chance flood event.
Flooding and channel migration pose a risk to commercial and
residential areas in the cities of Snoqualmie and North Bend and to
residential areas in unincorporated King County. The lower reaches of
the Middle and North Forks are subject to flooding and channel
migration where rural residential development and agricultural land
use are present.
Environment Along the Snoqualmie Valley River, the three forks (North Fork, South
Fork, Middle Fork) are vulnerable to sediment accumulation that
reduces channel capacity. This is the result of intense flooding causing
bank erosion and landslides. This can degrade salmonid habitats and
their ability to migrate.
10 King County. 2024. 2024 King County Flood Management Plan. Seattle: King County Department of Natural
Resources and Parks, Water and Land Resources Division.
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Operations A handful of government operations are located within the flood areas
of King County. For first responders we have, 3 out of 64 police stations
in the 0.2% annual chance floodplain (located in Skykomish, Redmond,
and Issaquah), 6 out of 161 fire stations (located in Skykomish, Seattle,
North Bend, Renton, Issaquah, and near Enumclaw), and 3 city
buildings (located in Snoqualmie, North Bend, and Carnation).
For critical facilities, there are 498 county-wide that could be exposed
to the 1% annual chance riverine flood event, and 26 for a coastal flood
event.
AGENDA ITEM #1. b)
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Chapter 11Hazardous Materials
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Chapter 11: Hazardous Materials
11-2
Chapter 11: Hazardous Materials
11.1 Hazard Description
Hazardous materials (hazmat) releases are among the most common types of incidents. These
“releases” can occur through spills, leaks, toxic vapor emissions, or any other process that allows a
material to escape its container, enter the environment, and create a potential hazard.1 Hazmat is
classified into nine different categories based on its characteristics:
Figure 11-1 Classifications of Hazardous Materials2
Common hazardous materials include substances like anhydrous ammonia (used as a refrigerant),
gasoline and diesel (used as fuels), paints and dyes (used in residential and commercial
applications), and various corrosives (used in industries such as aircraft manufacturing). Pipelines
and rail lines transport crude oil to refineries and finished fuels to homes (like natural gas) and retail
fueling stations.
Hazardous material releases can occur through a variety of causes, ranging from accidents and
mismanagement to natural disasters and malicious attacks.
1 US DOT Pipeline and Hazardous Materials Safety Administration, “List of Hazardous Substances and Reportable
Quantities” 49 CFR 172.101 Appendix A (n.d.)
2 FMCSA, “Nine Classes of Hazardous Materials (Yellow Visor Card)” Regulations (April 2013)
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• Accidents and Mismanagement: Hazmat releases can occur from leaking containers or
pipelines due to corrosion or punctures. Accidental overflows during the transfer of
hazardous materials, loading dock and warehouse accidents, careless handling, and even
illegal activities such as drug labs can also lead to dangerous spills. For example, when
someone dumps paint down a sewer, they are releasing hazardous material into the
environment. Similarly, illegal drug labs not only use hazardous substances but also create
hazardous waste, while car accidents that result in fuel, oil, or antifreeze spills also create
hazardous cleanup situations. Another growing concern is the dumping of electronic waste,
which releases toxic chemicals like lead, zinc, nickel, flame retardants, barium, and
chromium into the environment.
• Natural Hazards: Hazmat releases can also result from natural events like earthquakes,
volcanic activity, severe flooding, and wildfires, which can cause containers or pipelines to
rupture or overflow.
• Malicious Attacks: The risk of a CBRNE event (chemical, biological, radiological, or nerve
agent attack) is low, but its potential impacts would be severe. Despite the minimal daily
risk, it remains a top priority for counterterrorism planners due to the catastrophic
consequences. In Washington, over 20 billion gallons of oil and hazardous chemicals are
transported annually by various means.
11.2 Location
Hazardous materials can
be present in a variety of
locations, ranging from
residential homes and
workplaces to medical
facilities and industrial
sites. These materials can
include cleaning
products, engine fuels,
chemicals, and
everything in between.
Certain areas are more
prone to hosting or
interacting with
hazardous substances,
such as distribution
centers, ports, industrial
zones, Tier II facilities, and transportation networks (including highways, rail lines, and pipelines).
Additionally, there are identified contaminations sites such as Superfund and brownfield sites that
face both short- and long-term exposure to hazardous materials. Below is a detailed overview of
the most concerning areas.
Duwamish River clean up
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Figure 11-2 Tier II Facilities 3
There are 3,164 facilities that submitted Tier II
reports in 2023. In the City of Seattle alone
there are thousands of facilities with hazardous
materials regulated under the fire code. Other
areas with high concentrations of hazardous
materials usage include Auburn, Redmond and
the Kent Valley. Business types that commonly
use hazardous materials include: hospitals,
schools and universities, metal plating and
finishing, the aircraft industry, public utilities,
cold storage companies, the fuel industries, the
communication industry, chemical distributors,
research, and high technology firms. Each of
these facilities is required to maintain plans for
warning, notification, evacuation and site security under various regulations. Primary hazardous
materials stored are motor oil, sulfuric acid, and lead acid batteries. A facility failure, including an
explosion or release of chemicals, could endanger or kill many people. In Waco, Texas in 2013, an
ammonium nitrate explosion occurred at a distribution facility, leveling a neighborhood and killing
15 people. A train derailment in 2013 in Lac Megantic in Quebec, Canada killed 60 people and
destroyed much of the town.
Figure 11-3 Superfund National Priorities List (NPL) Sites4
There are currently 10 active superfund sites
and 8 brownfield sites in King County.
Superfund is a US EPA program that cleans up
severely contaminated sites that have
significant risk to the environment and public
health. On the other hand, a brownfield site is a
property, the expansion, redevelopment, or
reuse of which may be complicated by the
presence or potential presence of a hazardous
substance, pollutant, or contaminant.5
3 WA Department of Ecology, 2023
4 US Environmental Protection Agency, “Superfund National Priorities List (NPL) Where You Live Map” Learn About
Superfund (September 2024): https://www.epa.gov/superfund/search-superfund-sites-where-you-live#advanced
5 US Environmental Protection Agency, “Brownfield Overview and Definition” (n.d.):
https://19january2017snapshot.epa.gov/brownfields/brownfield-overview-and-definition_.html
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Figure 11-4 Pipelines in King County 6
King County is home to several major pipelines,
including those operated by Phillips 66,
TransMontaigne, Williams Pipeline, Northwest
Pipeline, Olympic Pipeline Company, Puget Sound
Energy, and Swissport Fueling. These pipelines
transport essential fuels and chemicals across the
region, but mismanagement and poor
maintenance can lead to failures or shutdowns,
which may cause contamination in nearby
communities and significant economic impacts,
including fuel shortages and price increases.
One notable incident occurred in 2023 when a
valve failure on the Olympic Pipeline in the Skagit
Valley, just north of King County, caused a spill of
approximately 30,660 gallons of gasoline. This spill
impacted nearby creeks not far from Mount
Vernon.7 The Olympic Pipeline's history also includes a tragic explosion in 1999, which killed three
people and caused over $58 million in property damage. Other past incidents include a 2005 spill in
Renton (40 gallons) and one in Bothell (30 gallons), as well as a 2020 spill in Bothell of 11.7 gallons.
Figure 11-5 Transport restrictions for hazardous materials
King County hosts a variety of unique
transportation and geographic conditions,
including one of the largest deep-water seaports
on the west coast, an International Airport in
SeaTac that handles cargo from all over the
world, as well as fuel pipelines running south
from Whatcom County through King County and
down into Portland carrying jet fuels, diesel,
gasoline, etc. Additionally, local highways like
Interstate-5, Interstate-90, Interstate 405, US
Highway 2, State Route (SR) 18, SR 516, SR 167,
US Highway 99 and others transport hazardous
materials throughout the region. Restricted HM routes include I-90 through Mercer Island, I-5 in
6 US DOT, “National Pipeline Mapping System (NPMS)” (n.d.): https://pvnpms.phmsa.dot.gov/PublicViewer/
7 Lauren Girgis, “Olympic Pipeline leak released 25,000 gallons of gasoline” The Seattle Times (December 2023):
https://www.seattletimes.com/seattle-news/environment/olympic-pipeline-leak-released-25000-gallons-of-
gasoline/
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Seattle under the Convention Center, SR-99 Seattle Tunnel, and 188th S in Sea Tac. An oil spill in
2016 in Mosier, Oregon along the Columbia River very nearly caused the destruction of the entire
town and an ecological catastrophe in the river. The community was saved by luck of the weather
and because most of the oil that spilled flowed into a water treatment plant, where it was safely
contained.
11.3 Magnitude
Several systems are used to evaluate the either release of hazardous materials or areas that
formerly acted as hazmat storage. These factors are based on contamination levels, risk to human
health, environmental damage (for soil and water), and local impact. Although the likelihood of
large numbers of fatalities from a single materials release is low, the effects can be devastating to
impacted communities, the economy and the environment. A major oil spill in Puget Sound would
destroy the fishery, including $4.5 billion in commercial fishing, plus tourism, and sport fishing. The
Puget Sound is also a culturally sacred and environmentally critical resource that cannot be
replaced or valued in dollars. In this way, the hazardous materials incident hazard is one of the most
complex. It includes frequent spills and releases from day-to-day human activities, the threat of a
major release from a massive spill or accident, and the threat of an intentional release from an
attack. The impacts from hazardous materials are also complex, including slow-acting releases that
kill people and the environment over years and catastrophes that kill thousands.
Figure 11-6 Reported spills to waterways in King County, 2019 – 2023 8
8 WA Department of Ecology, Spill Map (December 2024):
https://gis.ecology.wa.gov/portal/apps/experiencebuilder/experience/?id=591270509d254f189fb63d4c2d0af340
&page=Page&views=Reported-Incidents
Spill Quantity No. Incidents
1 to 10 3056
11 to 100 812
101 to 1000 145
over 1000 32
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Between 2019 and 2023, Washington State Department of Ecology received 4,045 reports of oil
spills of one gallon or more reaching a water source, including both running into storm drains and
running directly into a waterway. This only includes reported spills and only includes oil spills. This
does not include the uncountable quantity of micro-spills that occur and are later washed into
waterways by rain. For example, the rough spot of pavement in a parking lot that is the result of
fluids dripping onto the pavement from parked vehicles is an oil spill.9 In Washington, the state
Department of Ecology is the lead agency for hazardous materials. Local response is led by fire
services.
11.4 Previous Occurrences
Though they occur every day, many spills are not reported or go undetected. Some industrial spills
from the 1970’s and 1980’s are still being cleaned up in the Kent Valley, Harbor Island, Duwamish
corridor, and Seattle/South Park as federal Superfund cleanup sites. There are currently 10 active
superfund cleanup sites in King County and eight brownfield sites.10 Currently active sites include:
Table 11-1 Superfund and Brownfield sites within King County
Site Name City Site Type Description
Superfund Sites
Harbor Island (lead) Seattle Recycling Batteries/scrap metals/secondary
smelting/precious metal recovery
groundwater contains benzene, ethyl
benzene, xylene, mercury, cadmium, lead
and zinc with poly chlorinated bi-phenols
(PCB) sediments.
Lockheed West
Seattle
Seattle Manufacturing,
Processing,
Maintenance
Trucks/ships/trains/aircraft and related
components heavy metal contaminants:
arsenic, chromium, copper, lead, silver,
and zinc with butyl tins and PCBs.
Lower Duwamish
Waterway
Seattle Other Contaminated sediment site with no
identifiable source. River sediments are
contaminated with mercury, arsenic,
PCBs, dioxins, furans, and phthalates.
Midway Landfill Kent Waste
Management
Co-disposal landfill (municipal and
industrial). Ground water contaminated
with heavy metals and volatile organics.
9 Washington State Department of Ecology. Coastal Atlas. Accessed online on 7/2/19 from
https://fortress.wa.gov/ecy/coastalatlas/storymaps/spills/spills_sm.html.
10 U.S. Environmental Protection Agency. Superfund Sites Where You Live. Accessed online on 6/25/19 from
https://www.epa.gov/superfund/search-superfund-sites-where-you-live
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Site Name City Site Type Description
Pacific Car & Foundry
Co.
Renton Manufacturing,
Processing,
Maintenance
Trucks/ships/trains/aircraft and related
components. Soil is contaminated with
heavy metals, PCBs and solvents.
Approximately 37,000 obtain drinking
water from wells within three miles.
Pacific Sound
Resources
Seattle Manufacturing,
Processing,
Maintenance
Lumber and wood products/wood
preserving/treatment. Soil and ground
water contaminated by PCBs and heavy
metals from former wood treatment
operations.
Queen City Farms Maple
Valley
Waste
Management
Industrial waste facility (non-generator).
the site is a former landfill. Ground water,
surface water, and sludge contaminated
by volatile organic compounds. Soil
contaminated with PCBs and metals.
Quendall Terminals Renton Manufacturing,
Processing,
Maintenance
Chemicals and allied products. Soil and
ground water contaminated with
benzene and creosote from former
manufacturing plant. Contaminants
release to Lake Washington.
Seattle Municipal
Landfill (Kent
Highlands)
Kent Waste
Management
Landfill contains volatile organic
compounds like toluene, xylene, vinyl
chloride, and others – plus heavy metals.
Western Processing
Co. Inc.
Kent Recycling Chemicals/chemical waste (e.g., solvent
recovery). former industrial processing
facility ground water and sediment
contains volatile organic compounds,
PCBs, phenols, and heavy metals.
Brownfield Sites
Boathouse Inc Renton
Skyway
Seattle Dry cleaning
facility
The 0.48-acre site was formerly home toa
dry cleaning facility. The facility's
operations led to hazardous chemical
releases into the soil and groundwater.
Located 5,700 feet from the Duwamish
River and the Skyway Water District and
City of Renton are within 2 miles.
Rainier Court Seattle Housing 7-acre Rainier Court Property Phase IV
Development, built on land with
contaminated fill, has seen past uses such
as vehicle storage, welding, and small
residences with heating oil tanks.
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Site Name City Site Type Description
Goodwill Corp
Dearborn Campus
Seattle Retail, Storage,
Learning Facility
Goodwill site located in Seattle’s Central
District. Contaminants in the soil and
groundwater are linked to past activities,
including a dry cleaner, hazardous
materials storage, petroleum USTs, metal
plating, and contaminated fill.
Grand Street
Commons
Seattle Housing Located in Judkins Park neighborhood has
hosted manufacturing, dry cleaning, and
vehicle repair businesses, leading to
hazardous substance releases into the
soil and groundwater. Cleanup includes
excavation and disposal of PCE- and
petroleum-contaminated soil.
Additionally, groundwater treatment
began in June 2021.
Chubby & Tubby Seattle Gas Station Half acre commercial space formerly used
as a gas station that had petroleum
contaminated soil.
Boeing Auburn Auburn Manufacturing Auburn Plant has caused groundwater
contamination with volatile organic
compounds (VOCs), chemicals that emit
vapors. Contaminated groundwater flows
north and northwest from the site,
affecting areas in Algona and Auburn.
Betty Brite Cleaners SeaTac Dry cleaning
facility
This site has confirmed contamination of
halogenated solvents that could
potentially harm people and the
environment. Currently awaiting cleanup.
Mt Baker Properties Seattle Housing Since 2016, the Mt. Baker Housing
Association (MBHA) has been cleaning up
the contaminated site. Former business
activities impacted the soil and
groundwater, including contamination
from a former gas station and Mount
Baker Cleaners.
While the majority of incidents tend to involve petroleum products, a significant number involve
extremely hazardous materials. Extremely hazardous materials include chemicals like chlorine,
ammonia, sulfuric acid, nitric acid, some pesticides (EHS is a technical designation, so not pesticides-
although the chemistries used as pesticides might be on the EHS list), and other chemicals that can
cause immediate death or injury when inhaled, ingested, or come in contact with skin.
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An example of the cleanup costs for a Superfund site is illustrated by the Harbor Island Cleanup. The
former owner, RSR Corporation agreed to pay $8.5 million in fines toward the cleanup that will cost
(when completed) over $32 million.11 The cost to cleanup an illegal drug lab (in a home) can cost
between $5,000 and $100,000 depending on the size of the home. Often the occupants vacate or
abandon the sites – leaving a bank or credit union holding the mortgage and cleanup costs.12
11.5 Probability of Future Occurrences
Given the widespread use and distribution of hazardous materials across the county, including in
residential homes, medical facilities, and industrial sites, the risk of a hazmat release within the next
year is inevitable. Certain areas are more vulnerable to these incidents, such as the 3,164 reported
Tier II facilities, transportation networks like the Olympic Pipeline, and Superfund sites. Historical
data shows that most spills are relatively small, with over 75% involving 1 to 10 gallons oil and 20%
falling within the 11 to 100-gallon range. However, approximately 5% of spills exceed 101 gallons,
underscoring the potential for more substantial environmental damage.
11.6 Climate Change Considerations
Climate change increases the risk and impact of hazardous material (hazmat) releases due to more
extreme weather events like floods, storms, and wildfires, rising sea levels, and higher
temperatures. These factors can damage infrastructure, such as chemical storage tanks and
pipelines, causing spills and leaks. Changes in precipitation patterns, including droughts and heavy
rainfall, can overwhelm containment systems and lead to toxic runoff. Additionally, aging
infrastructure may be more vulnerable to climate stresses, and extreme weather can disrupt
emergency response efforts, making it harder to manage hazmat incidents. Climate change also
affects ecosystems, making them more susceptible to contamination from spills.
11.7 Impact Assessment
Public Potential Impacts to the public from a hazardous materials spill can vary widely.
Temporary or even permanent displacement through evacuation from an unsafe
area can result in relocation/displacement of populations. Employment
disruption, school closure, impacts to private and community wellheads and
other impacts can change whole communities. Long term exposure to toxic
11 U.S. Department of Justice. 2006. Former Harbor Island Smelter Operator to Pay $8.5 Million in Superfund
Cleanup Costs. Accessed online on 6/25/19 from
https://www.justice.gov/archive/opa/pr/2006/January/06_enrd_047.html.
12 Dewan, Shaila and Robbie Brown. July 25, 2009. When an ex-meth lab is home. The Seattle Times. Accessed
online on 6/25/19 from https://www.seattletimes.com/business/real-estate/when-an-ex-meth-lab-is-a-home/.
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chemicals can cause birth defects and temporary or permanent health problems
– especially for the young, old and infirm.13
Responders Hazardous materials make response and recovery activities in all disasters a
threat to the health and safety of responders. During local events, such as house
fires, stores of chemicals can catch fire and explode, injuring responders. During
larger events such as earthquakes, large-scale releases can surprise and
overwhelm responders without proper equipment. It can also be extremely
difficult to determine the chemical or chemicals that have been released from a
given spill, adding to first responder danger.
Continuity of
Operations
King County is the operator of several facilities that are vulnerable to hazardous
materials spills. The county has three waste water operations (South Plant, West
Point Treatment Plant, and Brightwater). These expensive facilities are
vulnerable to the introduction of chemicals (when in large volumes) to the
sanitary sewer system. The county also has solid waste (garbage) transfer
stations and a major landfill operation at Cedar Hills. While contaminants are
avoided, some material may make its way into the landfill and the ground water
table. Drinking water facilities including private and community well heads and
reservoirs may also be vulnerable to introduction of chemical or biological
contaminants. Any chemical spill that impacts a major roadway or rail line may
impact public transit routes in the county.
Property,
Facilities, and
Infrastructure
Property
Spills of hazardous materials to soil or buildings can result in extensive and costly
cleanup efforts. Cleanup standards are established by federal (U.S. EPA), state
(Washington State Department of Ecology), and local standards (fire agencies
and environmental agencies). Until a site is cleaned up to those standards,
residential or business occupancy can be denied under the Health Code. The
responsible party (property owner) may be required to pay for the cleanup.
Often this can lead to bankruptcy and clean up by state or federal agencies and
contractors. Contaminated property can drastically reduce the value of the
property and the King County subsequent property taxes available to local and
state government. Similar impacts can be expected for transportation accidents
with hazardous material spills.
Facilities
Hospitals can be overwhelmed by major releases of hazardous materials as
populations, both those exposed and those who feel they may have been, check
in at emergency rooms. Hospitals and pharmacies are also sources of hazardous
materials, including some radioactive materials such as those associated with
cancer treatment.
13 U.S. Centers for Disease Control. Health Effects of Chemical Exposure. Accessed online on 6/25/19 from
https://www.atsdr.cdc.gov/emes/public/docs/Health%20Effects%20of%20Chemical%20Exposure%20FS.pdf.
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Infrastructure
With hazardous materials being everywhere in our modern community, it is
possible to impact almost any critical facility in the county. Any roadway or rail
line is vulnerable to the many chemicals transported over them daily. Spills to
soils and surface water sources can impact drinking water and the environment.
Materials dumped into sanitary sewers can contaminate wastewater treatment
plants. Airborne chemicals can cause the evacuation of the area downwind of
the spill, including critical facilities. Damage to road surfaces from chemical spills
may require the removal and replacement of the entire road surface and
foundational roadbed. Transformers used in power transmission contain
chemicals called PCB (Poly chlorinated bi-phenols) that can be released during
wind storms or lightning strikes and traffic accidents. The impacts to business
from interrupted commute/road or railroads closures can last for hours, days,
weeks, or longer. White powder incidents have closed postal facilities and
government buildings until the substance was identified and removed
Environment Any chemical spill on or along rails, roads, pipelines, fixed industrial facilities or
illegal drug labs/dumping may impact the natural environment. Wetlands,
streams and rivers, lakes, and reservoirs may all be damaged from chemical
spills. In some cases these damages may injure the plant and animal life
irreparably. Birds, reptiles, amphibians, fish, and mammals may all be impacted.
Air pollutants may impact human inhabitants as well as the natural environment.
Recreational areas can be closed until a suitable solution can be found to recover
the natural environment.
Economy Small spills can close businesses and have a rather large impact on employment
and land use including the properties of neighbors not responsible for the
chemical release. Superfund sites can impact a community for decades until they
are cleaned up. The large salmon and fishing fleet that calls King County home
may be impacted when some of a year’s fish stock – or even the entire run is
impacted.
Public
Confidence in
Governance
The Community Right to Know Act, and other related legislation, resulted from
serious breaches in public confidence following massive releases, explosions, or
other failures in hazardous materials systems. Any major incident in and of itself
seems to offer proof to the public of a regulatory failure. Maintaining Local
Emergency Planning Committees and a regular structure to report and analyze
hazardous materials releases is critical to maintaining public confidence.
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11.8 Vulnerability Assessment
Vulnerable
populations
Vulnerable populations often live in closer proximity to facilities with
the risk of hazardous materials release. In King County, this includes
residences near the Duwamish industrial area, in Kent, Renton, and
south Seattle. These are also the locations of the superfund sites in the
region. In cases of major releases or system failures, the most impacted
populations are frequently lower-income, often ethnic minority
communities that live nearby. Populations with respiratory issues are
also at a heightened risk of impacts due to an airborne release of
chemicals.
Low-income communities in or around industrial facilities
Low-income communities are more likely to be impacted from major
releases due to the proximity of affordable housing to industrial areas
and historic environmental injustices.
Individuals with respiratory issues
Individuals with respiratory issues are more likely to succumb quickly to
an airborne release of a chemical.
Property Properties vulnerable to hazardous material (hazmat) release typically
include former industrial sites, dry cleaning facilities, gas stations with
underground storage tanks, landfills, and vehicle maintenance or repair
shops. These properties often suffer from contamination due to the
improper disposal or leakage of chemicals, solvents, petroleum
products, heavy metals, and other toxic substances. Sites with
contaminated fill or former military and chemical storage areas are also
at risk, as they may harbor pollutants that persist in the soil and
groundwater.
Environment Oil tankers are expected to traverse Puget Sound in growing numbers
due to Canada’s approval of a major pipeline and terminal in
Vancouver, BC. When this occurs, it will significantly raise the risk of a
spill that could destroy much of the aquatic life in Puget Sound.
Operations Transportation
Major transportation facilities store huge amounts of chemicals and
fuel in depots. A failure or fire at one of these facilities could damage or
destroy these assets.
Interstate highways are a major artery carrying chemicals. Accidents
happen every day and major chemical spills can shut down a roadway
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for an extended period of time. Additionally, oil slicks contribute to
traffic injuries and fatalities when it rains.
Rail facilities transport chemicals and fuels, including highly
combustible crude oil. There have been multiple derailments and spills.
In Mosier, Oregon in 2016, a train derailed causing a fire that nearly
destroyed the town, and the fuel avoided leaking in large quantities
into the Columbia River by luck.
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Risk Assessment
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High Overall Risk
Chapter 12Health Incidents
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Chapter 12: Health Incidents
12.1 Hazard Description
For the purpose of this risk assessment, health incidents are referred to as infectious disease
outbreaks affecting the population, agriculture, and/or wildlife. While there have been great
advancements in public health and medicine to address and even eradicate dangerous infectious
diseases, the emergence of evolving and novel pathogens, as well as increased mistrust in
government and health institutions, present new challenges for the coming years. This risk is a
growing concern for the county in the wake of the COVID-19 pandemic, which led to a substantial
morbidity (illness) and mortality (death) as well as strained healthcare systems and economic
losses. Proactive planning by federal, state, and local agencies is essential for mitigating the future
spread of illnesses and their impacts. The county’s primary concerns include communicable and
agricultural diseases.
Communicable diseases are vector-borne illnesses that people spread to one another through
contact with contaminated surfaces, bodily fluids, blood products, insect bites, or through the air.
Examples include influenza, norovirus, and hepatitis A.
Agricultural diseases encompass a variety of animal and crop diseases, pest infestation, and food
safety outbreaks. Examples include highly pathogenic avian influenza (HPAI), Chronic Wasting
Disease and e coli.
An outbreak can be characterized by the extent of spread of the disease:
• Endemic, seen in more common diseases, are at baseline levels within a community.
Animal and crop diseases are endemic in many parts of the world.
• Epidemic refers to an increase, often sudden, in the number of cases of a disease above
what is normally expected in that population in that area.
• Pandemic refers to an epidemic that has spread over several countries or continents,
usually affecting a large number of people.
Outbreaks of any scale can have significant impacts on public health and healthcare resources. New
or emerging diseases can also quickly become an epidemic or pandemic if there is little or no
immunity in the population.
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12.2 Location
All King County jurisdictions are susceptible to infectious disease outbreaks. However, several
factors can increase the likelihood of a disease spreading, including population density, the amount
of international travel and trade in an area, likelihood of exposure to animals, the availability of
accessible healthcare services, and the pre-existing health conditions of those exposed or infected.
Population Density
King County is the largest county in Washington State, home to over 2.2 million residents with a
population density of approximately 985 people per square mile. Comparatively, urban centers in
the county such as Seattle has a population density of about 9,000 people per square mile across its
83.83 square miles. Similarly, the City of Bellevue has around 4,612 people per square mile within
its 33.5 square miles. High population density in these cities create environments conducive to the
rapid spread of infectious diseases, as close human contact is a primary driver of transmission.
Port and Travel
Seattle is home to the eighth largest port and the eleventh busiest airport in the United States, and
the Seattle Tacoma airport is one of the first points of entry for international travelers across the
Pacific. The presence of major international air and sea ports, along with a thriving cruise ship
industry creates a steady flow of visitors to our area, raising the risk of importing (and exporting)
infectious diseases. Diseases that are not endemic to Washington have the potential for
introduction and spread among our residents. Vaccine preventable diseases (e.g., acute viral
hepatitis, measles, and influenza) are significant contributors to morbidity and potential mortality in
international travelers and can cause local outbreaks among susceptible persons. Furthermore,
unvaccinated individuals travelling abroad risk acquiring and spreading diseases that are not
common in the United States.1
Health Risk Populations
Those who are often hit the hardest by disease outbreaks include young children, the elderly, the
poor, and those with underlying health conditions. There is extensive healthcare infrastructure
within King County that provides care for the wider region, including one of the area’s only pediatric
hospitals and the only Level 1 Trauma center for Washington, Idaho, Montana, and Alaska.
Similarly, Airlift Northwest is the only life-flight agency serving the same four-state region. The
areas with the highest number of adults with high-risk health conditions, shown in Figure 12-1,
include Carnation, Duvall, Federal Way, Downtown Seattle, Queen Anne, Magnolia, Shoreline,
Ballard, Burien, and Kent.
1 CDC, “Routine Vaccines” CDC Travelers’ Health (September 2024): https://wwwnc.cdc.gov/travel/page/routine-
vaccines
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Figure 12-1 King County Map of Adults with High-Risk Health Conditions 2
The communities Shoreline, Burien, Federal Way, and Kent are also shown to have high percentages
of uninsured community members. People who experience homelessness often have limited access
to medical care and may not be fully represented in this data set.
Figure 12-2 King County Uninsured Population, 20223
2 “COVID-19 Vulnerable Communities Data Tool” Communities Count (n.d.):
communitiescount.org/covid19vulnerable
3 “Health Insurance” Communities Count (2023): communitiescount.org/health-insurance
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12.3 Magnitude
When monitoring communicable diseases, the King County Department of Public Health employs
the Centers for Disease Control and Prevention (CDC) Pandemic Intervals Framework (PIF), which
delineates the progression of an influenza pandemic through six distinct intervals. This widely
recognized framework not only visualizes fluctuations in disease activity but also provides a
standardized method for describing pandemic phases, thereby guiding public health responses
effectively.
Figure 12-3 CDC Pandemic Intervals Framework (PIF)4
The CDC PIF is also cross referenced with the World Health Organization (WHO) phases along with
federal, state, and local indicators which notes when one interval moves into another. The impact
of a disease can be tracked and characterized using several different indicators. These indicators
can help Public Health – Seattle & King County (PHSKC) assess and respond to potential disease
outbreaks.
4 “Pandemic Intervals Framework (PIF)” CDC Pandemic Flu (n.d.): https://www.cdc.gov/pandemic-flu/php/national-
strategy/intervals-framework.html
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Table 12-1 WHO Phases, CDC Intervals, Indicators 5
World Health
Organization phases
CDC intervals Federal indicators for
CDC intervals
State/Local indicators
for CDC intervals
Interpandemic phase:
Period between
influenza pandemics
Alert phase:
Influenza caused by a
new subtype has been
identified in humans
Investigation:
Investigation of novel
influenza A infection in
humans or animals
Identification of novel
influenza A infection in
humans or animals
anywhere in the world
with potential
implications for human
health
Identification of novel
influenza A infection in
humans or animals in
the United States with
potential implications
for human health
Recognition:
Recognition of
increased potential for
ongoing transmission
of a novel influenza A
virus
Increasing number of
human cases or
clusters of novel
influenza A infection
anywhere in the world
with virus
characteristics,
indicating increased
potential for ongoing
human-to-human
transmission
Increasing number of
human cases or
clusters of novel
influenza A infection in
the United States with
virus characteristics
indicating increased
potential for ongoing
human-to-human
transmission
Pandemic phase:
Global spread of
human influenza
caused by a new
subtype
Initiation:
Initiation of a
pandemic wave
Confirmation of human
cases of a pandemic
influenza virus
anywhere in the world
with demonstrated
efficient and sustained
human-to-human
transmission
Confirmation of human
cases of a pandemic
influenza virus in the
United States with
demonstrated efficient
and sustained human-
to-human transmission
Acceleration:
Acceleration of a
pandemic wave
Consistently increasing
rate of pandemic
influenza cases
identified in the United
States, indicating
established
transmission
Consistently increasing
rate of pandemic
influenza cases
identified in the state,
indicating established
transmission
Deceleration:
Deceleration of a
pandemic wave
Consistently decreasing
rate of pandemic
influenza cases in the
United States
Consistently decreasing
rate of pandemic
influenza cases in the
state
5 Sonja A. Rasmussen MD, et al., “Updated Preparedness and Response Framework for Influenza Pandemics” CDC
Morbidity and Mortality Weekly Report (MMWR) (September 2014):
https://www.cdc.gov/mmwr/preview/mmwrhtml/rr6306a1.htm#Tab
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Transition phase:
Reduction in global
risk, reduction in
response activities, or
progression toward
recovery actions
Preparation:
Preparation for future
pandemic waves
Low pandemic
influenza activity but
continued outbreaks
possible in some
jurisdictions
Low pandemic
influenza activity but
continued outbreaks
possible in the state
12.4 Previous Occurrences
Since 2000, there have been several large-scale health incidents around the world which have had a
devastating impact on lives and livelihoods, including the 2003 SARS outbreak, 2009 H1N1 influenza
pandemic, 2014 Ebola outbreak, 2015 Zika epidemic, COVID-19 pandemic, and the 2022-2023 mpox
outbreak.6 While the impacts, risk factors, and causes vary, infectious disease outbreaks are an
ongoing threat that requires preparedness and vigilance.
Table 12-2 Previous infection disease outbreaks in King County
Disease Time Description
E. coli. 1993 E. coli-contaminated hamburger meat from a local Jack in the Box
caused illness in 400 people and led to the death of two people
within one month in the Washington area. Cases were seen in
California, Idaho, and Nevada as well.
Pertussis 2002-
2005
Between 2002 and 2003 Public Health reported an 82% increase
in the number of Pertussis infections in infants, and a three-fold
increase in the number of cases in children <6 months. The
occurrence of Pertussis in adolescents and adults has been on the
rise since 1990, culminating in a national epidemic in 2005 when
25,616 reported cases nation-wide. Outbreaks within healthcare
facilities can occur quickly because the bacterial infection is highly
contagious.
Influenza 2009 The H1N1 outbreak of 2009 affected the young and healthy
populations as well as those with chronic diseases. This increase
in morbidity caused strain on the local healthcare system.
Although the H1N1 virus was not as virulent and there were not
6 Public Health – Seattle & King County (PHSKC), “Biological Incident Response Annex” (June 2024):
https://kingcounty.legistar.com/LegislationDetail.aspx?ID=6458573&GUID=7E04B4F2-35E5-47B8-BA78-
6FD7C85966AB
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nearly as many fatalities as previous pandemics, the outbreak
caused a larger than usual amount of disease in the community
than seasonal influenza virus does.
Hepatitis A 2017,
2019
In 2017, several state and local health departments responded to
hepatitis A outbreaks, spread through person-to-person contact,
that occurred primarily among persons who use injection and
non-injection drugs, and/or person who experienced
homelessness and their close contacts. Multistate outbreaks of
hepatitis A infections have also been linked to food products (i.e.
strawberries in 2016 and pomegranate seeds in 2013). A large
outbreak centered in Seattle would cause a strain on the public
health system and potentially have strong impacts on local
businesses, especially any that the public perceives as responsible
for the outbreak.7
COVID-19 2020-
Present
Severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2),
the virus that causes coronavirus disease 2019 (COVID-19), was
first identified in Wuhan, China in December 2019. On January 20,
2020, the first case of COVID-19 in the United States was
identified in Washington state. Since February 2020 there have
been almost 600,000 reported cases, close to 18,000
hospitalizations, and more than 3,600 deaths from COVID-19 in
King County.
Mpox 2022 In May 2022, an outbreak of mpox (formerly known as
monkeypox virus disease) suddenly and rapidly spread across
Europe, the Americas, and all six WHO regions, with 110 countries
reporting a combined approximate 87,000 cases and 112 deaths.
Cases of mpox were reported from countries where the disease
was not endemic and cases were increased in several endemic
countries, i.e., most confirmed cases with travel history reported
travel to countries in Europe and North America, rather than
West or Central Africa where the mpox virus is endemic. The
global outbreak affected primarily (but not only) gay, bisexual,
and other men who have sex with men and spread person-to-
person through touching, kissing, sex, or contact with
contaminated sheets, clothes, or needles.
Avian Influenza 2022 –
Present
A strain of H5N1 highly pathogenic avian influenzas (HPAI)
circulated in wild birds and poultry was first identified in
Washington state in May 2022. The first human cases of H5 avian
7 “Hepatitis A Outbreak Linked to Person-to-Person Contact” CDC Viral Hepatitis (April 2024):
https://www.cdc.gov/hepatitis/outbreaks/ongoing-hepatitis-a/index.html
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influenza were reported in Washington state in October 2024.
There are now 9 cases of human with H5. CDC currently the risk
to the general public’s health to be low.8
Varicella
(chicken pox)
2023 In May 2023, at least 3 confirmed cases of varicella among asylum
seekers at an encampment located in Tukwila.9
Measles 2024 In 2024, several confirmed cases of measles were reported in King
County, all linked to international travel. In April, a group of
international travelers in King County came into close contact
with a confirmed measles case in Georgia. Several of these
individuals lacked documented immunity to the virus. On May
10th and 11th, an adult with a confirmed case of measles passed
through Seattle-Tacoma International Airport. The individual is
believed to have contracted the virus while traveling in Europe or
while en route to the region. On June 10th, a child at Franciscan
Urgent Care in West Seattle was diagnosed with measles. The
child, who had not been vaccinated, likely contracted the virus
during international travel.
12.5 Probability of Future Occurrences
While it is impossible to predict the timing or nature of the next outbreak, history demonstrates
that they are not uncommon and can have devastating effects on communities. Although
advancements in medicine over the past century have enhanced our ability to combat diseases,
several factors—such as rapid population growth in our city centers, increasing number of
individuals without adequate healthcare, the evolution of antibiotic-resistant bacteria,
globalization, and societal upheaval —contribute to the rapid spread and increased severity of
outbreaks.
Emerging variants of COVID-19, novel strains of influenza, and severe acute respiratory syndrome
(SARS) all pose risks with the potential to trigger outbreaks. These diseases and variants can also
have limited or no medical countermeasure (therapeutic treatment or vaccine), posing as a high
risk/low frequency event that have the potential to broadly impact health and medical capacity as
well as disrupt critical resources and support infrastructure.
8 “Avian Influenza” Washington State Department of Health (DOH) (n.d.): doh.wa.gov/you-and-your-family/illness-
and-disease-z/avian-influenza
9 Public Health – Seattle & King County (PHSKC), “Varicella cluster in Tukwila, King County” King County (December
2023): https://kingcounty.gov/en/dept/dph/health-safety/disease-illness/health-advisories/2023/13-december
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12.6 Climate Change Considerations
Climate change and globalization have significantly heightened the reach of invasive species,
pathogens, and diseases affecting people, agriculture, and the environment. With extensive global
travel networks and increasing urbanization, novel pathogens can quickly spread far beyond their
origins. This rapid transmission poses a particular threat to individuals on the front lines of
exposure, especially those with fewer resources, as well as vulnerable populations.
Key ecological concerns include the introduction of diseases and parasites to wild species,
competition between wild and farm-raised species, threats from invasive species, and the negative
effects of pollution and fish farming on shellfish beds, among others. These climate-driven changes
in ecosystems further exacerbate the risk of emerging infectious diseases by altering the
interactions between humans, pathogens, and animals.10
Rising temperatures have also allowed the spread of diseases and vectors that previously were not
of concern to King County. For example, Coccidioides fungus that causes Valley Fever detected in
south-central Washington State and spreads through dust or disturbed soil.11 Warmer average
temperatures have resulted in expanding mosquito distribution. Warmer temperatures also speed
up the life-cycle of mosquitoes, allowing adult mosquitoes to mature faster, increasing people’s risk
of exposure to diseases such as West Nile virus (WNV).12 Between 2003 and 2023, more than 1
million cases of vector-borne diseases were reported in the United States. Rising temperatures and
changing rainfall patterns can boost mosquito and tick populations and make it easier for them to
spread harmful pathogens to people.
12.7 Impact Assessment
Epidemics directly affect the health of people who live, work, and visit a community. They have the
potential to be one of the deadliest hazards a community can face. As demonstrated during the
COVID-19 pandemic, they can have cascading impacts to the economy and society at large.
10 KC Ernest, et al., “Focus on Covid-19 and Climate Change” Fifth National Climate Assessment (2023):
https://doi.org/10.7930/NCA5.2023.F3
11 “Valley Fever (Coccidioidomycosis)” Washington State Department of Health (DOH) (n.d.):
https://doh.wa.gov/you-and-your-family/illness-and-disease-z/valley-fever-
coccidioidomycosis#:~:text=Valley%20Fever%2C%20also%20called%20coccidioidomycosis,severe%20forms%20of
%20the%20disease
12 “Infectious Diseases and Climate Change” Washington State Department of Health (DOH) (n.d.):
https://doh.wa.gov/community-and-environment/climate-and-health/infectious-
diseases#:~:text=Environmental%20Fungal%20Diseases,will%20change%20with%20changing%20environments
AGENDA ITEM #1. b)
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Chapter 12: Health Incidents
12-11
Public Infectious diseases can have a profound impact on human health, leading to a
range of negative consequences, including increased healthcare costs, lost
income due to time away from work, and, in the most severe cases, loss of life.
Responders Emergency services would be severely impacted during a serious outbreak
because they are likely to be exposed early due to public contact. As responders
become sick, response times and capabilities would be severely limited.
Public Health teams widely reported that they were overwhelmed with workload
during many phases of the COVID-19 pandemic. Response demands often
outpaced Public Health resources.13
Continuity of
Operations
Many government operations may cease to function on a normal basis during
the most severe outbreaks. Agencies may have to adopt work from home
policies and take other steps to protect employees. Due to employee illness,
many non-essential functions may have to be curtailed.
Property,
Facilities, and
Infrastructure
Facilities
King County has a large concentration of healthcare resources, but in an
epidemic or pandemic these resources can be stretched or overwhelmed by the
outbreak situation. As facilities become unable to take additional patients, it may
be possible to treat people in outpatient facilities.
Infrastructure
• Energy: There are no direct impacts, outside of employee absenteeism,
to the energy sector.
• Water/Wastewater: King County has many open reservoirs that provide
water to the city. These reservoirs could become contaminated and be a
source of infection for area residents. This system is a potential target of
bioterrorist activities.
• Transportation: A disease would not cause any direct damage to the
transportation system, but high absenteeism would affect it. Public
transit, shipping, and other services may only function at 50% during
especially severe outbreaks.
• Communications: There are no direct impacts, outside of employee
absenteeism, to the communications sector.
13 Public Health – Seattle & King County (PHSKC), “Biological Incident Response Annex” (June 2024):
https://kingcounty.legistar.com/LegislationDetail.aspx?ID=6458573&GUID=7E04B4F2-35E5-47B8-BA78-
6FD7C85966AB
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Chapter 12: Health Incidents
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Environment In the case of a pandemic that requires quarantine, the reduced amount of travel
can have positive effects on the local air quality, as decreased vehicular and
industrial activity reduces emissions of harmful pollutants and greenhouse gases.
Regarding agricultural diseases, there is large negative impact on natural
resources including landscape, livestock, and forests. In the event of a outbreak
of livestock such as avian flu, farmers are required to put down their flock in
order to prevent further spread of the virus.
Economic The economy may come to a virtual standstill for weeks on end during severe
outbreaks as people avoid public places. Many small businesses may lose too
much revenue and be forced to close.
On March 15, 2020, of non-essential businesses closed down in order to limit the
spread of COVID-19. This resulted in a dramatic increase in the number of people
laid off or furloughed in King County. Workers residing in King County filed an
average of more than 30,000 initial claims per week between March 1 and May
2, 2020.
During an outbreak of infectious disease in livestock, large‐scale depopulation of
livestock may be necessary to curb further spread of the pathogen and prevent
associated welfare problems arising. This puts large financial constraints on
farmers.
Public
Confidence in
Governance
The public understands that an outbreak is a severe natural event; however,
restrictions on public gatherings are not popular and create frustration. Some
people may believe they are not getting enough attention from the medical
community. Others may begin to doubt the efficacy of treatment options if the
disease worsens. In the most extreme cases, confidence in the medical system
can be shaken.
12.8 Vulnerability Assessment
Vulnerable Populations Data shows the burdens of infectious diseases are not evenly borne
across the population. Viruses have had disproportionate impacts on
the elderly, people with weakened immune systems, those with
several pre-existing chronic medical conditions and disabilities, and
communities of color. During a serious epidemic, older adults,
individuals with compromised immune systems, children, people
without health insurance, people who speak a language other than
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Chapter 12: Health Incidents
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English, and people who are recent immigrants to the country are
likely to be the most at-risk and suffer the worst impacts.
Young and Old People
People who are either old or young have weaker immune systems
and are usually more likely to succumb during an outbreak. In 2017-
2018 flu season, there were nearly 1,000,000 hospitalizations and
79,400 deaths. The most at-risk group is adults over 65 years of age
(70% of hospitalizations).14 Older adults account for nearly 90% of
deaths.
People with Disabilities and Compromised Immune Systems
People with disabilities experienced gaps regarding translation and
interpretation services, gaps in testing and vaccine site accessibility in
early phases of the pandemic, inadequate disability representation
on public health data dashboards, and limited transportation options
to obtain resources. Those with compromised immune systems are
also most likely to become infected and succumb from a serious
disease.
BIPOC
In King County, American Indian/Alaskan Native, Black, Hispanic, and
Native Hawaiian/Pacific Islander residents experienced higher rates
of COVID-19 cases, hospitalizations, and deaths than Asian and White
residents. Through June 12, 2022, King County has had 2,850 deaths
(0.6% of positive reported cases). Age-adjusted death rates of
confirmed cases are highest among residents who are Native
Hawaiian/Pacific Islander (749 per 100,000), American Indian/Alaska
Native (452 per 100,000), Hispanic/Latinx (260 per 100,000), and
Black (219 per 100,000). Case rates for most communities of color
are higher than among White residents (106 per 100,000).
Immigrants and Refugees
Immigrants and refugees make up more than 24% of King County
population. There are also over 100 languages spoken in King
County.15 This can lead to communication barriers on important
14 Centers for Disease Control, “Estimated Influenza Illnesses, Medical visits, Hospitalizations, and Deaths in the
United States — 2017–2018 influenza season” (November 2019) https://www.cdc.gov/flu/about/burden/2017-
2018.htm
15 Public Health – Seattle & King County (PHSKC), “Equity Response Annex” (June 2024)
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Chapter 12: Health Incidents
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health protocol. It also makes navigating the American health system
challenging.
People without health insurance
People without health insurance are more likely to delay getting
care, allowing the disease to spread farther before it is identified.
Healthcare Staff
Healthcare staff are on the front line of any infectious disease
outbreak. They come into regular contact with sick patients and are
likely to be exposed both before the illness is identified and during
treatment.
Property No property is vulnerable in the event of an infectious disease
outbreak.
Environment Certain environments can be a conduit for infectious diseases. They
can create conditions that support the spread of toxic fungi or the
increased population of virus transmitters such as mosquitoes.
However, the spread of communicable diseases in humans does not
have known impacts on the environment.
Operations The health system is likely to be overwhelmed in any serious
epidemic. In especially serious outbreaks, it may be inadvisable for
patients to even come to the hospital and treatment may have to
occur outside of hospital facilities. For example, many Public Health
employees during the early COVID response worked 80–100-hour
work weeks, often going months without a day off.16
16 Public Health – Seattle & King County (PHSKC), “Biological Incident Response Annex” (June 2024):
https://kingcounty.legistar.com/LegislationDetail.aspx?ID=6458573&GUID=7E04B4F2-35E5-47B8-BA78-
6FD7C85966AB
AGENDA ITEM #1. b)
Risk Assessment
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PC: WADNR
Chapter 13Landslide
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Chapter 13: Landslide
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Chapter 13: Landslide
13.1 Hazard Description
The term “landslide”
encompasses a variety of
geomorphic processes in which
masses of soil, rock, and debris
(a mixture of soil and rock)
become detached and move
downslope. Typically, this mass
is wet, saturated, or suspended
in water. Landslide movement
can occur rapidly or slowly, and
the displaced material may
remain solid or behave like a
liquid. The size of landslides can
vary significantly, ranging from
a few cubic yards to millions of
cubic yards. The specific nature
of this movement is referred to
as the "landslide style," which
depends on the local geology,
topography, and hydrology at
the site of the failure.
Causation
Landslides are generally considered secondary hazards, triggered by precipitation, earthquakes,
wildfires, and human activities. Smaller, shallower landslides often occur in response to short-term
storm events lasting hours or days, while larger, deep-seated slides may be initiated by prolonged
wet conditions persisting for months. Historical records and geological evidence indicate that
significant earthquakes, though infrequent, can also serve as powerful landslide triggers. Areas
affected by wildfires are particularly susceptible, as burn scars can lead to debris flows. Human
activities such as improper clearing, grading, or stormwater discharge can also contribute to
landslide occurrences. Additionally, landslides tend to occur in areas where there is a history of
previous occurrences. Five general styles of landslide phenomenon have been identified in King
County:
1996 Perkins Lane landslide in Seattle’s neighborhood Magnolia
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Chapter 13: Landslide
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Table 13-1 Landslide styles that occur in King County 1
Name Description
Deep-seated landslides
Deep-seated landslides are those that fail
below the rooting depth of trees and
vegetation. They are often slow moving but
can also move rapidly. Deep-seated landslides
can cover large areas and devastate
infrastructure and housing developments.
These landslides usually occur as translational
slides, rotational slides, or large block slides.
Deep-seated landslides are typically much
larger than shallow landslides, in terms of
both surface area and volume. A deep-seated
landslide may appear stable for years,
decades, or even centuries. These long-lived
features can be partially or entirely
reactivated for a variety of reasons.
Shallow debris slides
Shallow debris slides (also known as shallow
landslides, infinite slope failures, and colluvial
slides) are a common style of slope -
movement both in the Puget Lowland and
Cascade Mountains. Shallow landslides are
rooted in the soil layer and often form slumps
along roadways or fast-moving debris flows
down valleys. These types of landslides are
often called 'mudslides' by the news media.
Shallow landslides also occur as flows, slides,
or rockfalls and topples. Shallow landslides
typically occur during the winter months in
western Washington.
1 King County DNRP, “Mapping of Potential Landslide Hazards along the River Corridors of King County,
Washington” River and Floodplain Management Section, Water and Land Resources Division, Department of
Natural Resources and Parks (2016): https://your.kingcounty.gov/dnrp/library/2016/kcr2783.pdf
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Debris flows Debris flows and debris floods usually occur in
steep gullies, move very rapidly, and can
travel for many miles. Debris flows and floods
deposit material on alluvial or depositional
fans. They may contain more coarse material
than a mudflow when channelized. Slopes
where vegetation has been removed by fire
or humans are at greater risk for debris flows
and many other types of landslides.
Rock fall 2
Falls and topples are usually rapid, downward
movement of large pieces of rock or debris.
Sometimes this is enough rock to cover a road
or block a stream or river. Rockfalls and
topples are common in Washington’s
mountain highways.
Rock avalanches
Rock avalanche is a style of landslide
characterized by the simultaneous failure of
an entire bedrock hillslope and with the
dislodged mass cascading to the valley below.
Extremely rapid, massive, flow-like motion of
fragmented rock from a large rockslide or
rock fall. Although no rock avalanches have
occurred in King County in historical times,
fields of angular boulders at the base of steep
mountainsides are clear evidence of
prehistoric failures.
2 Washington Department of Natural Resources (DNR), “Falls and Topples” Landslides (n.d.):
https://www.dnr.wa.gov/programs-and-services/geology/geologic-hazards/landslides#types-of-landslides.9
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13.2 Location
King County is shaped by multiple glacial advances over the past two million years, the most recent
occurring around 14,000 years ago. Landslides are most prevalent in areas where post-glacial
erosion has created steep slopes in glacial deposits, particularly along beach bluffs, ravine slopes,
and river valley walls. Interestingly, some areas with lower slopes may actually be remnants of old,
deep-seated landslides that could be at risk of reactivation.
Key characteristics of landslide hazard areas include:3 4
• A slope greater than 40 percent
• Landslide activity or movement in the last 10,000 years
• Stream or wave action with erosion or bank undercutting
• The presence of a depositional fan that may indicate a history of debris flows, debris floods,
or rockfall
• The presence of impermeable soils, such as silt or clay, which are mixed with granular soils
such as sand and gravel
In 2019, The Washington Geological Survey (WGS) published a landslide inventory for Washington
State. The Landslide Hazards Program is actively creating inventories for densely populated areas,
successfully mapping 60% of King County where people and infrastructure are present. Utilizing
LiDAR derivatives, landslide geologists have identified and mapped 2,838 landslides and 1,251
alluvial fans. High landslide density was noted along Puget Sound bluffs, river corridors, and in the
upland areas of the Cascade Range.
3 Federal Emergency Management Agency (FEMA), “King County Risk Report: Landslide Exposure Assessment”
(2018): p 52.
4
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2025 King County Regional Hazard Mitigation Plan
Chapter 13: Landslide
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Figure 13-1 King County Landslide Inventory5
While landslide polygons indicate areas where landslides have already occurred, landslide
susceptibility attempts to highlight areas that could experience a landslide in the future. WA DNR
have not done landslide susceptibility for the county. But the USGS just published a national scale
landslide susceptibility map.
5 Washington Department of Natural Resources (DNR), “WSG Landslide Inventory” (2019):
https://www.dnr.wa.gov/programs-and-services/geology/geologic-hazards/landslides#find-mapped-landslidesl
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Chapter 13: Landslide
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Figure 13-2 Landslide inventory and susceptibility6
13.3 Magnitude
Landslides in King County, Washington, are most commonly of small magnitude, but they have the
potential to become large and highly destructive, especially when triggered by significant weather
events, human activities, or disturbances like major wildfires. For planning purposes, King County
focuses on three types of landslides, which are particularly deadly and often occur after extreme
weather events or other disruptions.
Warning time
Landslides are dangerous and unpredictable. Some landslides may show indications of impending or
incipient movement; others may happen suddenly without any warning signs. Warning signs of a
potential or impending landslide include:
• Rapidly growing cracks in the ground; downslope movement of rock, soil, or vegetation.
• Sudden changes in creek water levels, sometimes with increased sediment, especially
during or right after large or protracted storm events
• Sounds of cracking wood, knocking boulders, groaning of the ground, or other unusual
sounds, especially if the sound increases
6 United States Geological Survey (USGS),“US Landslide Inventory and Inventory.” (2024):
https://usgs.maps.arcgis.com/apps/webappviewer/index.html?id=ae120962f459434b8c904b456c82669d
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Chapter 13: Landslide
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• A hillside that has increased spring and (or) seep activity, or newly saturated ground,
especially if it was previously dry
• Formation of cracks or tilting of trees on a hillside
• New or developing cracks, mounds, or bulges in the ground
• Sagging or taut utility lines; leaning telephone poles, deformed fences, or bent trees
• Sticking windows or doors; new and (or) growing cracks in walls, ceilings, or foundations
• Broken or leaking utilities, such as water, septic, or sewer lines
• Separation of structures from their foundation; movement of soil away from foundations
• Changes in water well levels or water wells that suddenly run dry
Susceptible areas
King County's geography makes certain areas particularly susceptible to landslides. The most
vulnerable areas include:
• Puget Sound Shoreline: The region's stratigraphy, consisting of permeable sand and gravel
deposits over less permeable silts and clays, creates ideal conditions for landslides. When
sand and water accumulate on top of the clay layer, it can increase pore water pressure,
destabilizing the slope and causing it to fail.
• Steep Bluffs Along Incised Rivers: The steep, unstable bluffs along rivers in King County are
particularly vulnerable to landslides due to erosion and the shifting of materials over time.
• Eastern Cascade Foothills: In the eastern portion of the county, particularly in the Cascade
Range, weakly consolidated and tectonically deformed sediments make the area highly
susceptible to landslides. These areas often experience landslides after heavy rainfall or
during seismic activity.
• Fire Burn Scars: Areas that have been affected by wildfires are more prone to landslides due
to the loss of vegetation and soil stability. Without the root systems to anchor the soil,
heavy rains can quickly trigger landslides in these fire-impacted zones.
• Previous Landslide Zones: Areas that have experienced landslides in the past are more likely
to experience them again. Landslides often reoccur along the same paths, with new
movement triggered by a variety of factors, including stormwater, changes in vegetation, or
human development.
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2025 King County Regional Hazard Mitigation Plan
Chapter 13: Landslide
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13.4 Previous Occurrences
Figure 13-3 Reported landslides in King County by water year
Since 2006, there have been 10 disaster
declarations impacting the county, including
DR-4168 for the SR 530 (Oso) landslide in
Snohomish County. Landslides occur during
virtually every major storm event and
earthquake. Landslides are especially likely
in areas where they have been recorded
before. A good method of assessing
likelihood of a future landslide is to know if
the area has had a history of landslides.
WGS has complied and mapped reports of
landslides from a variety of media sources as
well as city, county, and state agencies.
Since 2016, there has been 98 landslides.
The bulk are occurring during December,
January, and February making about 80%
occur during rainy winter months.
The most significant landslide event in King County occurred in March 1997 in the Magnolia
neighborhood of Seattle, Washington, known as the Perkins Lane Landslide. The primary trigger for
the landslide was prolonged heavy rainfall in the days leading up to the incident. As the soil became
saturated from the continuous rainfall, its stability was compromised, and the added weight of the
water caused the deep-seated slide to reactivate. The landslide resulted in the collapse of five
homes situated at the top of the slope, causing significant property damage and displacement.
AGENDA ITEM #1. b)
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Chapter 13: Landslide
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Figure 13-4 King County’s Recent Landslides 2016-20237
Table 13-2 Past landslide disaster declarations in King County
Date Declaration # Description
2001 DR 1361 Nisqually Earthquake triggers landslides around the state. $66.7M
in Public Assistance was authorized.
2006 DR 1737 Severe storms trigger flooding and landslides. $29.5M in Public
Assistance (statewide) was authorized along with $5.4M in
Individual Assistance.
2007 DR 1734 Severe winter storms trigger landslides. $61.3M in Public Assistance
was authorized along with $21.2M in Individual Assistance.
2009 DR 1817 Sever winter storms trigger flooding and landslide.
7 Washington Department of Natural Resources (DNR), “WSG Recent Landslides” (2024):
https://wadnr.maps.arcgis.com/apps/webappviewer/index.html?id=ef7ea514f7e54dde8cf1e8eefd2037b4
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2011 DR 1963 Severe winter storms trigger flooding and landslides.
2012 DR 4056 Severe winter storms trigger flooding and landslides. $30.1M in
Public Assistance was authorized.
2014 DR 4168 A slope along SR 530 in Snohomish County fails, bringing with it an
entire neighborhood and killing 43 people. This is one of the
deadliest disasters in Washington State History. There is a long
history of landslides in this area and the tragedy leads the state to
invest in a new landslide mapping program.
2017 DR 4309 Severe winter storms trigger flooding and landslides. $12.5M in
Public Assistance was authorized.
2019 DR 4418 December 10 to December 24, 2018 - resulting from severe winter
storms, straight-line winds, flooding, landslides, mudslides, and a
tornado
2020 DR 4539 January 20 to February 10, 2020 - resulting from severe storms,
flooding, landslides, and mudslides
2024 DR 4775 January 5 to January 29, 2024 - resulting from severe winter
storms, straight-line winds, flooding, landslides, and mudslides
13.5 Probability of Future Occurrences
Due to the region's topography and geological conditions, the probability of landslides in King
County will continue to be moderate to high in specific areas, especially following heavy rainfall,
snowmelt, or other destabilizing events. As the climate warms, the frequency of heavy rainfall
events and extreme weather may increase, leading to more frequent landslides, particularly in fire-
impacted and urbanized areas.
13.6 Climate Change Considerations
Climate change is poised to significantly elevate the risk of landslides in King County, particularly in
unincorporated areas, due to a combination of wetter winters, drier summers, and increased severe
weather events. Projections indicate that more intense and frequent rainstorms will saturate soils,
making them more susceptible to movement, especially along coastal bluffs and river corridors. As
winter rains intensify, the saturation of soil increases the likelihood of landslides, particularly in
steep, unstable slopes common in the region.8
Rising summer temperatures and drought conditions contribute to an increase in wildfires, which
further destabilize the landscape. After wildfires, areas with exposed land—especially those with
glacial soils—become highly vulnerable to erosion. The loss of vegetation results in denuded
ground, depleting topsoil and exacerbating the risk of post-fire debris flows.
8 King County DNRP, “Mapping of Potential Landslide Hazards along the River Corridors of King County,
Washington” River and Floodplain Management Section, Water and Land Resources Division, Department of
Natural Resources and Parks (2016): https://your.kingcounty.gov/dnrp/library/2016/kcr2783.pdf
AGENDA ITEM #1. b)
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Chapter 13: Landslide
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Moreover, larger and more frequent storm events are expected to lead to increased flooding in
Pacific Northwest rivers, which may cause significant channel migration and bank erosion. These
changes can further destabilize steep slopes in river valleys, heightening the risk of landslides. While
sea level rise is less of a concern in the river corridors of unincorporated King County, it can still
accelerate erosion at the base of coastal bluffs, especially during high tides and storm surges,
compromising the stability of these marginally stable landforms.
13.7 Impact Assessment
People While the total number of people exposed to landslides is relatively small, and
the risk of a rapid slope failure has tended to be low, many homeowners do not
carry insurance to cover losses from landslide hazards. The total number of
people exposed to the landslide hazard is unknown since landslide hazards are
spatially limited and do not align with population information in Census data.
Responders Most commonly, homes are isolated and ready access to communities by first
responders is impeded by slide activity. Access to schools, businesses, and
public services may be impeded by road blockages from slide activity. While no
recent deaths or injuries have been reported in King County from land
movement, the incident in Snohomish County referred to as the SR 530 Slide or
the Oso Slide, 43 people were killed (2014).
Continuity of
Operations
Most impacts to King County delivery of essential services are indirect.
Roadways closed may impede the county work force from reaching work
locations. Transfer stations for solid waste management and sewer lines and lift
stations feeding the Metro South Plan, West Point Treatment facility or
Brightwater facility may be impacted by slide activity. Only a small number of
bus routes use roadways with the potential for impacts by slide activity. Slide
activity has resulted in first responder access issues and diverted road and
infrastructure maintenance resources. Resulting detours have also impacted the
commute of essential workers to their normal work locations. Some slide
activity has caused temporary access issues for solid waste transfer stations and
to the Cedar Hills Landfill locations.
Property,
Facilities, and
Infrastructure
Property
In total, 2.6 percent of structures in King County are identified as being within a
landslide hazard area, resulting in an estimated $9.8 billion in exposed value.
The City of Lake Forest Park has the highest percentage of structures exposed in
a landslide hazard area at 16.4 percent. The cities of Bellevue and Seattle and
unincorporated King County are estimated to each have over $1 billion of
estimated exposed value within landslide hazard areas. The slopes of Magnolia,
West Seattle, Burien, Des Moines, Vashon Island, Newcastle, Federal Way and
many areas of Bellevue have long been developed for their magnificent views of
Mount Rainier, the Cascade and Olympic Mountains, and Puget Sound. Homes
with vistas of the Olympic Mountains provide sunsets that are breathe taking –
and expose a risk of land movement damages to property build on poor soils.
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Homes built above, on, or below bluffs or slopes. Homes built on bluffs or other
slopes apply addition weight to a slope and increase the likelihood of slope
failure. Homes built below bluffs have also been destroyed by slope failure.
Transportation corridors, including on I-90 and Seattle-Everett BNSF rail line.
Transportation routes are often cut through steep areas or travel through
valleys with a history of landslides.
Facilities
No special impacts to health systems are expected from this hazard.
Infrastructure
• Power: Landslides pose some risk to transmission lines that cross
unstable slopes. Otherwise, landslides are not a primary concern for this
sector.
• Water/Wastewater: Landslides or debris flows in and around reservoirs
or waterbodies that support water systems can cause disruptions in
water services and the loss of infrastructure. Water supply pipelines may
cross unstable areas and be damaged by slope movement. Even if not
directly impacted by earth movement, systems that pull water directly
from impacted waterbodies will have to deal with increased turbidity or
a loss of supply if the water is temporarily cut off by earth damming or
rerouting a river. Finally, failures in water system transmission mains can
actually saturate a slope and trigger landslides.
• Transportation: Transportation routes can be closed for long periods by
landslides and rockslides. The following are some documented incidents.
In November 2008, State Road 410 was closed as the result of a debris
flow east of Enumclaw. A landslide caused damage to the Green River
Bridge on State Route 169 that resulted in the bridge being closed for
repairs for eight months. These incidents resulted in SBA loans to
impacted businesses. In May 2005, 11 homes were isolated after a small
slide on Mercer Island. That September, two lanes of I-90 west of
Snoqualmie Pass were closed after a rockslide. A January 15, 1997 slide
at Woodward in southern Snohomish County derailed five cars of a
freight train. Passenger and cargo rail traffic was interrupted for nine
days. Cargo traffic resumed first. Amtrak remained concerned for
passenger safety and did not travel on this section of track for several
weeks. This type incident can happen almost annually and sometime
more than once each year.
• Communications: There is limited risk to communications systems as a
whole from landslides. Given the redundancy in systems and
proliferation of cell towers, which tend to be less vulnerable, landslides
are not a primary concern.
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Environment Landslides that fall into streams may significantly impact fish and wildlife
habitat, as well as affecting water quality. Hillsides that provide wildlife habitat
can be lost for prolonged periods of time due to landslides. However, landslides
also provide integral resources for many ecosystems. They contribute needed
gravel and sediment or wood for building complex in-stream habitats, estuarine
marshes, and beaches that are important for fisheries, wildlife and recreation.
The Cedar River was partially dammed by slide debris from the Nisqually
Earthquake in 2001. Similarly, in March of 2004, a landslide near Renton
partially dammed the Cedar River again. All major rivers in King County support
salmon and/or steelhead spawning populations.
Vegetation removal
Vegetation removal due to logging, land development, view clearing, or wildfire
reduces the root strength that often anchors and reinforces shallow soils.
Shallow landslides often increases following vegetation removal and if debris
from such a slide enters a hillside swale it may transition into a debris flow that
can have devastating impacts far below and distant from the initial failure.
Coseismal landsliding
This Risk Profile addresses primarily landsliding for which our region has
significant collective experience. This includes of landslides triggered by weather
events and human disturbance. Geologic evidence is clear that this region is
subject to earthquakes from several sources larger than those that have been
well documented in the historical record. Widespread landsliding is likely to be
a secondary but significant and potentially catastrophic consequence of a future
occurrence of such a large earthquake.
Economic There have been direct and indirect impacts to the greater King County
community from landslide activity. Residential housing in the greater Puget
Sound area that have been built to enjoy the spectacular mountain of the
Olympics and Cascade ranges and water views of Lake Washington, Lake
Sammamish, and Puget Sound are vulnerable to land movement. Loss of
transportation can also have economic impacts. In November 2008, State Road
410 was closed as the result of a debris flow east of Enumclaw. A landslide
caused damage to the Green River Bridge on State Route 169 that resulted in
the bridge being closed for repairs for eight months. These incidents resulted in
SBA loans to impacted businesses. The SR 530 Oso landslide caused a complete
reroute of the main highway between Everett and Darrington, devastating the
local economy and forcing residents to commute several hours longer to work
each day.
Public
Confidence in
Governance
The 2014 SR 530 Oso landslide demonstrated some of the major weaknesses in
emergency management capabilities. It also demonstrated a lack of regulation
and foresight on the part of government in the permitting of development in
the area, which was a known slide area. Local critical areas ordinances do
require mitigation for construction in slide hazard areas, but in the Oso slide,
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this proved to be inadequate. A failure by developers, the government, and
residents to properly account for slide risk and protect people from it led to
multiple lawsuits and a general lowering of public confidence in government’s
ability to properly regulate land development.
13.8 Vulnerability Assessment
Vulnerable
Populations
People who live or travel through landslide-prone areas are at significant risk,
especially those who engage in outdoor recreation. The vulnerability of
recreational areas depends on the history of the trail, its maintenance, and
recent weather events that could trigger instability. In King County, low-income
communities, such as those near Renton along the Maple Valley Highway, are
particularly at risk from larger landslides. These areas, which may lack the
resources to properly mitigate landslide threats, could face substantial damage.
Property Properties located on or below bluffs or steep slopes are particularly vulnerable
to landslides. Homes built on these elevated areas contribute additional weight
to the slope, which can destabilize the soil and increase the likelihood of slope
failure. The added pressure from the structure, combined with factors such as
heavy rainfall or seismic activity, can trigger a landslide that may lead to
significant damage. Properties built below bluffs are also at risk, as the
downward movement of the slope can result in devastating consequences,
including the destruction of homes and infrastructure.
Environment Landslides create lasting damage to both terrestrial and aquatic habitats. The
loss of vegetation and the influx of debris into streams can disrupt ecosystems,
displacing wildlife and degrading water quality. The recovery process is slow,
often taking years for vegetation to return and stream habitats to stabilize. In
the meantime, affected species face significant challenges, and the overall
health of the ecosystem may be compromised for an extended period.
Operations Roads, bridges, and transit systems are highly susceptible to landslides. Major
transportation routes, including I90, and Seattle-Everett BNSF rail line go
through steep valleys with historic landslides can be blocked or damaged
during a landslide, disrupting the daily flow of traffic and emergency services.
AGENDA ITEM #1. b)
Risk Assessment
Scoring
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Very High Overall Risk
PC: Hailey Hoffman
Chapter 14Severe Weather
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Chapter 14: Severe Weather
14.1 Hazard Description
King County experiences a large variation of severe weather events that has the potential to impact
the entire region. Severe weather can include extreme heat events, winter storms, heavy rainfall,
and strong winds. These weather events are categorized as follows:
• Extreme heat, including heatwaves, are periods of high heat and humidity with
temperatures above 90 degrees Fahrenheit for at least two to three days.
• Drought is defined by Washington state statute as below 75% of normal water supply for a
given area.
• Extreme cold, also classified as a winter storm, is a storm having significant snowfall, ice,
and/or freezing rain; the quantity of precipitation varies by elevation.
• Heavy precipitation refers to instances during which the amount of rain or snow
experienced in a location substantially exceeds what is normal.
• High wind is a storm sustaining wind speeds greater than 39 miles per hour. Southwesterly
winds are associated with strong storms moving onto the coast from the Pacific Ocean.
Southern winds parallel to the coastal mountains are the strongest and most destructive
winds.
• Tornados are violently rotating columns of air touching the ground, usually attached to the
base of a thunderstorm. Wind speeds start at 65 miles per hour and can reach 300 miles per
hour. It is not unusual to have funnel clouds spotted during the winter season.
Severe weather events can lead to secondary hazards and cascading impacts. For instance, heavy
precipitation can cause flooding and landslides, resulting in road closures and property damage. In
rural or suburban areas, high winds can knock down trees and powerlines, leading to extended
power outages and road blockages. In urban areas, extreme heat or cold may disproportionately
affect the unsheltered population and families with limited resources, particularly those without
access to heating or cooling systems.
As the climate continues to change, many but not all of these events are expected to become more
frequent, intense, and prolonged, increasing the risk of widespread impacts across the county.
14.2 Location
King County's geographic location, bordered by Puget Sound and the Pacific Ocean to the west and
the Cascade Range to the east, plays a key role in shaping its climate. The region is heavily
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influenced by maritime atmospheric conditions, with the mountains acting as natural barriers that
trap-in in moisture. As moist air is forced upward by the Cascades, it cools and condenses, leading
to heavy precipitation on the windward side of the mountains. In addition to its natural climate
influences, the region is home to numerous urban centers and transportation networks that feature
impermeable surfaces, which contribute to the urban heat island effect.
Extreme Heat
Figure 14-1 King County Heat Island Map 1
Hotter summer temperatures affect
everyone in King County. However, the
impacts of that heat are not felt equally.
Figure 14-1 shows the county’s surface
temperatures with red and orange
indicating hot areas and blue indicating
cool. These elevated surface temperatures
are a result of the "urban heat island"
effect, where there is a concentration of
pavement and heat retaining material that
result in higher surface temperatures
compared to their surrounding areas.
Drought
Washington State approaches drought
emergencies from the perspective of water
supply, which can affect the entire county.
This includes residents and businesses who
depend on local water resources and well
as farmers and landowners who use water
resources for irrigation. A key factor contributing to drought in this region is reduced snowpack in
the Cascades. The snowpack acts as a critical source of runoff that feeds our watersheds and
replenishes reservoirs. While there is a slight projected increase in winter precipitation, the main
driver of declining snowpack is that more of this precipitation is falling as rain rather than snow due
1 King County Executive Climate Office (ECO), “King County Extreme Heat Mitigation Strategy” (July 2024): p. 6,
https://cdn.kingcounty.gov/-/media/king-county/depts/executive/climate-office/documents/c2-
240802_13570m_kc-extreme-heat-
strategy_prnt.pdf?rev=2cceaee431a14df29323d98bd817cfe5&hash=2C0B0D0227F7100C58DF612DB2351820
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to rising temperatures. This shift, combined with hotter, drier summers, reduces the amount of
snowmelt available in spring and summer, ultimately exacerbating drought risk.
Winter Weather
King County’s marine climate, that maintains relatively mild temperatures, results in very few
extreme cold weather events. Snow accumulation at elevations below 2,000 feet is considered rare,
and when snowstorms do occur, they usually last less than two days. However, since 1990, King
County has experienced an increasing frequency of prolonged cold spells. These events, which
generally last 10 to 14 consecutive days, typically occur in January or February each winter. The
heavy snowfalls and accompanying cold conditions often lead to power outages, disruptions to
transportation systems, school closures, and significant economic impacts on the region.
Heavy Precipitation
Though known for being wet, the Seattle metro area has around the same average annual
precipitation as Dallas, Texas, and much less than New York City, Houston, Atlanta, or New Orleans.
Higher amounts of rainfall occur as you move closer to the Cascades. King County owes its mild
climate to the influence of Puget Sound and the Pacific Ocean, which moderate the climate, and to
the protective barrier of the Cascade Mountain range, which blocks cold air from the interior.
Figure 14-2 King County Precipitation Map
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Rainfall in King County varies widely from city to city and area to area. The City of Seattle has an
average of 37 inches annually, while Enumclaw has an annual average of 57.9 inches and
Snoqualmie/North Bend has 61+ inches of precipitation. The majority of this precipitation occurs as
rain in the lowlands between October and early May with substantial snowpack in the Cascades
during the same time frames. Precipitation on Snoqualmie Pass in the unincorporated community
of Hyak (2800 feet) average 410 inches of snowfall from October to May.
High Wind and Tornados
High wind events are common in King County, especially during winter, with gusts frequently
reaching 40-45 mph and severe winds surpassing 90 mph. Certain areas of the county are more
prone to these events due to their geography and location relative to wind patterns.
The north Puget Sound region, particularly areas along the Strait of Juan de Fuca, regularly
experiences high winds during the winter. In certain conditions, the Strait acts as a wind funnel,
accelerating winds as they move eastward toward the interior of the region. Areas closer to the
water, such as Edmonds, Mukilteo, and Everett, are often more affected by these powerful gusts.
The build-up of high pressure east of the Cascades can trigger strong windstorms that surge through
lower passes in the Cascades, including Stampede Pass. These winds often impact communities
located to the east of the mountains, such as Enumclaw, which routinely experiences strong winds
due to its proximity to these wind corridors. The Enumclaw area, with its elevated position on the
foothills of the Cascades, is especially susceptible to wind gusts that can reach up to 70-80 mph.
Other parts of King County, such as the higher-elevation areas in Snoqualmie Pass and parts of the
foothills surrounding the Cascades, can also experience gusty winds, particularly when a low-
pressure system interacts with the mountainous terrain. During these systems, southerly winds are
often funneled between the Olympic and Cascade Mountains, creating a wind tunnel effect that can
intensify gusts in the lowlands. Additionally, south of Seattle, areas like Federal Way and Fife can
experience localized wind events as gusts push through the lower valleys.
14.3 Magnitude
Severe weather events in King County have the potential to cause significant disruptions, posing
both immediate and long-term risks to infrastructure, the economy, and public safety. High winds,
which can exceed 100 mph during certain storms, are a frequent cause of power outages, road
closures, and structural damage. The region also experiences intense heat, with temperatures
occasionally surpassing 110°F, and extreme cold, with lows dipping below -40°F, although these
cold extremes are rarer.
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Extreme Heat
Extreme heat is the number one cause of weather-related fatalities nationally. Current annual
losses in Washington State due to heat-related illness and heat-associated traumatic injury, death,
and productivity losses are calculated to be between $111 to $153 million annually. By 2030, heat-
related losses in labor productivity alone are projected to reach around $100 billion annually
nationally. A major factor that contributes to heat-related impacts is the fact that many residents
lack efficient cooling systems in their homes or businesses. A 2015 American Housing Survey data
shows that only 33.7% of Seattle area homes have air conditioning. For those aged 65 and older, the
percentage only jumps slightly, to 37%.2
Drought
Figure 14-3 shows the model median for projected percent change in April 1st snowpack over a 30-
year period compared to the 1980-2009 average. April 1st snowpack is an important indicator of
water stored in snow that will be available during the melt season. The brown areas on the map
indicate where snowpack is expected to decrease, with the most significant decline projected for
lower elevations in the Cascade Mountains.
Figure 14-3 Projected snowpack decline in King County 3
2 Seattle Office of Emergency Management (OEM), “Excessive Heat Events” City of Seattle CEMP – SHIVA (n.d.): p
9-6, https://www.seattle.gov/documents/Departments/Emergency/PlansOEM/SHIVA/SHIVAv7.0-Heat.pdf
3 UW Climate Impacts Group (CIG), “Climate Mapping for a Resilient Washington” University of Washington (n.d.):
https://data.cig.uw.edu/climatemapping/
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In the event of drought, the combined effect of reduced snowpack and warmer temperatures can
lead to severe water shortages, impacting agriculture, communities, and wildlife, including fish and
salmon. King County’s dependence on hydroelectric dams further complicates this issue, as drought
could affect the availability and cost of electricity, potentially leading to planned power outages
(brownouts) during severe conditions. These changes can have serious consequences, including
higher mortality rates for salmon and steelhead due to elevated water temperatures and low river
flows, negative impacts on local crops and livestock, and increased health risks, such as heat stress-
related emergency room visits. As drought becomes more common in the Northwest, driven by
variable rainfall patterns and rising temperatures, the risk of wildfires also increases, further
exacerbating the challenges for King County.
Winter Weather
King County is also vulnerable to extreme winter conditions, with heavy snowfalls and ice storms
disrupting transportation, power, and emergency services. While the region typically receives
moderate snow, events like the 2008 winter storm can paralyze the area for extended periods,
particularly in hilly communities such as Skyway, where limited resources exacerbate the effects of
severe weather. Given the rarity of extreme snow events, King County maintains a relatively low
budget for snow removal services. When major incidents do occur, vehicles and drivers can be
stranded almost anywhere in the county. Transportation impacts to buses, trains, roads, bridges
include snow routes, shelter needs, and power outages. The December 26, 1996 storm lasted 11
days. Multiple consecutive freezing days can threaten the lives of unsheltered and lower-income
individuals, requiring the opening of additional shelter beds or more heating assistance funding.
Heavy Precipitation
Intense precipitation is the primary cause of both river and urban flooding in King County. Areas
such as Snoqualmie, Auburn, and White River are particularly vulnerable to frequent flooding
following rain events. The larger, more destructive floods are often driven by atmospheric rivers—
narrow bands of concentrated water vapor in the atmosphere that can bring significant rainfall and
snow. The Pineapple Express, a type of atmospheric river, is a common source of severe weather,
where moisture picked up from warm areas of the Pacific Ocean near Hawaii is carried by the jet
stream and releases as intense precipitation when it rises over the Olympic and Cascade Mountains.
These atmospheric river events are major contributors to river flooding in King County.
Heavy rainstorms also lead to urban flooding, stressing the stormwater infrastructure and affecting
ground-floor structures and basements. This can cause widespread damage and pose a risk to
public safety, particularly in areas ill-equipped to manage such intense rainfall.
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High Wind
High wind events are common in King County, especially during winter, with gusts often reaching
40-45 mph and severe winds surpassing 90 mph. From the north Puget Sound region during the
winter season, the Strait of Juan de Fuca can also act as a wind funnel in the right conditions. High
pressure build-up in east of the Cascades can also cause strong windstorms that surge through
areas like Stampede Pass and the area immediately below it, Enumclaw.
These intense wind events often lead to widespread power outages, road and bridge closures, tree
damage, airport disruptions, and risks such as carbon monoxide poisoning and injuries to utility
workers, first responders, and the public. Notable examples of such events include the Inaugural
Day Windstorm on January 19, 1993, which saw winds exceed 90 mph in downtown Seattle, and the
Hanukkah Eve Windstorm on December 15, 2006, which caused significant damage to the Seattle
area power grid, leaving hundreds of thousands without power for weeks.
A particularly severe
event occurred on
November 19, 2024,
when Washington’s Puget
Sound region was struck
by an unprecedented
severe windstorm,
colloquially referred to as
a "Bomb Cyclone.” This
event was the result of
rapidly intensified storm
that experienced a
dramatic drop in
atmospheric pressure by
64 millibars in just 24
hours. This storm
generated powerful east
to southeast winds, with
wind gusts in the Seattle
Metropolitan Area
reaching 50–60 mph, while mountain areas saw gusts surpassing 70 mph. This intense storm caused
widespread destruction across King County, uprooting trees, downing powerlines, and leaving
approximately 520,000 customers without power. King County was the most severely affected
jurisdiction, with preliminary damage assessments estimating total losses at $17 million. The storm
also prompted a tornado warning and led to the sighting of a waterspout along the southwest coast
of Washington.
Tornado activity is relatively rare in the Pacific Northwest, but it has been recorded in the region,
including an EF1 tornado in Enumclaw in September 2009. Despite wind speeds reaching up to 110
mph, the most significant damage was caused by uprooted trees and roof damage, largely due to
November 20, 2024 bomb cyclone aftermath
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the preceding storm. Tornadoes are uncommon in the Puget Lowlands, though several have been
recorded. The Enhanced Fujita (EF) scale, which rates tornadoes from EF0 to EF5 based on wind
speed and damage, has noted tornadoes as strong as EF3 in the Puget Sound area.
14.4 Previous Occurrences
The majority of disaster declarations in King County are from severe weather events. Disasters are
usually declared for a combination of winter storms, mudslides, heavy rains, and straight-line winds.
The primary impacts and costs triggering these declarations include emergency protective measures
for, and damage to, utilities, roads, and bridges, and for costs associated with debris removal. A
recent example is the June 2021 Pacific Northwest Heat Dome, an event made 150 times more
likely because of climate change. The 2021 Heat Dome currently stands as the single most deadly
climate disaster event in Washington State with more than 125 reported heat related deaths
statewide, including 34 deaths in King County.
Table 14-1 Major Weather Disaster Declarations including King County
Date Hazard Description
November
2006
Rain Storm This event saw unusually intense rainfall in a short period,
leading to rapid runoff and increased flooding risks across
King County. The heavy rains overwhelmed the region’s
stormwater systems, causing localized flooding in urban
areas and exacerbating existing river flood conditions.
December
2006
Windstorm Hannukah Eve - Unusually intense levels of rainfall in a
very short period of time were immediately followed by
very heavy winds up to 69 miles per hour that felled
power poles and large, mature, healthy trees. The storm
overwhelmed Seattle City Light when 49% of its
customers lost power. 95% of customers were restored
within two days, but full restoration took a week
July 2009 Excessive Heat On July 29, 2009, the temperature reached 103˚at SeaTac
airport, an all-time record. Two people in Western
Washington died. The most brutal temperatures lasted
three days.4
August 2015 Windstorm The strongest August windstorm on record hit Western
Washington, with winds of 50-60 mph (46 mph at
4 Seattle Office of Emergency Management (OEM), “Excessive Heat Events” City of Seattle CEMP – SHIVA (n.d.): p 9-
4, https://www.seattle.gov/documents/Departments/Emergency/PlansOEM/SHIVA/SHIVAv7.0-Heat.pdf
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SeaTac). Almost half a million people lost power, two
people died from falling trees, two people died from
carbon monoxide poisoning, and four people were
injured.
August 2015 Excessive Heat Seattle’s hottest summer on record. The average high
temperature was 80.2 degrees Fahrenheit. July had 10
days with high temperatures in the 90s.
January 2019 Winter Storm The hefty snowfall (a daily record) bumped the city’s
monthly snowfall total to 20.2 inches, making February
2019 Seattle’s snowiest month in a half-century.
June 2021 Excessive Heat Between June 26 and July 2, 2021, an extreme heat event
caused by a “heat dome” descended upon the Pacific
Northwest, setting 128 all-time high temperature records
across Washington state and killing 126 Washingtonians
due to heat-related causes according to official
estimates.5 This includes 34 deaths in King County.6
December
2023
Rain Storm An atmospheric river event brought intense rainfall to
King County, significantly impacting local rivers, streams,
and urban drainage systems. This atmospheric river
caused widespread flooding and river overflow, leading to
property damage, transportation disruptions, and power
outages.
November
2024
Windstorm A bomb cyclone struck King County in November 2024,
causing widespread damage. This intense storm system
rapidly intensified, resulting in high winds, heavy rainfall,
and flooding. It caused power outages for over 520,000
customers and left an estimated $17 million in damages.
According to the US Drought Monitor, King County has experienced an increasing frequency of
moderate to extreme drought conditions over the past two decades. These conditions have become
5 UW Climate Impact Group (CIG), “In the Hot Seat: Saving Lives from Extreme Heat in Washington State”
University of Washington (2023): p. 1, https://cig.uw.edu/wp-content/uploads/sites/2/2023/06/CIG-Report-Heat-
202-pages.pdf
6 King County Executive Climate Office (ECO), “King County Extreme Heat Mitigation Strategy” (July 2024): p. 5,
https://cdn.kingcounty.gov/-/media/king-county/depts/executive/climate-office/documents/c2-
240802_13570m_kc-extreme-heat-
strategy_prnt.pdf?rev=2cceaee431a14df29323d98bd817cfe5&hash=2C0B0D0227F7100C58DF612DB2351820
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more pronounced in recent years, with significant spikes in extreme drought levels observed in
2015, 2019, and 2023. These periods of drought have been driven by a combination of low
snowpack, reduced rainfall, and higher-than-average temperatures, which have led to decreased
water availability in streams, rivers, and reservoirs.
Figure 14-4 Historic drought conditions for King County7
14.5 Probability of Future Occurrences
King County is projected to experience significant changes in weather patterns due to climate
change, particularly with regard to extreme heat and precipitation. All climate scenarios predict
hotter summers in the region. By the 2080s, the average maximum summer temperature is
expected to increase by 10.5°F (with a range of 7.4°F to 13.0°F). The number of days above 90°F will
also rise substantially, with projections indicating a median of 41 days per summer by the 2080s.
Additionally, nighttime temperatures are expected to increase, which is concerning from a public
health perspective. Nights with a humidex above 65°F are projected to occur 45 more nights (with a
range of 18-71 days), which can exacerbate heat-related health risks.
7 NIDIS, NOAA, “Drought Conditions for King County” The U.S. Drought Monitor (2024):
https://www.drought.gov/states/washington/county/King
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Figure 14-5 Projected change in frequency of extreme heat events in King County 8
In addition to extreme heat, King County is
likely to experience a decrease in summer
precipitation, intensifying drought
conditions. While projections for rainfall
are more uncertain due to the natural
variability of weather patterns in the
Northwest, the projections points to wetter
winters and drier summers in the future.
This shift in seasonal precipitation could
increase the risk of landslides, as more rain
in the winter may lead to greater soil
saturation. Furthermore, heavy
precipitation events are expected to
become more intense, with a projected
14% increase in intensity by the 2050s and
up to 30% by the 2080s. This is driven by
warmer air, which can hold more moisture,
resulting in the potential for more intense
rainfall events. These changes in
temperature and precipitation highlight the
need for adaptive strategies to address the increased risks of extreme weather events in the coming
decades.
14.6 Climate Change Considerations
Climate change is a significant concern for King County, as it is expected to alter the frequency,
intensity, and severity of extreme weather events in the region. These changes are projected to
result in hotter, drier summers and an increase in heavy rainfall events, which could lead to a range
of hazardous consequences, including floods, landslides, avalanches, droughts, and wildfires. The
economic impacts of these events could be severe, as communities are often unprepared for such
extreme weather.
In addition to the economic consequences, extreme weather events also pose a threat to public
health. For example, if global temperatures rise by 5.4 degrees Fahrenheit over pre-industrial levels,
some climate scenarios suggest that extreme heat events could result in hundreds of deaths in the
8 UW Climate Impacts Group (CIG), “Climate Mapping for a Resilient Washington” University of Washington (n.d.):
https://data.cig.uw.edu/climatemapping/
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Seattle area alone.9 Public health sensitivity to heat events is especially high in the Puget Sound
region due to the lack of widespread air conditioning. In response, Public Health Seattle-King County
has plans to activate cooling centers and issue public messaging during multiple days of heat in the
mid-80s. While global trends show a decrease in the number of cold events since 1950, some areas
in the Northern Hemisphere, including parts of the U.S., have experienced an increase in extreme
cold since 1990, potentially linked to changes in the polar vortex.
14.7 Impact Assessment
Below offers an overview on the impacts from severe weather events. Additional details on impacts
for each type of severe weather event are provided under 14.3 Magnitude.
Public Anyone present in King County at the time of a weather incident is
subject to the potential impacts of severe weather incidents. While the
likelihood of a winter weather incident is high, the likely of direct and
significant impacts is Moderate.
Impacts to residents may include personal property damages,
interruption of sports and recreation, extension of the daily business
commute, impacts to daycare and school closures, injuries, and
sheltering needs from power outages. Avalanche control may be
needed to reduce the impact to alpine and cross-country skiing
enterprises. Injuries and deaths do occur from avalanche impacts to
recreational skiers. Impacts from drought take time to materialize as
water shortage cause restrictions to water usage and issue of burn bans
to reduce the threat of wildfires, especially in suburban areas. Only the
most severe weather incidents have an impact on local employment.
Responders Portions of the population may be stranded or isolated from the results
of severe weather, like roads blocked by trees and power lines, snow-
and ice-covered roads, water or slides over roadways. Closure of the
mountain passes for heavy snow conditions or avalanche control is a
fairly common occurrence.
9 Evan Bush, “Seattle unprepared for deadly heat waves made worse by global warming, researchers say” The
Seattle Times. (June 14, 2019): https://www.seattletimes.com/seattle-news/environment/heat-waves-could-kill-
hundreds-more-in-seattle-as-globe-warms-researchers-say/.
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Excessive heat that extends over days or weeks or cold conditions for
similar timeframes may result in the need for cooling or warming
shelters. These especially impact the poor, elderly, young, and infirmed.
First responders will be impacted by limited road access, impacts of
heat and cold on operations. Conditions will require monitoring efforts
during incident response.
Continuity of
Operations
During the February 2019 snowstorm, King County took the
unprecedented step of closing many government offices to protect
employee safety. After two days, due to the growing amount of snow
and the need to resume services, offices were reopened. Even with the
reopening, many employees chose to telework due to safety concerns.
An earlier activation of the EOC for the 1996 snow/ice storm saw
activations for 11 days – 2 shifts per day when 16 inches of snow came
and stayed for weeks. During that time frame, buses were on snow
routes, up to 40% of the employees for King County government were
either unable to get to work or arrived very late. A major improvement
from 1996 to 2019 is that it is now much easier to telework, meaning
that non-public-facing positions can work remotely for days.
Hospitals, courts, detention facilities, businesses, law enforcement, fire
and emergency medical services were all severely impacted. Search and
Rescue volunteers transported medical personnel, emergency
management staff, and other essential employees to work and
between hospitals for the duration of the incident. During the February
2019 snowstorm, busses were on the most restrictive service routes
ever seen. These routes were established in response to previous snow
events. Similar impacts were observed for the January 2011 snow
storm that impaired King County government operations for 8 days.
Some damages were experienced at crucial facilities around the county.
See FEMA Disasters 1079 and 1817 above. The recent February 2019
snowstorm did not receive a disaster declaration.
During that time frame, most regional public services were impacted by
absenteeism, access restrictions to critical facilities, and damage to
vehicles like buses, police cruisers, and aid units. Busses and other
vehicles that use tire chains are especially vulnerable to breaking down,
which can delay a return to full service, even once the snow has
melted.
Property, Facilities,
and Infrastructure
Property
All structures in the county are subject to the direct impacts of severe
weather incidents. These same structures are subject to flood impacts
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where they may be in the flood plain. Structures along the coastline
(seawalls) may be eroded. Local urban flooding also occurs from storm
debris clogged sewers.
High winds that accompany winter weather fronts often cause
infrastructure damages, power outages, and communications
interruptions. Rain saturated soils may cause mudslides that close
roadways, damage bridges, and buried rail service interruptions
Private property damages to homes and vehicles from floods, trees
downed from wind and saturated soils are regular occurrences. Private
property experiencing repeated flood damages may require elevation
of the structure or offers of buy outs (mitigation efforts).
High winds, snow, and icy conditions can close airports or cause flight
delays and rerouting. Mountain pass conditions may be so severe that
they are closed to all traffic for days at a time. The floating bridges over
Lake Washington (I-90 and SR 520) experience closures for sustained
winds over 45 miles per hour. These closures extend the business
commute with increased traffic on surface streets and routes around
Lake Washington.
Impacts to emergency medical services from impacts to the roadways
of the county can delay response times, restrict emergency room staff
and supplies, and result in under staffing EMS and hospitals during
severe weather emergencies.
Facilities
Severe weather disrupts the regular schedule of patient visits and
regularly-scheduled appointments for chronic care. Severe weather
also can cause more demand on the health system as people are
injured or are unable to leave the hospital to return home. Any
disruptions to electricity and water supply also can be a threat, though
hospitals generally maintain backup generators.
During severe cold or warm spells, public health may be required to
provide additional patient transport services and to canvass for
homeless populations that may be in need of shelter. During the
February 2019 snowstorm, hospitals suffered major staffing shortages
as doctors and nurses were unable to get to work. Staff had to work
longer than normal hours and potentially stay temporarily at or near
the hospital.
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Although both requiring the expansion of sheltering services, heat and
cold differ because older and less health populations are especially at
risk to hot temperatures. One of the most famous examples is the 1995
Chicago heat wave, during with 739 people lost their lives, with the city
unprepared to provide support to residents who may be home bound
or offer sufficient cooling centers to support residents. In Seattle, where
few residents have air conditioners, deaths from heat events are a
growing threat.
Infrastructure
• Power: Downed trees caused by high winds and rain saturated
soils can damage transmission lines and cause power outages in
local areas for hours to days when multiple occurrences are
experienced. Utility crews from Puget Sound Energy, Bonneville
Power and Seattle City Light work around the clock to restore
services. The Inaugural Day Windstorm left 750,000 customers
without power. The Hanukkah Eve Windstorm winds and
subsequent heavy rains cut electricity to more than 1.8 million
customers, hundreds of thousand remained without power for
days. Downed power lines pose an electrocution hazard to
motorists, pedestrians and any unsuspecting by-standers.
During extremely hot temperatures, demands on the power
system can increase, especially as more residents install air
conditioning. As a winter-peaking system, however, this power
demand will still likely be lower than current winter demand.
• Water/Wastewater: Water and wastewater systems are
vulnerable to a multi-day loss of power as well as to serious
flooding. In February 2017, as a result of heavy rains, high tides,
and other severe weather, an equipment failure at King
County’s West Point Wastewater Treatment Plan led to the
dumping of over 235 million gallons of untreated wastewater
into Puget Sound. Drought can also impact water systems as
water levels in reservoirs and groundwater wells drop.
• Transportation: Events that impact transportation can include
severe snow, ice, wind, and rain. Storms may cause downed
trees and snow or ice that temporarily blocks roadways or can
cause large floods that can wash out or undermine roads and
bridges. For many parts of the state and county, such as around
the town of Skykomish, the loss of a single route due flooding
can completely cut the community off from the rest of the
county. This is especially a problem in the eastern parts of the
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county that are more rural and have fewer transportation route
options.
• Communications: Systems can be knocked out by high winds or
loss of power transmission. While the move to cell phones has
reduced the vulnerability of telephone lines to outage caused
by trees, a multi-day loss of power can still shut down a cell
transmission site. Furthermore, high winds can damage or
destroy critical equipment on cell towers. Most equipment is
built to withstand inclement weather; however, especially
severe conditions could still lead to outages.
Environment Severe weather can have impacts to the environment through flooding
and floodplain damages to salmon and steelhead habitat, wetland
impacts to amphibians and reptiles, and bird sanctuaries. This can occur
from both too much water (flooding or dam failure) or too little
snowpack and resulting drought conditions. Hillside destabilization can
occur where soil geology and saturation of soils occur.
The moisture content of vegetation drops throughout the summer. Dry
conditions can result in an increase in the threat of wildfires from
lightning strikes, unattended campfires, fireworks, sparks from
automobiles, cigarettes thrown from cars on roadways and other heat
sources.
One dilemma of drought conditions is the balance between human
water needs and the protection of the environment including plants,
wildlife, and fish that require minimum stream flows to support their
annual spawning migrations. Dry conditions also contribute to higher
water temperatures, which causes increased salmon mortality.
Economy There are several local ski areas important to King County: Crystal
Mountain (Chinook Pass); Alpental, Hyak, and Ski Acres (Snoqualmie
Pass); and Steven’s Pass (Steven’s Pass). Ski area closures can occur
from both large snowfalls and where snow is too light or melts off. This
can impact seasonal employment at the ski areas.
Also associated with the passes, as outlined in the avalanche chapter, a
WSDOT study claimed that a four-day closure at Snoqualmie Pass in the
winter of 2007/2008 cost the state $27.9M in economic output, 170
jobs, and $1.42M in state revenue (2008 dollars).
Businesses can be severely impacted when weather events impede
mobility during high seasons, such as around the holidays. Since a large
percentage of annual personal spending is spent during the November-
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December season, negative weather limits access to stores and can
cause stores to close.
Drought conditions can impact the regional agricultural output of fruits,
vegetables, and flowers grown in all the major river basin areas of King
County. Regional drought conditions can impact generation of
hydroelectric power and drive up electric rates as well as increase
usage during hot summers.
The most serious and longest-lasting impacts may be to low-income
individuals and families who may lose jobs or days of wages due to
snow closures. Debt traps caused by missed bills due to lost wages can
damage a family for months or years.
Public Confidence in
Governance
The 2008 and 2011 snowstorms highlighted the shortage of snowplows
and the management of the general response to the snow incident in
the City of Seattle.
The February 2019 event can be regarded by many as much more
successful on the public perception front. Successful coordination of a
regional call center in the Emergency Operations Center (EOC) to
support other county departments and take snow plowing requests
helped ensure the public always had someone to call. The county also
maintained substantial engagement with media outlets. The County
Executive was fully involved as well, helping to boost awareness and
public perception that county government was engaged in the storm
recovery effort.
14.8 Vulnerability Assessment
Below offers an overview on vulnerability from severe weather events. Additional details on
vulnerability for each type of severe weather event is provided under 14.3 Magnitude.
Vulnerable
Populations
Severe weather events, while usually concentrating impacts on
infrastructure and agriculture, can seriously threaten the lives of
vulnerable people. Cold and hot weather events can lead to an increase
in fatalities among the elderly and homeless populations. Immigrant
and low-income populations also have been known to succumb by
carbon monoxide poisoning that can occur when generators or grills
are lit indoors and without proper ventilation. Snow can trap people
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indoors for days, something especially threatening for people with food
insecurity or chronic health conditions that require access to medical
services. Any disruption to the economy is also especially threatening
to those who are low-income or who work in hourly work or in the
service sector. When those jobs are not open, they frequently do not
pay wages, which can threaten the entire livelihood of a low-income
family.
Unsheltered populations
Populations needing shelter are especially exposed during heat and
cold events. Since King County has a moderate climate, many of these
populations are unprepared. Cold events may require opening
additional shelter spaces and canvassing areas to offer shelter services.
Immigrant populations and those with limited English proficiency
Populations with limited English proficiency or who are inexperienced
with Northwestern climate are more likely to take risky actions, like
operating a generator or grill indoors for heat. These populations are
also less likely to receive information and warnings about weather
systems and to know where to go for help.
Low-income and minimum-wage populations
Populations working in low-wage professions such as extractive
industries and service industries can be severely impacted from multi-
day weather events that impact transportation systems. These events
can trigger a long-term decline in living standards or even
homelessness in these populations.
People dependent on public transportation
Public transit moved to the most restrictive routes ever recorded
during the February 2019 snowstorm. These cutbacks had apparent
disproportionate impacts on underserved areas, including some areas
with populations dependent on transit. When transit services are cut, it
can be impossible for these populations to get to work or
appointments.
People with chronic medical conditions
People requiring regular care from doctors are negatively impacted by
severe weather events. During heatwaves, people with chronic
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illnesses, especially heart and respiratory conditions, are also
disproportionately impacted.
Residents down private roads
Private roads are not eligible to be cleared by public snow removal
services. Many homeowner’s associations contract with the same set of
snow removal companies. These companies may become overwhelmed
during long-running events.
Service industry during peak periods
Many service businesses, especially retail, are heavily dependent on
income earned during certain months of the year. A major event
around the Christmas holidays, for example, can threaten the viability
of many businesses.
All residents during multi-day events
Although it is recommend having two weeks of food and supplies
available during these severe weather events, few residents follow this
guidance, regardless of income. After more than a few days, many
residents will run out of food for themselves and any pets.
Property Buildings on slopes of greater than 40% grade
Landslides are a major secondary hazard of severe precipitation events.
Buildings on or near slopes of greater than 40% grade are most at-risk.
Environment Severe weather events can have significant impacts on ecosystems,
disrupting habitats and threatening biodiversity in various ways. For
example, strong winds can lead to tree falls, habitat destruction, and
loss of vegetation, while heavy precipitation can cause soil erosion and
degradation, disrupting both wildlife and aquatic habitats. This damage
to soil and vegetation can also increase the risk of landslides, further
destabilizing the environment. During extreme heat events, prolonged
heat stress can reduce plant productivity, heighten susceptibility to
diseases, and lead to higher mortality rates for trees and other
vegetation. Drought conditions further exacerbate these issues by
reducing stream and river flows, which negatively impacts aquatic
species, particularly those that rely on specific water flow and
temperature conditions, like salmon. As vegetation dies off or becomes
desiccated, ecosystems become more vulnerable to wildfires,
compounding the environmental disruption.
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Operations Power
Power transmission systems, especially power lines, are frequently
damaged during storms with high winds by falling trees. During major
wind events, it is not uncommon to have hundreds of thousands of
residents without power.
Water/Wastewater
Damage to water and wastewater facilities can occur due to a
secondary hazard, flooding and tidal surge. These facilities are often
built in low-lying areas. The severe damage and release of untreated
water that occurred at King County’s West Point Treatment Plan
occurred during a severe weather event.
Waste Management
Garbage pickup can be delayed for weeks. This causes significant public
frustration.
Transportation
Rural transportation routes are lower priority and may not even be
cleared at all during a snow event.
Airports and Travelers
Airport facilities are frequently impacted by severe weather events, but
often have plans and procedures to contain disruption. During multi-
day events, however, passengers can be stranded and there can be a
shortage of hotel rooms since many airlines contract with the same
hotels.
AGENDA ITEM #1. b)
Risk Assessment
Scoring
1 Location
Ha
z
a
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2 Probability
3 Magnitude
2 Public
Im
p
a
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2 Responders
2 COP
2 PFI
2 Economy
2 Environment
2 PCG
2 People
Vu
l
n
e
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a
b
i
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2 Property
2 Environment
2 Operations
2 People
Ri
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2 Property
2 Environment
2 Operations
Moderate Overall Risk
PC: King County Sheriff’s Office
Chapter 15Terrorism
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Chapter 15: Terrorism
15.1 Hazard Description
Terrorism, as defined under Title 18 of the United States Code, is categorized into two primary
types: international terrorism and domestic terrorism. Both forms involve acts of violence or danger
to human life that violate U.S. criminal laws but differ in their geographic focus and intent.
International terrorism: means activities that—violent acts or acts dangerous to human life that are
a violation of the criminal laws of the United States or of any State, or that would be a criminal
violation if committed within the jurisdiction of the United States or of any State; appear to be
intended—(i) to intimidate or coerce a civilian population; (ii) to influence the policy of a
government by intimidation or coercion; or (iii) to affect the conduct of a government by mass
destruction, assassination, or kidnapping. [These acts] occur primarily outside the territorial
jurisdiction of the United States […].
Domestic terrorism: means activities that—involve acts dangerous to human life that are a
violation of the criminal laws of the United States or of any State; appear to be intended—(i) to
intimidate or coerce a civilian population; (ii) to influence the policy of a government by
intimidation or coercion; or (iii) to affect the conduct of a government by mass destruction,
assassination, or kidnapping. [This] occur primarily within the territorial jurisdiction of the United
States.1
The Federal Bureau of Investigation (FBI) designates terrorism as its top investigative priority,
further defines these two primary types as:
• International terrorism: Perpetrated by individuals and/or groups inspired by or associated
with designated foreign terrorist organizations or nations (state-sponsored).
• Domestic terrorism: Perpetrated by individuals and/or groups inspired by or associated
with primarily U.S.-based movements that espouse extremist ideologies of a political,
religious, social, racial, or environmental nature.
Domestic terrorism represents a complex and multifaceted threat to communities across the United
States. The motivations behind domestic terrorist activities are diverse, and the consequences—
both direct and indirect—are far-reaching. Understanding the nature of domestic terrorism and its
potential impacts is essential for crafting effective mitigation strategies, enhancing preparedness,
and ensuring a coordinated response to protect public safety and critical infrastructure.
1 Definitions. 2015. 18 USC §2331. https://uscode.house.gov/view.xhtml?path=/prelim@title18
/part1/chapter113B&edition=prelim.
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Domestic terrorism in the United States can be driven by various extremist ideologies, all of which
fall under the definition of Domestically Violent Extremists (DVE). DVEs Listed in Table 15-1, these
groups and individuals often have distinct motivations and methods of operation:
Table 15-1 US Domestically Violent Extremists (DVE) defined by FBI and DHS2
Group Name Description
Animal
Rights/Environmental
Violent Extremists
(AREVEs)
Groups or individuals who facilitate or engage in the unlawful use or
threat of force or violence or intent to intimidate or coerce, in
furtherance of political and/or social agendas by those seeking to end
or mitigate perceived cruelty, harm, or exploitation of animals or
perceived exploitation or destruction of natural resources and the
environment.
Anti-Government or
Anti-Authority Violent
Extremism
The potentially unlawful use or threat of force or violence in
furtherance of ideological agendas, derived from anti-government or
anti-authority sentiment, including opposition to perceived economic,
social, or racial hierarchies, or perceived government overreach,
negligence, or illegitimacy.
Homegrown Violent
Extremists (HVEs)
A person of any citizenship who has lived and/or operated primarily in
the United States or its territories who advocates, is engaged in, or is
preparing to engage in ideologically motivated terrorist activities
(including providing support to terrorism) in furtherance of political or
social objectives promoted by a foreign terrorist organization but is
acting independently of direction by a foreign terrorist organization.
Racially (or Ethically)
Motivated Violent
Extremists (RMVE)
Groups or individuals who facilitate or engage in the potentially
unlawful use or threat of force or violence with intent to intimidate or
coerce, in furtherance of political and/or social agendas, which are
deemed to derive from bias, often related to race or ethnicity, held by
the actor against others, including a given population or group.
In addition to organized groups, domestic terrorism can also involve lone actors—individuals who
commit violent acts independently, often motivated by personal grievances or a desire to retaliate
against perceived injustices. These individuals, sometimes referred to as "lone wolves," may have
no formal affiliation with extremist groups but are driven by personal ideologies or emotional
distress. A common example of this type of terrorism is school shootings, where individuals, often
with a history of social isolation or personal trauma, resort to violence to express their anger,
2 https://www.fbi.gov/file-repository/fbi-dhs-domestic-terrorism-definitions-terminology-methodology.pdf/view
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frustration, or desire for retribution. Another to consider is violent attacks against LGBTQ gathering
spaces and other protected classes of people.
15.2 Location
King County plays a prominent role as a major economic, governmental, and transportation hub in
Washington State. It is the state’s largest county, with a population exceeding 2.2 million residents.
It is geographically diverse, featuring a mix of high-density urban areas along the shores of Puget
Sound, suburban communities to the east, and rural areas to the southeast. Seattle, the county’s
largest city, is home to the eighth-largest port and the eleventh-busiest airport in the United States,
with Seattle-Tacoma International Airport serving as a primary entry point for international
travelers, particularly from the Pacific. King County also boasts the state’s largest labor market, with
a range of key economic sectors. These include government operations centered in Seattle,
technology hubs in Bellevue and Redmond, manufacturing in South King County, research facilities
associated with institutions like the University of Washington, and agricultural activities in the
Snoqualmie Valley. All which could be at risk of being targeted by various extremist groups, each
seeking to disrupt specific sectors or make a political statement through acts of violence or
intimidation.
Figure 15-1 Domestic Terrorism-Related Incidents by Category, from 2010 through 20213
Each domestic terrorist group has
distinct goals and motivations, and the
locations they target for attacks reflect
their ideological intentions and desired
impact.
• Animal Rights/Environmental Violent
Extremists (AREVEs), who are
concerned with the well-being of
animals or environmental degradation,
often target research laboratories
conducting animal testing, agricultural
facilities such as farms or
slaughterhouses, and environmental
impact areas like logging or mining
sites. They may also focus on corporate headquarters with large environmental footprints
or government buildings involved in the regulation of environmental issues. Washington is
the 4th highest state in the U.S. for individuals radicalized with AREVE.
3 https://www.gao.gov/blog/rising-threat-domestic-terrorism-u.s.-and-federal-efforts-combat-it
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• Anti-Government or Anti-Authority Violent Extremists primarily target government
institutions and operations, including law enforcement and military facilities. Their focus
also extends to critical infrastructure—such as power grids or water systems—political
institutions like capitol buildings, and public areas of symbolic significance, such as
monuments or government offices, to disrupt the legitimacy of state authority.
• Homegrown Violent Extremists (HVEs), inspired by foreign terrorist ideologies but acting
independently, are inclined to target U.S. government buildings, military and law
enforcement facilities, transportation hubs like airports and bus terminals, and public
venues or events, where their attacks can gain maximum visibility and cause widespread
disruption.
• Racially (or Ethnically) Motivated Violent Extremists (RMVEs) often focus on areas that serve
minority communities. These may include minority neighborhoods, schools with diverse
student bodies, religious institutions such as churches, synagogues, or mosques, and civic
organizations advocating for racial equity and social justice. In the Washington State 2022,
Domestic Terrorism Study, participants from the Jewish, Muslim, immigrant, and Asian
American and Pacific Islander communities expressed significant level of fear over potential
use of violence against their community.4
• Lone Wolves, individuals who are motivated by personal grievances or emotional distress,
typically target schools, workplaces, places of worship, night clubs, and public spaces with
high visibility, aiming for maximum casualties or media attention. They may also target
government buildings or institutions they believe have wronged them in some way, acting
without the support or coordination of larger extremist groups.
15.3 Magnitude
Terrorism is designed to instill fear in its intended audience, disrupting daily life and making
ordinary activities feel dangerous. It creates an environment where people are afraid to attend
events, send their children to school, or even gather in places of worship. The scope of domestic
terrorism has expanded significantly in recent years. The number of FBI investigations into domestic
terrorism has more than doubled since 2020, with open investigations skyrocketing from 1,981 in
Fiscal Year 2013 to 9,049 in FY 2021. Over the past decade, investigations into domestic terrorism
have surged by 357%. This increase is most pronounced in states with major metropolitan areas,
such as Seattle, Washington.
4 https://agportal-s3bucket.s3.amazonaws.com/2022%20Domestic%20Terrorism%20Study.pdf
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Figure 15-2 Domestic Terrorism Incidents by State, 2010 through 2021 5
Domestic terrorism threats continue to evolve rapidly, and combating them requires close
coordination between the FBI, the Department of Homeland Security (DHS), and other federal,
state, and local agencies. In Washington State, the Washington State Fusion Center serves as the
coordination hub for federal, local, and private sector partners involved in preventing, responding
to, and recovering from emergencies, including terrorist threats. The Fusion Center also tracks over
800 large gatherings annually in King County, encompassing events like parades, festivals, and
sporting events that draw large crowds.
Mass gatherings, particularly open-access events, remain a primary target for domestic terrorists.
These events, such as marathons, parades, protests, rallies, and festivals, are attractive to
extremists due to their public accessibility, the availability of detailed schedules, and the generally
unrestricted entry. Terrorists may also target gatherings near high-security events, such as tailgates
adjacent to major sporting events. Based on previous attacks, extremists are likely to continue
targeting civilian locations at such gatherings, exploiting perceived security vulnerabilities.
5 https://www.gao.gov/blog/rising-threat-domestic-terrorism-u.s.-and-federal-efforts-combat-it
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Terrorist attacks differ significantly from other types of man-made hazards, and their unique
characteristics often result in both immediate and long-term impacts on communities. For example,
incidents involving hazardous materials like chemical, biological, or radioactive agents are
particularly challenging because the presence of the threat may not be immediately identifiable,
complicating response efforts and posing serious risks to public health and safety. In addition to
physical dangers, terrorist attacks cause substantial emotional and psychological distress, evoking
intense reactions such as fear, anxiety, and anger, which can hinder recovery and affect first
responders. Furthermore, the economic toll of terrorism is often much greater than the direct cost
of the attack. Even failed terrorist attempts can result in significant financial losses, particularly in
sectors like critical infrastructure and government operations, as the long-term costs of heightened
security measures and the recovery process can far exceed the cost of the attack itself.
15.4 Previous Occurrences
Prior to the attacks on September 11, 2001, there were less than a dozen major terrorist events in
Washington State. Since then, violent extremism has become commonplace, on a global and
national scale, and the number of local terrorism and violent extremism cases continue to rise.6
Some of the most notorious terror cases in Washington State include the arrest of Ahmed Ressam,
the “Millennium Bomber,” in December 1999, the Earth Liberation Front (ELF) firebombing of
University of Washington’s (UW) horticulture center in May 2001, and the foiled Seattle Military
Entrance Processing Station attack plot in 2011.
Table 15-2 Past terrorist occurrences in Washington state and King County
Date Description
January 17, 2011 Kevin Harpham, an admitted white supremacist, placed a remote-
controlled backpack improvised explosive device (IED), with rat-poison
coated shrapnel, at a park bench near the marching route on the morning
of the Martin Luther King Jr. Day Parade in Spokane, WA. Prosecutors said
the device was “constructed with a clear, lethal purpose,” and Harpham
said it was intended to protest social concepts, such as unity and
multiculturalism.7
May 11, 2011 Joseph Brice of Clarkston WA was arrested for assembling, practicing, and
detonating explosive devices after an incident that occurred on April 18,
6 United Nations Development Programme. 2016. Prevent Violent Extremism Through Promoting Inclusive
Development, Tolerance and Respect for Diversity. Accessed online on 8/26/19 from
https://www.undp.org/content/dam/norway/undp-ogc/documents/Discussion%20Paper%20-
%20Preventing%20Violent%20Extremism%20by%20Promoting%20Inclusive%20%20Development.pdf.
7 Clouse, Thomas. December 20, 2011. MLK bomb maker gets 32 years in prison. The Spokane Spokesman-Review.
Accessed online on 8/26/19 from https://www.spokesman.com/stories/2011/dec/20/mlk-parade-bomber-seeks-
guilty-plea-withdrawal/.
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2010, when an explosive device he made prematurely ignited, causing him
significant injuries. He had a YouTube channel called “Strength of Allah,”
where he posted the videos in an attempt to support terrorism.8
June 22, 2011 Abu Khalid Abdul-Latif and Walli Mujahidh were arrested for planning to
attack the Military Entrance Processing Station (MEPS) in Seattle with
machine guns and grenades after previously planning, but discounting, an
attack at Joint Base Lewis McChord (JBLM). According to FBI investigators,
“Abdul-Latif said that ‘jihad’ in America should be a ‘physical jihad,’ and
not just ‘media jihad’.”9
September 8, 2011 Michael McCright was arrested and charged with second-degree assault
for a July 2011 incident where he intentionally swerved his vehicle at a
government-plated vehicle occupied by two U.S. Marines in Seattle.
Known on the Internet as “Mikhail Jihad,” McCright had ties to Abu Khalid
Abdul-Latif, a man convicted of plotting to kill federal employees and
military recruits in Seattle, WA.10
October 27, 2012
Abdisalan Hussein Ali, a 22-year old born in Somalia but raised in Seattle and
Minnesota, was the third American killed as an al-Shabaab suicide bomber in
Mogadishu. Ali was reportedly one of two bombers in an attack that killed
“scores of African Union peacekeepers.” He arrived in Seattle in 2000 and
moved to Minneapolis before being recruited into al-Shabaab and travelling to
Somalia in 2008.11
July 18, 2014 Ali Muhammad Brown was arrested after killing four people in WA and a
college student in NJ, as part of a personal vengeance against the U.S.
government for its actions in the Middle East. In 2004, he was arrested
and prosecuted for his role in a bank fraud scheme to finance fighters
traveling abroad, and had known links to a disrupted terror cell in Seattle,
WA and Bly, OR in 1999.12
8 Pignolet, Jennifer. Wednesday, June 12, 2013. Clarkston man convicted of trying to aid terrorists The Spokane
Spokesman-Review. Accessed online on 8/26/19 from https://www.spokesman.com/stories/2013/jun/12/bomb-
maker-sentenced/.
9 The Associated Press. June 5, 2012. Seattle terror suspect wants evidence tossed. Fox News. Accessed online on
8/26/19 from https://www.foxnews.com/us/seattle-terror-suspect-wants-evidence-tossed#ixzz28jz1MkOE.
10 Carter, Mike. May 29, 2012. Felon admits he tried to run Marines off I-5. The Seattle Times. Accessed online on
8/26/19 from https://www.seattletimes.com/seattle-news/felon-admits-he-tried-to-run-marines-off-i-5/.
11 Kron, Josh. October 30, 2011. American Identified as Bomber in Attack on African Union in Somalia. The New
York Times. Accessed online on 8/26/19 from https://www.nytimes.com/2011/10/31/world/africa/shabab-
identify-american-as-bomber-in-somalia-attack.html?_r=0.
12 Collins, Laura. September 18, 2014. Revealed, one man's terrifying 'jihad' on U.S. soil: Extremist 'executed four in
revenge for American attacks in the Middle East and carried out bank fraud for the Cause'. Daily Mail Online.
Accessed online on 8/26/19 from https://www.dailymail.co.uk/news/article-2759901/Revealed-terrifying-one-
man-jihad-U-S-soil-Extremist-executed-four-revenge-American-attacks-Middle-East-carried-bank-fraud-
Cause.html.
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January 1, 2014 Musab Masmari attempted to set fire to a gay nightclub on Capitol Hill in
Seattle, WA by spilling gasoline down a set of stairs and lighting it, while
750 people packed the club's New Year’s Eve event. According to
investigative documents, Masmari told a friend that “homosexuals should
be exterminated.” In July 2014, he was sentenced to ten years in federal
prison for arson.13
August 25, 2017 Melvin Neifert from Selah was arrested and charged with receiving
incendiary explosive device materials—specifically, potassium nitrate and
other materials to make a potassium nitrate-sugar bomb—that were to be
used in connection with the 2016 May Day events. Federal authorities
seized evidence and questioned Neifert on May 1, the same day anti-
capitalist demonstrations took place in Seattle.14
March 31, 2017 Muna Osman Jama of Reston VA and Hinda Osman Dhirane of Kent WA
were sentenced to 12 years and 11 years respectively, after being found
guilty of conspiracy to provide material support to al-Shabaab. The two
reportedly organized an all-female fundraising group, called the “Group of
Fifteen,” who provided monthly payments to al-Shabaab; facilitating and
tracking money sent through conduits in Kenya and Somalia.15
March 26, 2018 Thanh Cong Phan from Everett was arrested after mailing at least 11
suspicious packages to multiple military and government facilities in the
Washington, D.C. metropolitan area, which contained potential
destructive devices. He was charged with shipping of explosive materials,
after the packages were found to contain small amounts of black explosive
powder.16
13 Carter, Mike. July 31, 2014. Man who set fire in Capitol Hill nightclub sentenced to 10 years. The Seattle Times.
Accessed online on 8/26/19 from https://www.seattletimes.com/seattle-news/man-who-set-fire-in-capitol-hill-
nightclub-sentenced-to-10-years/.
14 Meyers, Donald W. August 31, 2016. Bail decision delayed in Selah explosives case. The Seattle Times. Accessed
online on 8/26/19 from https://www.seattletimes.com/seattle-news/crime/bail-decision-delayed-in-selah-
explosives-case/.
15 Department of Justice. Friday, March 31, 2017. Two Women Sentenced for Providing Material Support to
Terrorists. Accessed online on 8/26/19 from https://www.justice.gov/opa/pr/two-women-sentenced-providing-
material-support-terrorists.
16 Shayanian, Sara. March 28, 2018. Man charged with sending explosives to D.C. military sites. United Press
Internationa. Accessed online on 8/26/19 from https://www.upi.com/Top_News/US/2018/03/28/Man-charged-
with-sending-explosives-to-DC-military-sites/5591522255789/.
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15.5 Probability of Future Occurrences
The probability of domestic terrorist risks in King County, Washington, is a complex and evolving
concern, influenced by a range of factors including current security measures, historical incidents,
and future events such as the 2026 World Cup, which will be hosted in Seattle. Domestic terrorist
attacks are inherently difficult to predict and prevent due to their unpredictable nature and the
tendency of perpetrators to blend into society undetected by law enforcement. These attacks are
often carried out without warning, complicating efforts to identify potential threats in advance.
King County, being a major urban center and home to Seattle—one of the host cities for the 2026
World Cup—faces an increased risk of domestic terrorism, particularly in the lead-up to this
international event. Large-scale events like the World Cup attract global attention and a significant
influx of visitors, making them prime targets for domestic and international terrorists aiming to
cause disruption or gain media attention.
15.6 Impact Assessment
Public Certain groups within King County are more vulnerable to targeted attacks by
Domestic Violent Extremists (DVEs), but the broader population is susceptible to
the impacts of terrorism as a whole. The county's population as a whole remains
vulnerable to the broader consequences of terrorism. Public gatherings such as
marathons, protests, or festivals, as well as everyday locations like schools and
workplaces, are potential sites of attack, exposing civilians across the county to
direct harm. Additionally, the emotional and psychological toll of terrorist
attacks—fear, anxiety, and anger—will affect not only those directly targeted but
also the wider community, potentially altering everyday behaviors and impacting
mental health. The economic consequences of such attacks, including
disruptions to business and public services, further affect the county's residents
at large.
Responders First responders—including law enforcement, firefighters, emergency medical
services (EMS), and disaster recovery teams—face immediate risks when
responding to terrorism-related incidents, especially when dealing with
hazardous materials, active shooter situations, or explosive devices. The physical
danger posed by these incidents places responders at risk of injury or death.
Continuity of
Operations
Government facilities and employees are a common target for anti-government
extremists, and attacks on these facilities can severely disrupt daily operations
for extended periods. These disruptions can range from temporary shutdowns to
long-term closures, requiring significant recovery efforts. Essential services such
as public health, social services, and law enforcement could be delayed or
interrupted, affecting the county's ability to serve its residents effectively.
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Property,
Facilities, and
Infrastructure
Property
Property, including commercial buildings, venues, vehicles, places of worship, or
other areas are often damaged or destroyed during terror incidents. Trauma
from the incident can prevent the rebuilding of the facility in the same place.
Facilities
When facilities are targeted, the immediate impact is often physical destruction
or damage to the structure, systems, and equipment within. Employees and
existing patients could become injured or killed. Even in the event they are not
targeted, facilities could still become overwhelmed with patients in the
aftermath of attacks.
Infrastructure
• Energy: Energy facilities, including fuel pipelines, are common targets for
terrorists and saboteurs around the world. Many power facilities, such as
neighborhood substations, are relatively unguarded and, if lost, can have
immediate impacts on people and property in an area. Cyber-attacks are one
area where a large-scale attack on the energy system could cause widespread
disruption.
• Water/Wastewater: Water systems are considered a high-impact potential
target. A chemical attack on a water system, if not immediately detected,
could harm or kill thousands, depending on the size of the water-system
targeted.
• Transportation: transportation systems, especially public transit, have been
targets around the world, such as in the Madrid Train Bombings or the
London Subway Bombings. Attacks on busses are also common. These
incidents can cause a loss in public confidence in the transit system.
Furthermore, an attack on a tunnel, such as the I-90 tunnel across Lake
Washington, can impede mobility in our region over the long-term.
• Communications: Communications infrastructure, such as cell towers, are
relatively redundant and so somewhat less vulnerable to terrorist attacks.
There is a huge vulnerability, however, to cyber-terrorism, which can take
multiple facilities offline quickly.
Environment A major attack can pollute the environment and poison water and food sources.
This can have far-reaching, long-term consequences and damage animal and
plant life as well as people.
Economy In addition to the economic costs of stepped-up security, attacks can have a
huge impact on a region’s economy. Places seen as less safe are less attractive to
investors or visitors. Often, terrorist attacks attempt to destroy part of the
economy by killing tourists or destroying an important piece of infrastructure.
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Public
Confidence in
Governance
A failure to protect the public from a terrorist attack, even one that is thwarted
at the last moment, can cause a total failure in public confidence in government.
As seen after 9/11/2001 or after attacks by white supremacists against African-
American or Jewish congregations, groups begin to feel isolated, threatened, and
isolated from the community. This is especially true in cases where government
fails to quickly reassure impacted communities and support them morally and
with security resources.
15.7 Vulnerability Assessment
Vulnerable
Populations
Certain groups, particularly those from protected classes, are
particularly vulnerable to attacks by domestic terrorists. These
individuals or communities may be specifically targeted due to their
race, religion, ethnicity, gender identity, sexual orientation, or other
protected characteristics. Vulnerability arises because these groups are
often seen as symbols of the values or causes that extremists oppose,
making them more likely to be victims of violence, discrimination, or
intimidation. Terrorist attacks and attempted attacks in the northwest
have been motivated by white supremacy (targeting non-white
populations), xenophobia (targeting immigrants),
homophobia/transphobia (targeting gathering places of gay, lesbian,
and transgendered people), and anti-religious attacks against Muslims,
Jews, Christians, or other religious groups.
Individuals in positions of power—such as government officials and
those involved in corporations perceived as targets of domestic
extremist groups—are also particularly vulnerable to attacks by
domestic terrorists.
Terrorists have increasingly targeted mass-gatherings in densely
populated or high profile areas. Consequently, any major urban area in
Washington State could be considered at-risk as well as any crowded or
high profile critical infrastructure. The specific motivations of terrorists
will largely dictate target selection.
Property Infrastructure systems such as dams, water systems, bridges, and
public buildings are high-value targets to terrorists that both stand for
government order and, when lost, can cause significant regional harm
to people, property, and the economy.
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Environment Extremist can often exploit a range of environmental vulnerabilities
through attacks such as contaminating the city’s water supply, using
hazardous chemicals that could seep into the various ecosystems .
Operations A new challenge that is emerging is the increasing use of terror tactics
by non-terrorists. A number of evolved weapons, tactics, and targets
have emerged through the sheer volume of attacks within the last
decade. This normalization of violence has been further exacerbated by
extensive media coverage and the ease by which detailed instruction
manuals, ‘how-to’ videos, and online forums dedicated to weapons,
explosives, and tactics. It is “essentially shared community content,
easily accessible for extremists of all stripes to consume and put into
action” including those with no affiliation to foreign or domestic
extremism ideologies.17 Lessons learned from past attempts continue
to shape the means by which attackers develop plots—the push for
using small arms, edged-weapons and vehicle ramming against soft
targets—instead of the often-failed large-scale attacks.
17 Johnson, Bridget. March 21, 2018. The Austin bomber and our new age of open-source terrorism: How Mark
Anthony Conditt likely benefited from Al Qaeda tutorials. The New York Daily News. Accessed online on 8/26/19
from http://www.nydailynews.com/opinion/austin-bomber-new-age-open-source-terrorism-article-1.3888244.
AGENDA ITEM #1. b)
Risk Assessment
Scoring
2 Location
Ha
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2 Probability
3 Magnitude
2 Public
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1 COP
1 PFI
2 Economy
1 Environment
1 PCG
2 People
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a
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2 Environment
1 Operations
2 People
Ri
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2 Property
2 Environment
2 Operations
Moderate Overall Risk
PC: Duwamish River Community Coalition
Chapter 16Tsunami
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Chapter 16: Tsunami
16.1 Hazard Description
A tsunami is a series of fast, powerful, and highly destructive waves that radiate outward in all
directions from their point of origin. Tsunamis are typically triggered by the displacement of the
ocean floor, often due to an earthquake, or by the collapse of an underwater or aerial landmass.
Once generated, a tsunami can travel across entire oceans in less than a day, impacting coastal
areas far from its source.
In contrast, a seiches is a type of wave that forms in enclosed or semi-enclosed bodies of water—
such as lakes, bays, and rivers—due to wind, atmospheric pressure changes, or seismic activity.
Seiche waves can also affect harbors, canals, and other water systems with limited flow.
Causation
In King County, there are four main triggers for tsunami; distant earthquakes, localized earthquakes,
Cascadia subduction zone, and landslides. The most significant tsunami threat comes from seismic
activity along the Seattle Fault or other geological events within the Puget Sound Lowlands, such as
large underwater landslides or local fault movements. Additionally, smaller tsunamis can pose
maritime risks along the western coastlines of the United States.
• Distant earthquakes: Tsunamis generated by distant earthquakes or underwater landslides
can travel across vast stretches of ocean.1 Powerful tsunamis originating in the Pacific
Ocean can reach the Puget Sound, where they may cause damage to boats, docks, piers,
and navigation aids such as lighthouses and channel markers. Vessels, both moored and
underway, could also be impacted. A notable example of this is the Alaskan-Aleutian
subduction zone earthquake.
• Localized earthquakes: Local seismic events, particularly those along the Seattle Fault, can
trigger tsunamis in nearby large bodies of water. These localized tsunamis could cause
significant damage to port infrastructure and navigational terminals, especially in areas like
the Seattle waterfront.
• Cascadia subduction zone: A massive earthquake (magnitude 8-9) off the coast of
Washington, Oregon, or British Columbia could generate a catastrophic tsunami.
• Landslides: Underwater or coastal landslides—such as the one that occurred at Tacoma
Narrows—can displace enough water to create dangerous tsunami waves.
1 Washington State Department of Natural Resources (DNR), “Tsunamis” (n.d.):
https://www.dnr.wa.gov/programs-and-services/geology/geologic-hazards/Tsunamis#understanding-tsunamis.1
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16.2 Location
King County is home to the deep-water Port of Seattle and several cities along the Puget Sound,
including Shoreline, Seattle, Burien, Des Moines, and Federal Way. Together with Vashon Island,
unincorporated King County includes a great deal of industry, import/export activity, and
commercial and residential real estate that border bodies of water. These waterfront areas are
particularly vulnerable to the impacts of tsunamis or seiches, which can be triggered by
earthquakes occurring hundreds, if not thousands, of miles away from King County. There are four
likely triggers for a tsunami in King County. These include an earthquake on the Seattle Fault,
Cascadia Subduction Zone, and Alaska-Aleutian Subduction Zone, as well as a tsunami caused by a
major landslide into Puget Sound or another major body of water.
Seattle Fault Tsunami
Figure 16-1 Seattle fault scenario detailed tsunami inundation
The first wave of a tsunami caused by an earthquake
along the Seattle Fault would arrive to King County
shores within minutes. The worst flooding is
expected around Seattle, but especially the port and
industrial facilities around the Port of Seattle and
Magnolia. Harbor Island is expected to be
completely flooded because they are at sea level,
with inundation averaging 9–13 feet (3–4 meters).
Areas near Elliott Bay, like SoDo and Smith Cove,
could see flooding more than 20 feet (6 meters)
deep. Other places, like Magnolia Bluff and Alki
Beach, could see flooding up to 20 feet (6 meters)
deep, but it wouldn’t spread far because of steep
cliffs. The tsunami would also cause flooding along
rivers, including the Duwamish River. The first wave
of the tsunami will hit the northern shore of Elliott
Bay within minutes of the earthquake. The waves
will continue to affect the shorelines for at least 3
hours, and strong currents could last much longer.
The earthquake could also change the land’s height,
either lowering some areas or raising others.2
2 Dolcimascolo, Alexander; Eungard, D. W.; Allen, Corina; LeVeque, R. J.; Adams, L. M.; Arcas, Diego; Titov, V. V.;
González, F. I.; Moore, Christopher, 2022, Tsunami inundation, current speeds, and arrival times simulated from a
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Cascadia Subduction Zone Tsunami
A Cascadia Subduction Zone tsunami in a Cascadia event, the first wave will arrive in approximately
2 hours and 20 minutes. It would devastate the outer coast and seriously impact low-lying areas
around Everett and the San Juan Islands. The islands and the strait of Juan de Fuca protect King
County from the worst flooding impacts. Modeling suggests that little inundation would occur along
the coastline of south King County, though some flooding may be expected in areas of Seattle SODO
and Port. For example, Harbor Island in Seattle could see up to 3.7 feet of flooding, with water
speeds also between 0-3 knots (very low speed). at the Vashon Island Ferry Terminal, the modeled
flooding could reach up to 13 feet, with water moving at speeds of 0-3 knots. The Duwamish
Waterway would be among the most impacted areas with waves reaching 4 feet (1.2 meters) above
Mean High Water. The worst flooding is expected to occur at Portage Bay with estimated wave
amplitudes up to 13 feet (4 meters) above Mean High Water. Strong currents are also estimated at
Portage Bay near spits of land and in the narrows, which can be hazardous to the maritime
community. The first wave is expected to reach Seattle at approximately 2 hours and 20 minutes.3
Figure 16-2 Cascadia Subduction zone scenario – detailed tsunami inundation
large Seattle Fault earthquake scenario for Puget Sound and other parts of the Salish Sea: Washington Geological
Survey Map Series 2022-03, 16 sheets, scale 1:48,000, 51 p. text. [https://fortress.wa.gov/dnr/geologydata/tsuna
mi_hazard_maps/ger_ms2022-03_tsunami_hazard_seattle_fault.zip]
3 Dolcimascolo, Alexander; Eungard, D. W.; Allen, Corina; LeVeque, R. J.; Adams, L. M.; Arcas, Diego; Titov, V. V.;
González, F. I.; Moore, Christopher; Garrison-Laney, C. E.; Walsh, T. J., 2021, Tsunami hazard maps of the Puget
Sound and adjacent waters—Model results from an extended L1 Mw 9.0 Cascadia subduction zone megathrust
earthquake scenario: Washington Geological Survey Map Series 2021-01, originally published 2021, 16 sheets,
scale 1:48,000, 49 p. text. [https://fortress.wa.gov/dnr/geologydata/tsunami_hazard_maps/ger_ms2021-
01_tsunami_hazard_puget_sound.zip]
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Alaska-Aleutian Distant Source Tsunami
An earthquake along the Alaskan-Aleutian subduction zone could reach up to magnitude 9.2, similar
to the one that occurred in 1964. A tsunami generated by such an earthquake would be a distant-
sourced tsunami for Washington state. Preliminary modeling for a worst-case scenario of a
magnitude 9.2 earthquake in Alaska suggests that the resulting tsunami in King County would be
somewhat comparable to the Cascadia Subduction Zone event, but with roughly half the strength.
The highest wave amplitudes are estimated to reach up to 7 feet (2 meters), primarily affecting
Portage Bay, though they are not expected to overtop the northern spit. Unsafe currents may also
pose a risk to maritime operations, especially in Portage Bay. The first wave is predicted to reach
Seattle’s coastline approximately 6 hours after the earthquake.
Landslide Tsunami
In the last 200 years, landslides, not earthquakes, have caused all historical tsunamis in the Puget
Sound/Salish Sea. Since the 1800s, no seismic activity along the Seattle Fault has been recorded.
These locally generated tsunamis include 1820s Hat Island, 1894 Commencement Bay, and 1949
Tacoma Narrows. The 1949 Tacoma Narrows landslide, for example, was triggered by an
earthquake, but the tsunami was caused by the landslide itself. However, historical and oral
accounts, including those of the Salish peoples, describe numerous tsunamis, including a significant
Seattle Fault earthquake around 1,100 years ago (~900–930 CE). This study models that event for
planning purposes, aiding tsunami hazard preparedness in Puget Sound and the Salish Sea. Verbal
accounts among the Snohomish Tribe describe a great landslide-induced wave caused by the
collapse of Camano Head at the south end of Camano Island around the 1820s. The slide itself is
said to have buried a small village, and the resulting tsunami drowned people who were clamming
on Hat (Gedney) Island, 2 miles to the south. Bathymetry between Camano Head and Hat Island
could have contributed to the size and destructive power of the wave.4 In 1894 a large submarine
landslide occurred on the Puyallup River delta in Commencement Bay, resulting in two deaths and
the destruction of the Northern Pacific freight docks and other port facilities. It also destroyed 300
feet of the North Pacific docks and created at least a ten-foot wave in the Old Town section of
Tacoma. It washed over homes on the tide flats and resulted in one fatality.5 While no landslide
generated tsunamis are known to have impacted King County there is potential that a subaerial or
subaqueous slide may do so in the future.
4 Koshimura, Shunichi and Harold O. Mofjeld. 2001. Inundation modeling of local tsunamis in Puget Sound,
Washington due to potential earthquakes. ITS 2001 Proceedings, Session 7, Number 7-18. Accessed online on
6/11/19 from https://www.pmel.noaa.gov/pubs/docs/ITS2001/7-18_Koshimura.pdf.
5 Pierce County Natural Hazard Mitigation Plan, 2004-2009 Edition, Tacoma, Washington, Sub-Section 4.6, Pierce
County Tsunami Hazard, http://www.co.pierce.wa.us/xml/abtus/ourorg/dem/EMDiv/MP/PC%20Tsunami.pdf
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16.3 Magnitude
Tsunamis that could impact King County vary significantly in strength depending on their origin and
the type of event triggering them. The speed of a tsunami depends on the depth of the water it’s
traveling through. The deeper the water, the faster the tsunami. In the deep ocean, tsunamis are
barely noticeable, but they can move as fast as a jet plane, more than 500 mph. As they enter
shallow water near land, they slow to approximately 20 or 30 mph, which is still faster than a
person can run.6
Distant earthquakes, like those along the Pacific Rim, can create tsunamis that take hours to reach
the region. Despite traveling across vast distances, these tsunamis often lose much of their
destructive power by the time they reach the shallow waters of Puget Sound. For example, the
2011 magnitude 9.0 earthquake in Japan and the 1964 magnitude 9.2 earthquake in Alaska
generated tsunamis that reached King County, but the highest recorded wave heights were only
around 0.04 meters (~2 inches) and 0.12 meters (~5 inches), respectively. While these distant
tsunamis pose little immediate threat, studies show that tsunami inundation from large distant
earthquakes can still affect inland waters.7
In contrast, tsunamis generated by localized earthquakes, such as those occurring along the Seattle
Fault, would reach King County within minutes, causing more immediate danger. The Cascadia
subduction zone, a major fault off the Pacific Northwest coast, is capable of producing significant
tsunamis, with waves potentially reaching the region in tens of minutes. A tsunami generated by
such an earthquake would bring faster and more intense wave energy, making it a higher-risk
scenario. Similarly, landslides occurring within or near the Puget Sound region could also generate
tsunamis, with these events typically causing waves to strike within minutes, depending on the
location of the slide. The value and density of property along the waterfront suggests a potential for
moderate impacts from such an event.
16.4 Previous Occurrences
This paleo-seismic evidence and tree ring dating of landslides around the region suggests the last
tsunami occurred in King County was 923-924 AD when the local Seattle fault raised some
landmasses around the Puget Sound shoreline by as much as 26 feet.8 A scientific study focused on
seismic activity on the Seattle fault within the last 7,500 years found evidence for 6 additional
6 Washington State Department of Natural Resources (DNR), “Tsunamis” (n.d.):
https://www.dnr.wa.gov/programs-and-services/geology/geologic-hazards/Tsunamis#understanding-tsunamis.1
7 Washington State Military Department, Emergency Management Division, “Tsunami Maritime Response and
Mitigation Strategy - Port of Bellingham” (April 2021): https://mil.wa.gov/asset/60ad926bdefd6
8 B.A. Black, et al., “A multifault earthquake threat for the Seattle metropolitan region revealed by mass tree
mortality” Science Advances, v. 9, no. 39 (2023) p. 9 [https://doi.org/10.1126/sciadv.adh4973]
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earthquakes, however none of these are known to be tsunamigenic.9 This suggests a low probability
of a large earthquake to occur on the Seattle fault as the recurrence interval could be thousands of
years. Since 923 AD, tsunami waves in King County have been less than 18 inches in height and
caused little damage to boats and shoreline property.10 Multiple seiches have been generated in
King County from various local and distant seismic events.
Table 16-1 Past tsunami and seiche occurrences in the Puget Sound region
Date Type Location Trigger Description
923 -
924
Tsunami Seattle, WA Earthquake Caused by the Seattle Fault raising land
by 26 feet.
1820s Tsunami Hat Island Landslide Large landslide at Camano Head triggered
a tsunami that flooded an entire village.
Additional verbal accounts among the
Snohomish Tribe reported by Colin
Tweddell in 1953 described a great
landslide-induced wave caused by the
collapse of Camano Head at the south
end of Camano Island around the
1820s.11
1891 Seiche Lake
Washington
Earthquake Two earthquakes near Port Angeles
caused water in the Puget Sound to surge
onto beaches two feet above the high-
water mark and an eight-foot seiche in
Lake Washington.
1894 Tsunami Commence
Bay
Landslide Submarine landslide-triggered tsunami,
which cased 2 fatalities.
1906 Seiche Lake
Washington
Earthquake Mw 7.9 San Francisco earthquake caused
agitated wave activity on the west shore
of Lake Washington “so violently that
house boats, floats and bathhouses were
9 T.L. Pratt, et al., “Kinematics of shallow backthrusts in the Seattle Fault zone”
Washington State: Geosphere, v. 11, no. 6 (2015): p. 1948–1974, https://doi.org/10.1130/GES01179.1
10 NOAA, “Global Historical Tsunami Database. National Geophysical Data Center / World Data Service
(NGDC/WDS) (n.d.) doi:10.7289/V5PN93H7
11 Shunichi Koshimura, Harold O. Mofjeld, “Inundation modeling of local tsunamis in Puget Sound, Washington due
to potential earthquakes.” ITS 2001 Proceedings, Session 7, Number 7-18. (2001):
https://www.pmel.noaa.gov/pubs/docs/ITS2001/7-18_Koshimura.pdf.
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jammed and tossed about like leaves on
the water,” reported by the Seattle Post-
Intelligencer (4/19/1906).
1949 Seiche Lake Union,
Lake
Washington
Earthquake A magnitude-7.1 deep earthquake
occurred in Olympia that caused seiches
within Lake Union and Lake Washington,
but no damages were reported.
April 16,
1949
Tsunami Tacoma
Narrows
Landslide A 6-8 foot tall tsunami cased by a
landslide at after the Mw 6.8 Olympic
Earthquake
1964 Seiche Lake Union Earthquake The magnitude 9.2 Great Alaska
earthquake of 1964 created global
seiches, including in Lake Union that
damaged houseboats, buckled moorings,
and broke water and sewer lines.
1965 Seiche Green Lake Earthquake Magnitude 6.5 deep earthquake occurred
in the Puget Sound which caused a seiche
where water “sloshing back and forth like
soup in a shallow bowl” was observed at
Green Lake, North Seattle (reported by
the Seattle Times, 4/30/1965).
2002 Seiche Lake Union Earthquake Magnitude 7.9 Denali earthquake caused
seiches in Lake Union that damaged
houseboats, buckled moorings, and broke
water and sewer lines.
16.5 Probability of Future Occurrences
As stated in the earthquake risk assessment, there is a high probability that a high magnitude
earthquake will occur in King County which will likely be accompanied by a tsunami. However, when
that event will happen is still uncertain. The increasing population and development in tsunami-
prone areas mean that more people and critical assets are now exposed to these hazards. As
population growth continues, especially in areas around the Puget Sound and Pacific Coast regions,
the vulnerability to tsunamis increases.
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By 2050, an estimated 268,000 people will reside in coastal tsunami inundation zones in
Washington, representing a 3% increase from 2020. The development of coastal areas, coupled
with higher exposure to tsunami hazards, will further elevate the challenges in mitigating the
impacts of future events. As the state grows, this increased vulnerability highlights the need for
continued resilience efforts.
While inland landslide-driven tsunamis, often associated with human-made reservoirs, have
decreased in frequency since the 1950s, the threat of tsunamis generated by large subduction zone
earthquakes remains a serious concern. Despite the low probability of such catastrophic events, the
growing population and infrastructure in tsunami zones necessitate ongoing preparedness and
mitigation measures to reduce future risks.
16.6 Impact Assessment
Public While it would take a rather sizable tsunami along the shoreline of King County,
precautionary evacuations from houseboats, live aboard pleasure craft, cruise
ships, and property immediately adjacent to waterfronts of Puget Sound and
lakes Washington, Sammamish, and lake Union may be recommended.
Responders Along the shoreline of King County, precautionary evacuations from houseboats,
live aboard pleasure crafts, cruise ships, and property immediately adjacent to
waterfronts of Puget Sound and lakes Washington, Sammamish, and Lake Union
would cause impacts to the public. The volume of search and rescue efforts
along waterfronts affected from the tsunami may pose potential issues to first
responders (police, fire, EMS). There are only small number of scenarios where
this is a likely issue.
Continuity of
Operations
It is possible that Sounder traffic between Everett and Seattle or Tacoma and
Seattle could be impacted by any large tsunami in Puget Sound. Otherwise, it is
unlikely that King County governmental operations would be directly impacted
by a tsunami or seiche.
Property,
Facilities, and
Infrastructure
Property
Tsunami and seiche threats were not defined until recently. Most of the early
19th and 20th century structures located near the water were probably not
engineered to withstand impacts from a tsunami, seiche, or earthquake. The
properties along the entire Seattle Waterfront and those in Shoreline, Des
Moines, Federal Way, and Vashon Island are at risk from tsunami activity.
Facilities
There are no major health centers located in the mapped tsunami inundation
areas.
Infrastructure
• Power: Little to no impact directly from tsunami is expected.
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• Water/Wastewater: Tsunami may impact the West Point treatment
plant. The damage would depend on the height of the tsunami and a
significant event would be required. If such an event were to occur, the
plant would be rendered inoperable.
• Transportation: damage to port facilities are the primary threat to
infrastructure from a tsunami. Even relatively small tsunami surges, such
as the aforementioned example from Crescent City, have caused tens of
millions of dollars. Damage to low-lying rail and roads is also likely, but
less of a concern since it would not impact primary transportation
routes. Notably, Washington State Ferries have been conducting
infrastructure enhancements to the terminals to make them tsunami
resilient, that should be noted here.
• Communications: There is limited risk to communications systems as a
whole from tsunami.
Environment It is possible for a tsunami or seiche to have an impact on the natural
environment immediately adjacent to Puget Sound through the release of fuels
and hazardous materials or their storage facilities around the waterfront. This
may include fish habitat or natural and farmed shellfish beds, wetlands,
estuaries, and marsh areas.
Economy A tsunami or seiche that impacts port facilities, such as one triggered by the
Seattle Fault would have any sizable impact on the economy of the region.
Damage would run potentially in the billions and have far-reaching
consequences for Washington’s export-based economy.
Public
Confidence in
Governance
Coverage from major news outlets, including the Seattle Times and the New
Yorker magazine, have argued that Washington is highly underprepared for a
major seismic event large enough to generate a tsunami. Both media coverage
and reports from state emergency management has led Washington’s governor
to convene a Resilient Washington Subcommittee to look into mitigation actions
out of concern for the apparent low-level of public confidence in state and local
ability to manage major disasters. Data is available from Japan and New Zealand
that clearly demonstrate that policy level decisions and direct communication to
the public will greatly influence the public confidence in King County
government.
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16.7 Vulnerability Assessment
Vulnerable
populations
There are no additional anticipated direct impacts from tsunami to
vulnerable populations. As always, any disruption to services, the
economy, and infrastructure would cause more harm to lower-income
and marginalized communities.
Property Low lying homes
Homes and businesses along the many waterfronts would be damaged
or destroyed by a mid-sized tsunami and devastated by a local crustal
earthquake and tsunami.
Port/harbor facilities
Tsunamis are expected to devastate near-shore port infrastructure,
boats, and piers. This is the largest economic consequence of a
tsunami.
Environment Several areas in Central and South Seattle current hold and or are
impacted by the release of hazardous materials such as the Duwamish
River, Harbor Island and the SODO district. They also lie within the
tsunami inundation zone. The quantity and speed of a tsunami would
quickly spread these contaminants into adjacent aquatic ecosystems
and soil.
Operations Wastewater treatment facilities
West Point treatment plan is in the inundation zone for a Seattle Fault
tsunami. Historical records also suggest tsunamis have impacted this
area before.
AGENDA ITEM #1. b)
Risk Assessment
Scoring
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Moderate Overall Risk
PC: Richard Bowen
Chapter 17Volcano
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Chapter 17: Volcano
17.1 Hazard Description
Volcanic eruptions are the result of
geological activity beneath the earth’s
surface, often resulting in the release
of lava, rock fragments, gases, and
ash from a vent on the surface.
Deposits of rock, lava, and ash create
the structures we call volcanoes.
Washington State has five active
volcanoes, each posing varying levels
of risk to King County. Mt Adams is
classified by U.S. Geological Survey as
a “high” threat, while the remaining
four—Mount Baker, Glacier Peak,
Mount Rainier, and Mount St.
Helens—are classified as “very high”
threat due to their proximity to
developed areas.1 The regions
primary hazards associated with
volcanoes include lahars and volcanic
ashfall.
Lahars, also called volcanic mudflows
or debris flows, can have the
consistency of wet cement and are
historically one of the most damaging
elements of an eruption. When
enough water mixes with loose volcanic ash and rock on the side of a volcano, the mixture flows
downhill and forms a lahar. These mudflows can travel more than 50 miles from the volcano, and
commonly at speeds of 40 miles per hour.2 These flows pick up debris like trees and boulders, and if
sufficiently large and powerful, also houses, cars and anything else in their paths. They slow down
once they reach flatter gradients typical of distant river channels but are still an unstoppable mass
1 Washington Emergency Management Division (EMD), “Volcano” Washington State Enhanced Hazard Mitigation
Plan (2023): p. 71, https://mil.wa.gov/asset/651ec296d76a9/2023_WA_SEHMP_final_20231004.pdf
2 Washington Geological Survey, “Vocanic Hazards in Washington State” (n.d.): p. 4,
https://www.dnr.wa.gov/publications/ger_volcano_hazards_brochure.pdf
May 18, 1980 Mount St. Helens eruption taken by Richard Lasher
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of mud and debris, often pushing a flow of water ahead of them. The only personal protective
action available to avoid a lahar is evacuation to higher ground.
Ashfall is made up of tiny particles of broken rock, glass, and minerals. The fine particles may travel
hundreds of miles or more downwind. Even in tiny quantities, volcanic ash can be very disruptive,
as it lowers air quality, poses potential health hazards if ingested, especially to those with
pulmonary conditions, makes roads slippery to drive on, is abrasive, poses risks to aircraft, motor
vehicles and electronics, and is extremely difficult to clean up.
17.2 Location
Washington’s five volanoes are scattered along the Cascade Range. Mount Baker and Glacier Peak
are located in the north, Mount St Helens and Mount Adams are located in the south, and Mount
Rainier is central.
Figure 17-1 Washington State Volanoes 3
3 Washington Geological Survey, “Vocanic Hazards in Washington State” (n.d.): p. 2,
https://www.dnr.wa.gov/publications/ger_volcano_hazards_brochure.pdf
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Hazards from eruptions are typically divided into near-volcano hazards, those which impact areas
immediately on the slopes of the volcano, and distant hazards, which can put areas miles away from
the volcano at risk. Near-volcano hazards include pyroclastic flows (hot avalanches of gas, ash, and
rock fragments), lava flows, rock (tephra), debris flows, and landslides. Distant hazards, include
lahars, and volcanic ash. Lahars may travel tens of miles down river valleys, picking up debris and
inundating floodplains, and leave a cement-like deposit of sediment where they stop. For King
County, all Washington Volcano’s are distant hazards.
Mount St. Helens and Glacier Peak are the more highly explosive volcanoes in the Cascade Range. If
they were to erupt, prevailing winds could carry the ashfall into King County. Such ashfall could
prompt airport closure, disrupt communications system, and wreak general havoc.
Mount Rainer is also a distant hazard but with the additional threat of lahar. Figure 17-2 highlights
the communities at risk from a potential eruption and subsequent lahar, including Algona, Pacific,
Auburn, and the Muckleshoot Tribal Nation. Lahars along the White River would carry a mixture of
mud, ash, rocks, and debris, leaving behind thick layers of sediment, potentially tens of feet deep.
These flows could travel downstream into the Puget Sound via the Green and Duwamish Rivers.
The aftermath would likely result in widespread regional impacts. Excess sediment erosion and
transport down river valleys could disrupt transportation networks, including major highways like I-
5, and damage critical infrastructure such as the Port of Tacoma. The map also highlights areas at
risk of “post-lahar sedimentation” (shown in green), where sediment would fill riverbeds, create
new floodplains, and exacerbate local flooding. This sediment would continue to accumulate in
river systems for years, due to the unstable mountainous terrain. While Mount Rainier is not as
explosively active as volcanoes like Mount St. Helens or Glacier Peak, the threat of ashfall in King
County is relatively low. However, the potential for lahars and the long-term impacts of sediment
deposition are serious concerns for the region.
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Figure 17-2 Mount Rainier
17.3 Magnitude
The Volcanic Explosivity Index (VEI), shown in Figure 17-3, is a scale used to measure the size of
explosive volcanic eruptions. Ranging from 0 to 8, the VEI is a logarithmic scale, comparable to the
to the way magnitude of earthquakes is measured. For instance, the 1980 Mt St Helens eruption
followed a 5.1 magnitude earthquake and the amount of ash (1 Cubic Kilometer of dense rock
equivalent) scored a 5 on VEI.4
Each increment on the VEI represents a ten-fold increase in eruption size. The scale considers
factors such as the volume of magma erupted and the height of the eruption column. The 1980
eruption of Mount St. Helens, for instance, produced an eruption column that reached
approximately 15 miles in height. For Mount Rainier, the VEI of a major explosive eruption that
4 USGS, “1980 Cataclysmic Eruption” Mount St. Helens (November 2023): https://www.usgs.gov/volcanoes/mount-
st.-helens/science/1980-cataclysmic-eruption
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occurred between 30,000 and 100,000 years ago is tentatively estimated to be between 4 and 5.
This suggests that Mount Rainier is capable of eruptions ranging from moderate to very large in
scale.5
Figure 17-3 Volcanic Explosivity Index 6
Given it has been approximately 200 years since
Mount Rainier has last erupted, the measurement of
magnitude and extent has been based of the
evaluation of soil. For instance, the Osceola Mud Flow
5,600 years ago went 31 miles downstream and the
deposit of lahar was 26 feet thick.
Unlike Mount St. Helens, Mount Rainier is only a
moderate producer of ash (tephra) fall. Even so,
tephra fallout in populated areas is a health hazard,
will damage property, and may require Temporary
Flight Restrictions (TFRs) of airways over affected
areas. Further, Lahars can flow many tens of miles
from Mount Rainier and represent the greatest
volcanic threat to populated areas. They are capable
of burying and destroying anything in their path.
A lahar should not be seen as a singular event, but
rather as a mass movement of sediment requiring
significant time to recover from. Deposition of feet to
tens of feet of sediment along a river valley and its
floodplain creates long-term changes to the river
environment. Lahars from the 1980 eruption of Mt. St.
Helens themselves destroyed 27 bridges, and over 200 homes, and over 185 miles of roads. In
addition to this damage, it caused ongoing sediment deposition for years, that caused the need for
dredging the Columbia River multiple times, and for the Army Corps of Engineers to spend over a
million dollars building a sediment retention structure to mitigate this added hazard of lahars.7
After a lahar, mitigation measures may be necessary to prevent hazards from continued
sedimentation over the decades following the eruption. One such mitigation measure at Mount St.
5 National Research Council, “Mount Rainier: Active Cascade Volcano” The National Academies Press. (1994):
https://doi.org/10.17226/4546
6 National Park Service, “Volcanic Explosivity Index (VEI)” Volcanoes, Craters & Lava Flows (August 2022): https://
www.nps.gov/subjects/volcanoes/volcanic-explosivity-index.htm
7 USGS, “Lahar Hazards at Mount St. Helens” Mount St. Helens, (November 2023):
https://www.usgs.gov/volcanoes/mount-st.-helens/science/lahar-hazards-mount-st-helens
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Helens, a sediment retention structure built on the North Fork Toutle River, is intended to prevent
too much sand from reaching distant channel reaches and exacerbating flood potential. Dredging is
an option to remove sediment deposited in distant channel reaches, but it is expensive, must be
repeated, and requires substantial areas to deposit dredge spoil. Deposition of a large amount of
sediment on a floodplain may change floodplain character and can entomb structures built on the
floodplain.
17.4 Previous Occurrences
The Cascade Range has a long history of volcanic activity, evidenced both by geological deposits
that shape the landscape and in the oral histories of the Salish and Coast Salish tribes, passed down
through generations. Although the volcanoes in the Cascades remain active, their eruptions are
generally infrequent, with geological records indicating an eruption roughly a few times per
century. Figure 17-3 illustrates the number of eruptions along the Cascade Range over the past
4,000 years. Some volcanoes, such as Mount Baker and Mount Adams, experience relatively rare
eruptions, while others, including Glacier Peak, Mount Rainier, and Mount St. Helens, have shown
patterns of clustered eruptions.
Figure 17-4 USGS, Eruptions in Cascade Range in the Past 4,000 Years
In recent years, Mount St. Helens has been intermittent activity from 1980 to 1986 and continuous
activity from late 2004 to early 2008.
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• May 1980 eruption of Mount St Helens is the best examples of potential local damages from
volcanic activity. This eruption produced significant ash-fall over eastern Washington,
Oregon, Idaho, and Montana, with trace amounts falling over the Dakotas, Wyoming,
Nebraska, Colorado, Oklahoma, and Minnesota as well as Canadian provinces. Lahars
associated with the eruption damaged or destroyed over 200 homes, ruined 27 bridges, and
buried 185 miles of roadway. Community water supplies and sewer systems were disabled
and reservoirs partly filled with debris.
Mount Rainier began erupting 500,000 years ago and has had numerous eruptions and shed
numerous lahars since then. It is estimated that Mount Rainier has generated about 60 of these
lahars in the last 10,000 years, with about 10 large enough to reach the Puget Sound. Many
communities, including Orting, Puyallup, and Auburn, between Mount Rainier and the Puget Sound
are built on top of these deposits.
• 5,600 years ago (approx.), an eruption created a massive debris avalanche that transformed
into a very large lahar, called the Osceola Mudflow. That lahar traveled down the White
River valley and into the Puget Sound. It filled valleys of the White River system to depths of
more than 350 feet and moved at speeds of 40 to 50 miles an hour. Following the Osceola
Mudflow, many other eruptions and lahars occurred.
• 500 years ago (approx.), a large landslide-generated lahar originated on the west flank of
the volcano called the Electron Mudflow. That lahar traveled down the Puyallup River valley
through Orting and into Sumner and Puyallup. However, there is no evidence that this event
was triggered by a volcanic eruption.
17.5 Probability of Future Occurrences
According to the Washington State Enhanced Hazard Mitigation Plan, there is a 2.5% chance each
year that a volcanic disaster could lead to a formal disaster declaration.8 While this statistic
highlights the potential risk, it’s important to note that volcanic eruptions, particularly in the
Cascades, can be unpredictable. Volcanoes like Mount Rainier and others in the region can lie
dormant for hundreds or even thousands of years between eruptions, making it difficult to foresee
exactly when an eruption might occur. Despite this uncertainty, scientists do know that future
eruptions are likely.
Furthermore, the population of the Pacific Northwest continues to grow, the risk associated with
volcanic events is also increasing. Since the 1980 eruption of Mount St. Helens, there has been a
significant rise in both the number of people living in at-risk areas and the infrastructure exposed to
volcanic hazards. Advance warning of unrest and potential implications of unrest are critical to
8 Washington Emergency Management Division (EMD), “Volcano” Washington State Enhanced Hazard Mitigation
Plan (2023): p. 71, https://mil.wa.gov/asset/651ec296d76a9/2023_WA_SEHMP_final_20231004.pdf
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communities downstream from the volcanoes, because even a relatively small eruption could scour
and melt snow and glacier ice and produce lahars that could reach heavily populated areas.
17.6 Climate Change Considerations
Volcanic eruptions can influence climate, primarily through the release of gases, aerosols, and ash
into the atmosphere. While volcanic ash, which is injected into the stratosphere during major
explosive eruptions, typically falls back to Earth within days or weeks and has little lasting impact on
climate, the gases released can have significant effects.
For instance, sulfur dioxide (SO₂) can form aerosols that reflect sunlight, leading to temporary global
cooling. In contrast, carbon dioxide (CO₂), a greenhouse gas, can contribute to global warming by
trapping heat in the atmosphere. However, despite the release of CO₂ during contemporary
volcanic eruptions, it has not been shown to cause detectable global warming on a large scale.9
17.7 Impact Assessment
Public The estimated King County population that might be impacted from Mount
Rainier by a Case 1 lahar is 17,920, Case 2 is 3,527 and 49,486 in a post-lahar
sedimentation zone. The distance from Mount Rainier makes direct impact
of eruption from a pyroclastic event unlikely. Prevailing winds make ash fall
in the county a relatively low probability event. Lava flows and landslide
activity would impact the National Park and possibly part of Pierce County
but are unlikely to reach any portion of inhabited King County. Indirect
impacts from a major eruption might include a cooling climate from
atmospheric suspended ash clouds but this too is unlikely. Fine ash may
cause regional health impacts – especially respiratory for the duration of ash
fall or during any ash resuspension by strong winds. Impacts to vehicles and
air handling systems in homes and workplaces may have an employment
impact to the King County population. However, it is also worth noting many
Pierce County residents commute to jobs in King County, so disruptions in
Pierce could have economic ripple effects throughout the region.
Responders Responder vehicles need regular air filter changes during ashfall. Air filters in
the quantity required are likely not available. Responders will also be taxed
by high numbers of calls and dangerous roads caused by slick ash.
Continuity of
Operations
Potential impacts to county delivery of services from a Mount Rainier
eruption would be the result of damages to infrastructure, equipment
including machinery and vehicles, inaccessibility to service areas, impedance
9 USGS, “Volcanoes Can Affect Climate” Volcano Hazards Program (n.d.):
https://www.usgs.gov/programs/VHP/volcanoes-can-affect-climate
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to transportation routes used by the county workforce, and health impacts
to residents and the workforce. County services that might be interrupted
might include: Medic One response, King County Sheriff’s Office services like
9-1-1 dispatch, search and rescue and marine or aviation unit response,
adult detention, solid waste and waste water services. Services provided by
other government agencies and basic service providers might include
interruption of: power, phone and cell phone service, emergency medical
service, fire and law enforcement, water systems, and health/medical
facilities.
Property,
Facilities, and
Infrastructure
Property
The cities of Algona and Pacific are the most at risk from a Mount Rainier
lahar event, with over 90 percent of their structures exposed to the lahar.
While the percentage of structures is not as high, the City of Auburn has the
highest potential dollar-value losses. Other damages would include the loss
of HVAC and air filtration systems, and electrical systems shorting out.
Furthermore, following rains, ash hardens to a concrete-like consistency,
which can clog gutters and drains and cause them to fail or collapse.
Businesses that operate electronic systems will require decontamination
rooms to prevent ash from getting inside and damaging electrical
equipment.
Facilities
Health systems would be impacted by an expected dramatic rise in demand
for services as ash causes people to seek care for respiratory distress and
lahars can cause serious injuries. Health systems would also be hindered by
transportation system impacts. First responder vehicles should have air
filters changed a frequent as every 30 minutes during volcanic ash events
and there are not enough air filters on hand to meet this requirement.
Infrastructure
• Power: Ash can short out electrical systems and cause widespread
power failure. Ash accumulation may also cause issues with power
generation dams. Generation facilities may be shut down to prevent
damage to sensitive components.
• Water/Wastewater: Water systems, including reservoirs, could
quickly clog with ash, potentially polluting water supply.
• Transportation: volcanic ash is very slick and roadways would
become treacherous. Vehicles would need regular air filter
replacements and there are not sufficient air filters in the region to
offset the need. Airports in the region may require Temporary Flight
Restrictions (TFRs) of airways over affected areas. Any lahar could
potentially destroy major transportation routes, including I-5.
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• Communications: Electrical and communication impact can be
severely impacted during ashfall. Ash getting into electrical systems
can cause systems to short out.
Environment Any significant volcanic activity at Mount Rainier would have an impact to
the environment. Tephra (ash) fall, pyroclastic flows, large landslides, and
lahar activity would directly impact birds, fish, mammals, reptiles,
amphibians, trees, and vegetation. Sediment deposition would impact rivers
that support salmon and steelhead spawning. Large landslides and lahars
may change the course of rivers entirely. Lahars may cause hazardous
material releases that harm birds, fish and other wildlife. Recreational use of
ski areas and hiking trails would also be impacted. After four decades, timber
and wildlife at Mount St. Helens have not yet fully returned to pre-1980
levels.
Economy Many of the impacts to humans and the environment from a Mount Rainier
eruption would also impact the economy of King County. Aviation
interruption would likely occur from airborne ash. A lahar event would
impact rail and port service from direct damages to infrastructure like
bridges, rails, and roadways, or from inaccessibility to ports. Post-eruption
excess sedimentation would affect areas father downstream and exacerbate
flooding. Ash would cause interruption of all internal combustion engines or
vehicles that require filters would impact the workforce and movement of
food and supplies as well as repair crews. Abrasion from fine ash on all
mechanical parts would cause longer term damages to industrial operations
and the ports. Health and respiratory issues would make both indoor and
outdoor professions difficult. Medical facilities and the patients that rely on
them would have difficulty operating. The cost of debris removal following a
lahar or substantial ash fall would be enormous, even similar to efforts from
a major earthquake.
Volcanic ash can also have major impacts on agriculture if feed and water
sources are not taken care of properly. Farm animals can inadvertently grind
down their teeth while grazing on grasses that include volcanic ash over
time, and may suffer from stomach or intestinal injuries from drinking ashy
water.10
10 USGS, “Agriculture – Plants & Animals” Volcanic Ashfall Impacts Working Group, (December 2015):
https://volcanoes.usgs.gov/volcanic_ash/agriculture.html
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Public Confidence
in Governance
The public’s knowledge on volcanic eruption and evacuation protocols are
limited due to the infrequent eruptions in this region of the Cascades. The
last large eruption was Mount St. Helens in 1980. At the time, US scientists
had no direct experience with monitoring and forecasting eruptions of
explosive volcanoes, thus Mount St. Helens eruption didn’t come with early
warning. There was even confusion on the possibility that the volcano could
erupt sideways. This could give the impression that government isn’t well
prepared for another eruption. However, since that time, investments in
research, volcano monitoring, and public outreach have increased the ability
of the USGS to detect early signs of unrest and with local emergency
management to communicate factual, reliable, and actionable information
to government authorities and the public.
17.8 Vulnerability Assessment
Vulnerable
Populations
Impacts to individuals with access and functional needs will be
extremely serious. Transportation will be impacted, resulting in
difficulty accessing appointments. Individuals with chronic respiratory
vulnerabilities will be most negatively impacted by ash. While there are
limited numbers of King County residents in the path of the lahar, the
communities that are most impacted have higher rates of disability and
poverty than the statewide average. Communities downstream of the
direct lahar impact area will likely experience post-lahar excess river
sedimentation which can exacerbate flooding.
Communities in the path of lahar hazards
Communities in the vicinity of Mount Rainier, including the King County
communities of Algona, Pacific, and Auburn, are most vulnerable to a
large lahar generated by an eruption of Mount Rainier. Communities
further down valley are vulnerable to excessive river sedimentation in
the aftermath of an eruption and lahar.
Populations vulnerable to respiratory distress brought on by ash
Ash from any volcanic eruption can lead to disruption of daily life and is
a major threat to people with medical vulnerabilities.
Populations in the immediate vicinity of a volcano
Populations that use Mount Rainier National Park or work in the area
around the mountain are most susceptible to multiple near-volcano
hazards that can affect the immediate surroundings within minutes.
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Although advanced notice of a potential eruption is likely, it will be
impossible to predict the exact moment of eruption. Residents from
the town of Orting have approximately 45-minutes to evacuate
following onset of a large lahar in the Puyallup valley.
Property Property damage from lahars can include complete inundation and
destruction of any property in the lahar’s path. Furthermore, property
damage that can occur from ash fall include obstructed filters in HVAC
systems, clogged drainage systems in gutters, and corrosion on metal
roofs.
Environment Lahars along the White River, with post sedimentation in the Green and
Duwamish River can drastically alter the riverbed and changing water
flow dynamics. The added sediment can increase erosion downstream
and significantly impact aquatic life, leading to long-term ecological
disruption. Changes to floodplains can also create new areas of
vulnerability, potentially exposing hazardous materials and increasing
erosion risks during future flood events.
Operations Energy
Electrical systems may short out due to ashfall and power generation
can be curtailed as generation systems are shut off to protect sensitive
components.
Communication
Communications equipment has the same vulnerability as general
electrical systems and is subject to failure due to ash damage.
Air Travel
Airports may be closed for the duration of major ash dispersal including
ash remobilization due to wind.
Roads
Traffic signals may short out during ashfall. Ash can create a very
slippery driving surface. Ash can damage vehicle engines and scratch
windshields when wipers are being used. Driving is not recommended
during heavy ashfall.
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Chapter 18: Wildfire
18.1 Hazard Description
A wildfire is an
unplanned, unwanted
fire burning in a
natural area such as a
forest, grassland, or
prairie. Wildfire is a
historically natural
phenomenon that has
played a role in
reshaping and
regenerating our
ecosystems since time
immemorial. However,
the dangers wildfires
can pose to the public
and first responders
are significant.
Wildfires can damage
natural resources, destroy homes and structures, and threaten the safety of the public and first
responders. While King County and Western Washington have historically been viewed as having a
relatively low fire risk, the dense vegetation in our forests can serve as an ample source of wildfire
fuel if conditions are right for them to burn. In the last decade, the region has been experiencing
drier summers and longer fire seasons, with approximately 30-40% of wildfire starts in Washington
occurring on the west side of the Cascade Crest.1 Meanwhile, more and more people are moving
into the wooded areas of King County with a higher likelihood of exposure to fire. Of particular
concern is a wildfire that spreads from the wildlands to the urban environment.
While wildfires do start naturally through lightning strikes, 85% of wildfires in Washington are
started by human activity.2 Human-caused ignitions include arson but starts are more often the
result of a range of unintentional and avoidable causes such as sparks from vehicles dragging
1 Courtney Flatt, “Washington’s 2022 fire season has been the mildest in a decade” OPB (October 2022):
https://www.opb.org/article/2022/10/09/washington-wildfire-season-bolt-creek-fire-goat-rocks-fire-oregon-
wildfires/
2 Washington Department of Natural Resources (DNR), “Wildfire Resources” Wildland Fire Management Division
(n.d.): https://www.dnr.wa.gov/programs-and-services/wildfire-resources
2022 Bolt Creek Fire
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materials, fallen utility lines, negligent backyard debris burning, or pyrotechnics and recreational
fires that get out of control. Wildfires can spread rapidly when fueled by dense, dry, uninterrupted
vegetation, especially in areas with steep slopes, ridges, and during windy conditions with high
temperatures and low humidity.
To compound the situation, an area burned by an intense wildfire is more likely to experience
additional hazards such as flooding and landslides. Wildfire smoke is also a significant threat to
public health, and smoke annually impacts King County even when the source fires are well outside
of county boundaries. Wildfire smoke is made up of fine particulate matter (PM2.5) which can
cause a range of negative health impacts, especially for vulnerable populations including people
with chronic health conditions, children, pregnant women, and first responders who are exposed to
large amounts of PM2.5 through their work.
The wildland fire season in Washington generally starts in May and continues through October.3
Conditions such as drought, low snowpack, and local weather conditions can impact the length of
the fire season. In King County, the window of vulnerability to wildfire is from late August to
October. The most recent significant fire in King County, the 2022 Bolt Creek Fire, ignited in
September and burned through the end of October. The National Weather Service issues Red Flag
Warnings when warm temperatures, very low humidities, and stronger winds are expected to
combine to produce an increased risk of fire danger; August and September were the months when
the most Red Flag Warnings were issued from 2006-2022.4
To address concerns related to wildfire, King County will be publishing a countywide Community
Wildfire Protection Plan (CWPP) in 2025 that expands upon items listed in this chapter and
describes concerns, risk factors, and effective wildfire mitigation actions. Actions or mitigation plans
listed in the King County CWPP will be considered a part of the King County Regional Hazard
Mitigation Plan, regardless of the adoption date, and will be incorporated into this plan at the next
scheduled update.
3 Western Fire Chiefs Associate, “Washington Fire Season: In-Depth Guide” (April 2024): https://wfca.com/wildfire-
articles/washington-fire-season-in-depth-guide/
4 National Oceanic and Atmospheric Administration (NOAA), “Red Flag Warning” National Weather Service (NWS)
(n.d.):
https://www.weather.gov/mqt/redflagtips#:~:text=A%20Red%20Flag%20Warning%20means,increased%20risk%2
0of%20fire%20danger.
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18.2 Location
Figure 18-1 King County Wildland Urban Interface (WUI)5
Wildland-Urban Interface
The wildland-urban interface (WUI), or the zone of transition between structures and human
development and undeveloped land or vegetative fuels, is of particular importance for wildfire
mitigation. Figure 18-2 displays the current King County WUI map.
5 King County, “Wildfire Risk Reduction Strategy” Office of Emergency Management (July 2022):
https://your.kingcounty.gov/dnrp/climate/documents/king-county-wildfire-strategy-report.pdf
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• Interface areas are those in which development and structures are bordered by wildlands
on at least one side.
• Intermix areas are defined as a development or structure that is surrounded on two or
more sides by wildlands.
The WUI map above is not a wildfire risk map and simply demarcates where the wildlands and
urban areas meet and overlap; however, communities in the WUI have a higher likelihood of
exposure to wildland fires so it is an important area to consider for wildfire mitigation work.
Wildfire Smoke
Figure 18-2 Asthma Diagnosis Medicaid Members (All Ages), King County 20236
Wildfires in neighboring regions, including Eastern Washington, Oregon, and British Columbia,
frequently bring wildfire smoke into King County, leading to hazardous air quality conditions.
Recent studies on wildfire smoke exposure in Washington have revealed a significant link between
exposure to PM2.5 from wildfire smoke and increased visits to emergency rooms and outpatient
clinics.7 Vulnerable groups, particularly children with asthma and those experiencing childhood
respiratory or chest symptoms, are disproportionately affected. Chronic Obstructive Pulmonary
6 King County, “Asthma data dashboards - Asthma diagnosis among Medicaid members” Public Health – Seattle &
King County (PHSKC) (October 2024): https://kingcounty.gov/en/dept/dph/about-king-county/about-public-
health/data-reports/climate/asthma
7 https://deohs.washington.edu/hsm-blog/wildfire-smoke-tied-increased-risk-er-visits
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Disease (COPD) patients across all age groups also face heightened risks, as do individuals with
other respiratory conditions.
In 2021, The Puget Sound Clean Air Agency reported that the region’s unprecedented wildfire
smoke events resulted in the highest amounts of particulate matter in the air since air quality
monitoring for PM2.5 began in 1980.8 As climate change increases the likelihood of larger and more
severe wildfires, the number of days with poor air quality from smoke increases as well.
18.3 Magnitude
Wildfire Regime
Figure 18-3 Western Cascadia wildfire regime 9
To understand the magnitude and frequency of
wildfires, it is essential to understand the norms and
patterns of wildfires in our area over time, which is
known as the wildfire regime.10 King County has two
predominant wildfire regimes, demonstrated in
Figure 18-3. Parts of King County experience
frequent to moderately frequent and lower- to
moderate-severity wildfires. These fires are often
relatively small (<50,000 acres) and are more easily
limited by external factors such as weather, available
fuel, topography, and standard firefighting
techniques.
The other type of fire in our wildfire regime is
infrequent and high-severity wildfire. The most
likely scenario for a such a fire to occur is during a
major east-wind event when vegetative fuels are dry
and primed for burning; such fires can be massive
(100,000 to >1,00,000 acres), are incredibly difficult
to contain, and often burn at a severity that kills
entire sections of forest (what is known as a “stand-
8 Puget Sound Clean Air Agency, “2021 Data Summary” (2022): https://www.pscleanair.gov/673/2021-Data-
Summary
9 Matthew J. Reilly, et. al, “Cascadia Burning: The historic, but not historically unprecedented, 2020 wildfires in the
Pacific Northwest, USA” ESA (June 2022): https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecs2.4070
10 Emily Fales, Daniel Donato, “Key Insights for Wildfire Management in Western Washington: Fire Regime and
Forest Structure” Forest Stewardship Notes (February 2024):
https://foreststewardshipnotes.wordpress.com/2024/02/06/key-insights-for-wildfire-management-in-western-
washington-fire-regime-and-forest-structure/
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replacing” fire). Because the majority of the wildlands in King County are east of the populous areas
of the county, strong wind from the east could push a wildfire directly into the urban areas of King
County, a situation which would be dangerous and even deadly.
The challenge of the low-frequency, high-severity fire regime is that many of the major stand-
replacing wildfires that have impacted the region are out of living memory. The average return
interval between such wildfires is anywhere from 100-500 years. Because major westside fires
rarely occur, people in areas of higher risk may not realize just how vulnerable they are to a major
wildfire. Lack of awareness can lead to lack of preparedness, low interest in mitigation, and
inadequate precaution with potential ignition sources. Maps of fire risk in the United States – such
as the FEMA Risk Index map – show King County as “relatively low” risk, but this is because these
maps are calculated using annualized frequency fires.11 Such calculations convey the low frequency
of our wildfire regime but does not accurately capture the danger of a major fire if conditions are
right. Furthermore, the impacts of climate change are rapidly increasing the risk factors for wildfire.
We must not only plan for our historic fire regime but consider the likely worsening wildfire
scenarios of the future.
Severity of Wildfire
While a fire is actively burning, its impact can be measured several ways. The size of a fire is often
typically communicated to the public by the number of acres burned. Within the first responder
community, wildfires are categorized by the complexity of a response using Incident Command
System (ICS) typing. Table 18-2 describes the factors of a wildfire response that delineate incident
type, with Type 1 is the most resource-intensive.
Table 18-1 Incident Command System (ICS) for wildfire response
Type 5: Type 4: Type 3: Type 2: Type 1:
Very small
wildland fire only
Short duration
Few resources
assigned
(generally less
than 6 people)
Little complexity
Initial attack or first
response to an
incident
Few resources are
used (several
individuals or a single
strike team)
Normally limited to
one operational
period
Extended initial attack
on wildland fires
Resources may vary
from several single
resources to several
task forces or strike
teams
May extend into
another operational
period (12 hours), and
require an IAP
Large number of
resources utilized
Incident extends
into multiple
operational periods
Significant logistical
support is required
Multi-agency and
national
resources
Large number of
personnel and
equipment are
assigned to the
incident
It is a large,
complex incident
11 FEMA, “Wildfire” National Risk Index (n.d.): https://hazards.fema.gov/nri/wildfire
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Wildfire intensity is the amount of energy or heat given off by a forest fire at a specific point in time.
• Low Intensity: Flames are low, staying close to the ground making the fire spread slowly.
Not much heat is produced which makes it more manageable.
• Moderate Intensity: Flames are a bit higher but only by a few inches so the fire spreads at
moderate speed with moderate heat produced.
• High Intensity: Flames are high and can be tough to control. The fire moves considerably
faster and can be a challenge. The heat coming from the fire has noticeably increased in
temperature.
• Extreme Intensity: Flames are extremely high, towering above everything. The fire spreads
extremely fast and is hard to predict. The substantial heat generated poses a significant
threat to people and nature.
The intensity of a wildfire is a key indicator of the fire’s severity, or the measure of a fire’s impact on
the area burned. A low intensity fire may burn low-level vegetation but leave trees intact, so forests
can quickly rebound. Conversely, a high or extreme intensity fire can destroy the flora of an entire
area, leaving a lengthy road to recovery.
AQI for PM2.5 – Smoke
According to the Washington Department of Ecology, wildfire smoke is the largest source of particle
pollution in Washington.12 The effects of smoke exposure range from eye and respiratory tract
irritation to more serious health problems including reduced lung function, bronchitis, asthma
exacerbation, heart failure, and premature death. People with existing heart and lung diseases,
older adults, children and pregnant women are especially at risk of smoke-related health problems.
The Puget Sound Clean Air Agency monitors air quality and communicates the level of
unhealthiness with the Air Quality Index, which tracks concentrations of several pollutants including
PM2.5.13 In 2017, and especially 2018, smoke from wildfires inundated Seattle, causing unhealthy
air quality. This was due to wind patterns that blew smoke from fires in British Columbia, Oregon,
12 WA Department of Ecology, “Wildfire smoke information” (n.d.): https://ecology.wa.gov/air-climate/air-
quality/smoke-fire/wildfire-smoke
13 US Environmental Protection Agency (EPA),“Technical Assistance Document for the Reporting of Daily Air Quality
– the Air Quality Index (AQI)” (May 2024): https://document.airnow.gov/technical-assistance-document-for-the-
reporting-of-daily-air-quailty.pdf
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and Eastern Washington into the region. Warmer summers will increase the number of fires and
with more fires, more smoky days are likely.14
Table 18-2 Sensitive Groups and the Air Quality Index
According to the Washington
Department of Ecology, wildfire smoke
is the largest source of particle
pollution in Washington.15 The effects
of smoke exposure range from eye and
respiratory tract irritation to more
serious health problems including
reduced lung function, bronchitis,
asthma exacerbation, heart failure,
and premature death. People with
existing heart and lung diseases, older
adults, children and pregnant women
are especially at risk of smoke-related
health problems. The Puget Sound
Clean Air Agency monitors air quality
and communicates the level of
unhealthiness with the Air Quality
Index, which tracks concentrations of
several pollutants including PM2.5.16 In 2022, smoke from the Bolt Creek Fire and other area fires
reduced air quality in the region to the worst in the world for multiple days.17 According to a health
impact assessment by University of Washington researchers, a similar smoke episode in 2020
contributed to an estimated 92 excess deaths, several of which could have been prevented with
reduced exposure to PM2.5.18 Wildfire smoke is particularly dangerous when a wildfire burns
through the WUI, because the smoke contains fine particular matter along with toxins released
14 Greg Gilbert, “Smoky Seattle summers: expect more of them, scientists say” The Seattle Times (August 2018):
https://www.seattletimes.com/seattle-news/smoky-seattle-summers-expect-more-of-them-scientists-say/.
15 WA Department of Ecology, “Wildfire smoke information” (n.d.): https://ecology.wa.gov/air-climate/air-
quality/smoke-fire/wildfire-smoke
16 US Environmental Protection Agency (EPA),“Technical Assistance Document for the Reporting of Daily Air Quality
– the Air Quality Index (AQI)” (May 2024): https://document.airnow.gov/technical-assistance-document-for-the-
reporting-of-daily-air-quailty.pdf
17 Michelle Baruchman, “Seattle air quality among worst in world” Seattle Times (October 2022):
https://www.seattletimes.com/seattle-news/environment/seattle-air-quality-among-worst-in-world/
18 A. Doubleday, A, et. al., “Mortality associated with wildfire smoke exposure in Washington state, 2006‐2017: A
case‐crossover study” Environmental Health, 19(1) (2022):
https://pmc.ncbi.nlm.nih.gov/articles/PMC8101535/#gh2228-bib-0012
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from burning household hazardous materials, vehicles, and structures.19 Warmer summers will
increase the number of fires and with more fires, more smoky days are likely.20
Cascading Impacts
Post-wildfire flooding, landslides, and mudslides are deadly cascading impacts that result from
extreme wildfires in areas with steep slopes and are a serious threat to King County. Soils in areas
burned by fire not only lose their stabilizing vegetation but can also become hydrophobic (water
repelling), leading to massive water runoff that carries debris down slopes and into nearby
waterways. This can lead to large debris flows and mudslides when heavy rains occur that damage
infrastructure and communities downstream for several years after a fire. A fire in one of the
foothills communities could cause major mudflows and devastating flooding in communities in the
watershed impacted by the fire and through which rivers and creeks pass. Communities with
existing flood risk, such as along the Snoqualmie River, are especially vulnerable. Following a
wildfire, experts from the US Geological Survey and/or Washington DNR can conduct assessments
on burned areas to determine the likelihood of major debris flows from a burned area.21
18.4 Previous Occurrences
Modern recordkeeping on wildfires did not begin until the 20th century, so occurrences of major
fires before then in King County are not well documented. However, several high-intensity fires
similar to those anticipated here have been recorded on the west side of the Cascades. Table 18-4
notes past wildfires in King County that have burned at least 100 acres of timber.
Table 18-3 Previous large wildfire events in King County, 1893 - 2024
Date Event Name Description
September 1,
1893
n/a Several large, human-caused wildfires sparked during windy
conditions and burned from Snoqualmie Pass to Skykomish.
No acreage burned recorded.22
19 https://phys.org/news/2023-06-toxic-emissions-wildland-urban-interface.html
20 Gilbert, Greg. “Smoky Seattle summers: expect more of them, scientists say” The Seattle Times (August 2018):
https://www.seattletimes.com/seattle-news/smoky-seattle-summers-expect-more-of-them-scientists-say/.
21 US Geological Survey (USGS), “Miriam Fire Preliminary Hazard Assessment” (2018):
https://landslides.usgs.gov/hazards/postfire_debrisflow/detail.php?objectid=224.
22 Living Snoqualmie, Honoring Our Valley History: Past Fires of the Snoqualmie Valley” Snoqualmie Valley Info
(October 2022): https://prod.livingsnoqualmie.com/honoring-our-valley-history-past-fires-of-the-snoqualmie-
valley/
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May 31, 1922 n/a A human-caused wildfire started during a windy day in
eastern King County and destroyed half the town of Cedar
Falls. No acreage burned recorded.23
September 1,
2009
Lemah Fire A fire sparked in the Alpine Lakes Wilderness and burned
approximately 600 acres.24
August 11,
2017
Quarry Fire A wildfire started 30 miles northwest of North Bend and
burned 243 acres.25 The response cost $1,089,194.
September 4,
2017
Sawmill Creek Fire A fire started in the Green River Watershed burned 1,061
acres.26 The response cost $4,500,000.
*September
7, 2020
Labor Day Fires This series of fires was preceded by dry conditions and a
synoptic east-wind event, and the fires that sparked burned
approximately 840,160 acres in two weeks.27 The fires
prompted evacuation orders to 90,000 people and resulted
in millions of dollars in damage.28
September 8,
2020
Fish Fire A fire southeast of Enumclaw burned approximately 150
acres during the Norse Creek Fire.
August 18,
2022
Murphy Lake Fire A fire sparked by a lightning strike on August 18th grew to
170 acres, temporarily closing a section of the Pacific Crest
Trail.29
23 Washington Forest Protection Association (WFPA), “A Chronology of the First 100 Years of the Washington
Forest Protection Association 1908-2008” History Link (n.d.): https://www.wfpa.org/wp-
content/uploads/2022/11/100-Year-Chronology-small-file.pdf
24 The Associated Press, “Fire closes part of Pacific Crest Trail in central Cascades” Seattle Times (September 2009):
https://www.seattletimes.com/life/outdoors/fire-closes-part-of-pacific-crest-trail-in-central-cascades/
25 Northwest Interagency Coordinator Center (NWCC), “Northwest Annual Fire Report” (2017):
https://gacc.nifc.gov/nwcc/content/pdfs/archives/2017_NWCC_Annual_Fire_Report_FINAL.pdf
26 USDA, “Sawmill Creek Fire Update” USFS (September 2017): https://www.fs.usda.gov/detail/mbs/news-
events/?cid=FSEPRD558196
27 Matthew J. Reilly, et al., “Cascadia Burning: The historic, but not historically unprecedented, 2020 wildfires in the
Pacific Northwest, USA” Ecosphere (2022): https://www.fs.usda.gov/pnw/pubs/journals/pnw_2022_reilly001.pdf
28 Emily Fales, Daniel Donato, “Key Insights for Wildfire Management in Western Washington: Fire Regime and
Forest Structure” Forest Stewardship Notes (February 2024):
https://foreststewardshipnotes.wordpress.com/2024/02/06/key-insights-for-wildfire-management-in-western-
washington-fire-regime-and-forest-structure/
29 Northwest Interagency Coordinator Center (NWCC), “Northwest Annual Fire Report” (2017):
https://gacc.nifc.gov/nwcc/content/pdfs/archives/2017_NWCC_Annual_Fire_Report_FINAL.pdf
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September 9,
2022
Bolt Creek Fire September 9, the fire started 1.5 miles north of Skykomish,
prompted evacuations, and burned approximately 14,766
acres in the Mt. Baker-Snoqualmie National Forest.30
October 16,
2022
Loch Katrine Fire A wildfire spread during a Red Flag Warning 35 miles east of
Seattle and burned 2,000 acres.31
18.5 Probability of Future Occurrences
As the climate changes, there is a greater likelihood that high temperature and dry conditions will
be present along with the already-existing topographic, wind, and fuel conditions necessary to
support a large fire. Development is also expected to densify in the wildland-urban interface. The
building patterns in these areas are not in accordance with Fire Wise principles and many
communities have limited ingress and egress routes.
18.6 Climate Change Considerations
As the climate changes, it is expected to lengthen the fire season and increase the likelihood of
more wildfire in Western Washington.32 Prolonged summer heat, combined with high density
forests and areas of poor forest health, is increasing fire risk. Hotter and drier conditions are two of
the three factors that influence fire behavior and make a wildfire significantly more likely to occur in
King County. If emissions continue at their current rate, the annual average amount of acres burned
in the Pacific Northwest is expected to more than triple by the 2040s.33
18.7 Impact Assessment
Public Approximately 6% of King County’s total population (~352,000
people) who live in the Wildland Urban Interface (WUI) are more
likely to be directly exposed to wildfire than the rest of the county.
30 InciWeb, “10/2/2022 Bolt Creek Fire Update” (October 2022): https://inciweb.wildfire.gov/incident-
publication/wanws-bolt-creek-fire/1022022-bolt-creek-fire-update
31 Chris Bentley, “Loch Katrine Fire Swells to over 2,000 Acres Overnight Due to Severe Fire Weather” USDA, USFS
(October 2022): https://www.fs.usda.gov/detail/mbs/news-events/?cid=FSEPRD1067163
32 Alex W. Dye, et. al., " Simulated Future Shifts in Wildfire Regimes in Moist Forests of Pacific Northwest, USA”
AGU (February 2024): https://doi.org/10.1029/2023JG007722
33 H.A. Morgan, et. al, “Managing Western Washington Wildfire Risk in a Changing Climate” UW Climate Impacts
Group, Northwest Climate Adaptation Science Center (2019): https://nwcasc.uw.edu/wp-
content/uploads/sites/23/2019/04/Managing-Western-Washington-Wildfire-Risk-in-a-Changing-Climate-1.pdf
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This risk is growing due to climate change and new development in
the WUI. It’s also important to note that evacuations cannot be
enforced, thus in the event of wildfire outbreak, those who remain
in their homes located in or near the WUI are at higher risk.
The most frequent impact of wildfires King County residents will
experience is exposure to smoke. Wildfire smoke can cause
respiratory issues, prevent people from taking part in outdoor
activities, and increase emergency department visits.
Responders Growing numbers of wildfires will increase risk to firefighters. With
an increase in WUI fires, firefighting becomes more complex and
dangerous. Also, communities without proper ingress/egress
routes further increase risk to firefighters who may be called upon
to attempt evacuations in such communities. As climate change
exacerbates wildfires across the United States, increasing
frequency and severity of fires and extending wildfire season, it
increases the strain on firefighting resources. King County’s window
of vulnerability to wildfire is near the end of the current wildfire
season when resources are waning. If federal or state land
management agencies are targeted for staff reductions or
significant budget cuts, it will decrease the number of trained
responders assigned to protect large portions of land in King
County, putting increased pressure on mutual aid.
Continuity of operations Most King County government operations and facilities are in the
more urban areas of the county and unlikely to be directly
impacted by wildfires. However, a major wildfire might occupy
most of the region’s first responder capabilities, pulling resources
from other sectors and parts of the county through mutual aid.
Smoke, which is the most frequent impact of wildfires experienced
by King County, can cause an increase in employee absenteeism,
put a strain on the health systems, and prompt cancellations of
various outdoor activities and events.
Property, facilities, and
infrastructure
Property
King County is working on a countywide wildfire risk assessment that
will be published in our Community Wildfire Protection Plan (CWPP)
in 2025. Likely impacts to property include smoke damage to total
loss of facilities. Communities built with many homes close together
and constructed of flammable materials can be completely burned
in a short time, as seen in Paradise, CA, Superior, CO, and Lahaina,
HI.
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Facilities
Exposure to PM 2.5 is a significant health concern, because the
small size of the particle allows people to inhale it deep in the lungs
where the particles can directly enter the blood stream. The effects
of smoke exposure range from eye and respiratory tract irritation
to more serious health problems including reduced lung function,
bronchitis, exacerbation of asthma and heart failure, and
premature death. During extreme smoke pollution events, public
health systems are likely to be burdened by populations suffering
respiratory distress.
Infrastructure
• Energy: Many major transmission lines run through
wildland areas. While utilities have their own wildfire
mitigation plans and typically keep brush surrounding
transmission lines clear, wildfires in King County could
damage or destroy these systems. Rural and other interface
power lines would be burned in any fire, as has been seen
in numerous communities in Eastern Washington. Many
utility providers in the West, including Puget Sound Energy,
have implemented plans for Public Safety Power Shut-offs
(PSPS) to reduce the likelihood that energized lines will
start a fire during “red flag” fire conditions, affecting energy
customers, especially those reliant on electricity.
• Water/Wastewater: Many of King County’s watersheds and
primary water reservoirs are in forested areas and could be
impacted by wildfire that could burn power supplies to
pump stations or the pump stations themselves.
Furthermore, post-fire runoff and flooding could damage or
pollute reservoirs.
• Transportation: Fire can prompt road closures due to
visibility concerns, direct contact with fires, and to keep the
public away from an evacuated area. Another major risk is
post-fire flooding and debris flows that can damage or
destroy roads and bridges downstream or downslope from
a burned area after a rain. Additionally, SeaTac Airport has
had to cancel flights due to poor visibility during wildfire
smoke events.
• Communications: Cellular communications sites can lose
power or be damaged by wildfire. During these events, it
may be necessary to deploy cellular on wheels capabilities.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 18: Wildfire
18-15
The environment While wildfires can be beneficial to the landscape, a major wildfire
can be damaging in the near term. Fires can pollute water systems
and destroy old growth habitat. They can burn over springs and
increase evaporation. Following extreme fires, hydrophobic soils
make it difficult for plants to regrow in and the runoff over these
soils increases the turbidity of local streams, endangering fish and
other water animal populations.
The economy Wildfire suppression alone is incredibly expensive, with
Washington spending an estimated $145.3 million for wildfire
suppression in FY 2023.34 A high-severity wildfire impacting
structures could cause significant economic impact to an affected
community for years. Disaster recovery is a lengthy process and a
wildfire would likely result in displacement of residents and impact
local housing stock and prices.
Economic costs may be felt by a wildfire that does not impact
structures as well. Besides suppression costs, the impacts of
wildfire smoke inundation is likely to be limited and temporary. For
a wildfire he largest impacts on the economy are likely to be
indirect, including losses in work days because of poor air quality,
interrupted access to various services, and losses in tourist income.
Public confidence in
governance
Wildfire hazards have gained renewed importance in recent years.
WUI wildfires are particularly destructive and deadly, and several
recent such fires resulted in mistrust of responding institutions,
conspiracy theories about fires’ sources, and anger and blame at
parties in or near the fire. Government will need to be proactive in
managing this hazard, communicating clearly throughout a
response, and commit to recovery in order to maintain public
confidence, which is difficult to earn and easy to lose.
34 Washington State Legislature, “Emergency Fire Suppression Report for Fiscal Year 2023, Executive Summary for
November 2022” Department of Natural Resources (2023):
https://app.leg.wa.gov/ReportsToTheLegislature/Home/GetPDF?fileName=Copy%20of%20MONTHLY%20FIRE%20
SUPPRESSION%20REPORT%20FY23_FM17_November_FINAL_1.19.23_3f03aaee-f2de-4a60-ac08-
c0d89ef7d331.pdf
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18.8 Vulnerability Assessment
Vulnerable
populations
Populations suffering from respiratory ailments are at the greatest risk
from wildfire since smoke from fire. People with existing heart and lung
diseases, older adults, children and pregnant women are especially at
risk of smoke-related health problems.
Foothills/interface
Communities in or around areas at a higher risk of fire, such as those in
the foothills of the Cascades, are more susceptible to fire.
Fire Footprints
Major wildfires leave behind an environment that is more vulnerable to
flooding. When rains come, large quantities of water and debris and
rush down hillsides and destroy homes and infrastructure while causing
flooding in downstream communities.
Property There are several factors that put a structure at higher risk of damage
from a wildfire. Buildings in the WUI that do not have sufficient
defensible space surrounding them are likely to be damaged if directly
exposed to wildfire. This includes homes with flammable roofs,
proximity to dense brush or timber, or tightly packed neighborhoods
with space between buildings. Structures built in interface or intermix
areas are more likely to be exposed to fires, including from spotting and
embers ahead of a fire. Fires tend to burn up slopes and ridges,
endangering structures in those areas. Buildings less than 30 feet from a
slope of greater than 30% grade are at risk. Buildings more than five
miles away from fire services and with limited pressurized fire hydrant
access are more vulnerable.
AGENDA ITEM #1. b)
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Environment A wildfire that burns homes can significantly damage the environment
due to numerous quantities of household hazardous materials that
burn and release toxins into the air, ash, and soil. Wildfires can harm
riparian environments and other critical habitats, and ashfall can
decrease water quality.
Wildfires are also major carbon emitters. For example, 2023 wildfires in
North America released 640 million metric tons of carbon, an amount
comparable to annual emissions of a large, industrialized nation.35
Those areas eventually recover the ability to capture and store carbon
as they recover. This can take years, however, because mature forests
have the greatest carbon storage potential.36
Operations Ingress/Egress
Communities with a single route in or out of the area are much more
difficult to evacuate. Roads that are less than 24 feet wide, especially
those less than 20 feet wide, and those driveways without a
turnaround are highest risk.
35 NASA, “New NASA Study Tallies Carbon Emissions from Massive Canadian Fires” (August 2024):
https://www.jpl.nasa.gov/news/new-nasa-study-tallies-carbon-emissions-from-massive-canadian-fires/
36 NSF, “After the Fire: Studying Forest Recovery and Carbon Storage Potential” (February 2021):
https://www.neonscience.org/impact/observatory-blog/after-fire-studying-forest-recovery-and-carbon-storage-
potential
AGENDA ITEM #1. b)
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Chapter 19: Capabilities
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Chapter 19: Capabilities
King County includes 39 cities, over 129 special
purpose districts, and large unincorporated areas.
While each city and special purpose district is
responsible for its own hazard mitigation efforts,
King County supports these jurisdictions through
region-wide services and planning coordination,
including efforts associated with land use,
emergency management, and floodplain
management. County departments involved in
hazard mitigation efforts include Executive Services
(facilities management, emergency management),
Local Services (permitting, roads), Natural
Resources and Parks (wastewater, landslides,
floodplain management, climate change), and the
Office of the Executive (planning).
As the lead agency for hazard mitigation, the King
County Office of Emergency Management (KCOEM)
collaborates with a wide range of partners to
advance and support mitigation efforts through its
hazard mitigation program. KCOEM actively
promotes Hazard Mitigation Assistance grant
opportunities, offering technical support to help
develop competitive applications. KCOEM also
serves on interagency workgroups such as
comprehensive planning, climate adaptation, and
transportation as a way of promoting consistency in
risk assessment and reduction priorities.
The focus of the KCOEM’s hazard mitigation program is integration across plans, programs, and
departments and jurisdictions. Plan integration ensures that all partners utilize the best available
data and align their efforts to support a resilient future. Program integration connects partners with
funding sources and resources beyond their individual departments or programs. Departmental and
jurisdictional integration builds on the county's role through the Emergency Operations Center
(EOC), mobilizing resources to prioritize and implement the most effective hazard mitigation
strategies.
Hazard Mitigation Program
Hazard mitigation is most effective
when approached through a
systematic program that sets clear
priorities and recognizes that building
resilience requires widespread,
coordinated investments. A cohesive,
comprehensive strategy founded on
strong partnerships is essential to the
success of this program.
To support this approach, King County
Emergency Management facilitates
multi-agency committees, provides
technical assistance for federal
mitigation grants, aids partners in
planning and executing mitigation
projects, and continually updates the
King County Regional Hazard
Mitigation Plan to ensure it reflects
the evolving needs and priorities of
the region.
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A crucial component of this integration is the capabilities assessment, which evaluates the
community’s capacity to reduce or mitigate the impacts of disasters. By conducting this assessment,
KCOEM creates a comprehensive toolbox of plans, policies, ordinances, programs, and
departmental resources that address identified hazards. This ensures that all partners have a clear
understanding of their current capabilities and are equipped to effectively contribute to hazard
mitigation efforts. The assessment also serves as a roadmap for refining and enhancing existing
plans and ordinances, ensuring they are aligned with the broader hazard mitigation strategy and
responsive to evolving risks and needs.
19.1 Plan, Policies, & Ordinances
In King County, numerous plans, policies, and ordinances already exist that directly address or
influence the impact of hazard risks. These frameworks serve as a foundation for guiding mitigation
efforts, integrating risk reduction into everyday decisions, and ensuring that communities can
effectively reduce hazard vulnerabilities.
Gaps in policies for King County is National 2021 Wildlife Urban Interface (WUI) Code. Washington
state parts of the 2021 code in March 2024, however, jurisdictions are waiting to adopt the code
until new WUI mapping and amendments can be developed.
Table 19-1 Plans, policies, and ordinances capabilities
Plans, Policies, & Ordinances Description Lead Agency
30-Year Forest Plan
2021 King County 30-Year Forest Plan
provide a shared county-wide vision for
rural and urban forest cover and forest
health.
DNRP
Building and Development Codes Building and development codes are
adopted and modified from the 2021
IBC by Washington State Building Code
Council and King County. These codes
help ensure that new construction and
substantial improvements meet
international standards, accounting for
our hazard risk.
Department of
Local Services
(DLS) –
Permitting
Division
Build Code Effectiveness Grading
Schedule (BCEGS)
In November 2023, the Washington
Surveying and Rating Bureau (WSRB)
gave King County the BCEGS rating of
Class 4 for commercial properties and
Class 4 for one- and two-family
dwellings.
DSL
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Clean Water and Health Habitat
Strategic Plan
The 2020-2025 CWHH Strategic Plan
seeks to establish a strategic alignment
across all plans that impact clean water
and healthy habitat in order to achieve
“greater impact through clearer
definition, smarter investment,
partnerships, and innovation.” This
process is just starting, and it includes
over 20 separate plans and programs.
Department of
Natural
Resources and
Parks
Community Wildfire Protection
Plan
The Office of Emergency Management is
currently building upon the 2022 King
County Wildfire Risk Reduction Strategy
to develop the King County's first
Wildfire Protection Plan.
KCOEM
Comprehensive Emergency
Management Plan (CEMP)
The CEMP is for use by elected and
appointed County officials, and King
County government department
directors, managers and staff in
mitigating, preparing for, responding to,
and recovering from disasters. (2020)
KCOEM
Comprehensive Plan The 2024 King County Comprehensive
Plan is the long-range guiding policy
document for all land use and
development regulations in
unincorporated King County, and for
regional services throughout the County
including transit, sewers, parks, trails
and open space.
• Encourage updates to the critical areas
ordinance
• Provide feedback and comments on
the plan
Executive's
Office
Continuity of Government (COG)
Plan
The King County Continuity of
Government (COG) Plan addresses the
continuation, resumption, and recovery
of King County Government, and
focuses on critical areas pertaining to
government continuity:
Succession of leadership
Emergency authority
Command and control
All KC agencies
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The COG Plan identifies how the
responsibilities of King County
Government, as defined by the
Washington State Constitution and the
King County Charter, will be preserved,
maintained, or reconstructed in the
event of a disaster or other event. Much
of the content of the COG Plan is
derived from or a direct excerpt of
provisions in the King County Charter
and King County Code.
Continuity of Operations Plan
(COOP)
The purpose of King County's Continuity
of Operations (COOP) Plans are to
provide the framework for the
restoration of essential
functions/processes in the event of an
emergency or incident that affects
operations. COOP plans identify and
prioritize essential functions and
processes that must continue, and
include activation procedures,
establishing clear lines of succession,
defining who has the authority to make
decisions, identifying alternate
locations, and managing vital records.
COOP plans help us remain resilient and
capable of maintaining critical
operations, even under challenging
circumstances.
All KC agencies
Critical Area Ordinance The critical areas ordinance requires the
identification of geologically-hazardous
and frequently-flooded areas. These
areas must either be protected from
development or any development in
these areas must be designed to
account for hazard risk. Supplemental
changes to the ordinance are being
incorporated into the updated 2024
King County Comprehensive Plan.
DLS
Critical Facilities Plan
(Mitigation/Response/Recovery)
Capital facilities plans identify and
prioritize large-scale projects. Entities
involved in this include the King County
Facilities Management Division and the
King County Flood Control District.
Various
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• Integrate mitigation strategies from
capital plans
• Encourage the use of hazard
information to prioritize capital
improvements
• Support county departments with
funding gaps in accessing Hazard
Mitigation Assistance to complete or
expand projects that are identified as
important but are unfunded or partially
funded.
Debris Removal Plan The 2024 KC Debris Management
Framework is intended to aid all of King
County and its departments, including
individual jurisdictions, special purpose
districts, and tribes within the county.
This framework will be used to support
debris management activities in
unincorporated King County and when
individual jurisdictions, special purpose
districts, and tribes within King County
become overwhelmed or when there is
need to coordinate resources among
the various entities requesting
assistance. It is intended to facilitate
rapid response and recovery efforts
during and after a disaster.
DNRP
Equity and Social Justice
Ordinance
King County has deep and persistent
inequities – especially by race and
place–that in many cases are getting
worse and threaten our collective
prosperity. Launched by King County
Executive Ron Sims in 2008 and
formalized by Executive Dow
Constantine and the Metropolitan King
County Council via ordinance in 2010,
Equity and Social Justice (ESJ) is an
integrated part of the County’s work
and is supported by the Office of Equity
and Social Justice since it was
established in early 2015.
King County
Executive’s
Office, Office of
Equity and Social
Justice
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Equity and Social Justice Plan The 2016-2022 Equity and Social Justice
Strategic Plan is a blueprint for action
and change that will guide the county’s
pro-equity policy direction, decision-
making, planning, operations and
services, and workplace practices in
order to advance equity and social
justice within County government and in
partnership with communities.
• Follow guidance in the ESJ plan for the
prioritization of strategies
• Develop information on populations
vulnerable to hazards and share with ESJ
planning teams
Executive's
Office
Extreme Heat Mitigation Strategy The 2024 Extreme Heat Mitigation
Strategy focuses on reducing risks
associated with extreme heat events,
particularly for vulnerable populations
in urban heat islands.
ECO
Flood Management Plan The 2024 King County Flood
Management Plan is a functional annex
of the comprehensive plan. It outlines
the County’s approach to
comprehensive floodplain management
including land use planning, flood
mitigation efforts, and flood protection
facilities management.
• Work with department responsible for
floodplain management to write the
flood risk assessment.
• Work with local CRS coordinators to
ensure the mitigation plan is worth the
maximum number of points.
DNRP
Floodplain Ordinance Flood hazard areas covered by King
County’s regulations include the
floodplain, FEMA Special Flood Hazard
Area, King County zero-rise flood fringe
and zero-rise floodway, and channel
migration zones. King County’s flood
hazard reduction policies, as they relate
to land use and regulatory compliance,
are as follows: Consistent with
prerequisites for FEMA’s CRS program,
King County shall regulate development
DNRP
AGENDA ITEM #1. b)
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Chapter 19: Capabilities
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that occurs in flood-prone areas to avoid
and minimize damage to life and
property and necessary public
infrastructure, support other
Washington State Growth Management
Act (GMA) and King County
Comprehensive Plan policy goals,
accommodate preferred land uses
outlined by the Shoreline Management
Act, . King County should look for
opportunities to improve, modify, or
relocate existing county roads to ensure
safe ingress and egress during flood
events.
Growth Management Ordinance incorporated into the King County
Comprehensive Plan. The state of
Washington also has the Growth
Management Act.
Executive's
Office
National Pollutant Discharge
Elimination System (NPDES)
The County’s National Pollutant
Discharge Elimination System (NPDES)
municipal stormwater permit, which
contains specific requirements for
drainage review and inspection of
development projects. In addition to the
manual’s standards being applied
throughout the unincorporated areas,
many cities throughout King County
have adopted the manual and apply its
standards as part of their local
permitting processes.
DNRP
Post-Disaster Recovery Plan The Office of Emergency Management is
currently using the 2016 King County
Recovery Framework to develop the
King County Disaster Recovery Plan.
KCOEM
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Public Health Plans Public Health – Seattle & King County’s
2024-2029 strategic plan describes how
we will meet the most persistent and
urgent
health challenges facing King County,
embed Racism is a Public Health Crisis
into our everyday work, and strengthen
our core functions to protect and
promote health.
PHSKC
Sea Level Rise Risk Area
Regulation
King County created a new sea level rise
risk area for Vashon-Maury Island. The
risk area extends inland from the edge
of the existing 100-year floodplain.
Under these new regulations, new
homes built in the risk area must be
built three feet above the 100-year base
flood elevation and comply with other
floodplain regulations.
DNRP
Stormwater Management
Program Plan (SWMP)
The King County Stormwater Program
Plan is updated annually and guides the
many activities King County implements
to manage stormwater. These include
mapping the municipal stormwater
system, coordination among county
departments to eliminate barriers to
compliance with stormwater
requirements, controlling runoff from
new development and redevelopment,
updating design standards and
stormwater management regulations,
and operations and maintenance of the
stormwater system.
DNRP
Strategic Climate Action Plan The 2020 King County’s Strategic
Climate Action Plan (SCAP) is a five-year
blueprint for County action to confront
climate change, integrating climate
change into all areas of County
operations and its work in the
community. The SCAP is King County’s
blueprint for climate action and
provides a “one-stop-shop” for county
decision-makers, employees, and the
general public to learn about the
Executive Office
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County’s climate change goals, priorities
and commitments.
• Inter-workgroup participation
• Integrated mitigation strategies
• Consistent risk assessments
Strategic Plan for Road Services The 2014 Road Services Strategic Plan
lays out system needs and anticipated
service levels and an asset management
approach to road maintenance and
improvement.
• Integrate mitigation strategies
DLS
Surface Water Design Manual King County’s Surface Water Design
Manual is a technical guide that outlines
requirements for stormwater
management systems in King County. It
regulates proposed surface and
stormwater projects through a mixture
of best management practices (BMPs),
performance standards, and design
standards.
DNRP
Sustainable & Resilient Frontline
Communities (SRFC) Framework
Sustainable & Resilient Frontline
Communities (SRFC) Framework ensures
that climate preparedness efforts
address the disproportionate impacts of
climate change on frontline
communities.
ECO
Threats and Hazard Identification
and Risk Assessment (THIRA)
The Threats and Hazard Identification
and Risk Assessment (THIRA) is a three-
year process which helps a region
determine what threats and hazards the
are likely to experience, provides
context on those threats and hazards for
planning purposes, identifies potential
impacts to the region, and identifies
current and desired capabilities for
KCOEM
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responding to and recovering from
those threats and hazards. The THIRA
uses a combination of experience and
Subject Matter Expertise as well as
documented capabilities and gaps, such
as in After-Action Reports, to articulate
the regions readiness. The gaps listed in
the THIRA are often used as areas to
seek additional funding to build capacity
and close gaps.
19.2 Programs
The hazard mitigation planning process has engaged participants from across these programs in
order to establish a common assessment of hazards, identify potential mitigation strategies,
partnerships for future projects, and to assess county capabilities to implement mitigation projects.
The list below identifies King County programs that support and implement hazard mitigation and
assesses the effectiveness of each.
Table 19-2 Program and special district capabilities
Programs & Special Districts Description Lead Agency
ALERT King County ALERT King County is a regional emergency
public information and mass notification
service that uses voice, text, and email. Alerts
can be sent to the public to inform them
about potential hazards and threats in the
area. The system is administered through
CodeRed.
KCOEM
Flood Buyout Program Any structure located in a flood-prone area
of unincorporated King County may be
eligible for this program. Buyouts are
appropriate in areas where there is deep,
fast-moving water, serious bank erosion, and
significant risk of channel migration. Priority
applicants for the Buyout Program are:
structures located in the floodway, structures
located in the channel migration zone, and
FEMA Repetitive Loss Properties.
DNRP
Hazard Awareness Program King County’s Public Education & Outreach
program supports emergency preparedness
by integrating an all-hazards approach across
KCOEM
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prevention, response, recovery, and
mitigation. It provides strategic outreach and
education support to KCOEM’s emergency
planning and operations while engaging both
government stakeholders and community
members. Through initiatives such as public
input processes, open houses, and the
creation of educational materials, the
program empowers residents to understand
and manage risks.
Hazard Mitigation The hazard mitigation program works with
partners across county departments and local
jurisdictions to coordinate and promote
hazard mitigation projects.
The program also coordinates applications to
federal Hazard Mitigation Assistance grant
programs and conducts hazard mitigation
planning for the county in partnership with
local jurisdictions and special-purpose
districts.
KCOEM
King County Conservation
District
The King County Conservation District is an
independent special purpose district with
separately-elected commissioners. It
promotes water, land, soil, and forest
conservation and preservation and conducts
wildfire risk reduction activities.
King County
Conservation
District
King County Flood Control
District
In 2007, the King County Flood Control
District was established to provide a
proactive, regional approach to flooding as
well as funding to improve the county's
nearly 500 aging and inadequate flood
protection facilities.
Funding for the Flood Control District comes
from a county-wide property levy of 12.9
cents per $1,000 assessed value. This
amounts to $54 per year on a $416,000
home. The levy raises roughly $54.5 million a
year. This funding dramatically increases the
number of projects that can be completed
each year. The additional local funding also
enhances the District's ability to receive
federal and state matching funds.
The King County Flood Control District is a
separate special purpose district.
King County
Flood Control
District
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Land Use Planning and
Zoning
Land use planning and zoning establishes
growth and land use patterns that are
consistent with long-range plans and
supported by infrastructure.
King County
Executive’s Office
Landslide Hazards The Landslide Hazards program conducts
mapping and outreach associated with
landslide risk.
DNRP Water and
Land Resources
Division
Mutual Aid Agreement King County’s mutual aid strategy was
originally outlined in the Regional
Coordination Framework and included an
omnibus document that later became known
as “the Agreement.” While the broader
strategy is now being incorporated into the
county’s Comprehensive Emergency
Management Plan (CEMP), the Agreement
remains a separate, binding document. The
Agreement outlines the obligations and basic
procedures for resource sharing between
entities that have signed on. This framework
ensures that during emergencies, all parties
understand their roles and responsibilities in
facilitating mutual aid. By maintaining the
Agreement alongside the evolving CEMP,
King County reinforces a structured and
coordinated approach to emergency
response. Ultimately, this dual approach
strengthens the county’s overall emergency
management capabilities.
KCOEM
National Flood Insurance
Program (NFIP)
Communities that participate in the National
Flood Insurance Program adopt a floodplain
management code in exchange for FEMA
making flood insurance available to residents
and businesses.
DNRP, DLS –
Permitting
Division
NFIP Community Rating
System (CRS)
The CRS program rewards communities that
have established exceptional floodplain
management programs and undertaken
certain activities to reduce flood risk. King
County is one of the highest rated
communities in the country. The program
provides NFIP policyholders in floodplains
with a discount of up to 40% on their
insurance.
DNRP
DLS
KCEM
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Puget Sound Climate
Preparedness Collaborative
King County advances climate resilience
through collaborative initiatives such as the
Puget Sound Climate Preparedness
Collaborative. This initiative strengthens the
regional partnerships to advance climate
preparedness and foster cross-jurisdictional
coordination across the Puget Sound basin.
ECO
RainWise Rebate Program RainWise helps private property owners
install rain gardens and cisterns to help
manage the rain that falls on their roofs.
These installations can also add attractive
landscaping, provide water for summer
irrigation, and may reduce flooding. RainWise
rebates cover most or all of the cost of
installing cisterns and rain gardens on private
properties in eligible combined sewer
overflow basins. The average rebate is
approximately $4,740.
DNRP
Regional Code Collaboration
(RCC)
Jurisdictions across the Puget Sound Region
work together to share resources and
expertise to develop codes, policies, and
tools supporting sustainable building
practices that can be adopted/utilized locally.
DNRP
ShakeAlert The USGS ShakeAlert Earthquake Early
Warning system sends a warning to mobile
phone users that shaking is about to occur.
The system uses ground-motion sensors to
detect earthquakes that have already started
and estimates their size, location, and
impact. When it detects a significant
magnitude, the system issues a ShakeAlert®
Message, providing a warning a few seconds
before shaking begins.
USGS, PNSN
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Shoreline Master Program King County has nearly 2,000 miles of
shoreline along major lakes and rivers and
Vashon-Maury Island. These shorelines
provide habitat for fish and wildlife, places
for public enjoyment and space for wide-
ranging waterfront land uses. The Shoreline
Master Program helps preserve King County’s
nearly 2,000 miles of shoreline, thereby
reducing risk to hazards including sea-level
rise.
DLS – Permitting
Division
StormReady StormReady is an NWS planning tool to
become better prepared for hazardous
weather events. To become StormReady, the
county had to meet specific criteria, such as
having a 24-hour emergency operations
center, providing severe weather
notifications to residents, conducting public
awareness programs, and maintaining a
trained team of weather spotters. The goal is
to enhance the county's readiness to respond
to severe weather events, ensuring public
safety and effective communication during
storms.
National
Weather Service
(NWS)
The Integrated Public Alert
& Warning System (IPAWS)
IPAWS is FEMA's national system for local
alerting that provides authenticated
emergency and life-saving information to the
public through mobile phones using Wireless
Emergency Alerts (WEA), to radio and
television via the Emergency Alert System
(EAS), and on the National Oceanic and
Atmospheric Administration's Weather
Radio.
KCOEM
19.2.1 NFIP Participation
The National Flood Insurance Program (NFIP) provides federally backed flood insurance in exchange
for communities enacting floodplain regulations. Participation and good standing under NFIP are
prerequisites to grant funding eligibility under the Robert T. Stafford Act. The County and most of
the partner cities for this plan participate in the NFIP and have adopted regulations that meet the
NFIP requirements.
Many cities in King County have mapped flood hazard areas, and 37 of the 39 incorporated
municipalities participate in the NFIP; all are currently in good standing with the provisions of the
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19-15
NFIP. The five jurisdictions that do not currently participate in NFIP are Beaux Arts Village, Hunts
Point, Maple Valley, Newcastle and Yarrow Point. Except for Newcastle, these communities have no
special flood hazard areas.
Participants in the NFIP must, at a minimum, regulate development in floodplain areas in
accordance with NFIP criteria. Communities participating in the NFIP may adopt regulations that are
more stringent than those contained in 44 CFR 60.3, but not less stringent. The Washington State
Building Code Act requires new construction to be elevated to 1 foot above the base flood elevation
or to the design flood elevation, whichever is higher. Some communities in King County have
adopted more stringent standards. For example, a 3-foot freeboard (height above the 100-year
flood elevation) is standard for most structures in unincorporated King County.
Additionally, in the Puget Sound watershed, communities are required to regulate development in
floodplains in a way that doesn’t cause habitat loss or negative impacts to Chinook, coho, and
steelhead salmon species. This is part of the FEMA/NOAA Biological Opinion related to
communities’ participation in the National Flood Insurance Program.
In Washington State, the Department of Ecology is the coordinating agency for floodplain
management. Ecology works with FEMA and local governments by providing grants and technical
assistance, evaluating community floodplain management programs, reviewing local floodplain
ordinances, and participating in statewide flood hazard mitigation planning. Compliance is
monitored by FEMA regional staff and by Ecology. Maintaining compliance under the NFIP is an
important component of flood risk reduction. All planning partners that participate in the NFIP have
identified initiatives to maintain their compliance and good standing. Planning partners who do not
currently participate have identified initiatives to consider enrollment in the program.
Table 19-3 King County NFIP Participants
Community Name NFIP Participation Curr Eff Map Date Reg-Emer Date
Algona No (NSFHA) 5/25/1978
Auburn Yes 8/19/2020 6/1/1981
Beaux Arts Village No (NSFHA) 2/4/2000
Bellevue Yes 8/19/2020 12/1/1978
Black Diamond Yes 8/19/2020 10/30/1979
Bothell Yes 8/19/2020 6/1/1982
Burien Yes 8/19/2020 9/30/1994
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Carnation Yes 8/19/2020 3/4/1980
Clyde Hill No (NSFHA) 11/3/2008
Covington Yes 8/19/2020 4/19/2001
Des Moines Yes 8/19/2020 5/15/1980
Duvall Yes 8/19/2020 6/4/1980
Enumclaw Yes 8/19/2020 8/19/2020
Federal Way Yes 8/19/2020 6/21/1996
Hunts Point No (NSFHA) 1/11/2022
Issaquah Yes 8/19/2020 5/1/1980
Kenmore Yes 8/19/2020 11/13/1998
Kent Yes 8/19/2020 4/1/1981
King County Yes 8/19/2020 9/29/1978
Kirkland Yes 8/19/2020 6/15/1981
Lake Forest Park Yes 8/19/2020 2/15/1980
Maple Valley No
Medina No (NSFHA) 3/16/1979
Mercer Island Yes (NSFHA) 6/30/1997
Milton No (NSFHA)
Muckleshoot Indian Tribe No
Newcastle Yes 8/19/2020 9/15/2021
Normandy Park Yes 8/19/2020 11/2/1977
North Bend Yes 8/19/2020 8/1/1984
Pacific Yes 8/19/2020 12/2/1980
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Redmond Yes 8/19/2020 2/1/1979
Renton Yes 8/19/2020 5/5/1981
Sammamish Yes 8/19/2020 5/25/2000
SeaTac Yes 8/19/2020 9/30/1994
Seattle Yes 8/19/2020
Shoreline Yes 8/19/2020 3/4/1997
Skykomish Yes 8/19/2020 7/2/1981
Snoqualmie Indian Tribe Yes 8/19/2020 5/11/2007
Snoqualmie Yes 8/19/2020 7/5/1984
Tukwila Yes 8/19/2020 8/3/1981
Woodinville Yes 8/19/2020 10/10/1997
Yarrow Point No
19.2.2 CRS Participation
The Community Rating System is a voluntary program within the NFIP that encourages floodplain
management activities that exceed the minimum NFIP requirements and rewards discounts to
ratepayers in participating communities. King County is a Class 2 community. Flood insurance
premiums are discounted to reflect the reduced flood risk resulting from community actions
meeting the following three goals of the CRS:
• Reduce flood losses.
• Facilitate accurate insurance rating.
• Promote awareness of flood insurance.
For participating communities, flood insurance premium rates are discounted in increments of 5
percent. For example, a Class 1 community receives a 45-percent premium discount, and a Class 9
community receives a 5-percent discount. (Class 10 communities are those that do not participate
in the CRS; they receive no discount.) The CRS classes are based on 18 creditable activities in the
following categories:
• Public information
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• Mapping and regulations
• Flood damage reduction
• Flood preparedness
As of this writing, there are 10 CRS-rated communities in King County.
Table 19-4 King County CRS Participation
Community Name Class % Discount in SFHA % Discount in non-SFHA
Auburn 5 25% 10%
Bellevue 5 25% 10%
Issaquah 5 25% 10%
Kent 5 25% 10%
North Bend 5 25% 10%
Renton 5 25% 10%
Snoqualmie 5 25% 10%
Carnation 6 20% 5%
Redmond 5 25% 10%
King County 2 40% 10%
19.2.3 Flood Warning Program
The King County Flood Control District was established in 2007 to regionally manage flood hazards
and reduce risk, in partnership with the Department of Natural Resources and Parks’ River and
Floodplain Management Section. The newly updated 2024 King County Flood Management Plan
drives much of the work that both the District and King County do to reduce flood risk and manage
flood-related hazards.
King County has a long-established Flood Warning Program that has been monitoring river systems
for over 50 years. The King County Department of Natural Resources and Parks’ River and
Floodplain Management Section operates a Flood Warning Center that opens 24 hours a day when
flooding occurs on any of the river systems with gages. For the Flood Warning Program, the rivers
are measured by a “flood phase” system based on real-time flow information. When a river reaches
flood phase 2, the Center opens, coordinates with local, state, and federal agencies, and accepts
calls from the public requesting information about flooding. When a river reaches flood phase 3,
patrol teams are sent out to monitor flood protection facilities and any potential flooding impacts.
When a river reaches flood phase 4, additional staff are brought into the Flood Warning Center,
sent on flood patrols, and begin to collect damage information in case of a disaster declaration.
AGENDA ITEM #1. b)
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Table 19-5 Flood Warning Phase Thresholds
Phase South
Fork
Skykomish
River
Tolt
River
Snoqualmie Issaquah
Creek
Cedar
River
Green
River
White
River
1 6,000 cfs 2,500 cfs 6,000 cfs 6.5 ft 1,800 cfs 5,000 cfs 4,000 cfs
2 10,000 cfs 3,500 cfs 12,000 cfs 7.5 ft 2,800 cfs 7,000 cfs 5,000 cfs
3 18,000 cfs 5,000 cfs 20,000 cfs 8.5 ft 4,200 cfs 9,000 cfs 7,000 cfs
4 27,000 cfs 8,500 cfs 38,000 cfs 9.0 ft 5,000 cfs 12,000
cfs
9,000 cfs
19.3 Staffing & Departments
With over 15,000 employees and dozens of departments and offices, King County has a tremendous
capability to implement mitigation projects. Mitigation efforts are underway throughout the
county, including such organizations as the Rivers and Floodplain Management Section of DNRP and
the Wastewater Treatment Division of DNRP.
Staff & Departments Description Lead Agency
Building and
Development Code
Enforcement
The Department of Local Services, Permitting
Division is the agency that provides land use,
building and fire regulatory and operating
permits, code enforcement and a limited
number of business licenses for
unincorporated areas of King County. Other
local jurisdictions provide similar services
within incorporated areas. The Code
Enforcement Section investigates complaints
regarding violations of King County Codes
(KCC) related to zoning, building, property
maintenance, shorelines and critical areas in
unincorporated King County.
DLS– Permitting
Division
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Emergency Operations
Center
The King County Emergency Operations
Center (EOC) serves as the central hub for
coordinating emergency response and
managing resources during crisis situations. It
is operated by KCOEM staff who double as
Emergency Management Coordinators.
KCOEM
Facilities Management
Division
The Facilities Management Division (FMD)
oversees and maintains King County's real
estate assets. The Major Projects and Capital
Planning section is tasked with efficiently and
effectively delivering large-scale projects in
alignment with the policy directives of King
County government, the facility needs of
employees and the public, and for overall
service to the community. Part of this
includes the development of hazard-resilient
facilities.
Department of
Executive Services,
FMD
Information Technology KCIT leads the county’s response to, and
preparedness for, cyber incidents. KCIT has
helped local cities recover from ransomware
and other attacks.
KCIT
Local Emergency
Planning Committee
(LEPC)
The Local Emergency Planning Committee
(LEPC) covers all of King County, excluding
areas with other emergency plans, such as
the City of Seattle, the City of Kent, and
regions overseen by a Tribal Emergency
Response Committee. Its primary mission is
to enhance chemical safety and protect
public health and the environment. The LEPC
is responsible for developing a community
Hazardous Materials Response Plan,
conducting annual reviews of this plan, and
collecting and maintaining chemical
inventory forms and release reports. It also
provides chemical inventory information to
the public upon request.
KCOEM
Mapping Specialist (GIS) King County GIS provides analysis support,
mapping, and other data to all King County
departments. This data is valuable for hazard
mitigation planning activities.
KCIT
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NFIP Floodplain
Administrator
The NFIP (National Flood Insurance Program)
Floodplain Administrator oversees and
managing floodplain management activities
including enforcing floodplain regulations
and educating the public about flood
management.
DNRP
Office of Risk
Management Services
Risk Management investigates and resolves
claims against King County in a fair and
expeditious manner, and also provides
internal services to King County agencies,
including:
• Insurance: King County administers a self-
insurance program and purchases a variety of
other insurance policies and related services
consistent with good risk management
practices and the needs of the County.
• Contracts: Risk Management advises King
County agencies on insurance requirements,
indemnification, release, and hold harmless
provisions in all types of contracts. Risk
Management actively negotiates these
provisions and, together with the Prosecuting
Attorney's Office, assists agencies in pursuing
and tendering claims arising out of
contractual relations.
• Recovery Services: The recovery section of
Risk Management is charged with seeking
compensation for damages caused to King
County property or injury to King County
employees by negligent third parties.
• Loss Control Program: The Loss Control
Manager works with King County agencies to
identify areas of potential loss and
recommend strategies to reduce exposure to
liability. The Loss Control Program also
administers continuing workplace training
and education for King County employees.
Part of this work includes the development
and maintenance of a risk register of events
and information on how those events can
impact King County.
Department of
Executive Services
Road Services Division Road services builds and maintains over 2000
miles of road and 200 bridges. They are
responsible for many mitigation activities,
Department of Local
Services
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including those related to culvert
replacement, pavement preservation, and
bridge retrofits.
Wastewater Treatment
Division
Invest in upgrades to pipe and water
treatment facilities to make them more
resilient to earthquakes, severe weather,
flooding, and climate-change.
DNRP
19.3.1 Departments and Jurisdiction Coordination
Beyond departmental collaboration, King County works with local jurisdictions, special purpose
districts, and Tribes to support effective risk reduction. King County coordinates activities related to
emergency management and hazard mitigation through two bodies, the Emergency Management
Coordinating Committee (EMCC) and the Emergency Management Advisory Committee (EMAC),
which are each described in greater detail in the table below.
Table 19-6 King County Stakeholder Integration Capabilities
Committees Description Membership
Emergency
Management
Coordinating
Committee
(EMCC)
EMCC is charged by the King
County Council with
coordinating
interdepartmental
emergency preparedness
matters. EMCC works to
support departments in
developing continuity of
operations plans (COOP),
preparedness plans, and
hazard mitigation plans. It
also contributes to after
action reports. EMCC has
played an important role in
the mitigation plan update
process for the county by
identifying and dedicating
key staff to participate in
planning and by reviewing
and providing feedback on
planning team activities.
EMCC is made up of internal King County
agencies/departments. All county
departments are included in the EMCC. The
following are those who attend meetings
more regularly:
• Assessor
• Community and Human Services
• District Court
• Elections
• Executive Services
• Human Resources
• Judicial Administration
• Information Technology
• King County Council
• King County Executive
• Local Services
• Metro Transit
• Natural Resources and Parks
• Prosecuting Attorney
• Public Health
• Public Defender
• Sheriff
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• Superior Court
Emergency
Management
Advisory
Committee
(EMAC)
EMAC advises, assists,
reviews, and comments on
emergency management and
homeland security issues,
regional planning, and
policies. They measure and
prioritize core capabilities
and recommend homeland
security allocations and work
products to sustain and
enhance preparedness and
operational levels. Members,
as set forth in code, provide
regional and multi-
disciplinary perspective, and
represent cities, fire service,
law enforcement, hospitals,
the Port of Seattle,
government, special purpose
districts, tribes, utilities, non-
profit agencies, and the
private sector.
EMAC is made up of both internal and
external partners. The committee is
composed of members who represent the
following emergency management interests:
• Central region EMS and Trauma Care
Council
• City of Bellevue
• City of Kent
• City of Renton
• City of Seattle
• 1 Utility
• 1 Faith-Based Organization
• 1 Financial Community Organization
• American Red Cross
• KC DNRP
• KC Metro
• KC Roads
• KC Executive Office
• King County Fire Chief’s Association
• King County Fire Commissioner’s
Association
• King County Police Chief’s Association
• King County Sheriff’s Office
• KC Local Emergency Management
Planning Committee
• Muckleshoot Tribal Nation
• Northwest Healthcare Response
Network
• Port of Seattle
• 1 Private Industry Representative
• Public Health Seattle and King County
• Puget Sound Educational Services
District
• Snoqualmie Tribal Nation
• Sound Cities Association
• Washington Association of Building
Officials
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EMAC, in particular, serves as the advisory body designated by the funding requirements to provide
input from a stakeholder group. However, the committee's role has evolved over time, influenced
by how the federal and state guidelines for distributing funds—specifically the State Homeland
Security Grant Program (SHSP)—are structured. Members are tasked with forming a task force to
prioritize projects by discipline for submission to the state for competitive funding consideration.
EMAC’s involvement primarily focuses on the SHSP, though they are informed about other HSGP
awards (excluding UASI, which follows a separate process) for transparency and awareness.
19.4 Potential Funding Sources
Hazard mitigation projects are most often completed with funding from capital budgets as part of
the normal building and maintenance processes that occur in any jurisdiction. There is also source
and use-specific funding, such as that provided by the King County Flood Control District that is part
of regular program funding and is highlighted in the program section above. Beyond regular capital
funding, there are dedicated mitigation programs operated by state, county, and federal agencies.
Table 19-7 Potential sources of hazard mitigation funding
Program Lead Agency Description Project Types
Federal Programs
BUILD Grants Department of
Transportation
(DOT)
Grants support investments in
surface transportation infrastructure
and are to be awarded on a
competitive basis for projects that
will have a significant local/regional
impact.
Transportation and
related infrastructure
retrofits, including
stormwater projects
Building Blocks
for Sustainable
Communities
Environmental
Protection
Agency (EPA)
This EPA program provides targeted,
technical assistance to communities
to develop resilience plans,
development plans, sustainability
strategies, etc.
Planning and
feasibility studies
Climate
Resilience
Regional
Challenge grant
National
Oceanic and
Atmospheric
Administration
(NOAA)
A competitive grant program is
focused on collaborative projects
that increase the resilience of coastal
communities to extreme weather
and other climate change impacts,
including sea level rise and drought.
Coastal flooding, sea
level rise, restoration,
nature-based
improvements
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Community
Development
Block Grants
(CDBG)
Department of
Housing and
Urban
Development
(HUD)
CDBG funds comprehensive plans,
limited infrastructure
planning/construction, feasibility
studies, community action plans.
Income and population restrictions
apply.
Housing and
infrastructure
retrofits, feasibility
studies, planning
Cooperating
Technical
Partnership
Program
Federal
Emergency
Management
Agency
(FEMA)
The program creates partnerships
between FEMA and qualified local
and state partners to create,
maintain, and publicize up-to-date
flood and other hazard maps and
data.
Planning, outreach,
feasibility studies
Emergency
Watershed
Protection
Program
Natural
Resource
Conservation
Service (NRCS)
Emergency recovery measures for
runoff retardation and erosion
prevention to relieve imminent
hazards created by a natural
disaster.
Infrastructure
retrofits, slope
stabilization, source-
water protection,
flood risk reduction,
erosion prevention
Flood
Mitigation
Assistance
(FMA) Grant
Program
Federal
Emergency
Management
Agency
(FEMA)
FMA provides funding to local
jurisdictions and states for projects
and planning that reduces or
eliminates long-term risk of flood
damage to structures insured under
the NFIP.
Flood risk reduction
projects that benefit
the NFIP, including
acquisitions,
elevations, and some
structural mitigation
such as local risk
reduction structures
and dry
floodproofing.
Hazard
Mitigation
Grant Program
Federal
Emergency
Management
Agency
(FEMA)
HMGP is authorized statewide after
a disaster declaration and is the
most flexible of FEMA’s three
mitigation programs. Jurisdictions
must have an approved hazard
mitigation plan and projects must be
cost effective.
Most long-term risk-
reduction projects
that protect against
fire, flood,
earthquake, and
other natural hazards.
Post-Fire
Hazard
Mitigation
Grant Program
Environmental
Protection
Agency (EPA)
Program authorized following a Fire
Management Assistance Grant
(FMAG) declaration. Program
focuses on wildfire risk and post-fire
Fire-related
mitigation, including
defensible space,
generators, and post-
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risk mitigation, including fuels
reduction and post-fire flood control
projects. Program prioritizes the
county receiving the FMAG
declaration.
fire flood risk
reduction, planning,
feasibility studies
State Homeland
Security
Program (SHSP)
Federal
Emergency
Management
Agency
(FEMA)
SHSP is divided up into two sections,
the National Priority Area projects
are competitive at the state level and
voted on by the Homeland Security
Coordinators for each region. The
remaining funds are allocated direct
to each region for them to cover
other projects not approved through
the National Priority Area projects.
All projects must be primarily for
counter-terrorism projects.
Planning, staffing,
counter-terrorism,
equipment, training,
exercises
State & Local
Cybersecurity
Grant Program
(SLCGP)
Federal
Emergency
Management
Agency
(FEMA)
SLCGP is a federal program that
helps state, local, and tribal
governments improve cybersecurity
and protect their systems from
threats.
Firewalls, system
testing, cybersecurity
monitoring, identity
management (multi-
factor
authentication),
training, and policy
development.
Urban Area
Security
Initiative (UASI)
Federal
Emergency
Management
Agency
(FEMA)
The UASI functions through targeted
subcommittees that provide grant
projects to Urban Area Working
Group Voting Members for review
and finally to the Core Group for
approval. Each of the 5 jurisdictions
have one representative at each of
these levels. All projects must be
primarily for counter-terrorism
projects.
Planning, staffing,
counter-terrorism,
equipment, training,
exercises
Urban and
Community
Forest Program
Department of
Agriculture
(USDA)
Program provides technical,
financial, research and educational
services to local jurisdictions and
organizations for the preservation,
protection, and restoration of
forestlands.
Natural resource
protection, public
information, planning
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State Programs
Community
Economic
Revitalization
Board
WA
Department of
Commerce
CERB provides loan funding to local
jurisdictions for public infrastructure
to support private business growth
and expansion.
Infrastructure
retrofits, public-
private partnerships
Combined
Water Quality
Funding
Program
WA
Department of
Ecology
Fund sources for projects associated
with publicly-owned wastewater and
stormwater facilities. The integrated
program also funds nonpoint source
pollution control activities.
Drinking-water
system
improvements,
feasibility studies,
source-water
protection,
infrastructure
retrofits
Drinking Water
State Revolving
Fund
WA
Department of
Health
The Drinking Water State Revolving
Fund (DWSRF) provides loans to
drinking water systems to pay for
infrastructure improvements. In
some cases, partial loan forgiveness
is offered.
Infrastructure
retrofits, source-
water protection,
planning, drinking-
water system
improvements
Estuary and
Salmon
Restoration
Program
WA
Department of
Fish and
Wildlife (DFW)
ESRP provides funding restoration
and protection efforts in Puget
Sound, including projects such as
flood storage, erosion control, and
climate resilience measures.
Acquisitions, slope
stabilization, flood
risk reduction
projects, ecosystem
restoration
FireWise Fuel
Mitigation
Grant Program
WA
Department of
Natural
Resources
The Fuel Mitigation Grant provides a
cost share for communities engaged
in defensible space and fuels
reduction projects.
Wildfire fuels
reduction, defensible
space
Flood Control
Assistance
Account
Program
(FCAAP)
WA
Department of
Ecology
FCAAP provides two types of grants
to communities; (1) planning grant,
which supports integrated flood
hazard management planning by
communities. this planning has to be
related to a new or existing
comprehensive flood hazard
management plan or CFHMP; and (2)
emergency grant that supports local
emergency response activities.
Planning, mapping,
permitting,
engagement,
response, recovery,
federal match
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Floodplains by
Design
WA
Department of
Ecology
Floodplains by Design is the primary
grant program for projects that
reduce flood hazards while restoring
the natural functions that
Washington rivers and floodplains
provide.
Slope stabilization,
ecosystem recovery,
flood-risk recovery
Public Works
Board
WA
Department of
Commerce
Low-interest loans for pre-
construction or new construction for
replacement/repair of infrastructure
for stormwater, solid waste, road, or
bridge projects. Emergency loans are
available for public projects made
necessary by a disaster or imminent
threat to public health and safety.
Utility and
infrastructure
retrofits
Source Water
Protection
Grant Program
WA
Department of
Health
Projects and studies to identify
solutions to source water protection
problems, implement protection
plans, or update data that directly
benefits source water protection.
Source-water
protection, drinking
water system
improvements, other
retrofits, feasibility
studies
Transportation
Improvement
Board
WA
Transportation
Improvement
Board
TIB makes and manages street
construction and maintenance grants
to 320 cities and urban counties.
Infrastructure
retrofits, flood risk
reduction
Local Programs
Community
Climate
Resilience Grant
Program
King County The CCR Grant Program funds
community-based climate justice
projects in communities
disproportionally impacted by
climate change.
Community capacity
development, public
health, emergency
preparedness, heat
mitigation
Flood Control
District Flood
Reduction
Grants
King County
Flood Control
District
The Flood Reduction Grants target
medium and small local flood
reduction projects including projects
where the control of stormwater will
have a direct benefit in reducing
flooding. Eligible applicants include
Projects can address
either existing or
potential flooding and
proposals should
show that the
flooding has current
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homeowners, special districts, tribes,
cities, and county agencies.
or potential economic
impacts.
General Budget King County The two-year King County budget for
2019-2020 was approximately $11.6
billion dollars. Approximately 15% of
this money makes up the general
fund. Major Expenditures are: Metro
Transit (21%), Wastewater (14%),
Health & Human Services (13%), and
Law, Safety, & Justice (12%). There
are ~15,000 full-time-equivalent
(FTE) county employees with most
employed in Transit (35%), Criminal
Justice (25%), and Public Health (9%).
Various
Loss Control
Fund
King County
Office of Risk
Management
The Loss Control Fund is for internal
county projects and is limited to
emergent risks where advance
planning and budgeting were
unavailable. $2M has been
appropriated for the 2019-2020
biennium.
Emergent risks, to
include likely
infrastructure failure
Conservation
Futures Tax levy
King County
DNRP
Conservation Futures is an open
space acquisition grant program. Our
grants help buy parks and open
spaces such as natural lands, urban
greenspaces, forests, community
gardens, farms, and trails.
Land acquisitions
Parks Levy King County Revenue generated by the parks levy
goes to fund open space protection,
new parks, trails, and other assets.
This funding could theoretically be
used for the acquisition of
threatened properties for
preservation as open space.
Acquisition of high-
hazard properties for
preservation as open
space
Non-Government Organization (NGO) Programs
American Cities
Grant
Kresge
Foundation
Kresge Foundation seek efforts that
will result in expanded opportunity
for city residents, engage the
community in a meaningful way,
Varies
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have potential for long-term
sustainability or community impact,
and have potential for scalability or
translation to other communities.
We use an array of funding and
investment tools to foster change,
including project grants, operating
support, planning grants and
program-related investments.
Cooling
Program
ClimateWorks
Foundation
The ClimateWorks Cooling Program
leads the clean Cooling
Collaborative, an initiative advancing
efficient, climate-friendly cooling for
all. Clean Cooling Collaborative
focuses on solutions that cool people
and the planet, including super-
efficient appliances, climate-friendly
refrigerants, and passive cooling.
Extreme heat
Environment
Program Grants
Hwelett
Foundation
The Environment Program makes
grants to address climate change
globally and to conserve the U.S.
West. The Foundation make a wide
range of grants to protect the
extraordinary natural resources of
the Western United States, and back
efforts to build broad public support
and empower citizens who care
about the conservation of land,
water and air in the West.
Conservation
National
Climate
Solutions RFP
Paul G. Allen
Family
Foundation
This Paul G. Allen Family Foundation
initiative, with an RFP announced in
2024, will fund 3-5 rigorous, place-
based Natural Climate Solutions
efforts in the Pacific Northwest. The
foundation is looking to fund
programs that accelerate climate
change mitigation, while also
providing biodiversity and human
wellbeing co-benefits.
Resiliency, nature-
based solutions
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 19: Capabilities
19-31
Resilient
Community
Impact Fund
Resilient Cities
Network
(RCN)
RCN has established the Resilient
Community Impact Fund, providing
critical funding to cities and
organizations to initiate local
resilience projects. This fund
supports initiatives designed to help
communities withstand the impacts
of extreme weather events, including
heatwaves and flooding.
Resiliency, extreme
heat, fooding
Rural
Community
Assistance
Corporation
Rural
Community
Assistance
Corporation
Water, wastewater, stormwater, and
solid waste planning; environmental
work; to assist in developing an
application for infrastructure
improvements for small, rural
communities.
Planning, feasibility
studies
Rural Water
Revolving Loan
Fund
National Rural
Water
Association
The RWLF provides low-cost loans
for short-term repair costs, small
capital projects, or pre-development
costs associated with larger projects
to small, rural communities.
Source-water
protection, drinking
water system
improvements, other
retrofits
Wildfire
Resilience
Initiative
Moore
Foundation
The Wildfire Resilience Initiative aims
to support a transformation in the
role that fire plays and is perceived
to play in Western North America,
from an unwanted, destructive
threat to a vitalizing element in our
landscapes.
Wildfire
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-1
Chapter 20: Mitigation Strategies
The primary focus of this plan update was the creation of new comprehensive, operationally viable
hazard mitigation strategies and promote their implementation. Plan strategies were developed
using the following structure:
Hazard mitigation strategies were developed by KCOEM and various KC agencies as described in the
planning partner engagement section of the introduction.
The KCOEM Hazard Mitigation Team coordinated with each KC agency and assisted with each
developing and submitting a list of potential hazard mitigation strategies and projects.
Mitigation Plan Goal
Mitigation Plan
Strategies
Mitigation Actions
•The goal of the 2025 King
County Regional Hazard
Mitigation Plan is to
create a framework that
reduces the impact and
susceptibility of the
identified hazards on
people, property, and
the environment,
prioritizing historically
underserved
communities.
•These are broad
approaches to address a
problem and support the
Plan goals.
•These may live on from
plan to plan.
•These are the specific
action items to be taken
in support of the Plan
Strategies.
•These are on either a 2
year or 5 year timeline.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-2
20.1 Mitigation Plan Goal
The goal of the 2025 King County Regional Hazard Mitigation Plan is to create a framework that
reduces the impact and susceptibility of the identified hazards on people, property, and the
environment, prioritizing historically underserved communities.
20.2 Mitigation Plan Strategies
Mitigation Plan Strategies will be developed based on threats to essential assets and capabilities
from hazards within cities and unincorporated areas of King County. In the past these have included
strategies for risks such as land movement and flood impacts and projects such as bridge seismic
retrofits and generators for critical facilities. For this plan, hazard mitigation strategies are sets of
coordinated actions that, taken together, address a risk or vulnerability. They are comprehensive,
long-term, and designed to be regularly updated as actions are completed.
The updated strategy format will be used going forward in order to better support long-term
tracking of mitigation actions and strategies. The updated strategy template is displayed below.
Table 20-1 Mitigation strategy template
Lead Points of
Contact (Title)
Partner Points of Contact (Title)
Who else outside your jurisdiction
benefits from the strategy or will
help implement the strategy?
Hazards
Mitigated
Funding Sources
and Estimated
Costs
Strategy Vision/Objective
Long-term objective and vision for the strategy
Mitigation Strategy
Describe the program/proposed program
2-Year Objectives 5-Year Objectives Long-Term Objectives
AGENDA ITEM #1. b)
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Chapter 20: Mitigation Strategies
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Implementation Plan/Actions
This can provide a timeline, indicate partners, discuss implementation stages, etc. Use this to
discuss how the strategy/program will be implemented over the long term.
Performance Measures
With the support of King County Risk Management, this template will be built into a database
where strategies can be entered, updated, and projects can be tracked consistently and effectively.
The goal is for strategies to remain in place through future updates, while implementation plan
actions are changed.
20.3 Mitigation Plan Actions
Mitigation Plan Actions represent the specific work to be done to mitigate a risk or hazard.
Candidate actions will be developed and considered for and by each participating jurisdiction. These
actions will be taken into consideration when scoring the overall strategies for prioritization.
20.4 Prioritizing Mitigation Strategies
Emergency management is centered around communities and people – those who understand their
communities’ unique demographic, economic, and physical characteristics best and know the most
appropriate actions necessary to promote resilience and facilitate recovery from disaster. While
several studies show the disproportionate impacts of disasters, they also show that federal
response programs intended to support communities before and after disasters are also inequitable
and inaccessible for those most vulnerable. Likewise, the methods used to quantify disaster impacts
and justify risk reduction measures and mitigation projects do not account for the disparate impacts
of these hazards. This incomplete measure of the total effects lends itself to prioritizing projects
that can ignore measures that reduce the long-term consequences of disasters in these populations.
Moreover, the siloing of these impact considerations fails to acknowledge the compounding effects
these disasters can have on our built environments, nor do they offer tailored solutions designed to
meet the unique needs of these communities.
It’s no secret that humanity continues to have an adverse effect on weather, and human-induced
climate change has led to an increase in the frequency of catastrophic devastation caused by severe
weather. Historically marginalized populations, due to historic housing discrimination and housing
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-4
segregation, continue to suffer more damage from these disasters and take the longest to recover
(for a summary, see the Brookings memo “Hurricanes Hit the Poor the Hardest”). These
communities are most likely to exist in disaster-prone areas, lack sufficient financial resources for
emergencies, and generally are less resilient to climate change, natural disasters, and their
increasing devastation. Further, lower-income and minority communities are much more likely to
experience public forms of vulnerability, epitomized by substandard infrastructure and less public
infrastructure investment overall, and are in close proximity to hazardous materials with less public
protection. Previous research shows that the primary determinants of post-disaster recovery
include socioeconomic and demographic conditions, pre-existing vulnerability, and access to and
receipt of aid, of which the most marginalized and vulnerable communities struggle.
Too often, disaster risk reduction strategies and mitigation projects are assessed with an equity and
social justice lens too late in the process to be effective. However, with the right changes, we can
turn this around. In 2019, King County set out to apply an approach to prioritization of mitigation
projects designed to benefit those most vulnerable to disaster. With the adoption of the previous
iteration of our hazard mitigation plan, we became among the first counties in the nation that
applied an equity approach both in our base plan and subsequent annexes, as well as our project
prioritization. We recognize the continuing inequities present in our society and in our pre-disaster
preparedness and response, and, again, call for a reconsideration of all projects regardless of those
targeted. Our industry has only recently begun incorporating equity into our work, and the
prioritization methods used so far have not been effective. Likewise, research shows that
emergency managers have a long road ahead. By prioritizing disaster risk reduction and mitigation
projects that account for this institutional failure, we can make a significant and positive impact
over time, increasingly putting more resources in areas and communities where they are needed
most.
Methods
Before revising the previous method for ranking mitigation projects based on equity, the core
planning team reviewed the last version of the document and found several deficiencies:
1. Localities did not have rigid guidelines against which to rank their projects.
2. The language following the factors was either vague or supposedly inherent in the
mission of hazard mitigation.
3. Localities were given the 14 determinants of equity and informed on their importance
but needed to be given practical strategies to analyze these determinants and factors in
their projects.
4. Because the matrix lacked structure and guidelines, projects could be ranked in a
manner determined by an individual contributor that was inconsistent with other
rankings elsewhere in the county using the same matrix.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-5
This methodology solves several of these issues by providing localities annexing onto the hazard
mitigation plan guidelines on how to rank their projects, straightforward language and scoring
methods allowing for consistency in project rankings across the county. These methods were
discussed again with the larger hazard mitigation planning team and reviewed by internal Office of
Emergency Management Equity and Social Justice Change Team members, the Department of
Executive Services Intradepartmental Teams, and the Office of Equity, Racial, and Social Justice.
FEMA determined these methods to meet the Justice40 Initiative requirements for localities seeking
future federal funding for hazard mitigation projects.
King County developed a prioritization process based on criteria taken from national best practices
and priorities identified by the King County Executive. These criteria are used to prioritize projects
within strategies. Strategies are also prioritized in this way to identify those areas of emphasis for
KCOEM and the mitigation steering committee, though this may not impact which strategies are
implemented since many depend on exclusive funding sources. The below criteria will be used to
establish priorities. These priorities will be applied to projects annually for submission to FEMA
Hazard Mitigation Grants.
The updated scoring matrix broken into categories, like previous iterations. These categories are
Economics and Equity; Multi-Jurisdictional; Multi-Beneficial; Community Resilience and Long-
Term Vulnerability Reduction; Climate, Environment and Sustainability; Effectiveness; Urgency;
and Shovel-Ready. Each category is given a score between 0 and 4, with 0 being the lowest score a
project can receive in a certain category and 4 being the highest. Due to the close collaboration
between urban and land-use planners, public works and emergency management professionals,
environmental regulators, government officials, and community members needed to analyze these
projects we removed negative scoring as a component of this version. It's important to note that
communities should prioritize projects that have high marks in all categories, with a particular
emphasis on the first four, when funding becomes available. We do, however, recognize these
projects typically require significant financial investments well beyond the capacity of localities and
grant funding over several years and lower-ranked projects may be more feasible with limited
funding and time. Below you will find the factors for consideration and the process by which to
analyze and score potential mitigation projects.
• 0 Unsatisfactory for this factor
• 1 Minimal level of standards for this factor
• 2 Satisfactory level of standards for this factor
• 3 High level of standards for this factor
• 4 Outstanding or beyond expectations for this factor.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-6
Table 20-2 Mitigation strategy priority scoring matrix
2025 Hazard Mitigation Strategy:
Factors for Consideration 2025 Hazard Mitigation
Strategy Score
• Economics and Equity (project is designed to benefit,
account for, and include vulnerable populations,
especially those in the community most likely to suffer
harm from a disaster and those likely to take longest to
recover after a disaster)
• Multi-Jurisdictional (project is supported by multiple
jurisdictions or agencies)
• Multi-Beneficial (project has benefits beyond hazard risk
reduction, including environmental, social, or economic
benefits)
• Community Resilience and Long-Term Vulnerability
Reduction (project is designed to increase community
resilience and focus on the long term impacts to
vulnerable areas)
• Climate, Environment, and Sustainability (project helps
people, property, and the environment become more
resilient to the effects of climate change, regional growth,
and development)
• Effectiveness (project is designed to attain the best-
possible benefit-cost ratio)
• Urgent (project is urgently needed to reduce risk to lives
and property)
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-7
• Shovel-Ready (project is largely ready to go, with few
remaining roadblocks that could derail it)
Total Scores
Process Note: Once a jurisdiction has prioritized projects within that jurisdiction, those projects will
be advanced to the regional plan. If ever there is competition between projects advanced from
different jurisdictions, the RHMP Steering Committee, consisting of representatives from county
departments and jurisdiction partners, will establish the order of priorities based on the values
identified above. The Steering Committee will also organize priority projects with corresponding
strategies. It should be noted that while prioritized projects will be included in the plan, they may
not all receive funding. The Steering Committee may also seek to promote a diversity of projects so
that all plan goals receive some benefits. In the case of a tie between projects during scoring, the
higher prioritization may go to the less-represented mitigation strategy.
20.5 Crosswalk with the Strategic Climate Action
Plan
Several strategies appear in some form in both the 2025 SCAP and this plan. This was done to
ensure multiple avenues of implementation and monitoring and to help relevant actions gain a
higher profile with other departments. Below are strategies that appear in some form in both plans.
It is important to note that strategies can be added to this list throughout the lifecycle of both
plans.
Table 20-3 Mitigation strategies developed with the 2025 Strategic Climate Action Plan (SCAP)
Regional Hazard Mitigation Plan Strategy Strategic Climate Action Plan Action
Integrate Hazard Mitigation into County Plans OEM Hazard Mitigation Training
2024 Floodplain Management Enactment 2024 Floodplain Management Enactment
Resilience Hubs Resilience Hubs
Community Wildfire Protection Plan Community Wildfire Protection Plan
Extreme Heat Communications Implementation of Extreme Heat Strategy
Climate Change and Health Adaption PHSKC Climate Impacts
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-8
20.6 Mitigation Strategy 2020 Status Updates
The format for hazard mitigation strategies has been completely changed in the 2020 plan update.
All actions previously identified have been removed and/or incorporated into new mitigation
strategies. The updated strategy format will better support tracking and implementation of
mitigation strategies and their constituent actions. Strategies that are preparedness focused have
been removed, as well as those that are ongoing in nature and do not have specific targets or
responsible entities.
The following tables are taken from the 2023 annual progress report for the 2020 King County
Regional Hazard Mitigation Plan. This list only includes strategies submitted by King County
departments and countywide strategies. Individual jurisdiction action progress reports are included
in each annex. The new statuses for strategies include:
• Removed – Strategy is not carried forward into the new plan
• Complete – Strategy is complete and not carried forward into the new plan
• Updated – Strategy is updated and carried forward into the new mitigation plan.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-9
CURRENT PROGRESS ON 2020 ACTION PLAN INITIATIVES
Progress
(Yes/No) Timeline
Update
Status Comment (Describe progress or changed priority)
2025
Status
DLS – Roads: Reduce Flood Impacts to Unincorporated King County Road System
Yes Long
Term
Removed This study looks at different ways to reduce or
eliminate traffic problems caused by flooding in the
Snoqualmie Valley. It focuses on keeping at least
one of four existing roads and bridges that cross
the Snoqualmie River open during floods rather
than solving the flooding itself. The county and our
partners began the Cross Valley study in December
2022. The first phase was completed in October of
2024.
Ongoing
DLS – Roads: Increase Seismic Resilience of Bridges in Unincorporated King County
Yes Long
Term
Removed The study “Impacts of Cascadia Subduction Zone
M9 Earthquakes on Bridges in Washington State”
was published in June 2022. Work on retrofitting
bridges in King County continues.
Ongoing
DNRP – WLRD: Stormwater Outfall Erosion Hazard Inventory
Yes Long
Term
Removed The King County Stormwater Management Action
Plan was completed December 21, 2022. Seeking
funding for action items in the plan continues.
Ongoing
DNRP – WTD: Resilience in Design and Build of Critical Water Treatment and Conveyance Facilities
Yes Long
Term
Removed West Point is undergoing upgrades to make the
facility more resilient in the event of an
earthquake. King County is improving large,
enclosed sedimentation tanks that play a key role
in the wastewater treatment process. This project
began in 2021.
Ongoing
DNRP – WLRD: Landslide, Erosion, and Sedimentation Event Mapping
Yes Long
Term
Removed King County routinely updates its iMap layers
including landslide and erosion. This work is
expanded upon in the 2025 strategies.
Ongoing
DNRP – WLRD: Stormwater and Surface Water Infrastructure Risk Reduction
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-10
Yes Long
Term
Removed Action items for this strategy can be located in the
Stormwater Management Action Plan of 2022.
Ongoing
DNRP – WTD: Sea Level Rise Resilience in Wastewater Facilities
Yes Long
Term
Removed Work continues in addressing the impacts of
Climate Change on WTD facilities.
Ongoing
DNRP - WTD: Control System Security and Performance
Yes Long
Term
Updated Cyber-attacks continue to be an ongoing threat for
DNRP and other King County agencies. The work on
this strategy is expanded upon in the 2025
strategies.
Ongoing
DNRP – WTD: GIS Emergency Response Mapping and Real-Time Flow Data
Yes Long-
term
Updated In 2022 King County created the Equity in Response
Planning tool that addresses a majority of mapping
layers identified in this strategy. The work for
improving and updating those layers is an ongoing
project for King County.
Ongoing
KCIT- Emergency Communications Enhancements
Yes Short
Term
Removed All King County agencies have received new
800MHz Radios and routinely complete bimonthly
radio checks. KCOEM offers trainings to agencies on
how to use these radios.
Complete
DNRP – WTD: Emergency Event Management System
Yes Long-
term
Removed DNRP staff and other KC staff routinely test and
train on how to use WebEOC.
Ongoing
DNRP – Flood Services: Flood Warning System
Yes Long
Term
Updated The purpose of the King County Flood Warning
System is to warn KC residents about rising
floodwaters on major rivers so they can prepare
before serious flooding occurs. In most places, the
warning system provides at least 2 hours lead time
before floodwaters reach damaging levels. Since
flooding is a common occurring hazard in the
Ongoing
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-11
County, the work that the Flood Warning System
does is expanded upon in the 2025 strategies.
DNRP/KCOEM: Post-Flood Recovery Efforts
Yes Long
Term
Updated KCOEM continues to work with partners to create a
comprehensive Recovery Plan including recovering
from floods. KCOEM staff are routinely trained on
how to complete damage assessments in addition
to understanding how FEMA’s IA and PA programs
are implemented.
Ongoing
DNRP – Flood Services: Home Elevations
Yes Long-
term
Removed Homeowners located in a flood-prone area of King
County may be eligible for help from the Flood
Elevation Program. Currently funding is only
available for home elevation projects in the
Snoqualmie River Basin. The first floor of the home
must be below the Base Flood Elevation as
documented on a FEMA Elevation Certificate
produce by a licensed surveyor. There is usually
more property owners interested in this program
than funds available. King County maintains a list of
property owners who want to participate in the
program and will reach out to them as funds
become available. The elevation program is only for
properties where the owner has agreed to take
part in the program.
Ongoing
DNRP – Flood Services: Home Acquisitions and Relocations
Yes Long-
term
Removed The King County Flood Buyout Program purchases
homes at risk of damage from flooding. Buyouts are
voluntary. Flood-prone properties and structures
are sold to King County and all structures are
removed. Flood buyouts eliminate future flood
damages and health and safety risks for owners
and rescuers. This helps reduce the cost of
emergency response actions such as evacuations,
emergency shelters, temporary housing, debris
Ongoing
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-12
removal and repairs to damaged structures. After
all structures are removed, the property is restored
to permanent open space. This allows more room
for flood water storage and flow, and creates
natural space for fish, wildlife, and passive
recreation. Any structure located in a flood-prone
area of unincorporated King County may be eligible
for this program. Buyouts are appropriate in areas
where there is deep, fast-moving water, serious
bank erosion, and significant risk of channel
migration.
DNRP – WLRD: Protect and Restore Natural Floodplain Functions
Yes Long-
term
Removed The 2024 King County Flood Management Plan
outlines a vision for reducing flood and flood-
related risks countywide. It describes the actions
King County will take to manage risks associated
with flooding along our rivers, creeks, and
shorelines, including opportunities for the County
to work with cities, partners, and community
members to build flood resilience. These action
items include many that restore natural floodplain
functions.
Ongoing
DNRP – WLRD: Flood Risk Mapping
Yes Long-
term
Updated Flood maps are one tool that communities can use
to know which areas have the highest risk of
flooding. The maps help people make decisions
about where to live, what to build, and how to
reduce flood risks. Property owners, insurance
agents, and lenders can use flood maps to
determine flood insurance requirements and policy
costs. King County conducts flood studies using the
latest data and technology to produce more
accurate flood maps. These maps are submitted to
the Federal Emergency Management Agency
(FEMA) for adoption. King County routinely updates
Ongoing
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-13
its Flooding Layers in iMap with the most recent
data. This is expanded upon in the 2025 strategies.
DNRP/KCOEM: Public Information Flood Activities
Yes Long-
term
Removed Both DNRP and KCOEM update their public
websites including www.kcemergency.com which
provides residents on the latest information on
signification events happening in King County,
including flooding.
Ongoing
DNRP – Flood Services: Flood Insurance Promotion
Yes Long-
term
Removed King County has a Class 2 CRS rating. A Class 2
rating provides a 40 percent discount on flood
insurance premiums for all insurable properties
located within unincorporated King County. King
County was the first county in the nation to achieve
this rating in 2007 and remains one of only three
counties in the region with a Class 2 rating. In 2022,
flood insurance policyholders in unincorporated
King County saved $806,292, an average of $523
per annual policy. This work is located in the
updated Floodplain Management Plan.
Ongoing
DLS/DNRP: Enforce Higher Floodplain Management Regulations
Yes Long-
term
Removed This strategy is addressed in the 2024 King County
Floodplain Management Plan.
Ongoing
DNRP – Flood Services: Manage Flood Protection Facilities
Yes Long-
term
Removed This strategy is addressed in the 2024 King County
Floodplain Management Plan.
Ongoing
FMD: Seismic Evaluation of King County Courthouse and Maleng Regional Justice Center
No Long-
term
Removed King County was not awarded a PDM grant for this
project in 2020.
No
Progress
AGENDA ITEM #1. b)
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Chapter 20: Mitigation Strategies
20-14
FMD: Kent Valley Flood Facility Mitigation
Yes Long-
term
Removed Work identified for this strategy can be located in
the 2024 King County Floodplain Management
Plan.
Ongoing
KCOEM: Integrate ESJ into Mitigation, Response, and Recovery Activities
Yes Long-
term
Removed KCOEM continues to integrate ESJ into all aspects
of their work.
Ongoing
KCOEM/ECO: Mitigate Weather Impacts to Vulnerable Communities
Yes Long-
term
Removed The Extreme Heat Mitigation Strategy was
completed in 2024 and includes 20 actions. The
actions take a comprehensive approach to
equitably preparing people and places in King
County for the impacts of hotter summers and
more extreme heat events. The King County
Extreme Heat Mitigation Strategy was co-
developed in collaboration with state and local
governments, service providers, community-based
organizations, frontline communities, and other
partners to provide strategic direction for local and
countywide work on heat mitigation.
Ongoing
KCOEM: Seismic Lifeline Route Resilience
Yes Long-
term
Removed WSDOT updates its Online Map Center with Seismic
Lifeline layers. The last update was in June 2024.
Ongoing
KCOEM: Integrate Hazard Mitigation and Comprehensive Planning
Yes Long-
term
Removed KCOEM addresses hazard mitigation in the updated
county comprehensive plan.
Ongoing
KCOEM: Engage Community Organizations in Emergency Management
Yes Long-
term
Removed KCOEM has a robust public outreach program that
focuses on engaging underserved communities in
emergency management, reducing risk, and
disaster preparedness. This work is expanded upon
in the 2025 strategies.
Ongoing
AGENDA ITEM #1. b)
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Chapter 20: Mitigation Strategies
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KCOEM: Climate Integration Training
Yes Long-
term
Removed All programs in KCOEM consider climate and
climate induced hazard impacts in their planning
where applicable.
Ongoing
KCOEM: Disaster Skills Risk Reduction Training
Yes Long-
term
Updated King County Emergency Management continues to
deliver the county’s disaster education, and
provides year round free training and education to
county employees, residents, and
organizations/businesses via several programs and
activities aimed at promoting personal and
community risk reduction.
Ongoing
KCOEM: Dam Failure Risk and Impact Reduction
Yes Long-
term
Updated KCOEM continues to fund the role of Dam Safety
coordinator with the overall goal of lowering the
risk and impacts of dam failure in King County.
Ongoing
KCOEM: Wildfire Preparedness and Risk Reduction
Yes Short-
term
Removed In 2022 King County completed the Wildfire Risk
Reduction Strategy. This work is being expanded
upon by KCOEM in creating a Community Wildfire
Protection Plan (CWPP).
Complete
KCOEM: Hazard Mitigation Assistance Grant Support
Yes Long-
term
Updated KCOEM continues to assist local governments and
county departments with Hazard Mitigation
Assistance (HMA) grant applications, providing
guidance and support throughout the application
process. This includes trainings, webinars, and
guidance on how to properly create competitive
HMA grants for King County Agencies and eligible
partners.
Ongoing
KCOEM: Public Assistance Grant Support
Yes Long-
term
Removed KCOEM continues to assist eligible King County
applicants in FEMA’s PA program.
Ongoing
AGENDA ITEM #1. b)
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KCOEM: Language Accessible Video Emergency Messaging
Yes Long-
term
Updated KCOEM is continuing to expand its efforts to make
emergency messaging more accessible to county
residents.
Ongoing
PHSKC: King County Facilities Indoor Air Quality Monitoring Network
No Long-
term
Removed The county has yet to procure and deploy 280
Dylos DC1100 (indoor aire quality monitors). PHSKC
will continue to find methods of funding for this
strategy.
No
Progress
PHSKC: Medical Gas Seismic Detection & Emergency Shut Off
Yes Long-
term
Removed Work on retrofitting Harborview Medical Center is
ongoing.
Ongoing
Parks: Park and trail Facility Landslide Protection
No Long-
term
Removed KC Parks was not awarded a 2021 BRIC grant for
this project.
No
Progress
Parks: Seismic Evaluation and Retrofits of King County Parks Facilities
No Long-
term
Removed KC Parks was not awarded a 2021 BRIC grant for
this project.
No
Progress
20.7 Mitigation Strategies 2025
King County identified the following strategies through meetings among county departments. They
are a mix of current projects the County is working on as well as projects identified by the County
that require outside funds to complete. These strategies were scored by KCOEM’s Hazard
Mitigation Program using the prioritization criteria outlined earlier in this section. The strategies are
listed in no particular order. It is important to note that these strategies are evolving. King County
agencies are welcomed and encouraged to add strategies to this plan throughout the lifecycle of
the plan. As more strategies are created, both WA EMD and FEMA will be made aware of the
existence of new strategies. Below is the current list of King County Hazard Mitigation Strategies:
AGENDA ITEM #1. b)
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Chapter 20: Mitigation Strategies
20-17
Table 20-4 Mitigation Strategies 2025
STRATEGY PRIORITY (SCORE) LEAD AGENCY VISION
Expand King County
Jumpstart Program 23
Executive
Climate Office
(ECO)
To create a diverse, skilled
workforce capable of building
greener infrastructure and
advancing King County’s clean
energy goals.
Identify and Create
County-Wide
Resilience Hubs 19 KCOEM/ECO
As King County grows, and
awareness of climate change-
driven wildfire risk grows, King
County has a coordinated
strategy to support individuals
and local jurisdictions in
identifying and managing wildfire
risk, including risk to property and
public health.
Unreinforced Masonry
Mapping for King
County 16 KCIT/GIS
To enhance community safety
and resilience by accurately
mapping unreinforced masonry
(URM) buildings in King County,
enabling targeted mitigation
strategies that reduce the risk of
severe damage during seismic
events and other natural hazards.
Expand Dam Failure
Emergency Action
Plans 14 KCOEM
By 2030, all dams within King
County will have fully updated
Emergency Action Plans (EAPs)
and Emergency Operations Plans
(EOPs) to ensure coordinated and
timely responses to any potential
emergencies, enhancing public
safety and minimizing the impact
of dam-related disasters.
Expanding Public
Awareness of “Make It
Through” Website 20 KCOEM
To ensure every resident in King
County has the knowledge and
resources to prepare for and
respond to emergencies by
expanding the reach and impact
AGENDA ITEM #1. b)
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of www.makeitthrough.com,
providing timely, accessible, and
practical preparedness
information.
Climate Change and
Health Adaptation
Strategy 23 PHSKC
To create the necessary
conditions to prepare for, adapt
to, and mitigate the health
impacts of climate change in King
County, particularly in
communities that are most
vulnerable and disproportionately
impacted by climate hazards.
Expand King County
Energize! Program 21 ECO
To improve energy efficiency and
reduce environmental impacts in
King County homes by providing
affordable access to clean,
energy-efficient technology, such
as heat pumps, weatherization,
and electric appliances.
Risk Reduction
Through Equitable
Language Access 22 KCOEM
To enhance community resilience
by improving public translation,
cultural communications, and
community partnerships,
ensuring consistent and accurate
information delivery to all
residents in King County during
emergencies.
Extreme Heat Event
Communications
21 KCOEM
To ensure all King County
residents, especially those with
limited English proficiency, have
access to culturally relevant,
multilingual heat safety and
preparedness information to
increase community resilience to
extreme heat events.
Enhanced Cooling
Centers 21 KCOEM
To increase awareness,
accessibility, and utilization of
public cooling centers in King
County, ensuring all residents,
especially those in heat-impacted
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neighborhoods, have safe,
reliable access to cooling during
extreme heat events.
Shake Alert Sign Up
Campaign 18 KCOEM
To ensure that all King County
residents are registered for
ShakeAlert to receive timely
earthquake early warnings,
enabling them to take immediate
protective actions to reduce
injury and property damage
during seismic events.
Increase Alert King
County Registrations 24 KCOEM
To increase the number of
residents signed up for Alert King
County by fostering community
awareness, engagement, and
trust, ensuring that all residents
receive timely emergency alerts
to protect life and property.
King County
Community Wildfire
Protection Plan 25 KCOEM
To develop a county-scale
Community Wildfire Protection
Plan (CWPP) for King County that
enhances resilience against
wildfire risks through proactive
planning, stakeholder
collaboration, and public
involvement. This CWPP will
ensure the county’s
preparedness, response, and
recovery capabilities are robust,
inclusive, and community-driven.
Integration of Hazard
Mitigation into County
Plans 19 KCOEM
To ensure that hazard mitigation
strategies are seamlessly
integrated into all current King
County plans, strengthening the
community's resilience to
disasters and reducing long-term
risk to lives, property, and
infrastructure.
King County Flood
Warning Center 21 DNRP - Flood
To ensure timely and effective
flood warnings and response
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actions for King County residents,
minimizing loss of life, property
damage, and public health risks
during flood events.
Update Liquefaction
Mapping King County 21 DNRP
Enhance community resilience in
King County by updating and
improving liquefaction hazard
mapping, leading to better-
informed land use planning,
infrastructure development, and
disaster preparedness in areas
vulnerable to liquefaction during
seismic events.
Expanding Roadway
Access to Isolated
Communities in
Unincorporated King
County 18 DLS- Roads
To ensure that isolated
communities in unincorporated
King County have reliable and
safe access routes for evacuation
and emergency response,
particularly during wildfire events
and power outages. This strategy
aims to enhance community
resilience and improve public
safety by reducing the risk of
isolation during extreme events.
HVAC Upgrades for
Extreme Weather 18 FMD
To enhance the resilience of King
County facilities to extreme
weather events by upgrading
HVAC systems to ensure reliable
temperature control, air quality,
and energy efficiency,
safeguarding public health and
infrastructure, while reducing
long-term operational costs.
King County OEM
Zone Program 22 KCOEM
Overall, the role of the Zone
Liaison is to promote, support,
and facilitate regional
coordination, communication,
and collaboration, in an effort to
unify and/or connect region-wide
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emergency management
practices, with the aim of
maximizing benefits from
individual efforts and reducing
redundancies.
Actively Manage King
County Devices 20 KCIT
To establish a secure,
streamlined, and adaptive IT
environment within King County
by actively managing network
devices and software. Starting
with a controlled, known
baseline, King County will
minimize attack surfaces and
enhance its ability to adapt to
dynamic cybersecurity threats.
Multi-Factor
Authorization for King
County Devices 19 KCIT
To strengthen King County’s
cybersecurity posture by
prioritizing the protection of
accounts with elevated privileges,
remote access, and high-value
assets through the adoption of
multi-factor authentication (MFA)
and the reduction of reliance on
single-factor authentication
systems.
Timely Software
Updates for King
County Devices 19 KCIT
To ensure King County’s IT
systems remain secure and
resilient by applying all available
software updates immediately,
automating the update process
wherever possible, and
maintaining a high level of
vigilance against threats, reducing
the risk of exploitations and
ensuring the integrity of county
systems
Creation of County-
Wide Recovery Plan 20 KCOEM
To create a comprehensive,
resilient, and flexible county-wide
recovery plan that effectively
addresses the unique needs of all
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communities in King County,
ensuring a swift and equitable
recovery process after disasters.
This plan will integrate
community needs, enhance
preparedness, and optimize
resource allocation, providing
clear guidance for a seamless
recovery effort.
Wastewater
Treatment Division
Workforce
Development Program 21 DNRP
To create a sustainable and
diverse workforce for the clean
water sector by providing
comprehensive recruitment,
mentorship, training, and career
growth opportunities to entry-
level candidates. The program
ensures that individuals are
equipped with the skills and
knowledge necessary to thrive in
the wastewater treatment
industry while contributing to a
more equitable and inclusive
workforce
King Conservation
District Wildfire
Mitigation Program 22 KCD
To reduce the risk of wildfire
damage to homes and
communities in King County,
especially in the Wildland Urban
Interface (WUI), through
proactive risk assessments,
strategic wildfire mitigation
projects, and collaborative efforts
aimed at enhancing community
resilience.
Improving Emergency
Management Public
Outreach 21 KCOEM
To ensure that all residents of
King County are well-informed
and prepared to effectively
respond to and mitigate the
impacts of hazards, through
comprehensive and targeted
public outreach strategies. By
enhancing public awareness and
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providing accessible resources,
we aim to reduce vulnerability
and improve community
resilience.
Maintain LEPC in King
County 20 KCOEM
To ensure the continued
protection of King County
residents, workers, and the
environment by maintaining a
robust and effective Local
Emergency Planning Committee
(LEPC) focused on hazardous
materials. The LEPC will provide
proactive mitigation strategies,
streamline emergency response
coordination, and promote the
safe management of hazardous
materials throughout the county.
Strengthening and
Maintaining
Partnerships for
Emergency Response
and Coordination 20 KCSO
To create a coordinated, resilient
emergency response system by
maintaining strong and effective
partnerships between the King
County Sheriff's Office, the King
County Office of Emergency
Management, and the Fusion
Center, ensuring a rapid, unified,
and data-driven approach to
mitigating and responding to a
wide range of hazards.
Implementation of
2024 King County
Floodplain
Management Plan 22 DNRP
To reduce the vulnerability of
communities, infrastructure, and
ecosystems to flooding by
implementing the King County
Floodplain Management Plan,
fostering resilience through
sustainable land use, strategic
mitigation, and enhanced
floodplain management practices.
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Mount Si Road
Undergrounding
Project 18
Tanner
Electric/Roads
To enhance energy resilience and
mitigate wildfire and storm-
related risks for the North Bend
community by undergrounding
critical electrical infrastructure
along Mount Si Road, ensuring
consistent, safe, and
uninterrupted power supply to
residents, businesses, and
essential services.
Plan for Post-Wildfire
Community Recovery 23 OEM
Ensure King County is prepared to
support equitable, coordinated,
and efficient recovery from
wildfires—particularly those that
impact homes, public facilities,
and infrastructure—through a
dedicated planning framework
that guides action, accountability,
and access to recovery resources.
Standardize and
Promote Best
Management
Practices for Wildfire
Mitigation 19 DNRP
Reduce wildfire risk to homes,
infrastructure, and evacuation
routes in King County through
coordinated and standardized
best management practices that
can be easily adopted and
implemented by fire
departments, agencies, and
communities.
Expand Access to
Cooling Locations for
Communities 20 ECO
Ensure equitable access to safe,
welcoming, and community-
trusted cooling locations
throughout King County to
protect high-risk populations
during extreme heat events.
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Expand the Use of
Residential Flood Risk
Mitigation Tools
Countywide to Benefit
Those Who Are Most
Vulnerable to Flooding 23 DNRP
Expand access to effective,
equitable residential flood risk
mitigation tools across King
County—such as buyouts and
home elevations—to reduce the
impacts of flooding for the most
vulnerable and financially
burdened property owners while
also aligning with community
priorities and environmental
values.
Identify and Seek
Funding to Reduce
Sea Level Rise and
Flood Risks to On-Site
Wastewater
Infrastructure in
unincorporated King
County 19 PHSKC
Protect public health and
environmental quality by
proactively addressing the risks
that sea level rise and flooding
pose to on-site wastewater
infrastructure in vulnerable
unincorporated areas of King
County, with a focus on equitable
outcomes.
WSDOT Avalanche
Forecasting and
Control Program 15 WSDOT
Maintain the safety and reliability
of Washington’s mountain
highway corridors by proactively
forecasting and controlling
avalanches to reduce hazards for
motorists, freight traffic, and
recreational users.
AGENDA ITEM #1. b)
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Chapter 20: Mitigation Strategies
20-26
20.7.1 Expand King County JumpStart Program
Lead
King County
Executive Climate
Office (ECO)
Partners
County Agencies
Hazards Mitigated
Extreme Weather
Hazardous Materials
Cyber Incident
Earthquake
Funding Sources and
Estimated Costs
County Budget
Vision
To create a diverse, skilled workforce capable of building greener infrastructure and advancing King County’s clean
energy goals.
Description
JumpStart is a workforce development program designed to help young adults (ages 18-24) from underrepresented
communities pursue careers in clean energy and skilled trades. The program focuses on pathways in electrical,
HVAC, solar energy, and project management. Participants receive training in these fields and are then matched with
local contractors for 240 hours of paid work-based learning. This initiative provides opportunities to work on
sustainable, living-wage career paths, helping young people contribute to a cleaner, healthier King County.
2-Year Objectives
• Recruit young adults (ages 18-24) for
participation in skilled training programs
• Partner with at least 10 local
contractors to join the JumpStart
Network
• Train 150+ young adults in clean
energy-related career pathways
• Provide paid internships to 100+
program participants
• Build a strong, diverse workforce ready
to take on jobs in clean energy and
trades
5-Year Objectives
• Expand partnerships with additional
pre-apprenticeship and training
organizations
• Increase the number of clean energy
infrastructure projects within King
County
• Develop a long-term pipeline for
workers in fields such as HVAC,
electrical, solar, and project
management
• Ensure sustainable employment for
at least 80% of participants in the
program’s work-based learning phase
• Help contractors successfully
integrate young, diverse talent into
their workforce
Long-Term Objectives
• Contribute to King County's
clean energy goals by
significantly increasing the
number of skilled workers in
the sector
• Ensure a lasting and diverse
workforce capable of building
and maintaining green
infrastructure across the
region
• Foster an inclusive and
equitable clean energy
transition with job
opportunities for historically
underrepresented
communities
• Enable sustained career
success for program
participants, helping to close
gaps in access to well-paying
jobs in green sectors
AGENDA ITEM #1. b)
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Chapter 20: Mitigation Strategies
20-27
Implementation Plan/Actions
• Recruit young adults for training in electrical, HVAC, solar, and project management pathways
• Partner with training program providers to deliver hands-on learning opportunities
• Match participants with JumpStart Network contractors for work-based learning opportunities
• Promote the JumpStart program to local businesses and contractors to grow the network and increase job
opportunities
• Work with local contractors to train the next generation of skilled workers
• Provide resources and guidance to contractors on contracting opportunities with King County and clean energy
incentives
Performance Measure
• Number of young adults recruited into training programs
• Number of local contractors participating in the JumpStart Network
• Number of paid internships completed by participants
• Number of participants employed in clean energy and skilled trades positions post-program
• Feedback from contractors regarding the readiness and performance of program participants
• Retention rates of participants in the clean energy and trades sectors after completing the program
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-28
20.7.2 Identify and Create County-Wide Resilience Hubs
Lead
KCOEM and ECO
Partners
DNRP, WLRD, DNRP, Parks, DLS,
Permitting
KC Fire Districts, WA DNR, King
Conservation District, Tribes,
USFS, KC Climate Preparedness
Public Health Seattle-KC
Hazards Mitigated
Wildfire
Extreme Weather
Flood
Funding Sources and
Estimated Costs
Existing Resources
Vision
As King County grows, and awareness of climate change-driven wildfire risk and extreme weather grows, King
County has a coordinated strategy to support individuals and local jurisdictions in identifying and managing risk,
including risk to property and public health.
Description
Partner with King County communities, fire districts, and other organizations to develop an integrated King County
strategy for wildfire. The strategy will review current efforts to address wildfire risk in King County and develop
recommendations for addressing identified gaps and opportunities. These recommendations will be carried out
through a coordinated Firewise technical assistance program, likely led by DNRP. This effort will be coordinated with
a SCAP action seeking a similar outcome. This strategy will be based in part on the results of WA DNR effort to map
the Wildland Urban Interface in King County.
2-Year Objectives
• Convene a multiagency
committee to develop a
strategy
• Request funding for outreach
5-Year Objectives
• Implement the strategy
through coordinated technical
assistance between the
county and local communities
Long-Term Objectives
• Maintain consistent
outreach to
potentially-impacted
communities.
Implementation Plan/Actions
• KC EM will work with DNRP, WLRD and the Climate Preparedness team to identify partners.
• Continue to partner with WA DNR and DLS to map WUI areas – ultimately use this map to target
strategy priorities.
• Socialize results of WUI mapping efforts with comprehensive plan staff and look into planning
policies that could limit density or development in fire-prone areas.
• Convene multiagency committee once WA DNR WUI maps are closer to being finalized
• Identify existing preparedness actions and gaps, including areas that are/are not receiving
Firewise outreach and support.
• Develop wildfire preparedness and mitigation coordination strategy and socialize it.
• DNRP to request $150k funding for an additional FTE to support Firewise efforts.
• Look into model codes, ordinances, or other strategies to promote in addition to Firewise.
• Host an annual tabletop at the wildfire workshop held each year by KCEM.
AGENDA ITEM #1. b)
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Chapter 20: Mitigation Strategies
20-29
Performance Measure
• KC EM was successful/not successful in convening all the necessary partners to establish a unified
strategy for community wildfire preparedness and risk reduction.
AGENDA ITEM #1. b)
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Chapter 20: Mitigation Strategies
20-30
20.7.3 URM Mapping Specific to King County
Lead
DNRP
GIS
Partners
KCOEM
Hazards Mitigated
Earthquake
Extreme Weather
Funding Sources and
Estimated Costs
County Budget
HMGP
Vision
To enhance community safety and resilience by accurately mapping unreinforced masonry (URM) buildings in King
County, enabling targeted mitigation strategies that reduce the risk of severe damage during seismic events and
other natural hazards.
Description
Unreinforced masonry buildings (URMs) pose a significant risk during earthquakes due to their structural
vulnerabilities. In King County, the exact number and distribution of these buildings are not fully mapped or
documented. This strategy aims to conduct a comprehensive update of the URM building mapping within King
County. The updated data will guide mitigation measures such as retrofitting, building code updates, and prioritizing
resources for emergency response.
2-Year Objectives
• Complete a comprehensive update of
URM building data within King County
using available building permits,
structural reports, and GIS mapping
tools.
• Conduct outreach to property owners,
developers, and local jurisdictions to
improve building data accuracy.
• Establish a baseline risk assessment for
all identified URM structures in high-risk
seismic zones.
• Initiate educational campaigns for
property owners on the importance of
retrofitting and strengthening URM
buildings.
5-Year Objectives
• Complete the full retrofitting or
replacement of a significant number of
high-risk URM buildings in King County
through targeted funding and grants.
• Implement local ordinances requiring
retrofitting for URMs in high-risk zones.
• Develop a collaborative funding
program with local municipalities to
subsidize retrofitting for private
building owners.
• Improve local zoning codes to
encourage safer construction in areas
with high concentrations of URM
buildings.
Long-Term Objectives
• Achieve a substantial
reduction in URM-related
fatalities and injuries in the
event of a major earthquake
in King County.
• Establish a system for
regularly updating URM
building data and conducting
periodic re-assessments of
seismic vulnerabilities.
• Foster long-term community
resilience by ensuring all
vulnerable buildings are
retrofitted or replaced with
more seismically resilient
structures.
Implementation Plan/Actions
• Action 1: Collaborate with local governments to compile existing data on URM buildings.
• Action 2: Utilize GIS tools and risk assessment software to update building vulnerability data across King County.
• Action 3: Launch public outreach programs to inform property owners about the importance of retrofitting URMs
and available funding programs.
• Action 4: Establish partnerships with structural engineering firms to evaluate and propose retrofitting solutions for
the most at-risk URM buildings.
• Action 5: Secure funding from federal and state sources for high-priority retrofitting projects.
• Action 6: Integrate updated URM mapping into King County’s broader hazard mitigation and emergency response
planning frameworks.
• Action 7: Provide ongoing training for local emergency responders on identifying URMs and the associated risks in
disaster scenarios.
AGENDA ITEM #1. b)
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Chapter 20: Mitigation Strategies
20-31
Performance Measure
• Completion of updated URM building mapping within King County (measured as a percentage of total URM
buildings mapped).
• Number of URM buildings assessed for retrofit or replacement within the first 2 years.
• Percentage of URM buildings identified as high-risk that undergo retrofitting within the 5-year timeframe.
• Increase in the number of URM building owners participating in voluntary retrofitting programs.
• Reduction in the estimated number of injuries and fatalities in future seismic events due to URM vulnerabilities.
AGENDA ITEM #1. b)
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Chapter 20: Mitigation Strategies
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20.7.4 Dam Failure EAPs
Lead
KCOEM
Partners
SPU
Washington State Department
of Ecology
Hazards Mitigated
Dam Failure
Flooding
Terrorism
Funding Sources and
Estimated Costs
County Budget
FEMA Grants
Vision
By 2030, all dams within King County will have fully updated Emergency Action Plans (EAPs) and Emergency
Operations Plans (EOPs) to ensure coordinated and timely responses to any potential emergencies, enhancing public
safety and minimizing the impact of dam-related disasters.
Description
King County is home to a variety of dams that serve critical functions for flood control, water supply, and
recreational purposes. However, as some of these dams are aging, it is crucial that up-to-date Emergency Action
Plans and Emergency Operations Plans are in place for each. This strategy focuses on ensuring that every dam within
the county has comprehensive, actionable, and regularly updated plans by 2030. These plans will be aligned with
state and federal standards and will involve coordination with key emergency response agencies to ensure a swift
and efficient response in the event of a potential dam failure or other emergency scenarios.
2-Year Objectives
• Complete an initial review and
assessment of all dams within King
County to evaluate the status of their
current Emergency Action Plans and
Emergency Operations Plans.
• Identify gaps or outdated components
within existing plans and develop a
prioritized action plan to address them.
• Establish a working group with key
partners (Emergency Management,
DNRP, state agencies) to guide the
process of updating plans.
• Begin the process of updating EAPs and
EOPs for the highest-priority dams
(based on risk and condition).
5-Year Objectives
• Update Emergency Action Plans and
Emergency Operations Plans for at
least 50% of the dams in King County.
• Conduct at least two county-wide
emergency response exercises
involving dam failures, ensuring the
participation of local, state, and federal
agencies.
• Create a public awareness campaign
to inform the community about dam
safety and emergency preparedness in
the region.
• Establish a long-term plan for
maintaining and regularly updating
EAPs and EOPs, ensuring they are
revisited every 2-3 years.
Long-Term Objectives
• Ensure that 100% of dams in
King County have updated
EAPs and EOPs by 2030.
• Improve public and agency
preparedness and response
times in case of dam failure
events.
• Continuously enhance
coordination and
communication protocols
between local, state, and
federal agencies in managing
dam emergencies.
• Secure long-term funding
mechanisms to maintain up-
to-date plans and facilitate
regular drills.
Implementation Plan/Actions
• Conduct a comprehensive inventory of all dams in King County, identifying those with outdated or missing
Emergency Action Plans and Emergency Operations Plans.
• Collaborate with local, state, and federal agencies to develop a unified approach to updating the EAPs and EOPs.
• Hire consultants or experts to assist with plan updates and ensure compliance with state and federal regulations.
• Provide training for all relevant stakeholders, including local emergency responders and community leaders, to
ensure they understand the updated plans.
• Schedule regular drills and simulations to test the effectiveness of the updated plans and refine response
protocols.
• Establish a system for regular plan reviews and updates, with an emphasis on technological advancements and
emerging threats such as climate change.
AGENDA ITEM #1. b)
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Chapter 20: Mitigation Strategies
20-33
Performance Measure
• Percentage of dams with up-to-date EAPs and EOPs by 2025 and 2030.
• Number of drills and exercises conducted each year to test the response capabilities related to dam emergencies.
• Feedback from local agencies and responders on the clarity and effectiveness of the updated plans.
• Reduction in response times during dam-related emergency events.
• Number of gaps identified and corrected during regular assessments.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-34
20.7.5 Expanding Public Awareness of “Make It Through” Website
Lead
KCOEM
Partners
PHSKC
ECO
DNRP
KCIT
Hazards Mitigated
Avalanche
Terrorism
Volcano
Earthquake
Health Incident
Extreme Weather
Wildfire
Cyber Incident
Hazardous Materials
Funding Sources and
Estimated Costs
General Fund
Vision
To ensure every resident in King County has the knowledge and resources to prepare for and respond to
emergencies by expanding the reach and impact of www.makeitthrough.com, providing timely, accessible, and
practical preparedness information.
Description
This strategy aims to increase awareness of and engagement with www.makeitthrough.com, a critical online
resource designed to help King County residents prepare for various hazards, including earthquakes, flooding,
wildfires, and other public health emergencies. Through targeted outreach, educational campaigns, and strategic
partnerships, the goal is to ensure that residents have the necessary tools, knowledge, and motivation to prepare
themselves and their communities for a range of disaster scenarios.
2-Year Objectives
• Increase website traffic by 50%
through targeted campaigns and
outreach.
• Reach at least 20% of King County
residents through media campaigns (TV,
radio, social media).
• Partner with 15 local organizations to
promote the website and offer
preparedness workshops.
• Develop and distribute preparedness
materials in 5 languages widely spoken
in King County.
5-Year Objectives
• Achieve a 100% increase in website
traffic, with ongoing sustained
engagement.
• Establish long-term partnerships with
50+ local organizations to ensure
continuous promotion and education.
• Ensure 75% of King County residents
report being aware of the website in
post-campaign surveys.
• Introduce and promote regional
preparedness events featuring
www.makeitthrough.com resources.
Long-Term Objectives
• Make
www.makeitthrough.com a
widely recognized tool for
emergency preparedness
across King County.
• Ensure King County
residents are among the best-
prepared populations in the
nation for emergencies.
• Maintain a long-term,
continuous education
program to keep
preparedness information
relevant and up-to-date.
Implementation Plan/Actions
• Website Enhancements: Improve user experience and mobile access on www.makeitthrough.com.
• Media Campaigns: Launch multi-channel campaigns (social media, print, radio, TV) to drive awareness of the
website.
• Partnership Development: Establish partnerships with schools, local businesses, nonprofit organizations, and
community groups to share the website.
• Community Outreach Events: Host preparedness fairs, workshops, and town halls featuring the website's
resources.
• Material Distribution: Create bilingual, culturally relevant preparedness pamphlets and digital resources to
distribute to local organizations.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-35
• Public Service Announcements: Collaborate with local media outlets to air public service announcements about
www.makeitthrough.com.
• Surveys and Feedback: Conduct regular surveys and community feedback sessions to assess awareness levels and
adjust strategies as needed.
Performance Measure
• Website traffic analytics (visits, unique users, page views) from the website’s analytics platform.
• Survey results measuring awareness of www.makeitthrough.com among King County residents.
• Number of media impressions (TV, radio, social media reach).
• Number of partnerships established and the number of preparedness events conducted.
• Feedback from community organizations and participants on the effectiveness of outreach materials and events.
• Number of preparedness materials distributed in targeted languages and communities.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
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20.7.6 Climate Change and Health Adaptation Strategy
Lead
PHSKC
Partners
ECO
Hazards Mitigated
Avalanche
Flood
Health Incident
Landslide
Extreme Weather
Wildfire
Funding Sources and
Estimated Costs
County Budget
Vision
To create the necessary conditions to prepare for, adapt to, and mitigate the health impacts of climate change in
King County, particularly in communities that are most vulnerable and disproportionately impacted by climate
hazards.
Description
The Climate Change and Health Adaptation Strategy focuses on improving community resilience to climate-related
health risks, including extreme heat, wildfire smoke, and floods. Through co-created risk communication campaigns,
community capacity building, evidence-based solutions, and integration of climate data, the strategy aims to
mitigate adverse health impacts while promoting equitable climate change programs and policies. This multi-year
initiative includes outreach efforts, technical assistance, the development of climate-related health data systems,
and collaboration with healthcare and community organizations to reduce inequities caused by climate change.
2-Year Objectives
• Co-create and deliver risk
communication campaigns with
communities impacted by extreme heat,
wildfire smoke, and floods
• Increase awareness in
disproportionately impacted
communities about how to mitigate and
adapt to climate change
• Support community programs
addressing the health impacts of heat
and wildfire smoke with technical
assistance and evidence-based solutions
• Begin data collection and improvement
for key climate, health, and resilience
indicators
• Establish collaborative partnerships for
integrating climate change into Public
Health programs aligned with the
Strategic Climate Action Plan
5-Year Objectives
• Expand technical assistance to
support communities in adapting to
the health impacts of heat and wildfire
smoke
• Enhance the use of climate data
dashboards for tracking health impacts
and support policy changes based on
qualitative and quantitative data
• Ensure health services providers and
partners across the region prioritize
climate resilience through quarterly
healthcare collaborative meetings
• Strengthen partnerships with BIPOC
communities to co-develop programs
and policies that address climate-
related health impacts
• Increase community capacity to
mitigate and adapt to climate hazards
by scaling successful programs and
strategies
Long-Term Objectives
• Influence regional and
statewide leadership on
climate policies focused on
decarbonization, data use,
and climate change resilience
• Ensure health equity
through the integration of
climate data into public health
decision-making and policy
• Establish King County as a
national leader in addressing
the health impacts of climate
change through community
programming, research, and
collaborations
• Build long-term
sustainability in community
resilience through ongoing
education, partnerships, and
adaptation strategies
AGENDA ITEM #1. b)
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Implementation Plan/Actions
• Collaborate with community partners to develop and disseminate educational resources in multiple languages
• Implement strategies and solutions co-created with BIPOC communities to reduce health impacts from climate
hazards
• Establish and continuously improve a robust data system to monitor climate, health, and resilience indicators
• Provide technical assistance to partners and support community-based programs addressing climate health
impacts
• Integrate climate change considerations into public health programs, ensuring alignment with King County’s
Strategic Climate Action Plan
• Convene quarterly healthcare collaboratives to drive regional climate and health leadership
• Collect and analyze data to support public health action and address health inequities
Performance Measure
• Number of community-specific communications campaigns and strategies developed
• Number of technical-assistance consultations provided and community partners engaged
• Number of data requests, visits to the climate data dashboard, and feedback on data usage
• Number of healthcare partners engaged annually in climate and health initiatives
• Number of evidence-based programs successfully implemented to reduce health impacts of climate hazards
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-38
20.7.7 Expand King County Energize! Program
Lead
ECO
Partners
North Highline and Skyway-
West Hill communities
Hazards Mitigated
Extreme Weather
Funding Sources and
Estimated Costs
CCA
FEMA
Vision
To improve energy efficiency and reduce environmental impacts in King County homes by providing affordable
access to clean, energy-efficient technology, such as heat pumps, weatherization, and electric appliances.
Description
The Energize! Heat Pump Program focuses on installing heat pumps and other clean technologies in homes in the
North Highline and Skyway-West Hill unincorporated areas of King County. The program targets income-qualified
residents who may be eligible for 100% cost-coverage, while other residents may receive discounts. Heat pumps,
which provide efficient heating and cooling, are part of King County's effort to reduce energy use and help residents
lower their energy bills. In 2025, the program will expand through funding from the Climate Commitment Act (CCA)
to include electric appliances, plumbing improvements, home energy audits, and weatherization services for single-
family homes and small businesses across King County.
2-Year Objectives
• Install heat pumps and other clean
technology in homes in North Highline
and Skyway-West Hill
• Provide energy audits and
weatherization services
• Expand program eligibility to include
small businesses in targeted areas
• Increase awareness of the program to
encourage broader participation from
residents in the designated regions
5-Year Objectives
• Install heat pumps and energy-
efficient upgrades in across King
County
• Reduce energy consumption and
lower energy bills for participating
households
• Expand the program to additional
communities in King County
• Support the installation of energy-
efficient technologies for small
businesses in King County
Long-Term Objectives
• Contribute to King County's
clean energy goals by reducing
reliance on fossil fuels for
home heating and cooling
• Improve air quality and
lower carbon emissions in the
region
• Achieve widespread
adoption of energy-efficient
technology in homes and
small businesses across King
County
• Ensure that lower-income
and historically underserved
communities have equitable
access to clean energy
solutions
Implementation Plan/Actions
• Continue installing heat pumps and energy-efficient technology in North Highline and Skyway-West Hill
• Increase outreach to income-qualified residents for 100% cost-coverage opportunities
• Partner with local contractors and service providers to ensure high-quality installations and services
• Expand program offerings to include electric appliances, plumbing improvements, home energy audits, and
weatherization in 2025
• Use CCA funding to support program expansion and increase coverage for additional residents and businesses
• Track and evaluate energy savings and customer satisfaction for program improvements
AGENDA ITEM #1. b)
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Performance Measure
• Number of homes and small businesses participating in the program
• Total energy savings achieved through heat pump installations and other energy-efficient upgrades
• Reduction in energy bills for participating households
• Number of income-qualified residents who receive 100% cost coverage or discounts
• Customer satisfaction and feedback on program services and installation quality
• Successful implementation of the expanded program in 2025, with a measurable increase in participation and
coverage
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
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20.7.8 Risk Reduction Through Equitable Language Access
Lead
KCOEM
Partners
PHSKC
Trusted Partner Network
Hazards Mitigated
Cyber Incident
Dam Failure
Earthquake
Flood
Hazardous Materials
Health Incident
Landslide
Extreme Weather
Terrorism
Tsunami
Volcano
Wildfire
Funding Sources and
Estimated Costs
County Budget
Preparedness Grants
Vision
To enhance community resilience by improving public translation, cultural communications, and community
partnerships, ensuring consistent and accurate information delivery to all residents in King County during
emergencies.
Description
COVID-19 demonstrated the vital role of timely, accurate, and culturally relevant communication in protecting public
health and the economy. King County engaged with community leaders and trusted partners to tailor messages for
specific ethnic and language groups, focusing on vulnerable and marginalized populations. This initiative relied on
various outreach methods such as webinars, social media, and direct communications to disseminate essential
information during the pandemic. Building on this experience, the goal is to refine and expand these efforts to
improve public hazard resilience, enhance language access, and sustain these partnerships for future emergency
responses.
2-Year Objectives
• Refine and build on the lessons learned
from COVID-19 to strengthen community
partnerships and cultural communication
networks.
• Invest in language access resources,
including translation, interpretation, and
media outreach, to ensure consistent
services for all residents.
• Formalize the network of Community
Navigators to enhance the development
and dissemination of in-language
communications for emergency
preparedness.
5-Year Objectives
• Expand the use of digital and virtual
outreach platforms (social media,
online platforms) for broader
communication access.
• Broaden the role of Community
Navigators in post-disaster recovery,
providing continuous community
engagement.
• Foster community partnerships to
ensure that the public health
communication system can quickly
adapt to new types of hazards.
Long-Term Objectives
• Establish a sustainable
framework for language and
cultural communications in all
future emergency
preparedness and mitigation
efforts.
• Ensure that King County is
well-equipped to provide
rapid, appropriate, and
accurate information to
diverse populations in future
emergencies.
• Integrate community
partnerships into long-term
resilience planning for
environmental, biological, and
physical hazards.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
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Implementation Plan/Actions
• Expand language access resources, such as translation and interpretation services, to provide clear messaging for
all King County residents.
• Strengthen and formalize the Community Navigator network to ensure culturally appropriate information
dissemination.
• Increase community outreach efforts through social media and digital platforms to maintain flexibility and
consistency in communication during emergencies.
• Engage in continuous training and collaboration with local ethnic and media outlets to ensure that all
communication is clear, timely, and accessible.
Performance Measure
• Increase in the number of residents receiving emergency communications in their preferred language.
• Number of community events and outreach initiatives conducted with diverse ethnic groups.
• Effectiveness of public health messaging, as measured by surveys or feedback from target communities.
• Tracking the engagement levels in virtual and social media outreach platforms.
• Evaluation of the Community Navigator network's impact on reaching vulnerable populations.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
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20.7.9 Extreme Heat Event Communications
Lead
KCOEM
Partners
PHSKC
ECO
Community based
organizations
Hazards Mitigated
Extreme Weather
Wildfire
Funding Sources and
Estimated Costs
County Budget
Vision
To ensure all King County residents, especially those with limited English proficiency, have access to culturally
relevant, multilingual heat safety and preparedness information to increase community resilience to extreme heat
events.
Description
Language and cultural barriers can limit the effectiveness of heat preparedness and mitigation efforts. This action
focuses on the development and distribution of multilingual, culturally relevant materials about heat safety to better
serve communities in King County, particularly those in the hottest areas. These areas have a high proportion of
limited English-speaking residents who are more vulnerable to heat-related health impacts. Through collaboration
with community organizations, local governments, and multilingual media, the aim is to increase the reach and
impact of heat safety messages before, during, and after heat waves.
2-Year Objectives
• Develop and distribute multilingual and
culturally relevant heat safety and
preparedness materials.
• Partner with community organizations
to evaluate heat messaging needs and
priorities.
• Increase the use of community
networks and media to distribute heat
safety messages, especially in
communities with limited English
proficiency.
• Ensure the inclusion of heat safety
content in various formats, such as print,
digital, and multimedia.
• Ensure preparedness messaging is
provided well before heat waves to
encourage early actions like purchasing
cooling items.
5-Year Objectives
• Co-create comprehensive,
community-specific heat safety
materials with a diverse set of local
partners.
• Build sustainable distribution
channels for multilingual heat safety
information, integrating them into
community networks and media.
• Provide consistent access to
multilingual heat safety content in
areas with high heat vulnerability.
• Enhance outreach to include
information on supporting at-risk
populations, including low-income
seniors and people with disabilities.
Long-Term Objectives
• Ensure equitable access to
heat preparedness
information for all residents,
particularly those in the
hottest areas of King County.
• Make multilingual heat
safety resources a consistent
part of community resilience
and public health efforts.
• Foster long-term
partnerships between King
County, local governments,
and community organizations
for heat safety outreach and
preparedness.
Implementation Plan/Actions
• Co-create culturally relevant content: Partner with community-based organizations, service providers, and
residents to develop heat safety materials that reflect community needs and priorities.
• Expand distribution networks: Work with local, multilingual media and community-trusted organizations to adapt
and distribute heat safety information in multiple languages through various formats (e.g., printed materials, digital
media, video).
• Integrate heat safety into pre-summer messaging: Begin heat safety messaging early in the year, especially to
encourage the purchase of cooling devices during the off-season.
• Focus on high-risk communities: Prioritize outreach to areas with the highest temperatures and most limited
English-speaking populations.
• Collaborate on cross-strategy multilingual materials: Develop multilingual resources related to heat safety, in-
AGENDA ITEM #1. b)
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Chapter 20: Mitigation Strategies
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home support for vulnerable populations, urban tree canopy management, and energy efficiency.
• Facilitate access via an online clearinghouse: Add multilingual heat safety materials to the extreme heat online
clearinghouse (Action 19: Partnerships for Implementation) for easier access.
Performance Measure
• Increased distribution of multilingual heat safety materials, measured by the number of materials distributed and
the reach of messaging.
• Increased engagement with community-based organizations and media partners to co-create and distribute
content.
• Higher levels of community awareness and preparedness for heat events, as measured through surveys and
feedback.
• Reduced language and cultural barriers to heat safety information, as indicated by the number of communities
with limited English proficiency receiving the materials.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-44
20.7.10 Enhanced Cooling Centers
Lead
KCOEM
Partners
Local Community Organizers
ECO
Hazards Mitigated
Extreme Weather
Funding Sources and
Estimated Costs
County budget, grants,
public-private partnerships
(cost estimation to be
determined)
Vision
To increase awareness, accessibility, and utilization of public cooling centers in King County, ensuring all residents,
especially those in heat-impacted neighborhoods, have safe, reliable access to cooling during extreme heat events.
Description
In response to community feedback and surveys by King County’s Office of Emergency Management, there is a need
for increased awareness, access, and services at existing public cooling centers. This action focuses on increasing the
utilization of these centers through staffing improvements, enhanced amenities, and better transportation options,
particularly targeting communities with elevated heat risks. Although cooling centers are available, utilization has
been low, primarily due to a lack of awareness, family-friendly programming, and transportation barriers. This action
calls for collaborative efforts to address these challenges and increase accessibility.
2-Year Objectives
• Increase public awareness of cooling
center locations and services.
• Improve transportation options to
cooling centers, particularly in heat-
impacted neighborhoods.
• Enhance amenities at cooling centers,
such as snacks, water, Wi-Fi, and device
charging capabilities.
• Increase staff capacity and operational
budgets to ensure extended hours of
access.
5-Year Objectives
• Achieve a significant increase in the
utilization rates of public cooling
centers, especially in identified heat
islands and underserved communities.
• Establish a comprehensive,
multilingual communications strategy
for cooling center outreach and
updates during heat events.
• Ensure long-term sustainability of
funding for cooling center operations
and staffing.
Long-Term Objectives
• Ensure year-round, reliable
cooling center access for King
County residents during
extreme heat events.
• Create a model of
community engagement and
center utilization that can be
replicated in other regions
facing similar challenges.
• Establish consistent funding
and infrastructure to support
cooling centers as essential
community resources.
Implementation Plan/Actions
• Collaborate with local governments and agencies to identify gaps in cooling center services and transportation
access, particularly in heat-impacted neighborhoods.
• Promote transit options to and from cooling centers, ensuring accessibility for all community members.
• Provide incentives at cooling centers, including snacks, bottled water, Wi-Fi access, and charging stations.
• Increase communications and outreach about cooling center availability, focusing on heat events, multilingual
messaging, and disability accessibility.
• Budget for additional staff and operational resources to support extended hours and improved services at cooling
centers.
Performance Measure
• Increased utilization of cooling centers, measured by attendance data and community feedback.
• Greater awareness as indicated by surveys and outreach tracking.
• Improved accessibility, measured by transportation utilization rates and increased family participation in programs.
AGENDA ITEM #1. b)
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• Satisfaction levels of residents accessing cooling centers, as measured through surveys and community
engagement.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-46
20.7.11 Shake Alert Sign Up Campaign
Lead
KCOEM
Partners
WAEMD
USGS
Local Jurisdictions
Hazards Mitigated
Earthquake
Funding Sources and
Estimated Costs
General Fund
FEMA Preparedness Grants
Vision
To ensure that all King County residents are registered for ShakeAlert to receive timely earthquake early warnings,
enabling them to take immediate protective actions to reduce injury and property damage during seismic events.
Description
ShakeAlert provides critical early warnings seconds before an earthquake strikes, allowing residents to take
protective actions such as "Drop, Cover, and Hold On." Despite its importance, many King County residents remain
unaware of ShakeAlert or are not registered to receive notifications. This strategy will focus on increasing awareness
of the system, educating residents on how to sign up, and expanding accessibility to ensure that ShakeAlert reaches
all King County residents, especially those in vulnerable communities.
2-Year Objectives
• Conduct at least 10 public outreach
events in community centers, schools,
and libraries to promote ShakeAlert
• Distribute ShakeAlert promotional
materials to 100,000 households in King
County
• Launch a targeted social media and
digital advertising campaign to educate
residents about ShakeAlert
• Implement ShakeAlert registration in at
least 50 local schools and businesses
5-Year Objectives
• Achieve a 50% increase in ShakeAlert
registrations across all demographics in
King County
• Establish permanent partnerships
with schools, libraries, and community
organizations to continue ShakeAlert
education and registration
• Integrate ShakeAlert information into
existing emergency preparedness
initiatives across King County
• Expand ShakeAlert accessibility to
populations with limited access to
smartphones or the internet
Long-Term Objectives
• Ensure that 90% of King
County residents are
registered for ShakeAlert
• Establish King County as a
national model for earthquake
early warning systems, with
widespread participation
• Foster a resilient community
where earthquake
preparedness is ingrained in
daily life
Implementation Plan/Actions
• Community Outreach and Engagement: Conduct in-person outreach at local community centers, schools, and
libraries to demonstrate ShakeAlert registration and educate residents about the system's importance.
• Partnership with Schools and Businesses: Collaborate with local schools and businesses to encourage staff and
students to register for ShakeAlert, ensuring that these groups are well-informed and can spread the message to
families.
• Public Awareness Campaign: Use digital and traditional media (TV, radio, social media) to spread the word about
ShakeAlert. Develop eye-catching ads that explain how to register and the benefits of receiving early earthquake
warnings.
• Multilingual Outreach: Provide materials in multiple languages spoken in King County, such as Spanish, Chinese,
and Somali, to ensure wide accessibility.
• Incentivize Registration: Host contests or offer small prizes for residents who sign up and engage in ShakeAlert
awareness campaigns.
• Mobile App Partnerships: Work with mobile phone carriers to include ShakeAlert sign-up prompts or integration
directly within their apps to make the process seamless for users.
• Targeted Education for Vulnerable Populations: Focus on outreach efforts to populations that may be harder to
reach, including seniors, low-income households, and people with disabilities, providing them with information on
how to register for ShakeAlert via different methods (e.g., text messages, landline phones, apps).
AGENDA ITEM #1. b)
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Performance Measure
• Registration Metrics: Track the number of new ShakeAlert sign-ups in King County over time and measure the
percentage increase in registrations.
• Outreach Effectiveness: Monitor participation in community events, workshops, and other outreach efforts,
measuring attendance and engagement through sign-up rates.
• Social Media Engagement: Evaluate the effectiveness of digital campaigns through social media analytics, such as
likes, shares, comments, and click-through rates on ShakeAlert registration links.
• Demographic Data: Assess the demographic breakdown of ShakeAlert registrants (e.g., age, language, location) to
ensure equitable access and participation across all communities in King County.
• Community Feedback: Collect feedback from community organizations, schools, and local leaders to evaluate the
impact of outreach efforts and identify areas for improvement.
AGENDA ITEM #1. b)
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Chapter 20: Mitigation Strategies
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20.7.12 Increase Alert King County Registrations
Lead
KCOEM
Partners
Local Jurisdictions
Hazards Mitigated
Avalanche
Civil Disorder
Cyber Incident
Dam Failure
Earthquake
Flood
Hazardous Materials
Health Incident
Landslide
Extreme Weather
Terrorism
Tsunami
Volcano
Wildfire
Funding Sources and
Estimated Costs
General Budget
Vision
To increase the number of residents signed up for Alert King County by fostering community awareness,
engagement, and trust, ensuring that all residents receive timely emergency alerts to protect life and property.
Description
Alert King County is a critical system for delivering emergency notifications to King County residents. However, a
large portion of the population remains unregistered, especially among underserved communities, people with
disabilities, and those with limited access to technology. This strategy will focus on outreach, education, and
incentives to increase sign-ups, with particular emphasis on those vulnerable populations. By engaging residents and
community organizations, we aim to raise awareness about the importance of timely alerts for disaster
preparedness.
2-Year Objectives
• Increase Alert King County registrations
by 20%
• Expand outreach to at least 50
community organizations and
institutions
• Host at least 10 community events
focused on Alert King County registration
• Collaborate with local schools and
libraries to reach families and seniors
• Develop multilingual promotional
materials and outreach methods
5-Year Objectives
• Achieve a 50% increase in Alert King
County sign-ups across all demographic
groups
• Establish sustainable, ongoing
partnerships with local organizations to
ensure consistent outreach
• Integrate Alert King County
registration into emergency
preparedness training and public
health campaigns
• Improve access to Alert King County
for residents with disabilities or those
without smartphones or internet
access
Long-Term Objectives
• Ensure 90% of King County
residents are signed up for
Alert King County
• Create a robust public
engagement model that can
be adopted by other regions
in Washington State
• Foster an emergency
preparedness culture that
includes all communities,
particularly vulnerable
populations
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Implementation Plan/Actions
• Develop a Comprehensive Communication Campaign: Launch targeted digital, print, and in-person outreach
efforts. Use local radio, social media, and direct mail to inform residents about the benefits of registering.
• Host Community Registration Events: Work with local libraries, community centers, schools, and places of worship
to set up registration booths and provide live demonstrations.
• Incentivize Registration: Offer rewards or incentives, such as raffle entries for prizes, to encourage people to sign
up.
• Collaborate with Local Media: Engage local news outlets to broadcast reminders and alerts about Alert King
County registration.
• Multilingual Outreach: Provide materials and registration assistance in Spanish, Russian, Somali, Mandarin, and
other languages spoken in King County.
• Train Community Leaders: Educate community leaders on the importance of emergency alerts, so they can share
the information with their networks and encourage sign-ups.
• Address Accessibility Needs: Partner with organizations that serve people with disabilities to ensure that Alert King
County registration is accessible to all.
Performance Measure
• Registration Metrics: Track the number of new registrants over time and compare it to baseline data to gauge the
increase in sign-ups.
• Engagement Analytics: Measure the effectiveness of outreach campaigns through website analytics (e.g., clicks on
registration links), social media interactions, and event attendance.
• Community Feedback: Gather feedback from community organizations and participants to assess the impact of
outreach efforts.
• Demographic Breakdown: Track the demographic breakdown of registrants (e.g., age, race, language, location) to
ensure equitable outreach efforts.
AGENDA ITEM #1. b)
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20.7.13 King County Community Wildfire Protection Plan
Lead
KCOEM
Partners
KCSO
DNRP
KCD
KCECO
Hazards Mitigated
Wildfire
Funding Sources and
Estimated Costs
HMGP/FEMA/State Grants
Vision
To develop a county-scale Community Wildfire Protection Plan (CWPP) for King County that enhances resilience
against wildfire risks through proactive planning, stakeholder collaboration, and public involvement. This CWPP will
ensure the county’s preparedness, response, and recovery capabilities are robust, inclusive, and community-driven.
Description
The King County Office of Emergency Management (KCOEM) is spearheading the development of King County’s first
county-scale Community Wildfire Protection Plan (CWPP). Over the next 18 months, KCOEM will hire a Temporary
Limited Term planner to lead the planning process, working alongside key local agencies and jurisdictions. The CWPP
will be developed through stakeholder collaboration, involving public, private, and Tribal entities to enhance wildfire
preparedness, response, and recovery across King County. The plan will include a county-wide risk assessment,
capabilities assessment, public outreach, and prioritization of mitigation actions.
2-Year Objectives
• Hire and onboard a Temporary Limited
Term planner to lead the CWPP
development.
• Develop a comprehensive risk
assessment using GIS tools to identify
wildfire risks and vulnerable populations
in King County.
• Complete the first draft of the CWPP
and begin public outreach and
community engagement.
• Facilitate workshops with stakeholders
and local communities to ensure a
broad, inclusive planning process.
5-Year Objectives
• Finalize and submit the King County
CWPP for Federal and State review.
• Create annexes for individual
communities to provide detailed,
localized wildfire mitigation plans.
• Develop prioritized mitigation actions
based on the risk assessment, forest
health, and community input.
• Implement priority wildfire risk
reduction actions, including fuels
reduction and structural hardening
projects.
Long-Term Objectives
• Achieve increased resilience
of King County forests and
infrastructure to wildfire risks.
• Enhance the wildfire
preparedness, response, and
recovery systems for all
communities within the
county.
• Ensure ongoing public
engagement and updates to
the CWPP to reflect evolving
wildfire risks and mitigation
strategies.
Implementation Plan/Actions
• Convene a core planning team from relevant county departments, agencies, and external partners.
• Conduct risk assessments, including overlaying critical infrastructure, vulnerable populations, and historical wildfire
data in a unified GIS tool.
• Perform community outreach, surveys, and meetings to gather local knowledge and input.
• Develop and prioritize mitigation actions, focusing on fuels reduction, defensible space, and structural hardening
across the county.
• Facilitate the creation of annexes for individual communities, offering tailored wildfire mitigation strategies.
• Ensure the CWPP aligns with broader state and national wildfire strategies, including the National Cohesive
Wildland Fire Management Strategy.
Performance Measure
• Completion of the CWPP within 18 months, with ongoing updates to the annexes.
• Engagement of key stakeholders, local communities, and the public throughout the planning process.
• Number of mitigation actions prioritized and completed, as well as funding secured for implementation.
• Feedback and participation levels from affected communities, particularly vulnerable populations in the WUI.
AGENDA ITEM #1. b)
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20.7.14 Integration of Hazard Mitigation into County Plans
Lead
KCOEM
Partners
All County Agencies
Hazards Mitigated
Avalanche
Civil Disorder
Cyber Incident
Dam Failure
Earthquake
Flood
Hazardous Materials
Health Incident
Landslide
Extreme Weather
Terrorism
Tsunami
Volcano
Wildfire
Funding Sources and
Estimated Costs
County Budget
Vision
To ensure that hazard mitigation strategies are seamlessly integrated into all current King County plans,
strengthening the community's resilience to disasters and reducing long-term risk to lives, property, and
infrastructure.
Description
The King County Office of Emergency Management (KCOEM) will lead efforts to integrate hazard mitigation
strategies into existing countywide planning processes. This will involve updating current plans—such as the
Comprehensive Emergency Management Plan (CEMP), land use planning, transportation, and infrastructure
development—so that mitigation actions are explicitly included and prioritized. By embedding hazard mitigation into
these planning documents, KCOEM will enhance long-term resilience, reduce future disaster impacts, and ensure
that mitigation strategies are a consistent part of local government and community actions. The integration process
will engage stakeholders, incorporate data-driven risk assessments, and ensure that mitigation actions are
incorporated into all planning phases, from preparedness to recovery.
2-Year Objectives
• Conduct an inventory of all existing
King County plans and identify
opportunities for hazard mitigation
integration.
• Develop a framework for embedding
hazard mitigation strategies into key
county planning documents.
• Work with local jurisdictions to align
hazard mitigation with existing regional
plans, including the Regional Hazard
Mitigation Plan.
• Integrate risk reduction measures into
at least two major planning documents
(e.g., transportation or land use plans).
• Provide training and resources for
5-Year Objectives
• Ensure hazard mitigation strategies
are fully integrated into at least 75% of
all major King County planning
documents.
• Establish a regular review process for
incorporating updated hazard
mitigation information into planning
documents and procedures.
• Collaborate with local governments
and regional partners to incorporate
mitigation into hazard-specific plans
(e.g., floodplain management, wildfire
prevention, heat preparedness).
• Build capacity for communities to
implement hazard mitigation actions
Long-Term Objectives
• Achieve widespread
adoption of hazard mitigation
strategies across all King
County plans, ensuring a
holistic approach to disaster
resilience.
• Create a long-term,
sustainable framework for
ongoing integration of hazard
mitigation into new plans and
projects.
• Foster a culture of resilience
where hazard mitigation is a
standard consideration for all
county planning and
development activities.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-52
county departments and local
governments on incorporating hazard
mitigation into their operations and
planning.
through grants, funding programs, and
technical support.
Implementation Plan/Actions
• Conduct an assessment of current plans: Review King County’s existing plans and identify gaps where hazard
mitigation strategies can be integrated (e.g., CEMP, Comprehensive Plan, transportation plans, capital improvement
plans).
• Develop a hazard mitigation integration framework: Create a standard framework for including hazard mitigation
actions and policies in all relevant county plans, with clear guidelines and objectives for each department and
jurisdiction.
• Engage stakeholders: Collaborate with local governments, community organizations, and other stakeholders to
ensure that hazard mitigation strategies are reflective of community needs and priorities.
• Update plans: Integrate specific hazard mitigation actions and strategies into at least two major planning
documents, and ensure that new planning processes include mitigation considerations.
• Provide training and support: Offer training and resources to King County departments and local governments on
how to include hazard mitigation strategies in their planning processes, including best practices and available
funding sources.
• Track and review: Implement a process for ongoing tracking, monitoring, and updating of hazard mitigation
integration efforts to ensure continued alignment with county goals and evolving hazard risks.
Performance Measure
• Number of King County plans that integrate hazard mitigation strategies, tracked by specific document reviews and
updates.
• Percentage of departments and jurisdictions that have adopted the hazard mitigation integration framework into
their planning processes.
• Feedback from stakeholders, including community organizations and local governments, on the effectiveness and
relevance of integrated mitigation strategies.
• Number of hazard mitigation actions implemented from countywide plans.
• Progress on reducing risk and enhancing resilience in specific hazard areas, measured through post-event analysis
and risk assessments.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-53
20.7.15 King County Flood Warning Center
Lead
DNRP
Partners
NWS
PHSKC
KCOEM
Hazards Mitigated
Flood
Funding Sources and
Estimated Costs
County Budget
Vision
To ensure timely and effective flood warnings and response actions for King County residents, minimizing loss of life,
property damage, and public health risks during flood events.
Description
The King County Flood Warning Center (FWC) provides critical flood monitoring, alerts, and decision support during
flood events in King County. The FWC utilizes a combination of real-time flood monitoring tools, hydrologic
modeling, and collaboration with local agencies and the National Weather Service to provide flood forecasts and
warnings. It works closely with local jurisdictions and public health agencies to ensure communities have the
necessary information to protect lives, property, and the environment. The center also supports public outreach,
ensuring flood information is accessible, especially for vulnerable populations.
2-Year Objectives
• Improve real-time flood monitoring
and forecasting capabilities to enhance
flood warnings.
• Expand community outreach and flood
awareness programs, ensuring residents
understand flood risks and warnings.
• Develop and distribute multilingual
flood preparedness materials.
• Strengthen coordination with local
jurisdictions and agencies to ensure
efficient flood response.
• Continue improving flood mapping and
risk assessment tools.
5-Year Objectives
• Increase community trust and
engagement with flood warning
systems through outreach and
educational programs.
• Enhance the capacity of the FWC to
issue timely, accurate flood warnings
across all flood-prone areas.
• Develop an integrated flood response
plan that involves all local, regional,
and state partners.
• Provide equitable flood warning and
preparedness materials for all King
County communities, with a focus on
underserved populations.
Long-Term Objectives
• Establish a fully integrated
and automated flood warning
system that can predict and
respond to flood events across
King County in real-time.
• Build long-term resilience in
communities, reducing
vulnerability to flooding
through education,
infrastructure improvements,
and emergency preparedness.
• Expand floodplain
management strategies to
reduce future flood risks and
enhance sustainable flood
mitigation efforts.
Implementation Plan/Actions
• Enhance flood monitoring capabilities: Continue to upgrade and integrate flood monitoring tools, hydrologic
models, and real-time data from streams and rivers.
• Increase public awareness: Provide ongoing public education on flood preparedness through workshops, outreach
programs, and multilingual resources.
• Collaborate with local and regional partners: Coordinate flood monitoring and warning efforts with local
governments, public health agencies, and the National Weather Service to provide timely, accurate information to
communities.
• Improve accessibility: Develop and distribute flood warning alerts and preparedness materials in multiple
languages to ensure accessibility for all residents.
• Refine flood forecasting: Invest in tools and resources to improve the accuracy of flood forecasting, integrating
new technologies and data sources.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-54
Performance Measure
• Timeliness and accuracy of flood warnings issued by the FWC, measured by the lead time provided before flood
events.
• Increased public awareness and understanding of flood risks, as assessed through surveys and community
engagement.
• Number of communities reached through multilingual flood preparedness messaging.
• Reduced flood-related impacts in communities, such as property damage or loss of life, as measured through post-
event assessments and data analysis.
• Enhanced coordination and response times among local, regional, and state partners during flood events.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-55
20.7.16 Update Liquefaction Mapping in King County
Lead
DNRP
GIS
Partners
EMD
USGS
KCOEM
Hazards Mitigated
Earthquake
Funding Sources and
Estimated Costs
KC General Fund
HMGP
Vision
Enhance community resilience in King County by updating and improving liquefaction hazard mapping, leading to
better-informed land use planning, infrastructure development, and disaster preparedness in areas vulnerable to
liquefaction during seismic events.
Description
Liquefaction, a process where saturated soil temporarily loses strength during an earthquake, poses a significant risk
to buildings, infrastructure, and people in King County, particularly in low-lying areas. While previous mapping
efforts have identified many areas at risk, updated and more accurate mapping, including new geotechnical data,
advancements in seismic research, and changing land-use patterns, is needed to better understand the spatial
distribution and intensity of liquefaction hazards.
The updated liquefaction hazard maps will inform land-use policies, zoning, building codes, emergency preparedness
plans, and mitigation strategies, ultimately reducing the risk of property damage, loss of life, and economic
disruption in the event of a significant seismic event.
2-Year Objectives
• Conduct a comprehensive review of
existing liquefaction hazard maps and
identify areas requiring new data or
more refined analysis.
• Secure funding and develop
partnerships with state, local, and
federal agencies.
• Complete geotechnical field studies in
key areas of King County to update soil
and seismic data.
• Develop a draft of the updated
liquefaction hazard maps for peer
review.
5-Year Objectives
• Finalize and publish the updated
liquefaction hazard maps for King
County.
• Integrate updated maps into local
land-use planning and development
guidelines.
• Conduct a series of outreach
programs and workshops to educate
local governments, developers, and the
public about the updated maps and
their implications.
• Implement mitigation strategies
based on the updated maps, including
targeted infrastructure improvements
and building code updates.
Long-Term Objectives
• Monitor the effectiveness of
the updated liquefaction maps
and mitigation measures in
reducing risk to people,
property, and infrastructure.
• Expand the scope of the
liquefaction mapping to cover
areas outside of King County
with potential future seismic
risks.
• Continue ongoing data
collection and modeling to
refine maps as seismic
research advances.
• Ensure continuous
integration of updated maps
into emergency management
systems and protocols.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-56
Implementation Plan/Actions
Year 1-2
• Coordinate with the Washington State EMD, USGS, and local jurisdictions to establish the scope of the
project and secure funding.
• Identify critical areas of King County lacking detailed liquefaction data and prioritize them for field studies.
• Conduct geotechnical surveys and collect new data in high-priority areas (e.g., downtown Seattle, Bellevue,
and South King County).
• Revise and update the preliminary liquefaction hazard maps.
• Review existing policies and zoning codes to incorporate updated hazard mapping requirements.
Year 3-5
• Conduct peer reviews of the updated maps with seismic experts and stakeholders to ensure accuracy and
applicability.
• Finalize the updated liquefaction hazard maps and publish them online and in public forums.
• Integrate the updated maps into King County’s GIS system and collaborate with local municipalities to
update their land-use and building codes.
• Develop and implement an outreach strategy to inform developers, planners, and residents about the new
data and its implications for construction and safety measures.
• Explore funding for infrastructure improvements in identified high-risk areas.
Ongoing
• Monitor seismic events and update maps as necessary based on new data and research.
• Periodically assess and refine mitigation measures to enhance community resilience.
• Maintain and update collaboration with state, local, and federal agencies to ensure continuous
improvement in hazard mitigation efforts.
Performance Measure
• Completion of updated liquefaction hazard maps by the end of Year 2.
• Integration of updated maps into at least 80% of local jurisdictions' land-use policies and building codes by Year 5.
• Engagement with at least 500 stakeholders (e.g., community members, developers, emergency responders)
through workshops, webinars, and outreach materials.
• 75% of identified high-risk infrastructure sites implement mitigation measures (e.g., retrofitting, land-use
restrictions) within five years of map publication.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-57
20.7.17 Expanding Roadway Access to Isolated Communities in
Unincorporated King County
Lead
DLS -Roads
Fire Districts
Partners
KCOEM
Eastside Fire and Rescue
Hazards Mitigated
Wildfire
Extreme Weather
Funding Sources and
Estimated Costs
Existing Budget/BRIC/HMA
Grants
Vision
To ensure that isolated communities in unincorporated King County have reliable and safe access routes for
evacuation and emergency response, particularly during wildfire events and power outages. This strategy aims to
enhance community resilience and improve public safety by reducing the risk of isolation during extreme events.
Description
Many isolated communities in unincorporated King County are vulnerable to wildfires and power outages due to
limited or poorly maintained access roads. These roadways are crucial not only for evacuation but also for the
delivery of essential services and the ability of emergency responders to reach affected areas. This strategy focuses
on improving and expanding roadway access to these communities, ensuring that critical infrastructure can
withstand and respond effectively to the challenges posed by wildfires, storms, and other natural disasters.
Key actions include road upgrades, clearing vegetation to create defensible spaces, and building alternative routes to
avoid blocked roads during emergencies. The project will focus on both short-term improvements (such as road
widening, emergency turnouts, and vegetation management) and long-term efforts (such as permanent road
upgrades and redundancy in evacuation routes).
2-Year Objectives
• Conduct a comprehensive
assessment of road access to all
isolated communities in
unincorporated King County,
identifying the most critical and
vulnerable areas.
• Prioritize roadways in high-risk
wildfire zones and areas with limited
access to power grid infrastructure.
• Initiate vegetation management and
clearance along key roads to
improve accessibility during wildfire
events and storms.
• Establish agreements with fire
districts, emergency medical
services, and utility companies to
facilitate coordinated response
efforts during emergencies.
5-Year Objectives
• Complete roadway upgrades (e.g.,
widening, resurfacing) for the
highest-priority access routes to
isolated communities, focusing on
fire-prone and remote areas.
• Develop alternative evacuation
routes in at least 50% of identified
communities to reduce the risk of
blockage from wildfire or flooding.
• Improve road resilience by
reinforcing infrastructure (e.g.,
reinforcing bridges, culverts, and
other critical structures) to
withstand extreme weather events
and wildfire risks.
• Complete community engagement
efforts to inform residents about
emergency preparedness,
evacuation plans, and available
access routes.
Long-Term Objectives
• Achieve 100% access to
all identified isolated
communities with
multiple, resilient, and
well-maintained
evacuation routes that
are safe during wildfire,
storms, and power
outages.
• Ensure that all access
routes are equipped with
necessary emergency
signage, lighting, and
traffic management
systems for easy
navigation during crises.
• Fully integrate the road
access improvements
with the King County
Emergency Response Plan
to ensure coordination
between first responders,
residents, and emergency
services.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
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• Secure long-term funding
and partnerships to
maintain roadways,
manage vegetation, and
ensure consistent access
for emergency response
and recovery efforts.
Implementation Plan/Actions
Initial Roadway Assessment & Community Engagement:
• Complete a detailed analysis of current road conditions, identifying high-risk areas for wildfire or power
outages.
• Consult with community members to understand local challenges and needs regarding road access and
emergency response.
• Establish a prioritization framework for addressing the most urgent areas based on risk, accessibility, and
population density.
Roadway Improvements:
• Begin widening key roads, particularly those serving remote areas, to allow for easier access for emergency
vehicles, evacuation traffic, and utility crews.
• Install emergency turnouts, pull-offs, and strategic points for firefighting vehicles to ensure better response
times and safety.
• Implement firebreaks and vegetation management along critical access roads to reduce the risk of road
blockage due to wildfires or fallen trees.
• Improve road signage, emergency markers, and reflective materials to aid nighttime navigation during
power outages or smoke-filled conditions.
Develop Alternative Routes:
• Identify and design secondary or backup evacuation routes that could be used if primary roads are
compromised by wildfires, flooding, or other events.
• Construct or upgrade bridges, culverts, and other critical infrastructure to improve the durability of these
alternative routes.
• Work with landowners and local stakeholders to secure rights-of-way and easements for new roads or
alternate routes.
Coordination with Emergency Services:
• Work with local fire districts, emergency medical services (EMS), and law enforcement to create
coordinated evacuation plans and response protocols.
• Train community members and emergency responders on the new road access options and the routes for
evacuations.
• Establish communication protocols for when roads become impassable or when alternative routes are
needed during a crisis.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-59
Maintenance and Long-Term Sustainability:
• Develop a long-term plan for maintaining and upgrading roadways, including regular vegetation
management, pothole repairs, and culvert maintenance.
• Seek federal, state, and local funding sources to sustain roadway improvements and ensure continued
access for both regular use and during emergencies.
• Monitor changes in climate and infrastructure to adapt the roadway network to future challenges, such as
more frequent wildfires or heavier storm events.
Performance Measure
• Improvement in Access and Evacuation Times: Measure the reduction in evacuation times and the ability of
emergency responders to reach isolated communities compared to baseline data.
• Road Condition Assessment: Track improvements in the physical condition of roads, including road width,
surface quality, and clearance levels for wildfire defense and emergency access.
• Community Feedback and Engagement: Monitor community satisfaction through surveys to assess the
effectiveness of the improvements and how well residents understand and use the new access routes.
• Emergency Response Metrics: Measure the response times of fire, medical, and utility services to the upgraded
areas, comparing pre- and post-upgrade metrics.
• Frequency of Road Closures and Access Denials: Track the reduction in instances of blocked or impassable
roads during wildfire and storm events.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-60
20.7.18 HVAC Upgrades for Extreme Weather
Lead
FMD
PHSKC
Partners
KCOEM
Hazards Mitigated
Extreme Weather
Funding Sources and
Estimated Costs
BRIC/FEMA/WAEMD
Vision
To enhance the resilience of King County facilities to extreme weather events by upgrading HVAC systems to ensure
reliable temperature control, air quality, and energy efficiency, safeguarding public health and infrastructure, while
reducing long-term operational costs.
Description
The purpose of this hazard mitigation strategy is to ensure that King County’s facilities are equipped with HVAC
systems that can effectively handle extreme weather conditions. These upgrades will address the increasing
frequency of heatwaves, cold snaps, wildfires, and other weather-related events that can disrupt normal operations
and threaten the safety and comfort of occupants.
These improvements include the installation of climate-resilient systems capable of maintaining optimal indoor
conditions, even during power outages or extreme environmental conditions. The strategy will involve the
integration of smart HVAC technologies, renewable energy sources (solar, battery storage), and emergency air
filtration systems to protect public health in the event of poor outdoor air quality.
2-Year Objectives
• Conduct a comprehensive audit of
all King County facilities’ HVAC
systems to assess current
vulnerabilities to extreme weather
conditions.
• Prioritize facilities based on usage,
vulnerability to climate risks, and
the population served, focusing on
high-risk areas first.
• Implement immediate upgrades to
HVAC systems in high-priority
facilities (e.g., public health centers,
emergency shelters, senior housing).
• Establish a task force to evaluate
HVAC system designs, incorporating
energy efficiency, sustainability, and
climate adaptability.
5-Year Objectives
• Complete HVAC system upgrades
for at least 75% of all county
facilities in high-risk areas,
including smart thermostats,
emergency power backup, and air
filtration systems.
• Install renewable energy-powered
HVAC units or integrate battery
storage systems in at least 30% of
King County facilities.
• Improve air quality monitoring
systems and ensure that HVAC
systems can filter out smoke and
pollutants from wildfire events in
all key facilities.
• Develop a county-wide emergency
HVAC operations plan for use
during extreme weather events or
power outages.
Long-Term Objectives
• Achieve 100% HVAC
system resilience in all
King County facilities,
with real-time monitoring
and automatic
adjustments for extreme
weather.
• Reduce the county's
carbon footprint from
HVAC operations by 40%
through sustainable
energy solutions, such as
solar and geothermal
systems.
• Establish King County as a
regional model for
climate-resilient public
infrastructure, with HVAC
systems that are
adaptable, energy-
efficient, and
environmentally
sustainable.
• Integrate HVAC resilience
into broader climate
adaptation strategies for
King County.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-61
Implementation Plan/Actions
1. HVAC System Audit:
o Conduct detailed assessments of all existing HVAC systems in King County facilities to determine
areas of improvement.
o Identify facilities at highest risk based on location, function, and building age.
o Establish a baseline for energy use, HVAC system age, and vulnerabilities.
2. System Design & Selection:
o Research and select HVAC technologies that provide optimal resilience for extreme temperatures,
air quality, and energy efficiency.
o Focus on systems that are capable of utilizing renewable energy sources, especially solar or wind
power, where feasible.
o Develop a comprehensive retrofit plan for each facility based on audit findings.
3. Upgrade Implementation:
o Begin upgrades in facilities with the greatest immediate need, such as hospitals, shelters, senior
centers, and community hubs.
o Install smart thermostats, backup power solutions (battery storage), and high-efficiency filters.
o Include systems that can adjust to extreme weather patterns (e.g., high heat or low temperatures).
4. Staff Training & Emergency Planning:
o Train maintenance staff and facility managers in HVAC system operation and emergency protocols.
o Develop standard operating procedures (SOPs) for HVAC systems during power outages or extreme
weather.
o Integrate HVAC operations into King County’s broader emergency response plans.
5. Public Engagement & Communication:
o Provide community outreach regarding HVAC improvements, focusing on vulnerable populations
that may be affected by extreme weather events (e.g., seniors, low-income residents).
o Ensure all facility occupants are informed of HVAC system changes, particularly in terms of air
quality and temperature regulation during emergencies.
Performance Measure
• HVAC system performance during extreme weather events: Measure the ability of upgraded systems to
maintain comfortable and safe indoor environments during heatwaves, cold spells, or power outages.
• Energy savings and sustainability metrics: Track reductions in energy consumption and carbon footprint in
facilities with upgraded HVAC systems.
• Public health outcomes: Monitor the incidence of heat-related illnesses, respiratory issues due to poor air
quality, and other health impacts before and after HVAC upgrades.
• Completion rates for HVAC system upgrades: Measure the percentage of King County facilities with upgraded
HVAC systems over the 2-year, 5-year, and long-term objectives.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-62
20.7.19 KC Zone Program
Lead
KCOEM
Partners
Zone 1 & 3 Partner jurisdiction
and special purpose districts
and unincorporated county.
Hazards Mitigated:
Avalanche
Civil Disorder
Cyber Incident
Dam Failure
Earthquake
Flood
Hazardous Materials
Health Incident
Landslide
Extreme Weather
Terrorism
Tsunami
Volcano
Wildfire
Funding Sources and
Estimated Costs
~$220k
Vision
Overall, the role of the Zone Liaison is to promote, support, and facilitate regional coordination, communication,
and collaboration, in an effort to unify and/or connect region-wide emergency management practices, with the aim
of maximizing benefits from individual efforts and reducing redundancies.
Description
The focus of these regional efforts will be developed in partnership with King County Emergency Management and
the zone partners, with input and advice from the Regional Emergency Managers group (the designated emergency
manager for each city) and the Emergency Management Advisory Committee (EMAC).
2-Year Objectives
• By the end of two years, the Zone
Liaison will have achieved 75%
participation in monthly meetings
with all zone agencies, facilitated
the completion of at least 24 zone-
wide meetings, and supported six
regional training or exercise
initiatives. The Zone Liaison will also
ensure timely situational updates
and emergency activation
responses, improving regional
coordination and preparedness
outcomes.
5-Year Objectives
• Within five years, the Zone Liaison
will have established a robust
network of engaged zone partners,
evidenced by 85% compliance with
meeting and training objectives,
and increased participation in
preparedness initiatives across all
partner agencies. This effort will
enhance regional emergency
management capabilities and
ensure seamless collaboration
during emergencies and planned
events.
Long-Term Objectives
• The Zone Liaison will
serve as a cornerstone for
sustainable regional
emergency management
practices, fostering
enduring partnerships
and achieving measurable
improvements in
preparedness and
operational readiness
across all mission areas.
Through consistent
leadership and
innovation, the Zone
Liaison will help create a
unified, resilient region
capable of addressing
evolving threats and
challenges
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
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Implementation Plan/Actions
• Facilitate Regional Coordination: Represent zone partners' interests at regional and state emergency
management events, ensuring their needs and concerns are addressed in work plans and capability
assessments.
• Maintain Situational Awareness: Regularly collect and distribute updates on training, exercises, planning
efforts, and operational issues to King County Emergency Management and regional partners.
• Strengthen Relationships: Meet individually with each zone agency and organization monthly to foster
collaboration, mentorship, and stakeholder engagement in preparedness efforts.
• Lead Preparedness Initiatives: Organize and facilitate monthly zone-wide meetings, lead training and
exercise programs, and assist in the development of plans, policies, and tools to enhance regional
capabilities.
• Support Emergency Operations: Act as a liaison during emergencies, ensuring effective communication and
coordination between the zone, King County Emergency Management, and other partners.
Performance Measure
Facilitate Regional Coordination:
• Measure: Attend at least 90% of regional and state emergency management events and meetings annually.
• Measure: Submit quarterly reports demonstrating how zone partner needs and concerns are incorporated
into regional work plans and capability assessments.
Maintain Situational Awareness:
• Measure: Provide at least biweekly situational awareness updates to King County Emergency Management,
including information on training, exercises, and operational issues.
• Measure: Ensure situational updates are shared with all zone partners within 48 hours of receiving new
information relevant to the region.
Strengthen Relationships:
• Measure: Conduct one-on-one meetings with at least 95% of zone agencies and organizations each month.
• Measure: Provide feedback from zone partners during quarterly reviews to demonstrate active engagement
and relationship-building.
Lead Preparedness Initiatives:
• Measure: Organize and facilitate 12 monthly zone-wide meetings annually, with attendance from at least
80% of zone partners at each meeting.
• Measure: Lead or support at least three training sessions, exercises, or plan development initiatives per
quarter, with participation from multiple zone partners.
Support Emergency Operations:
• Measure: Respond to emergency activation requests within one hour, with a 100% response rate during
activated events.
• Measure: Provide a post-event report for each incident or event within 72 hours of its conclusion, highlighting
actions taken and outcomes achieved.
20.7.20 Actively Manage Network Devices and Software
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-64
Lead
KCIT
Partners
King County Risk Management
Hazards Mitigated
Cyber Incident
Funding Sources and
Estimated Costs
General Fund
Vision
To establish a secure, streamlined, and adaptive IT environment within King County by actively managing network
devices and software. Starting with a controlled, known baseline, King County will minimize attack surfaces and
enhance its ability to adapt to dynamic cybersecurity threats.
Description
This strategy involves conducting a thorough inventory of all network devices and software within King County’s IT
infrastructure. By identifying and removing unwanted, unneeded, or unexpected hardware and software, King
County will significantly reduce its network's attack surface. Starting from a clean, known baseline allows for better
control over the operational environment, making it easier to identify and mitigate security threats.
Once the inventory is complete, ongoing active management will be key. This includes managing devices,
applications, operating systems, and security configurations to ensure systems are secure, scalable, and adaptable.
Active enterprise management enables King County to respond effectively to emerging threats while streamlining
administrative tasks and optimizing resource allocation.
2-Year Objectives
• Complete a comprehensive
inventory of all devices and software
across King County’s IT
environment.
• Remove at least 90% of unwanted,
unneeded, or unexpected devices
and software from the network.
• Establish a baseline configuration for
devices, applications, and security
settings.
• Implement a centralized
management system to actively
monitor and manage network
devices and software.
• Conduct regular audits to ensure
compliance with the inventory and
management processes.
5-Year Objectives
• Achieve 100% accuracy in the
inventory of devices and software
across King County.
• Fully integrate centralized
management tools across all
departments to streamline
operations and improve response
times.
• Establish continuous monitoring
systems for identifying and
responding to changes or additions
to the network that may introduce
risks.
• Reduce the number of security
incidents related to unpatched
software and unauthorized devices
by at least 75%.
Long-Term Objectives
• Create a dynamic,
scalable IT environment
where all devices and
software are continuously
tracked, and the system
automatically adapts to
new threats.
• Foster a culture of
security awareness across
all King County
departments, where all
personnel actively
contribute to maintaining
secure and controlled IT
operations.
• Achieve and maintain
cybersecurity compliance
with local, state, and
federal regulations,
particularly in areas
related to system
configuration and device
management.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-65
Implementation Plan/Actions
Conduct an Inventory of Network Devices and Software
• Utilize automated inventory management tools to catalog all devices, applications, and software currently
in use across King County’s network.
• Work with department heads to ensure all devices and software are accounted for and included in the
inventory.
Remove Unwanted or Unnecessary Devices and Software
• Identify and eliminate any unauthorized or redundant devices and software that do not contribute to
operational needs or security.
• Develop a decommissioning process for safely removing these devices from the network.
Establish a Known Baseline for Security Configurations
• Define and document a standard baseline for security configurations across devices, operating systems, and
applications.
• Apply these configurations uniformly across all departments to ensure consistency.
Implement Centralized Management and Monitoring Systems
• Deploy centralized tools for managing and monitoring the security configurations of devices and software.
• Integrate these tools with existing cybersecurity measures for enhanced visibility and control.
Ongoing Active Management and Adaptation
• Continuously monitor and manage network devices, applications, and security configurations to ensure they
remain secure and up-to-date.
• Adapt the management practices to address emerging threats and scale with changing needs.
Regular Audits and Compliance Checks
• Conduct periodic audits to ensure compliance with the inventory and active management protocols.
• Address any discrepancies or gaps identified during audits to maintain a secure environment.
Performance Measure
• Inventory Accuracy: Percentage of devices and software accurately inventoried and tracked within the
system.
• Reduction in Unauthorized Devices/Software: Percentage reduction in unapproved or unnecessary devices
and software on the network.
• Compliance with Baseline Configurations: Percentage of devices and systems configured according to the
defined security baseline.
• Incident Reduction: Reduction in the number of security incidents linked to unauthorized devices, software
vulnerabilities, or misconfigurations.
• Audit Compliance: Results of regular audits showing adherence to inventory and management policies.
• Management Tool Integration: Percentage of departments using centralized management and monitoring
tools for device and software management.
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20.7.21 Multi-Factor Authorization for King County Devices
Lead
KCIT
Partners
King County Risk Management
Hazards Mitigated
Cyber Incident
Funding Sources and
Estimated Costs
General Fund
Vision
To strengthen King County’s cybersecurity posture by prioritizing the protection of accounts with elevated privileges,
remote access, and high-value assets through the adoption of multi-factor authentication (MFA) and the reduction
of reliance on single-factor authentication systems.
Description
This strategy focuses on enhancing authentication security across King County’s IT systems, particularly for high-risk
accounts, including those with elevated privileges, remote access, and access to critical or sensitive assets. Single-
factor authentication (SFA), such as password-based authentication, is vulnerable to a variety of threats, including
credential theft, phishing attacks, and password reuse across systems.
To mitigate these risks, King County will implement multi-factor authentication (MFA) with a focus on using physical
token-based systems (e.g., smart cards, hardware tokens) to supplement knowledge-based factors such as
passwords and PINs. This will significantly reduce the chances of unauthorized access, ensuring that even if a
password is compromised, access to sensitive systems and data remains secure.
The migration away from single-factor authentication to MFA will prioritize accounts that pose the highest risks,
including administrative accounts, remote access accounts, and those tied to high-value assets.
2-Year Objectives
• Implement multi-factor
authentication (MFA) for all
accounts with elevated privileges or
remote access within the first year.
• Complete a risk assessment to
identify high-value assets and
systems requiring immediate
implementation of MFA.
• Provide training for all IT staff and
administrators on the secure use of
MFA systems.
5-Year Objectives
• Achieve 100% deployment of MFA
across all user accounts with
elevated privileges, remote access,
and high-value assets.
• Phase out the use of single-factor
authentication across all non-
administrative accounts.
• Achieve a reduction in
unauthorized access attempts and
cyber incidents linked to credential
theft by at least 75%.
• Ensure compliance with federal
and state cybersecurity standards
and regulations for authentication
systems.
Long-Term Objectives
• Establish King County as a
leader in cybersecurity
best practices, with MFA
fully integrated across all
IT systems and user
access points.
• Continuously evaluate
and update
authentication methods
as new technologies and
best practices emerge,
maintaining the highest
level of security.
• Foster a cybersecurity-
aware culture across King
County where secure
authentication practices
are the norm.
Implementation Plan/Actions
1. Identify High-Risk Accounts and Systems
o Conduct a comprehensive audit of King County IT systems to identify accounts with elevated
privileges, remote access, and access to high-value assets.
o Prioritize MFA implementation for these accounts based on their associated risks.
2. Deploy Multi-Factor Authentication (MFA)
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o Select and implement physical token-based MFA systems (e.g., hardware tokens, smart cards,
biometric systems) for high-risk accounts.
o Integrate MFA with existing authentication systems across King County’s IT infrastructure.
3. Migrate Away from Single-Factor Authentication (SFA)
o Gradually phase out single-factor authentication for non-administrative accounts, replacing them
with MFA systems.
o Provide clear timelines and training for all staff members transitioning to MFA.
4. Training and Awareness
o Provide training sessions for all relevant King County staff on the importance of MFA and how to
use the new systems effectively.
o Increase awareness of common authentication risks, such as phishing and password reuse, and
educate staff on avoiding them.
5. Ongoing Monitoring and Evaluation
o Continuously monitor the effectiveness of MFA deployment, tracking system usage and incidents
related to authentication breaches.
o Regularly evaluate and update MFA protocols to keep pace with emerging threats and new
technologies.
Performance Measure
• MFA Deployment: Percentage of high-risk accounts protected by MFA.
• Reduction in Breaches: Reduction in the number of unauthorized access incidents due to credential theft or
misuse.
• Staff Training: Percentage of relevant IT staff and users who have completed MFA training and are actively using
MFA.
• Compliance Rate: Percentage of King County systems compliant with the updated MFA policies.
• Incident Monitoring: Number of cybersecurity incidents linked to authentication vulnerabilities after MFA
implementation.
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20.7.22 Timely Software Updates from KCIT
Lead
KCIT
Partners
King County Risk Management
Hazards Mitigated
Cyber Incident
Funding Sources and
Estimated Costs
KCIT Budget
Vision
To ensure King County’s IT systems remain secure and resilient by applying all available software updates
immediately, automating the update process wherever possible, and maintaining a high level of vigilance against
threats, reducing the risk of exploitations and ensuring the integrity of county systems
Description
This strategy aims to implement a robust software update and patch management process to protect King County’s
IT systems from vulnerabilities. Cybersecurity threats, especially those related to unpatched software, are a
significant risk to public safety and data security. Threat actors often take advantage of delays in patching, using
exploits shortly after a patch is released—referred to as N-day exploits. The strategy emphasizes the importance of
rapid, thorough software updates, using automation tools to ensure timely application of patches, and relying on
authenticated vendor updates delivered through secure channels.
By automating the patching process and ensuring updates are applied promptly, King County will reduce the time
available for threat actors to exploit vulnerabilities, thereby minimizing the risk of breaches or system failures.
2-Year Objectives
• Implement an automated patch
management system across all
critical King County IT systems.
• Apply 100% of available software
updates within 24 hours of release,
reducing patch application times
significantly.
• Establish an authentication
verification process for all vendor-
provided software updates to
ensure integrity.
• Conduct quarterly internal audits to
assess the effectiveness of patch
management.
5-Year Objectives
• Ensure that 100% of all county-
wide systems are covered by the
automated patch management
system.
• Achieve a reduction in cyber
incidents related to unpatched
software vulnerabilities by 75%.
• Partner with vendors to streamline
update delivery processes and
integrate further security
measures into patching protocols.
• Regularly update training for IT
staff on the latest patch
management tools and security
trends.
Long-Term Objectives
• Establish King County as a
leader in cybersecurity
resilience within local
government by ensuring
all software systems are
continuously updated and
secure.
• Create a dynamic
cybersecurity culture
across King County
departments, where
proactive patching and
security measures are
ingrained in daily
operations.
• Achieve zero successful
exploitation of known
vulnerabilities in County
systems within 12 months
of patch release.
Implementation Plan/Actions
Automate Software Updates
• Deploy patch management automation tools to ensure all critical systems automatically receive and apply
updates.
• Work with key departments to ensure integration of automated patching into day-to-day IT operations.
Vendor Coordination and Authentication
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• Set up a system to only accept vendor updates that are signed and transmitted over secure channels,
ensuring the integrity of all patches.
• Work with vendors to streamline update delivery and verify authenticity of updates.
Patch Cycle Management
• Create and enforce a policy that software patches are applied within 24 hours of release for critical
vulnerabilities.
• Develop a detailed patching calendar that aligns with known release cycles of major software vendors.
Monitoring and Reporting
• Monitor the status of updates across all systems and ensure compliance with patching timelines.
• Implement dashboards and alerts for IT staff to track update status in real-time.
Training and Awareness
• Provide continuous training for IT staff on best practices for patch management and cybersecurity.
• Raise awareness across departments about the importance of timely software updates.
Performance Measure
• Patch Application Speed: Percentage of software patches applied within 24 hours of release.
• Automation Coverage: Percentage of IT systems covered by the automated patch management system.
• Incident Reduction: Reduction in the number of cybersecurity incidents related to known unpatched
vulnerabilities.
• Audit Results: Results of quarterly patch management audits, measuring compliance and effectiveness.
• Staff Training: Number of IT staff trained on patch management best practices and tools.
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20.7.23 Creation of County Wide Recovery Plan
Lead
KCOEM
Partners
DNRP
PHSKC
ECO
FEMA
Hazards Mitigated
Avalanche
Civil Disorder
Cyber Incident
Dam Failure
Earthquake
Flood
Hazardous Materials
Health Incident
Landslide
Extreme Weather
Terrorism
Tsunami
Volcano
Wildfire
Funding Sources and
Estimated Costs
General Fund
Vision
To create a comprehensive, resilient, and flexible county-wide recovery plan that effectively addresses the unique
needs of all communities in King County, ensuring a swift and equitable recovery process after disasters. This plan
will integrate community needs, enhance preparedness, and optimize resource allocation, providing clear guidance
for a seamless recovery effort.
Description
The goal of this strategy is to update and enhance King County’s County-Wide Recovery Plan, ensuring that it reflects
current risks, best practices, and lessons learned from past disasters. The plan will improve the coordination
between local municipalities, agencies, and partners, integrating the entire county into the recovery process. It will
focus on an equitable, community-driven recovery approach, with particular attention given to vulnerable and
underserved populations.
The updated plan will address key areas of recovery, such as housing, public health, infrastructure, utilities, and
economic recovery, providing specific action items, timelines, and responsibilities. Additionally, the plan will be
flexible to accommodate different types and scales of disasters, ensuring that King County can respond effectively to
both common and rare events.
2-Year Objectives
• Complete a comprehensive review
of the current recovery plan and
identify gaps or outdated sections.
• Engage with at least 15 community
organizations to incorporate their
perspectives into the updated plan.
• Conduct a series of public
workshops and stakeholder
meetings to gather input and
feedback from King County residents
and local leaders.
5-Year Objectives
• Fully integrate recovery planning
with King County’s hazard
mitigation strategies.
• Establish a coordinated recovery
task force composed of key
agencies, local governments, and
community representatives.
• Develop a county-wide recovery
resource network, including
logistics, supplies, and personnel,
that can be quickly activated
during an emergency.
Long-Term Objectives
• Achieve a recovery plan
that is adaptable,
scalable, and inclusive,
with a focus on the most
vulnerable populations
and critical infrastructure.
• Ensure that King County’s
recovery processes are
fully integrated with state
and federal systems,
enabling swift resource
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• Develop and implement an updated
recovery framework with clear
action steps for each recovery phase
(immediate, short-term, long-term).
• Update the recovery plan to reflect
new hazards, such as climate
change-related events, and new
recovery needs, such as mental
health and economic recovery.
• Implement a training program for
recovery personnel across King
County, ensuring readiness for all
disaster recovery phases.
• Conduct a large-scale recovery
exercise with local municipalities
to test the updated plan’s
effectiveness.
allocation and
coordination.
• Foster a culture of
continuous improvement
through annual updates,
community engagement,
and post-disaster reviews.
• Create a recovery plan
that is recognized as a
model for other counties
across the state or region,
with lessons learned
shared widely.
Implementation Plan/Actions
Comprehensive Review and Assessment
• Conduct a detailed review of the current county-wide recovery plan.
• Identify areas where the plan is outdated, insufficient, or needs to be enhanced based on emerging threats
(e.g., climate change).
• Engage emergency management experts, local municipalities, and community stakeholders to evaluate the
plan’s effectiveness.
Community and Stakeholder Engagement
• Host public workshops and focus groups to solicit feedback on the recovery plan from residents, local
businesses, and community organizations.
• Collaborate with vulnerable communities to ensure the plan reflects their specific needs and concerns
during recovery.
• Build partnerships with local utilities, transportation authorities, and non-profit groups to understand their
recovery roles and challenges.
Plan Update and Enhancement
• Revise and update the recovery plan with current data, guidelines, and best practices for disaster recovery.
• Create clear, actionable steps for recovery in critical areas such as housing, public health, economic
recovery, and infrastructure restoration.
• Integrate recovery strategies into King County’s overall emergency management framework, linking
recovery efforts to mitigation and preparedness activities.
Training and Capacity Building
• Develop training materials and exercises for county staff, recovery personnel, and partners, focusing on
roles and responsibilities during recovery.
• Conduct workshops and simulations to test the effectiveness of the new recovery plan.
• Build a recovery team within KCOEM and local municipalities that will be ready to implement the plan in the
aftermath of a disaster.
Testing and Drills
• Conduct multi-agency recovery exercises to simulate a real disaster recovery scenario.
• Identify any weaknesses or challenges in the recovery process and refine the plan accordingly.
• Ensure all recovery partners are well-versed in the plan’s procedures and their individual responsibilities.
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Performance Measure
• Plan Completion: Percentage of recovery plan sections updated and reviewed (e.g., housing, infrastructure,
health).
• Stakeholder Engagement: Number of community members, organizations, and agencies engaged in the
planning process.
• Training Participation: Number of recovery personnel trained on the new recovery framework.
• Recovery Exercises: Successful completion of recovery drills and exercises, with identified improvements
incorporated into the plan.
• Plan Activation Time: Time taken to activate and implement the recovery plan after a disaster.
• Post-Disaster Evaluation: Feedback from the community and stakeholders on the recovery process, assessing
satisfaction and areas for improvement
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20.7.24 Wastewater Treatment Division Workforce Development
Program
Lead
DNRP – WTD
Partners
Local partners
Hazards Mitigated
Extreme Weather
Funding Sources and
Estimated Costs
King County Budget
Vision
To create a sustainable and diverse workforce for the clean water sector by providing comprehensive recruitment,
mentorship, training, and career growth opportunities to entry-level candidates. The program ensures that
individuals are equipped with the skills and knowledge necessary to thrive in the wastewater treatment industry
while contributing to a more equitable and inclusive workforce
Description
WTD’s Workforce Development Program focuses on recruiting, training, mentoring, and placing entry-level
candidates into long-term careers in the clean water sector. The program supports individuals who are either
building their skills or are new to the field by providing them with hands-on experience, site visits, and challenging
assignments across different WTD work groups. Cohort members are hired in small groups and exposed to various
areas within WTD, such as planning, engineering, project management, and construction management. The
program’s goal is to help individuals discover their passion and secure permanent positions within the organization.
After completing the program, cohort members are encouraged to apply for open positions within WTD and will
have an advantage due to their familiarity with the agency’s operations and culture. Graduates typically transition
smoothly into roles across different units, such as planning, engineering, and project management, and contribute to
WTD's diverse workforce.
2-Year Objectives
• Recruit and onboard 4 to 8 new
cohorts of entry-level candidates
each year.
• Place 70% of cohort members into
permanent positions within WTD by
the end of their program.
• Increase the diversity of the
applicant pool by 20%.
• Develop and implement mentorship
programs for cohort members to
support career growth.
5-Year Objectives
• Expand the program to include
additional work groups within
WTD, such as operations and
maintenance.
• Achieve a 90% placement rate of
cohort members into permanent
positions within WTD.
• Ensure that 40% of cohort
graduates come from
underrepresented communities in
the clean water sector.
• Develop partnerships with
community colleges to offer
accredited certifications in
wastewater treatment for cohort
members.
Long-Term Objectives
• Establish WTD’s
Workforce Development
Program as a national
model for clean water
sector career training and
inclusion.
• Fully integrate workforce
development initiatives
into WTD’s long-term
staffing and succession
planning strategies.
• Ensure that all cohorts
reflect the demographic
diversity of King County
and are prepared to meet
the future workforce
needs of the clean water
industry.
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Implementation Plan/Actions
Recruitment and Onboarding
• Launch targeted recruitment campaigns to attract entry-level candidates, especially from diverse and
underserved communities.
• Provide extensive onboarding that includes tours of WTD facilities, introductions to various teams, and
detailed orientation sessions.
• Organize site visits and team rotations for cohorts to gain exposure to different work groups within WTD.
Mentorship and Career Support
• Assign mentors to cohort members to guide them through their training and career development within
WTD.
• Offer regular check-ins and professional development workshops to help individuals progress in their
careers.
• Facilitate peer networking and collaboration opportunities within the cohort and across different WTD
teams.
Training and Skill Development
• Provide cohort members with challenging, hands-on assignments that build relevant skills in areas such as
engineering, project management, and construction.
• Offer continuous learning opportunities such as online courses, certification programs, and technical
training to enhance career readiness.
Placement and Retention
• Actively track the progress of cohort members toward securing permanent roles within WTD.
• Create a streamlined internal application process for cohort members to apply for open positions within the
agency.
• Maintain a strong relationship with graduates and provide ongoing support to ensure retention in the clean
water sector
Performance Measure
• Cohort Success Rate: Percentage of cohort members successfully placed in permanent roles within WTD.
• Diversity Metrics: Increase in the diversity of cohort participants, including gender, race, and background.
• Program Retention: Retention rates of cohort members within WTD, measured over a 2- and 5-year period.
• Graduation Rates: Percentage of cohort members completing the program and transitioning into desired roles.
Employee Satisfaction: Cohort members’ satisfaction with mentorship, training, and career growth
opportunities (survey results).
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20.7.25 King Conservation District Wildfire Mitigation Program
Lead
King Conservation
District (KCD)
Partners
Eastside Fire and Rescue
DNRP
Hazards Mitigated
Wildfire
Funding Sources and
Estimated Costs
KCD Budget
Vision
To reduce the risk of wildfire damage to homes and communities in King County, especially in the Wildland Urban
Interface (WUI), through proactive risk assessments, strategic wildfire mitigation projects, and collaborative efforts
aimed at enhancing community resilience.
Description
The King Conservation District’s (KCD) Wildfire Mitigation Program provides wildfire risk assessments and mitigation
planning to increase community resilience against wildfires. KCD partners with local fire districts, the Washington
State Department of Natural Resources, and other organizations to assist homeowners and communities in the
Wildland Urban Interface (WUI). By assessing properties, providing mitigation recommendations, and offering cost-
share funding for implementation, KCD helps reduce wildfire risk and prepare areas vulnerable to wildfire events.
KCD conducts individual and community-wide risk assessments, focusing on practical steps such as vegetation
removal, roof maintenance, and forest health improvement. Through funding and planning assistance, KCD supports
homeowners and communities to take preventative actions, including thinning, fuel management, and creating
defensible spaces.
2-Year Objectives
• Complete 200 wildfire risk
assessments in King County,
focusing on homes and communities
within the WUI.
• Begin 50 wildfire mitigation projects,
providing cost-share funding for
eligible homeowners and
communities.
• Engage at least 10 community
organizations to help expand
wildfire mitigation outreach.
5-Year Objectives
• Complete 500+ wildfire risk
assessments across King County’s
high-risk wildfire zones.
• Successfully implement wildfire
mitigation projects on 200
properties and community-owned
forests.
• Achieve a 25% reduction in wildfire
risk within assessed areas as
measured by post-project
assessments.
Long-Term Objectives
• Establish wildfire
mitigation as a key part of
all residential and
community planning in
King County.
• Ensure that all homes and
communities in the WUI
have access to wildfire
risk assessments and
mitigation resources.
• Strengthen public-private
partnerships to enhance
wildfire resilience through
expanded cost-share and
technical assistance
programs.
Implementation Plan/Actions
Wildfire Risk Assessments
• Conduct individual and community-wide assessments within the WUI.
• Focus on the 100-foot defensible space around each home and forest health assessments for community-
owned forests.
• Provide homeowners and community associations with a list of mitigation recommendations based on the
assessments.
Wildfire Mitigation Project Planning and Cost-Share
• Offer project planning assistance to homeowners and community associations.
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• Provide cost-share funding, reimbursing 75% of eligible project costs for activities such as vegetation
removal, gutter/roof maintenance, and fire break creation.
• Prioritize funding for projects that reduce wildfire risk to homes and improve community resilience.
Outreach and Community Engagement
• Develop and distribute informational materials to educate residents about wildfire risks and mitigation
actions.
• Collaborate with local fire districts, the Red Cross, and other partners to reach underserved and at-risk
populations.
• Host workshops and training sessions on wildfire preparedness and mitigation strategies.
Forest Health and Fuel Management Projects
• In community-owned forests, assess forest health and implement projects such as thinning, brush
management, and fuel breaks.
• Work with local agencies and fire districts to coordinate larger-scale mitigation projects that benefit
multiple properties and forested areas.
Performance Measure
• Risk Assessment Completion: Number of wildfire risk assessments completed annually.
• Mitigation Projects: Number of mitigation projects funded and successfully implemented.
• Community Engagement: Level of participation in outreach efforts (workshops, surveys, etc.).
• Impact on Wildfire Risk: Percentage reduction in wildfire risk within the targeted areas as measured through
post-implementation evaluations.
• Cost-Share Utilization: Amount of cost-share funding distributed, and the number of households/communities
receiving support.
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20.7.26 Improving Emergency Management Public Outreach
Lead
KCOEM
Partners
Local jurisdictions within the
county
Hazards Mitigated
Avalanche
Civil Disorder
Cyber Incident
Dam Failure
Earthquake
Flood
Hazardous Materials
Health Incident
Landslide
Extreme Weather
Terrorism
Tsunami
Volcano
Wildfire
Funding Sources and
Estimated Costs
King County Budget
Vision
To ensure that all residents of King County are well-informed and prepared to effectively respond to and mitigate
the impacts of hazards, through comprehensive and targeted public outreach strategies. By enhancing public
awareness and providing accessible resources, we aim to reduce vulnerability and improve community resilience.
Description
The King County Office of Emergency Management seeks to improve its public outreach efforts to raise awareness
about local hazards, promote preparedness actions, and encourage mitigation strategies. By using a combination of
media, community partnerships, educational initiatives, and social engagement, the strategy will ensure that
residents of all backgrounds understand the risks they face and how to reduce them. This outreach initiative will
focus on diverse communities, ensuring inclusivity and accessibility to the county's mitigation programs.
2-Year Objectives
• Increase public engagement through
digital campaigns and social media
platforms.
• Develop partnerships with 10 new
community organizations to amplify
hazard mitigation messaging.
• Conduct 5 community
preparedness workshops targeting
underserved populations.
5-Year Objectives
• Establish a countywide public
education program integrated with
schools, community centers, and
local businesses.
• Increase public awareness about
hazard mitigation by 30% as
measured through surveys.
• Implement a mobile application
for hazard alerts and mitigation
resources.
• Achieve a 15% increase in the
adoption of preparedness plans
among residents and businesses in
King County.
Long-Term Objectives
• Create a culture of
resilience where all King
County residents are
knowledgeable about
hazards and
preparedness.
• Ensure that all at-risk
neighborhoods have
access to tailored hazard
mitigation and
preparedness
information.
• Make hazard mitigation a
priority in every public
and private sector
planning effort.
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Implementation Plan/Actions
Community Engagement Campaigns
• Launch digital media and social media campaigns to inform the public about mitigation practices.
• Use targeted outreach strategies for at-risk communities, utilizing culturally relevant content.
• Conduct public service announcements through local media.
Educational Outreach
• Create and distribute educational materials (flyers, posters, websites, brochures) to key stakeholders such
as schools, libraries, and community centers.
• Develop and promote interactive tools (e.g., hazard scenario simulations) to educate residents on risks and
mitigation actions.
• Host workshops and town halls focusing on hazard preparedness and mitigation.
Collaboration and Partnerships
• Partner with local businesses, schools, and non-profit organizations to expand outreach and engage more
residents.
• Coordinate with local emergency services and public health officials to integrate hazard mitigation into
public health campaigns.
• Engage influencers and local celebrities to help spread key messages on social media and at community
events.
Data and Research
• Gather data through surveys and focus groups to assess the effectiveness of outreach efforts and areas
needing improvement.
• Develop and share annual reports on the public's understanding of hazard risks and mitigation actions.
Performance Measure
• Engagement Metrics: Social media interaction rates, attendance at public outreach events, and engagement
with online resources.
• Survey Results: Improvement in public understanding of hazard risks and mitigation actions through pre- and
post-campaign surveys.
• Participation Rates: The number of residents who complete mitigation action steps, such as signing up for
emergency alerts or attending preparedness workshops.
• Outreach Reach: Number of educational materials distributed, community organizations involved, and media
coverage achieved.
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20.7.27 Maintain LEPC in King County
Lead
KCOEM
Partners
Local Fire Departments
KCSO
PHSKC
Hazards Mitigated
Hazardous Materials
Funding Sources and
Estimated Costs
KCOEM Budget
Vision
To ensure the continued protection of King County residents, workers, and the environment by maintaining a robust
and effective Local Emergency Planning Committee (LEPC) focused on hazardous materials. The LEPC will provide
proactive mitigation strategies, streamline emergency response coordination, and promote the safe management of
hazardous materials throughout the county.
Description
The King County LEPC is dedicated to reducing the risks associated with hazardous materials in the community. This
strategy seeks to maintain and enhance the effectiveness of the LEPC in response to hazardous materials incidents.
The committee works collaboratively with government agencies, local businesses, fire and emergency responders,
and the public to prepare for and mitigate the risks of hazardous materials.
Key activities of the LEPC will include:
• Developing and maintaining emergency response plans for hazardous materials incidents
• Organizing regular training for first responders and community stakeholders
• Maintaining an up-to-date inventory of hazardous materials in King County
• Ensuring public awareness and education about hazardous materials
• Conducting hazard assessments and implementing mitigation actions to reduce risk exposure
2-Year Objectives
• Maintain a fully operational LEPC with
diverse membership across sectors
(government, private industry, first
responders).
• Complete a comprehensive hazardous
materials inventory across King County.
• Conduct a county-wide hazardous
materials risk assessment and prioritize
mitigation actions.
• Increase public education campaigns
focused on hazardous materials safety
and emergency preparedness.
• Provide at least two full-scale
hazardous materials emergency
response exercises for local responders.
5-Year Objectives
• Establish a regional hazardous
materials response network to ensure
seamless collaboration across
jurisdictions.
• Develop and implement new hazard
mitigation actions based on evolving
hazardous materials risks (e.g.,
transportation routes, facility
operations).
• Achieve a 25% reduction in
hazardous materials-related incidents
through risk mitigation efforts.
• Secure long-term funding
mechanisms to sustain LEPC activities
beyond initial federal and state grants.
Long-Term Objectives
• Incorporate new
technologies (e.g., real-time
data collection, advanced
response equipment) into
LEPC operations.
• Expand the LEPC’s scope to
include emerging
environmental threats, such
as climate change impacts on
hazardous material risks.
• Develop a county-wide
certification program for
businesses and industries
involved in hazardous
materials handling.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-80
Implementation Plan/Actions
• Action 1: Maintain LEPC Membership and Leadership
• Ensure diverse participation from all relevant stakeholders, including local government, fire departments,
health agencies, and industry partners.
• Schedule quarterly LEPC meetings to review progress, address concerns, and discuss evolving hazards.
• Action 2: Hazardous Materials Inventory and Risk Assessment
• Survey and document all facilities in King County that store or handle hazardous materials.
• Conduct a risk assessment to evaluate the potential for chemical spills, accidents, and other hazardous
materials incidents.
• Prioritize the most critical locations for mitigation efforts.
• Action 3: Emergency Response Plan Updates and Drills
• Update the King County hazardous materials emergency response plan annually.
• Conduct regular training for first responders on the use of hazardous materials response equipment.
• Organize annual full-scale exercises that simulate hazardous materials incidents for training purposes.
• Action 4: Public Outreach and Education
• Develop educational materials for residents and businesses regarding hazardous materials risks and
emergency procedures.
• Launch a public awareness campaign on hazardous materials safety, especially in high-risk areas.
• Action 5: Funding and Resource Development
• Identify new federal, state, and private funding opportunities to sustain the LEPC’s efforts.
• Explore partnerships with local industries to secure in-kind donations and resources for training and
mitigation activities.
Performance Measure
• Successful execution of at least one full-scale hazardous materials emergency exercise per year.
• Completion of a hazardous materials inventory for 100% of King County facilities within 2 years.
• Achieving sustainability through securing long-term funding sources for LEPC activities by Year 5.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-81
20.7.28 Strengthening and Maintaining Partnerships for Emergency
Response and Coordination
Lead
KCSO
Partners
KCOEM
Fusion Center
Hazards Mitigated
Terrorism
Civil Disorder
Funding Sources and
Estimated Costs
General Fund
Vision
To create a coordinated, resilient emergency response system by maintaining strong and effective partnerships
between the King County Sheriff's Office, the King County Office of Emergency Management, and the Fusion Center,
ensuring a rapid, unified, and data-driven approach to mitigating and responding to a wide range of hazards.
Description
The partnership between the King County Sheriff's Office, King County Office of Emergency Management, and the
Fusion Center is vital for providing effective emergency response and mitigation strategies. This strategy aims to
sustain and strengthen this collaboration by improving communication, sharing resources, and enhancing training
and preparedness. The goal is to ensure a seamless response to emergencies, optimize resource allocation, and
enhance public safety by addressing a wide array of threats, from natural disasters to public safety concerns.
2-Year Objectives
• Formalize and enhance communication
protocols between KCSO, KCOEM, and
the Fusion Center for real-time data and
situational awareness
• Establish regular joint training
exercises and tabletop scenarios
involving all partners
• Update and review emergency
response plans and protocols for cross-
agency collaboration
• Strengthen information-sharing
networks and systems between the
agencies
• Secure initial funding for technology
improvements that enable faster, more
secure data sharing
5-Year Objectives
• Develop an integrated emergency
response plan that incorporates all
relevant agencies and ensures efficient
resource deployment
• Expand the Fusion Center's role in
coordinating intelligence and public
safety data across jurisdictions
• Increase the frequency of joint
exercises and develop more advanced
scenarios
• Achieve regional coordination
agreements with neighboring counties
and agencies for large-scale
emergencies
• Enhance cross-training programs to
build mutual understanding of each
agency's capabilities and limitations
Long-Term Objectives
• Fully integrate emergency
response systems across King
County with real-time data
sharing and multi-agency
collaboration
• Establish a robust regional
and statewide network of
fusion centers for better
intelligence and situational
awareness
• Ensure all staff at KCSO,
KCOEM, and the Fusion
Center are trained on
advanced emergency
response protocols and
technologies
• Strengthen public trust and
cooperation through
transparent emergency
management efforts and clear
public communication
strategies
• Increase efficiency in
resource deployment during
large-scale emergencies,
reducing response times by
20%
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-82
Implementation Plan/Actions
• Develop a comprehensive communication and data-sharing framework that outlines roles, responsibilities, and
protocols during an emergency
• Conduct bi-annual joint exercises and simulation drills between KCSO, KCOEM, and the Fusion Center, focusing on
realistic scenarios, including natural and man-made disasters
• Integrate data management systems between the KCSO, KCOEM, and Fusion Center to allow seamless flow of real-
time information during emergencies
• Regularly review and update emergency response plans to ensure they reflect changes in technology, population
growth, and evolving threats
• Advocate for and apply for state and federal funding to enhance technology and infrastructure for inter-agency
coordination
• Establish clear points of contact and dedicated personnel responsible for ensuring the continuity of communication
and collaboration during emergencies
• Create a public education campaign that outlines the roles of each agency in emergency response, fostering
community awareness
Performance Measure
• Number of joint training exercises conducted and the level of participation from all partners
• Speed and accuracy of information exchange during emergencies, measured by response time and situational
awareness
• Increased integration of data systems, tracked by the implementation of new technology and successful data-
sharing tests
• Satisfaction surveys from participating agencies evaluating the effectiveness of coordination and response efforts
• Secured funding for technology enhancements and collaborative infrastructure
• Improved response times during actual emergencies, measured through after-action reports and evaluations
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-83
20.7.29 Implementation of 2024 King County Floodplain
Management Plan
Lead
DNRP
Partners
Flood Control District
Hazards Mitigated
Flooding
Extreme Weather
Funding Sources and
Estimated Costs
Vision
To reduce the vulnerability of communities, infrastructure, and ecosystems to flooding by implementing the King
County Floodplain Management Plan, fostering resilience through sustainable land use, strategic mitigation, and
enhanced floodplain management practices.
Description
The 2024 King County Floodplain Management Plan outlines a comprehensive strategy for flood risk reduction,
environmental restoration, and improved community resilience. This mitigation strategy focuses on managing
floodplains as dynamic ecosystems while enhancing the capacity to manage flood risks through collaboration and
smart growth planning. The goal is to protect vulnerable communities and the environment from flood hazards,
improve floodplain health, and provide a resilient, sustainable foundation for future generations.
2-Year Objectives
• Complete a comprehensive floodplain
risk assessment and mapping update for
priority areas
• Develop and implement a public
education campaign about flood risk and
preparedness
• Initiate floodplain restoration projects
in high-priority areas
• Secure FEMA funding for flood
mitigation infrastructure improvements
• Collaborate with municipalities to align
local planning policies with floodplain
management goals
5-Year Objectives
• Expand floodplain restoration efforts
across King County's flood-prone
regions
• Complete the construction of at least
three major flood mitigation
infrastructure projects
• Achieve a 15% reduction in flood risk
exposure for critical infrastructure in
high-priority zones
• Integrate floodplain resilience
measures into regional development
and land use policies
• Build community partnerships for
ongoing public engagement in
floodplain management
Long-Term Objectives
• Reduce flood risk for 50% of
the county's flood-vulnerable
communities
• Ensure the restoration of
500 acres of floodplain habitat
• Fully integrate floodplain
management and resilience
into regional land use and
development planning
• Achieve a 25% reduction in
the economic impact of
flooding to the local economy
• Increase public awareness
and preparedness for flood
events by 30%
Implementation Plan/Actions
• Update flood risk maps and floodplain zoning regulations to reflect the latest data
• Identify and prioritize floodplain restoration sites, focusing on high-risk areas for both communities and
ecosystems
• Develop and implement hazard reduction measures (levees, flood barriers, natural flood control systems) in high-
priority flood zones
• Provide ongoing training for local governments and first responders on floodplain risk management and
emergency preparedness
• Create a dedicated funding pool to support local governments’ flood mitigation projects
• Facilitate community-based planning processes, ensuring that vulnerable populations have a voice in floodplain
management decisions
• Expand the role of technology and data in flood monitoring and prediction
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-84
Performance Measure
• Reduction in flood risk to critical infrastructure (measured through floodplain risk assessments)
• Acres of floodplain restored and improved
• Number of local municipalities that have updated their floodplain policies and zoning laws
• Percentage increase in community awareness and preparedness as measured by surveys and public engagement
metrics
• Amount of funding secured from federal and state sources for flood mitigation projects
• Number of completed flood mitigation and infrastructure projects in high-priority areas
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-85
20.7.30 Mount Si Road Undergrounding Project
Lead
Tanner Electric
Cooperative
Partners
OEM
DLS - Roads
Hazards Mitigated
Wildfire
Severe Weather
Funding Sources and
Estimated Costs
$3.5 Million
Vision
To enhance energy resilience and mitigate wildfire and storm-related risks for the North Bend community by
undergrounding critical electrical infrastructure along Mount Si Road, ensuring consistent, safe, and uninterrupted
power supply to residents, businesses, and essential services.
Description
The Mount Si Road Undergrounding Project proposes the installation of approximately 1.63 miles of underground
three-phase electrical distribution lines using Schedule 40 PVC conduit in North Bend, Washington. Initiated by
Tanner Electric Cooperative, the project seeks funding to significantly improve the resilience of energy infrastructure
historically vulnerable to wildfires, winter storms, and high winds.
The existing overhead distribution lines—exposed for over five to six decades—are a known source of power
outages and fire ignition risks. Undergrounding will eliminate these overhead vulnerabilities, ensure consistent
energy supply to 486 meters (approximately 1,290 residents), and support critical infrastructure such as local water
tanks, communications booster stations, and private wells. The affected section currently relies on a radially fed
circuit with limited access, which complicates repair and restoration during outages.
Underground infrastructure will provide virtually maintenance-free power delivery, increased longevity, and
significantly reduced risk of outages. It will also prevent power shutoffs during red flag wildfire events when Tanner
currently implements one-shot policies and delays re-energizing lines until full inspection by daylight.
2-Year Objectives
• Complete project design and
permitting
• Secure construction contracts
• Begin trenching and conduit
installation
5-Year Objectives
• Complete full underground
conversion of the 1.63-mile section
• Transition affected customers to the
underground system
• Decommission overhead lines and
poles in project area
Long-Term Objectives
• Achieve near-elimination of
weather-related outages in
project zone
• Reduce wildfire ignition risk
from power lines
• Ensure reliable service for
critical utilities and
community resilience during
extreme events
Implementation Plan/Actions
• Finalize engineering design and secure environmental approvals
• Engage local stakeholders and residents for public input and support
• Coordinate with North Bend and utility partners for water and communications systems
• Procure and install underground conduits and cables
• Transition electrical loads to underground service and remove old infrastructure
Performance Measure
• Reduction in outage frequency and duration in the Mount Si Road area
• Elimination of power shutoff events during red flag warnings
• Decreased wildfire risk tied to electrical infrastructure
• Improved reliability metrics and maintenance savings over 10+ years
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-86
20.7.31 Plan for Post-Wildfire Community Recovery
Lead
OEM
Partners
ECO
DLS – Roads
DNRP
PHSKC
Hazards Mitigated
Wildfire
Funding Sources and
Estimated Costs
County Budget
Vision
Ensure King County is prepared to support equitable, coordinated, and efficient recovery from wildfires—particularly
those that impact homes, public facilities, and infrastructure—through a dedicated planning framework that guides
action, accountability, and access to recovery resources.
Description
Post-wildfire recovery is a complex and multi-faceted challenge. To improve outcomes for affected communities,
King County will develop a wildfire-specific annex to the King County Disaster Recovery Plan. This annex will:
• Define agency roles and responsibilities during post-wildfire recovery
• Outline key actions for short- and long-term recovery
• Include protocols for accessing FEMA Public and Individual Assistance, SBA loans, and HUD-supported
housing recovery programs
• Be reviewed and updated every five years or after major wildfire disasters
The annex will guide recovery following disasters that damage homes, infrastructure, and public facilities and will
ensure that recovery efforts are inclusive, timely, and aligned with other county and regional resilience efforts.
2-Year Objectives
• Convene key partners and begin
development of the wildfire-specific
annex
• Identify recovery needs and equity
gaps through stakeholder input
• Draft and publish initial version of the
annex as part of the broader Disaster
Recovery Plan
5-Year Objectives
• Operationalize the annex through
partner training and plan exercises
• Establish coordination protocols for
post-wildfire funding and housing
support
• Update annex with new best
practices and lessons learned from any
wildfire events
Long-Term Objectives
• Institutionalize wildfire
recovery planning as a core
element of King County’s
emergency management
• Improve recovery outcomes
and speed for wildfire-
impacted communities
• Reduce long-term disparities
in disaster recovery support
and outcomes
Implementation Plan/Actions
• Collaborate with local, state, and federal partners to define post-wildfire recovery pathways
• Integrate the annex into the King County Disaster Recovery Plan
• Identify recovery funding mechanisms and align with existing support programs
• Build capacity among local jurisdictions and departments to support implementation
• Include equity-centered planning and community engagement throughout
Performance Measure
• Completion and adoption of the wildfire-specific annex
• Number of trainings or exercises conducted using the annex
• Time to initiate and coordinate recovery actions post-wildfire
• Amount of federal and state recovery funding accessed through the plan
• Stakeholder and community satisfaction with post-wildfire recovery support
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-87
20.7.32 Standardize and Promote Best Management Practices for
Wildfire Mitigation
Lead
DNRP -WLRD
Partners
ECO
DLS
Parks
Hazards Mitigated
Wildfire
Funding Sources and
Estimated Costs
County Budget
Vision
Reduce wildfire risk to homes, infrastructure, and evacuation routes in King County through coordinated and
standardized best management practices that can be easily adopted and implemented by fire departments,
agencies, and communities.
Description
Wildfires pose increasing threats to King County, particularly in Wildland-Urban Interface (WUI) areas. Evidence
shows that mitigation is cost-effective—every dollar spent yields $4 in avoided future losses. To address this growing
risk, King County will lead the development and promotion of standardized wildfire mitigation Best Management
Practices (BMPs). These practices will be:
• Focused on home hardening, infrastructure protection, and evacuation planning
• Designed for integration into services provided by fire departments, local governments, and technical
assistance providers
• Distributed to relevant partners and programs for implementation across the County
This effort will ensure consistent, effective wildfire preparedness and risk reduction countywide.
2-Year Objectives
• Develop and finalize a countywide set
of wildfire mitigation BMPs
• Distribute BMPs to local agencies, fire
departments, and partners
• Begin incorporating BMPs into
technical assistance services and
programs
5-Year Objectives
• Train partner organizations and
service providers to implement BMPs
• Integrate BMPs into relevant County
plans and community wildfire
education efforts
• Monitor uptake and use across
jurisdictions and agencies
Long-Term Objectives
• Establish BMPs as the
standard wildfire mitigation
approach in King County
• Demonstrate reduced
wildfire losses in areas where
BMPs have been implemented
• Strengthen community and
agency capacity for long-term
wildfire resilience
Implementation Plan/Actions
• Convene partners to co-develop wildfire mitigation BMPs
• Coordinate with existing wildfire programs and risk reduction strategies
• Create user-friendly materials and distribute BMP guidance
• Support training and technical integration through county departments and partners
• Monitor and evaluate adoption of BMPs over time
Performance Measure
• Completion and distribution of BMP guidance materials
• Number of agencies and partners adopting BMPs
• Number of properties or facilities implementing BMP-aligned practices
• Feedback from partners on BMP usability and effectiveness
• Reduction in property loss or evacuation disruptions in BMP-implemented areas
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-88
20.7.33 Expand Access to Cooling Locations for Communities
Lead
ECO
Partners
DCHS
OEM
PHSKC
Hazards Mitigated
Severe Weather
Funding Sources and
Estimated Costs
TBD
Vision
Ensure equitable access to safe, welcoming, and community-trusted cooling locations throughout King County to
protect high-risk populations during extreme heat events.
Description
Extreme heat poses serious health risks, especially for vulnerable populations. Community-based organizations
(CBOs) are uniquely positioned to host culturally relevant and accessible cooling spaces. King County will work with
CBOs and local jurisdictions to identify, equip, and support these facilities.
Support will include:
• Identifying and vetting potential cooling sites
• Assisting with upgrades and cooling-related resources
• Training staff from CBOs to operate cooling sites
• Connecting interested partners to the Resilience Hub model and resources
This approach builds long-term community capacity while addressing short-term extreme heat response needs.
2-Year Objectives
• Identify and engage with CBOs and
jurisdictions to develop a list of potential
cooling sites
• Provide technical assistance and small-
scale resources for site readiness
• Launch pilot cooling locations in
priority neighborhoods
5-Year Objectives
• Expand number of operational
cooling sites across the county
• Create a resource network linking
cooling sites and Resilience Hubs
• Develop long-term partnerships and
shared protocols for heat events
Long-Term Objectives
• Establish a sustainable,
community-led network of
cooling locations countywide
• Reduce heat-related health
disparities in vulnerable
communities
• Integrate cooling location
planning into broader climate
resilience strategies
Implementation Plan/Actions
• Convene CBOs and jurisdictional partners for collaborative planning
• Map areas of greatest need based on heat vulnerability and population risk
• Support training and operational readiness of facility staff
• Leverage county and grant funds to support capital and operational upgrades
• Align with the Energize Program and Resilience Hub development efforts
Performance Measure
• Number of operational community cooling sites established
• Geographic coverage of cooling access in high-risk areas
• Number of individuals served during extreme heat events
• Community feedback and satisfaction with site accessibility and cultural relevance
• Reduction in heat-related health incidents in served areas
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-89
20.7.34 Expand the Use of Residential Flood Risk Mitigation Tools
Countywide to Benefit Those Who Are Most Vulnerable to
Flooding
Lead
DNRP -WLRD
Partners
OEM
FEMA
FCD
Hazards Mitigated
Flooding
Funding Sources and
Estimated Costs
TBD
Vision
Expand access to effective, equitable residential flood risk mitigation tools across King County—such as buyouts and
home elevations—to reduce the impacts of flooding for the most vulnerable and financially burdened property
owners while also aligning with community priorities and environmental values.
Description
Flood mitigation tools like voluntary buyouts and home elevations are underutilized in King County due to barriers
including geographic limitations, funding challenges, upfront homeowner costs, and variable interest. These
constraints often leave the most vulnerable communities unprotected.
This strategy focuses on expanding voluntary residential flood mitigation programs countywide to better support at-
risk property owners—especially those with financial need. King County will:
• Identify residential properties at highest risk from current and future flooding
• Prioritize assistance based on vulnerability and documented harm
• Expand mitigation efforts to additional river basins (beyond the Snoqualmie)
• Target repetitive loss areas including Sammamish, Skykomish, Green, Cedar, and Snoqualmie River Basins,
and Vashon Island
• Seek federal and local funding to broaden the program’s reach
• Align mitigation actions with farmland protection when applicable
2-Year Objectives
• Identify high-risk flood areas and
assess residential property vulnerabilities
• Develop equity-based criteria for
prioritizing mitigation support
• Apply for federal and local grants to
support program expansion
5-Year Objectives
• Increase the number of homes
participating in voluntary mitigation
programs
• Expand geographic coverage of home
elevation efforts
• Build partnerships with community-
based organizations to improve
outreach and access
Long-Term Objectives
• Reduce the number of
repetitive loss properties in
King County
• Ensure that flood mitigation
benefits are equitably
distributed countywide
• Establish a sustainable, well-
funded, and flexible
residential flood mitigation
program
Implementation Plan/Actions
• Map and prioritize residential flood risk based on current and future projections
• Secure funding from the Flood Control District, FEMA, and other sources
• Expand community engagement, especially in historically impacted neighborhoods
• Coordinate with farmland protection efforts to avoid conflicts
• Implement mitigation actions through voluntary buyouts, elevations, or repairs
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-90
Performance Measure
• Number of homes mitigated through buyouts, elevations, or repairs
• Funding secured and leveraged for mitigation
• Reduction in repetitive flood loss claims
• Increased participation from vulnerable or low-income homeowners
• Equity outcomes tracked and reported
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-91
20.7.35 Identify and Seek Funding to Reduce Sea Level Rise and
Flood Risks to On-Site Wastewater Infrastructure in
Unincorporated King County
Lead
PHSKC
Partners
DNRP
SPU
Hazards Mitigated
Flooding
Severe Weather
Funding Sources and
Estimated Costs
TBD
Vision
Protect public health and environmental quality by proactively addressing the risks that sea level rise and flooding
pose to on-site wastewater infrastructure in vulnerable unincorporated areas of King County, with a focus on
equitable outcomes.
Description
Sea level rise and increased precipitation-driven flooding present growing risks to on-site wastewater systems in
unincorporated King County. Building on 2025 sea level rise assessments for Vashon and Maury Island, the County
will identify areas most at risk—specifically on Vashon-Maury Island and in the lower Duwamish Valley adjoining
South Park. Emphasis will be placed on identifying where equity-related needs are greatest, then working with
partners to secure funding and implement infrastructure improvements.
2-Year Objectives
• Conduct targeted assessments to
identify high-risk locations
• Engage community-based
organizations and other partners for
localized insights
• Seek initial grant funding opportunities
5-Year Objectives
• Secure funding and initiate design
and implementation in priority areas
• Begin infrastructure improvements in
areas with highest vulnerability and
equity needs
Long-Term Objectives
• Complete infrastructure
resilience upgrades in all
identified high-risk areas
• Integrate long-term flood
resilience and equity priorities
into countywide wastewater
infrastructure planning
Implementation Plan/Actions
• Identify priority locations using environmental data and community input
• Collaborate with partners to align on equity and infrastructure needs
• Apply for and secure external funding (grants)
• Implement infrastructure improvements through phased project delivery
Performance Measure
• Number of high-risk locations identified and assessed
• Amount of funding secured
• Number of wastewater systems improved or relocated
• Community satisfaction and participation levels in planning and implementation
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 20: Mitigation Strategies
20-92
20.7.36 WSDOT Avalanche Forecasting and Control Program
Lead
WSDOT
Partners
NWS
OEM
WSP
Hazards Mitigated
Avalanche
Funding Sources and
Estimated Costs
State Budget
Vision
Maintain the safety and reliability of Washington’s mountain highway corridors by proactively forecasting and
controlling avalanches to reduce hazards for motorists, freight traffic, and recreational users.
Description
The WSDOT Avalanche Forecasting and Control Program includes two regional teams of full-time and seasonal
avalanche professionals. These teams monitor mountain weather, forecast avalanche risks, and execute control
operations using explosives, trams, and artillery. They work fall through spring to protect critical corridors like I-90
Snoqualmie Pass and US 2 Stevens Pass. The program combines active control (e.g., detonations) and passive
infrastructure (e.g., berms, catchment basins) to manage avalanche hazards. Seasonal closures occur where safety
cannot be maintained. Public education and enforcement help mitigate risks associated with recreational
backcountry use. New technologies, such as drones and Remote Avalanche Control Systems (RACS), are currently
under evaluation.
2-Year Objectives
• Continue testing and evaluation of
remote avalanche monitoring
technologies like drones
• Expand educational outreach to
backcountry users
• Improve mapping and public
accessibility of Avalanche Atlas tools
5-Year Objectives
• Integrate RACS technology in high-
risk areas to reduce reliance on military
surplus artillery
• Reduce average road closure times
by 10% through operational efficiency
• Enhance collaboration with ski areas
and law enforcement to reduce
recreational intrusions into avalanche
zones
Long-Term Objectives
• Achieve near-complete
transition from manual to
remote-controlled avalanche
control in accessible zones
• Eliminate injuries/fatalities
due to recreational intrusion
in avalanche zones
• Maintain full accessibility on
key corridors throughout
winter, barring severe
weather extremes
Implementation Plan/Actions
• Continue use and maintenance of cable trams, explosives, and artillery
• Expand deployment of passive infrastructure (e.g., diversion dams, catchment basins)
• Close roads temporarily during high-risk periods and perform control operations at night when possible
• Post avalanche zone warnings and enforce hitchhiking bans
• Collaborate with law enforcement and ski areas to manage backcountry user behavior
• Pilot and assess effectiveness of drones and RACS
• Update and maintain the Avalanche Atlas map interface for public use
Performance Measure
• Reduction in number and duration of road closures
• Number of avalanches successfully mitigated without incident
• Decrease in unauthorized recreational entry into avalanche zones
• Number of successful remote-control operations conducted
• Improvement in response time and forecasting accuracy
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 21: Plan Maintenance
21-1
Chapter 21: Plan Maintenance
21.1 Monitoring and Updating
The King County Office of Emergency Management (KCOEM) hazard mitigation team will internally
track mitigation strategies submitted by the county and participating annexes. All participating
jurisdictions will convene on a biannual basis to provide progress updates on their respective
strategies. These updates are solicited by the county for inclusion in the countywide annual report.
As part of the 2025 update to the Regional Hazard Mitigation Plan, each participating jurisdiction
agrees to convene its internal planning team at least once annually to assess progress and maintain
accountability.
Tracking will be organized using a standardized format, as illustrated below:
ID
Ju
r
i
s
d
i
c
t
i
o
n
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r
a
t
e
g
y
Vi
s
i
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a
d
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g
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y
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i
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r
i
t
y
(H
i
g
h
,
Me
d
i
u
m
,
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o
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)
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z
a
r
d
(
s
)
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t
e
n
t
i
a
l
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u
n
d
i
n
g
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c
e
(
s
)
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t
i
m
a
t
e
d
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o
s
t
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m
e
l
i
n
e
(Ong
o
i
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g
,
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t
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r
m
,
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g
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r
m
)
St
a
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s
(Not
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r
t
e
d
,
In
Pro
g
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e
s
s
,
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p
l
e
t
e
)
In addition to biannual check-ins, working groups will be formed by identifying shared
characteristics among strategies. These groupings may be based on approach (e.g., code updates,
public education programs, ecological restoration), hazard type, or funding sources. These working
groups will foster collaboration by enabling participants to share resources, exchange best practices,
learn from one another’s experiences, and better understand the capabilities and assets available
across jurisdictions.
To enhance implementation, key partners and county departments will be invited to clarify
processes and next steps. Additionally, KCOEM will work to build public-private partnerships by
engaging nonprofits and corporations with aligned missions to help secure future mitigation
funding.
As part of its leadership role in the countywide planning effort, KCOEM will also distribute federal
Notices of Funding Opportunity (NOFOs). Proposals submitted by partners will be assessed
according to the prioritization process identified in this plan and the county will, where possible,
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 21: Plan Maintenance
21-2
support those partners submitting grant proposals. This will be a key strategy to implement the
plan.
King County Office of Emergency Management (KCOEM) will schedule annual check-ins to evaluate
and revise the identified hazards risk analysis along with each hazards impact and vulnerability
analysis.
The next plan update is expected to be due in September 2030. All jurisdictions will submit letters of
intent by 2028, at least two years prior to plan expiration. The county will lead the next regional
planning effort, beginning at least 18 months before the expiration of the 2025 plan.
In addition to the updates for mitigation strategies, the expected publication of data from several
programs may trigger an update.
• Publication of the Department of Homeland Security Regional Resiliency Assessment
Program report
• Publication of the countywide landslide susceptibility map from Washington Department of
Natural Resources
• Publication of the Wildland Urban Interface wildfire risk map from Washington Department
of Natural Resources
• Publication of tsunami inundation data from Washington Department of Natural Resources
21.2 Integrating into Existing Planning
Mechanisms
To ensure a comprehensive and cohesive approach to hazard mitigation, the data and insights from
the RHMP will be seamlessly integrated into existing county, regional, and local plans and
frameworks. These include comprehensive plans, emergency operations plans, regional strategies,
and sustainability initiatives, all of which contribute to a holistic approach to risk reduction. This
integration effort is already underway with the incorporation of hazard risk and vulnerability data
into the 2025 update of the countywide planning processes.
Many of these plans have been updated simultaneously, allowing for the development of data and
mitigation strategies to made in partnership other departments. As a result, several strategies are
now reflected in multiple county plans, such as the Flood Management Plan and the Strategic
Climate Action Plan. This approach ensures that mitigation actions are implemented and monitored
across multiple channels, increasing their visibility and support across departments. By embedding
these strategies in various plans, we help elevate their profile and facilitate more comprehensive
execution.
It’s important to note that additional strategies may be added to this list throughout the lifecycle of
both plans, as new opportunities for collaboration and integration arise. This continuous process
ensures that the RHMP remains dynamic and aligned with evolving county goals and priorities.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 21: Plan Maintenance
21-3
21.3 Continued Public Involvement
To foster transparency, continuous improvement, and community collaboration, King County is
committed to maintaining an effective communication strategy throughout the ongoing
maintenance of the RHMP. Following biannual meetings dedicated to RHMP updates, KCOEM will
leverage its official Emergency Blog and social media platforms as primary communication channels
to keep the public informed. These platforms will provide timely updates on the status of mitigation
actions, key developments, and upcoming initiatives.
Regular updates will not only highlight the progress of specific mitigation actions but also offer
concise summaries of completed and ongoing efforts. In addition, whenever updates or addendums
are introduced to the RHMP, King County will actively open channels for public input. This ensures
that the community remains a vital and engaged participant in the planning process. Residents, local
stakeholders, and other interested parties will be encouraged to provide comments, voice concerns,
and offer valuable feedback on proposed changes to the plan.
AGENDA ITEM #1. b)
2025 King County Regional Hazard Mitigation Plan
Chapter 22: Plan Adoption
22-1
Chapter 22: Plan Adoption
The King County Regional Hazard Mitigation Plan is submitted first to Washington State Emergency
Management for review and then to FEMA for final review and preliminary approval. Each
jurisdiction, along with the base plan, must meet all FEMA requirements outlined in the FEMA Local
Hazard Mitigation Plan Review Guide. If requirements are found to not be met, the jurisdiction
involved must revise the plan and resubmit. Once preliminary approval is secured, FEMA will send a
notice of Approval – Pending Adoption.
The RHMP is adopted by each participating jurisdiction, primarily through a resolution passed by
the council or commission responsible. The King County Council is expected to adopt this plan
before the expiration date of 9/30/2025, following notice of approval, pending adoption from FEMA
and Washington State Emergency Management. This plan will be effective on 10/1/2025 FEMA and
will expire 5 years to the day, 9/30/2030.
AGENDA ITEM #1. b)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 1
City of Renton Plan Annex
Introduction
Brief History
Originally an important fishing area for Native Americans, Renton
experienced a migration of people of European descent in the 1850s,
leading to the displacement of the Duwamish people. As the influx
of settlers continued, the early Renton economy developed around
coal, timber, and clay production from the surrounding hills. In 1911
a major flood provided the impetus for diverting the channel of the
Cedar River to prevent future flooding in the city. The building of
the Renton Boeing plant during World War II brought thousands to
Renton for jobs. Renton is also home to several other major
corporations and important regional government facilities.
Climate
Renton’s climate is moderate. Mild winters, an average of 154
precipitation days per year, with warm, dry summers. Annual average
temperatures range from 36 to 79 degrees, rarely below 28 or above
87 degrees. Annual rainfall is 42 inches. Monthly precipitation varies
from 6 inches in November to January to under an inch in July and
August. Average annual snowfall is 11 inches. Humidity varies
between 44 percent and 95 percent in summer and winter,
respectively. Winds vary and prevail from the south/southeast at an
average speed of 7 mph, seldom over 22 mph.
Development Trends and Demographics
Renton has a mix of land uses. Industrial and commercial uses are primarily in the Green River Valley and
downtown Renton. The city center includes mixed-use residential and commercial land, with single and multi-
family homes. Single family residences dominate the eastern and southeastern portions of the city, where most
residential growth has occurred. There are pockets of mixed-use commercial centers aimed at providing services
for residents along the eastern edges of the city.
The Comprehensive Plan provides a vision for Renton’s development 20 years into the future. The vision includes
an emphasis on infill development in existing neighborhoods and an increase in multi-family housing in the
downtown area rather than sprawl. This infill has increased the number
of residents living in both the 500-year floodplain of the Cedar River
and the high liquefaction earthquake risk area in downtown Renton.
The new Longacres development plan will add 3,000 homes to the
Green River floodplain, an area also classified as having a high
liquefaction risk. As the city's population and development continue to
grow, more people and property will be exposed to flooding and
earthquake hazards. With the population growth and associated high
language diversity in the city, this creates challenges in communicating
risk to the increasing number of residents who speak English less than
very well.
City of Renton Profile
Date of Incorporation:
9/6/1901
Governance: Optional
municipal code city governed
by a mayor/council form of
government
Population as of 4/1/2024:
108,800
Area: 25 square miles
Location and Description:
Western Washington State,
Central Puget Sound, South
King County
Jurisdiction Point of Contact/
Plan Prepared By:
Name: Deborah Needham
Title: Emergency Management
Director
Entity: City of Renton
Phone: 425-430-7725
Email: dneedham@rentonwa.gov
EXHIBIT B AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 2
City of Renton Risk Summary
Hazard Risk and Vulnerability Summary
HAZARD RISK SUMMARY VULNERABILITY SUMMARY IMPACT SUMMARY
Avalanche n/a n/a n/a
Civil
Disturbance
Civil disorder may result
from many situations and
encompass a broad
spectrum of civil action
that ranges from peaceful
events to other forms of
disturbance caused by a
group of people. The
severity of such
disturbances often
reflects the degree of
public displeasure or
expression of discontent.
Examples of civil
disorder include but are
not necessarily limited to:
violent demonstrations
and other forms of
obstructions, riots,
sabotage, and other forms
of crime. Civil disorder
can be a dangerous
condition that can
become increasingly
chaotic and volatile.
Civil disorder can erupt
anywhere but the most likely
locations are those areas with
large population groupings or
gatherings. Sites that are
attractive for political rallies or
offices should be viewed as
potential locations for the
epicenter of civil disorder
events.
Disruption of critical
infrastructure may occur during
very severe civil disorder events.
Public services such as water,
power, communication, and
transportation may be
temporarily unavailable.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 3
HAZARD RISK SUMMARY VULNERABILITY SUMMARY IMPACT SUMMARY
Cyber
Incident
A cyber incident is
defined by the
Department of
Homeland Security
(DHS) in the 2016
National Cyber Incident
Response Plan as “an
event occurring on or
conducted through a
computer network that
actually or imminently
jeopardizes the
confidentiality, integrity
or availability of
computers, information
on communication
systems or networks,
physical or virtual
infrastructure controlled
by computers or
information systems, or
information resident
thereon.”
Wherever information
technologies exist and are used,
cyber incidents can occur. As
the city becomes more and
more dependent on its
information technology (IT)
infrastructure it also becomes
more vulnerable to IT related
disruptions. Most cyber
incidents can be categorized as
malicious attacks, human
errors, or system glitches. More
than 50% of the incidents are
estimated to be caused by
malicious or criminal attackers.
Minor cyber incidents that are
detected early and quickly
recovered may briefly disrupt
daily operations before fully
contained but will not have a
significant impact on the city. A
significant incident can have a
major impact not only on the
city but on the county and the
region. Such incidents may result
in safety and health risks,
financial losses for the city and
the region, reputational damage,
and inability to comply with
regulatory requirements
including penalties and fines. It
may also affect the city’s ability
to achieve critical strategic
objectives and fulfill executive
priorities.
Dam
Failure
There are two major
dams in Renton, on the
Green River and Cedar
River respectively, and
numerous levees along
both rivers. A failure of
either a dam or a levee
would cause severe
flooding not seen since
the two dams were built.
A dam failure with a full-
pool scenario will likely
be much more severe
than a typical flooding
scenario.
Renton is near or at the end of
the drainage basin for the
Green River and the Cedar
River. As a relatively low-lying
area, it becomes the collector
for floodwaters along those
rivers. The Green River Valley
is a thriving commercial and
industrial area. The area around
the Cedar River is primarily
residential development. There
are schools and several senior
residential communities in the
floodplain. There is great
potential for loss of life for
those not able to evacuate
ahead of the floodwaters.
In the Green River Valley
hundreds of millions of dollars
of real property would be
destroyed in Renton, primarily
businesses, causing them to
permanently close their doors,
with a loss of revenue for the
city. A Chester Morse Dam
failure on the Cedar River would
destroy hundreds of millions of
dollars of mostly residential
property, leaving many
homeless.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 4
HAZARD RISK SUMMARY VULNERABILITY SUMMARY IMPACT SUMMARY
Earthquake The city is subject to a
major earthquake
generated by the Seattle
Fault to the north, and
the Cascadia Subduction
Zone offshore to the
west, which is capable of
generating an earthquake
in the 8.0-9.0 range.
Additional minor faults
may generate smaller
earthquakes, and faults
further away can still
cause damage.
Much of the historic downtown
area is comprised of
unreinforced masonry (URM)
buildings that are vulnerable to
collapse and present a life
safety hazard. Most of Renton’s
commercial development,
including the historic
downtown, is built on soils
with high liquefaction risk.
Many homes were built before
seismic code was changed to
acknowledge the seismic risk of
the area, which will lead to
extensive damage of many
structures.
The city was damaged in 1965
from the 6.7 Puget Sound quake,
with severe damage to the
Boeing plant. In 2001 the city
was again damaged by the 6.8
Nisqually quake, primarily
cracked masonry and collapsed
chimneys, but with no deaths in
Renton. More structures and
residents are at risk today
because of multifamily infill
development in the liquefaction
zone.
Flood Much of Renton’s
commercial and
institutional development
is located within the
floodplain of either the
Green River or Cedar
River, and a considerable
amount of residential
development within the
Cedar River floodplain.
6.35% of the total land
area of the city is within
the Special Flood Hazard
Area. The city has good
floodplain management
regulations and has
limited development;
however, there are many
structures already present
in the floodplain.
Renton is near or at the end of
the drainage basin for the
Green River and the Cedar
River. As a relatively low-lying
area, it becomes the collector
for floodwaters along those
rivers. The Green River Valley
is a thriving commercial and
industrial area. The annual risk
of a catastrophic flood in that
area is 1:140. The area around
the Cedar River is primarily
developed as residential. There
are schools and several senior
residential communities in the
100-year floodplain, as well as
the city’s largest employer. The
historic downtown area is
located within the 500-year
floodplain.
In the last two decades, the city
has experienced repeated
moderate flood events causing
nearly $22 million in damages
and response costs. As climate
change and development have
altered the floodplain, more
structures are thought to be at
risk to a similar event today.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 5
HAZARD RISK SUMMARY VULNERABILITY SUMMARY IMPACT SUMMARY
Hazardous
Materials
Hazardous materials
releases are one of the
most common incident
types. They can occur due
to an accident or be
secondary to other
primary hazards such as a
terrorist attack,
earthquake and volcanic
activity, severe flooding,
and fires. There are
frequent smaller spills and
releases that result from
day-to-day human
activities including
loading dock and
warehouse accidents,
careless handling, traffic
accidents, and illegal
activities like drug labs.
There is also the threat of
a major release from a
massive spill or accident,
either from a
transportation incident,
or from an accidental
release at one of the many
hazardous materials-using
facilities in Renton,
including Renton’s water
treatment facilities. Two
major pipelines traverse
the city, and fuel storage
facilities hold significant
quantities of explosive or
flammable fuels. There is
also the threat of an
intentional release or
contamination from a
terrorist attack.
Additionally, past
byproducts of industry
have left some areas with
chronic contamination,
including two Superfund
Sites within the city.
Stormwater runoff can
carry excess nutrients into
waterways, and create
toxic algal blooms.
Minor hazardous materials
releases do not generally have a
serious impact on life, property,
or the environment. Although
the risk of a major hazardous
materials emergency is low, the
population in general does not
have the means to protect
themselves against it beyond
taking shelter in place or
evacuation measures that may
be ordered. Exposure to
hazardous materials can result
in serious illness, major organ
damage, and death. Explosive
hazardous materials not only
can destroy public and private
property but can seriously
maim and kill people. The
environment may be damaged
for years or even decades and
may be unable to be remediated
for certain kinds of hazardous
materials incidents. Major
cultural sites may become
inaccessible or unusable.
The impacts from hazardous
materials are complex, including
slow-acting releases as well as
sudden catastrophes that kill or
injure thousands. Although the
likelihood of large numbers of
fatalities from a single materials
release is low, the effects can be
devastating to impacted
communities, the economy, and
the environment.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 6
HAZARD RISK SUMMARY VULNERABILITY SUMMARY IMPACT SUMMARY
Landslide/
Sinkholes/
Ground
Subsidence
Areas of steep slopes and
high erosion hazard can
be found throughout the
city. As a former coal-
mining town, many
abandoned coal mines
crisscross the
underground landscape.
There is a high-water
table and some of the
city’s soil types are known
to be prone to landslide
or subsidence.
Some landslide-prone areas had
already been developed prior to
institution of stricter
regulations. The Maple Valley
Highway has experienced
repetitive landslide issues that
have forced its closure at times.
Smaller landslides occur more
regularly in other areas of the
city. Sinkholes in roadways and
pipeline rights-of-way have
occurred within the past five
years. These hazardous
incidents have the potential to
injure or kill people, damage
public and private property,
and block transportation
corridors.
Climate change predictions
include shifting rainfall patterns
to include greater bursts in short
periods, thus increasing the
landslide risk over time. As soils
continue to settle, there will
likely be an increase in the
frequency of sinkhole formation
and coal mine collapse, which
can be related.
Public
Health
Emergency
Communicable disease
outbreaks can be caused
by many agents and
transmitted in several
ways. While public health
measures have controlled
many diseases in this
country, there remains a
risk from new agents
such as new COVID-19
variants, novel strains of
influenza, or severe acute
respiratory syndrome
(SARS) that emerge with
the potential to cause
outbreaks. Emerging
conditions or novel
diseases that have limited
or no medical
countermeasure
(therapeutic or vaccine)
pose as a high risk/low
frequency event that has
the potential to broadly
impact health and medical
capacity as well as disrupt
critical resources and
support infrastructure.
Periodic outbreaks, including
COVID-19 and novel strains of
influenza and other viruses are
a likely hazard in Renton. The
city’s connection to the global
economy and the ease of
national and international travel
increases the potential for a
new disease being introduced
here. Additionally, natural
disasters could result in
displaced populations and mass
sheltering, which increase the
potential for communicable
disease outbreaks. A portion of
Renton's population is
particularly vulnerable,
including young children, the
elderly, and individuals with
preexisting medical conditions
that may increase their risk to
public health emergencies.
When large numbers of the
population are affected, they
cannot work, and thus a public
health emergency can generate
supply chain and critical service
shortages.
A public health emergency can
lead to widespread impacts,
including disrupted healthcare
access, increased risk of
infectious disease transmission,
environmental contamination,
mental health challenges, food
insecurity, and worsening health
inequalities. These effects are
particularly severe for vulnerable
populations and stem from
disruptions to essential services
and infrastructure.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 7
HAZARD RISK SUMMARY VULNERABILITY SUMMARY IMPACT SUMMARY
Severe
Weather
Tornados are rare in this
region, but the city is
prone to damaging high
winds during seasonal
storms. Trees frequently
fall during such storms.
Some neighborhoods are
built entirely within large
stands of tall trees.
Lightning storms create
additional risk of fire.
High summer
temperatures cause health
problems for those
without air-conditioning,
and drought is a potential
consequence. Freezing
temperatures are not
uncommon for several
days in the winter,
although prolonged hard
freezes in the 20s or
below are rare. Snow or
ice are relatively common
occurrences.
In Renton, most power lines
are overhead rather than
underground, and vulnerable to
wind damage. This frequently
causes power outages and road
closures due to fallen trees.
Snow and ice storms similarly
lead to power loss, blocked
roads, and hazardous
conditions, increasing the risk
of accidents and economic
losses for businesses. Typically
mild summers mean many
homes lack air conditioning,
heightening health risks for
vulnerable individuals during
extreme heat. Additionally,
most homes do not have
basements, limiting shelter
options in the rare event of a
tornado. Severe winter weather
can leave residents housebound
for days, restricting access to
food, medications, and medical
care. Freezing temperatures can
burst pipes in businesses and
homes, including fire sprinkler
systems. In a major snow or ice
event, the weight of
accumulation can pose a risk of
roof collapse. For Renton’s
homeless population, exposure
to extreme cold presents a
direct threat to life if adequate
shelter is unavailable.
Over time, the increasing
average annual temperature will
create additional health risks due
to extreme heat and generate an
increase in thunderstorm activity
with lightning/wildfire risk and
localized high winds, including
tornado potential. The risk of
drought could impact the city’s
water supply, which is 98%
dependent upon groundwater
sources (wells and springs).
Seattle Public Utilities provides
approximately 2% of the city’s
water supply. The city’s water
utility supplies water to 73% of
the total city area. The remaining
27% of the area within the city is
served by adjacent water districts
(Soos Creek Water and Sewer
District, Water District #90 and
others). Severe winter weather
will continue to recur, causing
transportation disruption,
personal injury, economic injury,
and property damage.
Terrorism Terrorism falls into two
categories: domestic
terrorism and
international terrorism.
The threat of both has
been increasing
significantly since 9/11,
particularly due to three
specific factors: the
internet, social media, and
Homegrown Violent
Extremists (HVE).
The form and locations of
many natural and/or manmade
hazards are identifiable and
even, in some cases,
predictable, however, there is
no defined geographic
boundary for terrorism. Based
on previous historical events, it
is presumed that critical
facilities, services, and large
gatherings of people are at
higher risk.
Large gatherings are considered
a soft target for terrorist attacks.
The potential for mass
casualties, the strain on medical
and law enforcement resources,
and the negative psychological
effects of fear in the community
are substantial. Hard targets of
terrorism, like critical
infrastructure, when affected,
can jeopardize the health, safety,
mobility, and communications
capability for the entire city, and
compromise other essential
services and lifelines.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 8
HAZARD RISK SUMMARY VULNERABILITY SUMMARY IMPACT SUMMARY
Tsunami/
Seiche
The city would not be
impacted directly by a
tsunami, but it may
experience seiches.
Seiches may form on
enclosed or semi-
enclosed bodies of water
(e.g., lakes, rivers, etc.)
from wind, atmospheric
pressure, or seismic
waves. An earthquake
would be the most likely
cause of a seiche in
Renton.
Many homes and businesses,
including Boeing’s
manufacturing facility, the
Seahawks headquarters and
practice facility, the Renton
Municipal Airport, a King
County Library, and many
small businesses are located on
the shores of the Cedar River
or Lake Washington.
Additionally, several roads and
bridges are within reach of a
seiche.
Structures near the water -
including residential and
commercial buildings, roads,
bridges, and other infrastructure
- may be impacted by a seiche,
leading to injuries, loss of life,
property destruction, and
damage to public infrastructure
Volcano Although the city is
outside of a direct lahar
flow from any volcano,
secondary flooding on the
Green River could be the
result of a Mt. Rainier
eruption. Mt. Rainier, and
potentially other area
volcanoes, depending on
wind direction, can
generate ashfall that
significantly impacts the
City of Renton.
Ashfall causes premature wear
and failure of automobile
engines and electronics. It
disrupts air travel, shorts out
electricity on power lines
causing widespread power
outages, clogs gutters, causes
property damage, accumulates
on flat roofs creating roof
collapse risk, creates slippery
road surfaces resulting in traffic
accidents, and triggers
significant health issues in
vulnerable individuals.
The risk of an ashfall event from
the nearest volcano, Mt. Rainier,
remains constant over time. The
power outages, damage to
homes and businesses,
compromised automobiles and
electronics, and health risks to
some residents would have a
significant impact on the city.
Wildfire Power lines, railroad cars,
structure fires, lightning,
and human behavior can
start fires anywhere. Parts
of the City of Renton are
heavily treed or covered
in brush, and some are in
the Wildland-Urban
Interface putting
residents and businesses
there even more at risk.
Some areas of Renton have
poor evacuation options and
limited access for fire
apparatus. A wind-driven
structure fire like the Regency
Woods apartment fire of 2014
can rapidly engulf neighboring
homes, trapping residents in
areas without sufficient road
capacity to handle an
evacuation and threatening
critical electrical infrastructure.
As climate change generates
higher average temperatures
annually and increased drought
risk, the fire danger for Western
Washington is increasing.
Climatologists predict that
eventually Western Washington
fire risk will equal that of the
much drier and historically fire-
prone Eastern Washington.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 9
Hazard and Asset Overview Maps
Figure 1: Composite hazard map of Renton.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 10
Figure 2: Earthquake liquefaction susceptibility.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 11
Figure 3: Flood hazard areas in the mapped floodplains.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 12
Figure 4: Known landslide hazard areas.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 13
Figure 5: Known coal mine hazard areas.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 14
City of Renton Assets at Risk
ASSET VALUE ($) HAZARD SUMMARY VULNERABILITY
SUMMARY
IMPACT SUMMARY
Fire Stations $59,694,672 Fire stations in Renton
may be affected by
many hazards including
earthquake, flooding,
liquefaction, and
wildfire. There are seven
stations spread across
the city, each may face
varying degrees of the
hazard based on its
proximity to fault lines,
flood-prone areas,
liquefaction zones, and
potential wildfire areas.
Six fire stations have been
retrofitted with modern
building code standards
designed to reduce
vulnerability to
earthquakes, however one
remains to be updated.
The fire stations are
structurally susceptible to
earthquake, flooding,
liquefaction, and wildfire.
Damage to a fire station
from any of the
aforementioned hazards
could lead to operational
downtime, reducing
emergency response
capabilities for the entire
city. Structural damage
would necessitate costly
repairs or temporary
relocation of staff and
equipment. Water
damage could impact
firefighting equipment
and vehicles.
Urgent Care
Clinics and
Hospitals
$366,004,200 Urgent care clinics and
hospitals in Renton may
be affected by hazards
such as earthquakes,
floods, severe storms,
cyber incidents, and
pandemics. There is one
urgent care clinic and
one hospital across the
city, each facing varying
degrees of susceptibility
to fault lines, flood-
prone areas, power
outages, cyber-attacks,
and patient surge
capacity.
Urgent care clinics and
hospitals are vulnerable to
structural damage as well
as functional disruptions.
These clinics and hospitals
rely heavily on medical
supplies and electricity,
making them vulnerable
during power outages and
supply chain disruptions.
In a pandemic, shortages
of staff and supplies, and
increased patients can
worsen these
vulnerabilities.
Damage to urgent care
clinics and hospitals
could disrupt critical
healthcare services for
the community.
Structural damage may
necessitate repairs or
even temporary closures,
reducing local healthcare
capacity. Power outages
may disrupt the delivery
of medical treatments,
delaying medical care.
Pandemics may
overwhelm urgent care
clinics and hospitals and
lead to wider public
health impacts.
Government
Infrastructure
$20,506,687 Government
infrastructure in
Renton, such as City
Hall and public works
buildings may be
impacted by hazards
such as earthquake,
floods, severe storms,
and cyber-attacks. There
are 20 city-owned
facilities across the city
that are susceptible to
fault lines, flood-prone
areas, power outages,
and cyber-attacks.
Government
infrastructure in Renton
that is not seismically
retrofitted to modern
standards is vulnerable to
structural damage from
earthquakes. Power
outages from storms may
disrupt city services.
Reliance on digital systems
makes government
infrastructure vulnerable
to cyber-attacks, which
may impair city services.
Damage to government
infrastructure may
severely hinder the city's
ability to provide
essential services.
Damages may require
temporary relocation of
services, disruption of
operations, and delayed
communication. Digital
disruptions from a cyber
incident may
compromise critical
systems and reduce the
city's services.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 15
ASSET VALUE ($) HAZARD SUMMARY VULNERABILITY
SUMMARY
IMPACT SUMMARY
Community
Infrastructure
$6,127,924 Community
infrastructure, including
community and senior
centers in Renton, may
be affected by most
hazards. There are two
community centers and
one senior center in
Renton that are
susceptible to fault-
lines, flood-prone areas,
power outages, and
extreme weather.
Renton's community
infrastructure is built to
modern building codes.
The centers are vulnerable
to power outages, which
disrupt building operations
and communications. The
centers serve at-risk
populations who are more
vulnerable during extreme
weather events, which can
result in serious health
consequences.
Damage to these
community infrastructure
facilities could result in
temporary closures,
disrupting services and
programs to the
community, especially
vulnerable populations
who rely on these centers
for social support, meals,
and shelter.
Schools $1,168,853,362 Schools in Renton may
be vulnerable to many
hazards including
earthquakes, floods,
severe storms, and
severe weather. There
are 29 public schools
and several private
schools across the city
that may be susceptible
to fault-lines, flood-
prone areas, power
outages, and extreme
heat and cold weather.
Renton school
infrastructure is vulnerable
to earthquakes, and 10
buildings are in the
process of being
retrofitted or built to
modern building codes.
School campuses are also
vulnerable to flooding in
low-lying areas and power
outages due to storms.
School infrastructure is
also vulnerable in extreme
weather, putting students
and staff at risk in extreme
heat and cold weather.
Damages to school
infrastructure could lead
to closures, disrupting
education and creating
safety concerns for all
students and food
insecurity for students
who rely on schools for
meals. Temporary
relocation of school
infrastructure or school
closures could strain the
school system and
impact parents and the
broader community.
Disruption to power may
disrupt heating, cooling,
technology, and limit
school activities.
Roadways $217,000,000 Roadways in Renton are
exposed to earthquakes,
flooding, landslides, and
severe storms. There are
753 miles of roadways
in Renton, which can be
susceptible to fault lines,
flood-prone areas,
unstable soils, and
severe weather.
Roadways in Renton are
vulnerable to ground
shaking and liquefaction
during earthquakes and
washouts and standing
water in flood-prone areas
impacting the integrity of
road surfaces. Both severe
storms and landslides may
increase debris over
roadways.
Damage to Renton's
roadways may
significantly disrupt
transportation and
hinder movement of
people, goods, and
emergency vehicles.
Extensive damage may
lead to lengthy road
closures, repairs, and
restricted access, which
complicate evacuation
routes and isolate
neighborhoods.
Prolonged road closures
disrupt daily commuting
and commercial activity,
with economic
consequences.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 16
ASSET VALUE ($) HAZARD SUMMARY VULNERABILITY
SUMMARY
IMPACT SUMMARY
Bridges $300,000,000 Bridges in Renton are
exposed to earthquakes,
flooding, landslides, and
severe storms. There are
26 vehicle and one
pedestrian bridges in the
Renton Public Works
bridge inventory, many
of which span fault
lines, flood-prone rivers,
and areas of unstable
soil. Severe weather
conditions such as
heavy rain, snow, and
high winds also pose
risks to bridge
structures.
Many bridges in Renton
are aging and eight have
not been designed or
retrofitted to withstand
seismic activity and thus
have been identified for
further evaluation for
seismic upgrades. 23
bridges in Renton cross
rivers that are prone to
flooding. Bridges in areas
of unstable soil are at
higher risk of damage due
to landslide or
liquefaction.
Damage to Renton's
bridges could disrupt
critical transportation
routes for emergency
response, critical
resources, and daily
commutes. Bridge
closures could result in
significant economic
losses, delays in
emergency services, and
increased congestion on
alternative routes.
Drinking
Water System
(distribution
reservoirs,
pump
stations,
wells, and
treatment
systems)
$107,661,633 The Renton drinking
water system consists of
nine active wells and
one spring water supply
facility, with seven water
treatment systems and a
water treatment plant
that serves three wells at
the Maplewood Golf
Course. There are 10
water storage reservoirs,
50 pressure reducing
valve stations, 12
booster pump stations,
and 318 miles of water
distribution pipe system.
The water systems in
Renton are exposed to
earthquakes, flooding,
landslides, severe
storms, and cyber
incidents. The drinking
water system can be
susceptible to seismic
events, flood-prone
areas, unstable soils,
severe weather
conditions, and cyber-
attacks.
The drinking water system
is vulnerable to seismic
and liquefaction activity.
The water supply wells
and spring, along with
portions of the
distribution system in
Renton are located near
rivers or low-lying areas at
risk of flooding. Hazards
such as landslides and
severe storms can cause
power supply outages or
damage both above
ground and underground
infrastructure leading to
potential contamination
and service disruptions.
Damage to the Renton
drinking water systems
would have immediate
and widespread impact
on Renton's residents,
businesses, and
emergency services. A
disruption in water
supply or contamination
of water sources could
pose serious public
health risks, limit
firefighting capabilities,
and affect critical
facilities such as hospitals
and schools. Recovery
from severe damage to
these systems could have
long-term effects on the
community and
economy.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 17
Plan Update Process
To convene the planning team, the city expanded the existing Emergency Management Group’s membership,
which has representation from each department and the Renton Regional Fire Authority. The invitation included
subject matter experts who could contribute to the plan.
The planning process began with some staff attending the King County Hazard Mitigation Plan kickoff meeting
and workshops. The planning team met twice in joint work sessions to review assets and infrastructure, to
determine threats and assess risk, and to identify mitigation solutions to reduce those risks. Planning team
members then worked outside the group session to develop the mitigation strategies that are included in this plan
revision.
Jurisdiction Planning Team
NAME TITLE ORGANIZATION CONTRIBUTION
Daniel Alexander Captain Renton Regional
Fire Authority
Strategy discussions, worksheets,
share information, plan review
Chris Barnes Transportation
Operations Manager City of Renton Strategy discussions, worksheets,
share information, plan review
Ethan Belen Civil Engineer III City of Renton Strategy discussions, worksheets,
share information, plan review
Chester Bennett Civil Engineer City of Renton Strategy discussions, worksheets,
share information, plan review
Steve Brown Parks Maintenance
Manager City of Renton Strategy discussions, worksheets,
share information, plan review
Sean Clagget Recreation Supervisor City of Renton Strategy discussions, worksheets,
share information, plan review
Sean Conway Recreation Supervisor City of Renton Strategy discussions, worksheets,
share information, plan review
Manuel Cruz Airport Director City of Renton Strategy discussions, worksheets,
share information, plan review
Alan Findlay Structural Plans Examiner City of Renton Strategy discussions, worksheets,
share information, plan review
Stephen Forsythe Street Maintenance
Supervisor City of Renton Strategy discussions, worksheets,
share information, plan review
Abdoul Gafour Utility Engineering
Manager City of Renton Strategy discussions, worksheets,
share information, plan review
Jayson Grant Pavement Management
Technician City of Renton Strategy discussions, worksheets,
share information, plan review
Ian Gray Urban Forestry & Natural
Resources Manager City of Renton Strategy discussions, worksheets,
share information, plan review
Brian Hammon Facilities Manager City of Renton Strategy discussions, worksheets,
share information, plan review
Matt Herrera Planning Director City of Renton Strategy discussions, worksheets,
share information, plan review
Cailín Hunsaker
Parks & Trails Director City of Renton Strategy discussions, worksheets,
share information, plan review
John Kalmbach Street Maintenance
Manager City of Renton Strategy discussions, worksheets,
share information, plan review
Krista Kolaz Risk Manager City of Renton Strategy discussions, worksheets,
share information, plan review
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 18
Angel Laycock Communications Manager City of Renton Strategy discussions, worksheets,
share information, plan review
Katie Medina Civil Engineer City of Renton Strategy discussions, worksheets,
share information, plan review
Hannah Miller Admin Assistant to
Executive Services City of Renton Strategy discussions, worksheets,
share information, plan review
Jeffrey Minisci Facilities Director City of Renton Strategy discussions, worksheets,
share information, plan review
Deborah Needham Emergency Management
Director City of Renton
Renton planning coordination,
strategy discussions, worksheets,
research, share information, plan
review, RHMP Steering Committee
lead Renton representative
Laura Pettit Communications Director City of Renton Strategy discussions, worksheets,
share information, plan review
Curt Russell Senior Risk Management
Analyst City of Renton Strategy discussions, worksheets,
share information, plan review
Robert Shuey Development Services
Director City of Renton Strategy discussions, worksheets,
share information, plan review
Jennifer Spencer Recreation Director City of Renton Strategy discussions, worksheets,
share information, plan review
Ronald Straka Utility Systems Director City of Renton Strategy discussions, worksheets,
share information, plan review
MJ Thomas Emergency Management
Coordinator City of Renton
Strategy discussions, worksheets,
research, share information, plan
review, RHMP Steering Committee
alternate Renton representative
Brett Tietjen Network Systems
Manager City of Renton Strategy discussions, worksheets,
share information, plan review
Alex Tuttle Senior Assistant City
Attorney City of Renton Strategy discussions, plan review
Guy Williams Human Services Manager
(Parks & Rec) City of Renton Strategy discussions, worksheets,
share information, plan review
Young Yoon IT Director City of Renton Strategy discussions, worksheets,
share information, plan review
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 19
Plan Update Timeline
PLANNING ACTIVITY DATE SUMMARY ATTENDEES
City of Renton
Hazard Mitigation
Planning Group
Meeting
2/1/2024 Introduction of Plan
Review Tool and Hazard
Mitigation Plan major
revision timeline.
City of Renton Hazard Mitigation
Planning Group
City of Renton
Hazard Mitigation
Planning Group
meeting
4/11/2024 Update on timelines and
expectations.
City of Renton Hazard Mitigation
Planning Group
RHMP Steering
Committee
4/18/2024 Equity and social justice
discussion.
Renton Hazard Mitigation Planning
Group lead
RHMP Steering
Committee Meeting
5/9/2024 Equity discussion. Renton Hazard Mitigation Planning
Group lead
Regional Hazard
Mitigation Annex
Workshop
7/11/2024 Guidance on development
of annexes.
Renton Hazard Mitigation Planning
Group lead
Breakout sessions of
City of Renton
Hazard Mitigation
Planning Group
9/17/2024-
9/30/2024
Updates to project
statuses, generation of
2024 and overall project
progress reports.
Select Renton Hazard Mitigation
Planning Group members
City of Renton
Hazard Mitigation
Planning Group
meeting
10/3/2024 Review of draft updates,
generate new mitigation
strategy ideas.
City of Renton Hazard Mitigation
Planning Group members
Breakout sessions of
City of Renton
Hazard Mitigation
Planning Group as
needed
10/3/2024-
12/5/2024
Reference and integrate
with other plans, data
collection related to
floodplain administration
questions, assets at risk
inventory, update data in
plan, generate new or
revised strategies.
Select City of Renton Hazard
Mitigation Planning Group members
RHMP Steering
Committee Meeting
10/24/2024 Rankings, capability
assessments, strategy
update discussion.
Renton Hazard Mitigation Planning
Group lead
RHMP Steering
Committee
11/14/2024 Mitigation strategy
discussion
Renton Hazard Mitigation Planning
Group lead
City of Renton
Hazard Mitigation
Planning Group
Meeting
12/5/2024 Review compiled draft
plan, prioritize citywide
projects, identify gaps.
City of Renton Hazard Mitigation
Planning Group
RHMP Steering
Committee
1/16/2025 Final review for city
partners, identify gaps.
Renton Hazard Mitigation Planning
Group lead and alternate
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 20
Public Outreach
Public Outreach Events
EVENT DATE SUMMARY ATTENDEES
Special web page and
online survey
published
12/8/2023 Published a new informational
web page on mitigation and the
mitigation plan revision.
Published a survey to gather
resident/business input for the
plan revision. Solicited input
from the public on hazard
mitigation.
Aware: 254
Informed: 83
Engaged: 15
Survey: 14 responses
Published in “This
Week In Renton”
(TWIR)
12/20/2023
Published the invitation to
comment in TWIR
Total sent to: 23,377
Total opens: 10,055
Unique opens: 7,015
Total clicks: 337
Unique clicks: 306
Social media posts
about hazard
mitigation plan update
1/3/2024
Published an announcement and
invitation for input to the plan
revision on Facebook.
Facebook: Engagement - 49
Instagram: Engagement -72
X: Engagement - 20
Web page updated
with information and
draft plan prior to
review by King County
2/4/2025 Demonstrate incorporation of
comments and feedback from
the public.
Page hits were pending at time
of submission.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 21
City of Renton Hazard Mitigation Program
Hazard mitigation strategies were developed through a two-
step process. The City of Renton met with an internal
planning team, an expansion of the existing Emergency
Management Group that meets monthly in the city, to identify
a comprehensive range of mitigation strategies. These
strategies were then prioritized using a process established at
the county level and documented in the base plan.
Each department or agency that has submitted a strategy plan
will continue to work towards progress on that strategy. This
includes advocacy for budget allocations, workload
assignments, and grant applications that support
accomplishment of those strategies.
Plan Monitoring, Implementation, and Future Updates
King County leads the mitigation plan monitoring and update process and schedules the annual plan check-ins and
bi-annual mitigation strategy updates. Updates on mitigation projects are solicited by the county for inclusion in
the countywide annual report.
As a participant in the 2025 update to the Regional Hazard Mitigation Plan, the City of Renton agrees to convene
their internal planning team at least annually to review their progress on hazard mitigation strategies and to update
the plan based on new data or recent disasters. This will be a breakout session of members of the city’s Emergency
Management Group that will convene in August, October, or December to conduct this review.
When King County Emergency Management sends federal notices of funding opportunity for the Hazard
Mitigation Assistance Grant Program, the city will evaluate the viability of projects eligible for such grants and will
submit grant applications if appropriate to align with the priorities of the Hazard Mitigation Plan. This will be a
key strategy to implement the plan.
The next plan update is expected to be due in April 2030. The City of Renton will submit a letter of intent by
2028, at least two years prior to plan expiration. The county will lead the next regional planning effort, beginning
at least 18 months before the expiration of the 2025 plan.
Continued Public Participation
The City of Renton already maintains substantial public outreach capabilities, focusing on personal preparedness
and education. Updates on the progress of hazard mitigation plan implementation will be incorporated into public
outreach efforts. This will provide Renton residents, already engaged in personal preparedness efforts, with
context and the opportunity to provide feedback on the county’s progress and priorities in large-scale mitigation.
In the vertical integration of risk-reduction activities from personal to local to state and federal, it is important that
the public understand how its activities support and are supported by larger-scale efforts.
The outreach and mitigation teams will also continue to work with media and other agency partners to publicize
mitigation success stories and help explain how vulnerabilities are being fixed. When possible, public tours of
mitigation projects will be organized to allow community members to see successful mitigation in action.
King County Overall Plan
Goals
The goal of the 2025 King County
Regional Hazard Mitigation Plan
is to create a framework that
reduces the impact and
susceptibility of the identified
hazards on people, property, and
the environment, prioritizing
historically underserved
communities.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 22
Hazard Mitigation Authorities, Responsibilities, and Capabilities
Plans
PLAN TITLE RESPONSIBLE AGENCY POINT OF CONTACT RELATIONSHIP TO HAZARD
MITIGATION PLAN
Comprehensive
Plan
City of Renton Community
and Economic
Development Department
Community &
Economic
Development
Administrator;
Planning Director
Includes policies applicable to
sensitive areas and principles for
future development.
Comprehensive
Emergency
Management
Plan
City of Renton Office of
Emergency Management
Emergency
Management Director
Comprehensive Emergency
Management Plans currently
include mitigation approaches
with roles/responsibilities of
city departments and
community partners.
Capital Facilities
Plan
City of Renton Public
Works Department
Finance Department
Parks and Recreation
Department
Parks and Recreation
Administrator
Finance Administrator
Public Works
Administrator
Identifies critical facilities and
major improvement or
construction projects that need
to consider
hazards/vulnerabilities, and
appropriate mitigation measures.
Urban Forest
Management
Plan
City of Renton Parks and
Recreation Department
Urban Forestry and
Natural Resources
Manager
Details annual tree maintenance
and inspection protocols for
public safety. Well maintained
trees are inherently less
hazardous and prone to
catastrophic failure. Urban tree
canopy cover also mitigates
problems from urban heat.
Includes a risk tree inspection
plan and staff training program.
Staff includes ISA Certified Tree
Risk Assessors.
Utilities plans Water Utility System Plan;
Long Range Wastewater
Management Plan; Surface
Water Utility System Plan
Utility Systems
Director
Identifies systems and essential
services that need to consider
hazards/vulnerabilities, and
appropriate mitigation measures.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 23
Programs, Policies, and Processes
PROGRAM/POLICY RESPONSIBLE AGENCY POINT OF CONTACT RELATIONSHIP TO HAZARD
MITIGATION PLAN
Building Codes City of Renton
Community and
Economic Development
Department
City of Renton Building
Official
Building code development
should be based on a
common understanding of
hazards described in this plan.
Emergency
Management
Program
City of Renton
Executive
Department/Emergency
Management Division
Emergency Management
Director
Tracking of disaster impacts,
new or changing hazards,
public engagement around
mitigation.
Critical Areas
Ordinance
Community and
Economic Development
Community & Economic
Development Administrator,
Planning Director
Regulate development in
sensitive areas.
City of Renton
Utility Services
Public Works
Department
Public Works Administrator
Utility Systems Director
Maintenance Services
Director
Solid Waste Program
Manager
Maintenance of working
systems should be based on a
common understanding of
hazards described in this plan.
Fire Code Renton Regional Fire
Authority
Fire Marshal Fire code development should
be based on a common
understanding of hazards
described in this plan.
Entities Responsible for Hazard Mitigation
AGENCY/ORGANIZATION POINT OF CONTACT RESPONSIBILITY(S)
Community and
Economic Development
Department
Community and
Economic Development
Administrator,
Planning Director
Policy and planning input to decrease community
vulnerability over time and react to emergencies.
Parks and Recreation
Department
Parks and Recreation
Administrator
Mitigating damage to and preserving natural
resources.
Executive Services
Department
Deputy Chief
Administrative Officer,
Emergency Management
Director, Information
Technology Director
Planning process oversight, public education and
engagement, and hardening of cyber infrastructure.
Police Department Police Chief, Police
Commander - Patrol
Law enforcement, including mitigation and response
to civil disturbances and acts of terrorism.
Public Works
Department
Public Works
Administrator
Critical infrastructure mitigation (roads, bridges,
utilities, etc.), floodplain management, mitigating
damage to city facilities, hazardous materials
mitigation, emergency response and recovery.
Renton Regional Fire
Authority
Fire Chief Wildfire mitigation, public education and engagement,
fire code development and enforcement, hazardous
materials mitigation, emergency response and
recovery.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 24
National Flood Insurance Program
The City of Renton is a member of and actively participates in the National Flood Insurance Program, which
makes flood insurance available to Renton property owners. The city oversees compliance with the National Flood
Insurance Program requirements for new construction and provides information to property owners in Special
Flood Hazard Areas regarding flood insurance requirements.
National Flood Insurance Program Compliance
What department is responsible for floodplain
management in your community?
Shared responsibility and partnership between the
Community and Economic Development
Department and the Public Works Department.
Who is your community’s floodplain administrator?
(title/position)
Community and Economic Development
Department Administrator.
What is the date of adoption of your flood damage
prevention ordinance?
May 8, 1981 (Ordinance 3537), last update on
July 5, 2015 Ord. 5757.
When was the most recent Community Assistance
Visit or Community Assistance Contact?
June 17, 2019, Matt Gerlach, Regional NFIP
Coordinator and Dave Radabaugh, Washington
State Department of Ecology Shorelands and
Environmental Assistance Program
Does your community have any outstanding NFIP
compliance violations that need to be addressed? If
so, please state what they are?
No outstanding NFIP compliance violations.
Do your flood hazard maps adequately address the
flood risk within your community? If so, please state
why.
Once the new King County DFIRM follows the
letter of final determination from FEMA, the
flood hazard maps will adequately address flood
risks in Renton except for in the portion of the
Green River floodplain in Renton. The Green
River floodplain is identified as a seclusion area in
the DFIRM that still utilizes the old FEMA
Flood Insurance Rate Maps until an updated
Flood Insurance Study and map is completed.
Does your floodplain management staff need any
assistance or training to support its floodplain
management program? If so, what type of
training/assistance is needed?
Yes, overview of NFIP current requirements for
new and existing employees. Training on the
information needed and how to complete the
updated Building Elevation Certificate and
training needed for becoming a certified
floodplain manager.
Does your community participate in the Community
Rating System (CRS)? If so, what is your CRS
Classification and are you seeing to improve your
rating? If not, is your community interested in joining
CRS?
Yes. CRS Classification 5. The City of Renton is
seeking to maintain this rating and possibly
improve our rating as part of the next CRS
verification review.
How many Severe Repetitive Loss (SRL) and
Repetitive Loss (RL) properties are located in your
jurisdiction?
SRL: 0
RL: 0
Has your community ever conducted an elevation or
buy out of a flood-prone property? If so, what fund
source did you use? If not, are you interested in
pursuing buyouts of flood-prone properties?
n/a
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 25
Hazard Mitigation Strategies
The city has made notable progress in mitigation projects over the past five years. Major accomplishments include
planning for a major dredging project on the Cedar River to prevent flooding; completion of existing conditions
assessments and the design phase for improvements to the levees and floodwalls; installation of standby
emergency power generators at key locations; completion of a water system assessment and emergency plan; and
amending sheltering plans to mitigate health effects of wildfire smoke.
In the reformatting of this plan, several strategies have been reevaluated, and some have been deprecated. Others
have been converted into the new format of strategies. Those changes have been indicated in the table below.
2020 Hazard Mitigation Strategy Status
STRATEGY DESCRIPTION PRIORITY STATUS
Airport
Earthquake
and Seismic
Mitigation
Recent survey has identified the
Seaplane Ramp is settling and
developed significant cracking
due to a developed void
underneath. The Airport needs
to rebuild/reinforce the ramp.
Multiple conduits and water
mains are routed under the
runway. Reinforcing this
infrastructure to resist seismic
activity would prevent loss of air
traffic control communication
capabilities and hydraulic mining
under the runway surface.
High From 2020-2024 the city submitted
multiple grant pre-applications, attempting
to secure funding for this seismic mitigation
project. As this strategy has been
unsuccessful, the city is now pursuing
funding to replace the tower. Three
applications have been made to different
funding sources but as yet have not been
awarded. This project scope is being
rewritten to reflect this different approach.
Cedar River
Section 205
Flood Hazard
Reduction
Project –
Operation
and
Maintenance
The objective of this program is
to operate and maintain the
levees in accordance with the
Operation and Maintenance
Manual (O&MM) and maintain a
minimally acceptable rating
following each United States
Army Corps of Engineers
(USACE_ levee inspection.
Medium The city continued to operate and maintain
the Cedar River Section 205 levee in
accordance with the operation manual and
the sponsorship agreement with the US
Army Corps of Engineers. The levee has
continued to receive a minimally acceptable
rating and continued to pass every routine
and periodic inspection conducted by the
Corps and thus remains eligible for federal
sponsorship and emergency assistance
under public law 84-99.
Cedar River
Gravel
Removal
Project
The objective of this project is
to periodically (every 12-18
years) dredge the bed of the
Cedar River to reduce the risk of
flooding and protect adjacent
properties.
Medium Following the 2016 gravel removal project,
the city entered a 10-year post construction
mitigation monitoring and reporting phase
that will extend to 2027. In addition to the
mitigation requirements, the city continues
to monitor sediment deposition and is
anticipated to initiate design and permitting
for the next gravel removal project in 2026.
STRATEGY DESCRIPTION PRIORITY STATUS
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 26
Cedar River
Section 205
Levee
Certification
Project
Several sections of the levees
and floodwalls need
improvements in order to
provide sufficient freeboard or
increase structural stability to
meet current levee certification
standards. The City of Renton is
permitting, designing, and
constructing these
improvements.
Medium The city completed design of the levee
improvements aimed at achieving FEMA
accreditation of the Cedar River Section
205 Levee as providing protection from the
100-year flood. Construction is planned for
2026, pending completion of section 408
review with the US Army Corps of
Engineers and Endangered Species Act
compliance with FEMA.
Coal Mine
Study
Mitigation
Strategy
Update and verify historic maps
of coal mine features and overlay
these with vulnerable
infrastructure to assist in
identifying potential hazards.
Identify methods to stabilize
areas where critical infrastructure
is at risk from subsidence.
Low This project, originally anticipated to begin
in 2020, was deferred due to shifting
priorities and personnel changes subsequent
to the onset of the COVID pandemic. Staff
and resource allocation had not yet been
identified to begin work on this mitigation
strategy.
Funding/
Partnership
Mitigation
Strategy
Reach out to community
partners to determine shared
concerns and priorities around
hazard mitigation, and negotiate
cost-share agreements for shared
projects, or allocate matching
funds from city budget to meet
grant requirements.
Low The city has continued to vie for project
funds through the Hazard Mitigation/BRIC
grant programs. City representatives have
submitted pre-applications, but Renton
projects have not yet been funded.
Lower Cedar
River Flood
Risk
Reduction
Feasibility
Study
This study would explore
measures to prevent localized
flooding and reduce the flooding
risks during extreme events and
the feasibility of achieving such a
level of protection.
Medium The city completed an existing conditions
assessment and is exploring scenarios
reflecting climate change that would be
analyzed under future conditions.
Alternative measures to reduce flood risk
during extreme events and the feasibility of
achieving a higher level of protection than
the 100-year flood will be assessed.
Maintenance
Facility
Standby
Emergency
Power
The maintenance facility
currently only has back-up
power generation that allow for
partial operation, which impacts
the city’s ability to respond to
hazards that result in power
outages. The increased back-up
power generation will provide
full power to the facility for
hazard emergency response
without limitation due to only
partial power at the City of
Renton Maintenance Shop
Facility.
High A standby emergency power generator was
installed at the maintenance facility in 2021.
Additional maintenance facility electrical
panel switch modifications are planned to
increase the amount of power the
maintenance facility can accept for the
standby power generator.
STRATEGY DESCRIPTION PRIORITY STATUS
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 27
Regional
Planning
Mitigation
Strategy
This plan will identify
opportunities to support
countywide initiatives identified
in the overall King County
Regional Hazard Mitigation Plan
and actively participate in the
plan maintenance strategy
identified.
Medium The city is actively engaged in contributing
to countywide initiatives, with
representatives serving on the regional
steering committee for the county’s five-
year major plan revision during 2024-2025.
This commitment is reflected in the
Emergency Management Strategic Plan for
the city and will be carried into the next
plan review cycle.
Utility
Pumping
Facilities
Back-Up
Power
The city will evaluate emergency
standby power options,
including installing on-site
generators and increasing fuel
storage, to lessen the impact of
future power outages at utility
pumping facilities.
High A new standby emergency power generator
was installed at the West Hill pump station
in 2024. Proposed emergency generator to
be installed at South Talbot pump station in
2025-2026.
Volcanic Ash
& Wildfire
Smoke
Mitigation
Strategy
May 18, the anniversary of Mt.
St. Helen’s eruption, will serve as
an annual ash and wildfire
smoke awareness campaign
launch. It will include social
media and public
communications regarding
education on the risk to Renton
residents; appropriate actions if
the hazard occurs; and ways to
lessen the impact of poor air
quality on human health, as well
as transportation and general
visibility.
Low This strategy has been advanced through
extensive public education efforts regarding
wildfire smoke risks. Messaging was
developed by Public Health – Seattle and
King County and Puget Sound Clean Air
Agency and amplified through city
channels. Additionally, the city amended
sheltering operational plans to include
thresholds and protocols for providing
shelter options to the general public based
on air quality due to wildfire smoke to
mitigate the health hazards associated with
poor air quality.
Water System
Risk
Assessment
The risk assessment will 1)
inventory at-risk water
infrastructure that contribute to
critical functionality of the water
system; 2) evaluate the risk and
known vulnerabilities to
significant threats and hazards;
and 3) implement prevention,
protection, and mitigation
activities for identified threats
and hazards. The Water Utility
will develop partnerships with
local emergency response and
planning groups to foster hazard
mitigation activities.
Medium The city has completed the Water System
Risk & Resiliency Assessment and
Emergency Response Plan update in
December 2020.
STRATEGY DESCRIPTION PRIORITY STATUS
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 28
Water Utility
Seismic
Resilience
The Water Utility will apply to
participate in Pacific Northwest
Seismic Network’s new pilot
program that monitors
earthquake activity using a
network of sensors distributed
across the region.
High The city has completed the Water Utility
Seismic Resilience Plan as part of the Water
System Risk & Resiliency Assessment and
Emergency Response Plan update in
December 2020. The ShakeAlert project
was abandoned after a failed grant
application, and instead there are plans to
install seismic valves on reservoir outlet
pipes.
2025 Hazard Mitigation Strategies
The following strategies emerged as the best mitigation focus for the City of Renton over the next five years,
with some projects in a monitoring status, such as the Cedar River Gravel Removal Project after dredging, to
determine longer range mitigation needs 10 years out or more. All strategies represent the city’s intention to
mitigate where possible and in the manner described within each proposed strategy. However, the ability of
the city to carry out specific proposals may be affected by unforeseeable circumstances or context (such as
immediate disaster response and recovery needs taking precedence), changing legal or regulatory
requirements, and resource availability (i.e., grant funding, budgetary constraints, staffing, etc.).
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 29
2025 Hazard Mitigation Strategies
STRATEGY LEAD AGENCY/POC TIMELINE PRIORITY
Airport Seismic Mitigation Renton Public Works/Airport
Manager
2025–2027 High
Cedar River Section 205 Flood
Hazard Reduction Project –
Operation and Maintenance
Renton Public Works/Surface Water
Engineering Manager
Ongoing Medium
Cedar River Gravel Removal
Project
Renton Public Works/Surface Water
Engineering Manager
2031–2037 Medium
Cedar River Section 205 Levee
Certification Project
Renton Public Works/Surface Water
Engineering Manager
2025 Medium
Civil Disturbance Mitigation Renton Police/ Police Commander -
Patrol
Ongoing Low
Coal Mine Study Mitigation
Strategy
Renton Community and Economic
Development/Planning Director and
Building Plan Reviewer
2025–2030 Low
Cyber Incident Disaster
Recovery Site
Renton Information
Technology/Information Technology
Director
2025 High
Funding/Partnership
Mitigation Strategy
Renton Emergency
Management/Emergency
Management Director
2025 and
ongoing
Low
Hazardous Materials Public
Education
Renton Public Works Solid Waste
Program Manager
2026 and
ongoing
Low
Lower Cedar River Flood Risk
Reduction Feasibility Study
Renton Public Works Surface Water
Engineering Manager
2025 Medium
Maintenance Facility Standby
Emergency Power
Public Works Department Facilities
Director
2025 High
Public Health Emergency
Mitigation
Renton Emergency
Management/Emergency
Management Director
2025 and
ongoing
Low
Regional Planning Mitigation
Strategy
Renton Emergency
Management/Emergency
Management Director
Ongoing Medium
Terrorism Mitigation Renton Police/Commander –
Administrative Services
Ongoing Low
Tsunami/Seiche Renton Community and Economic
Development/Planning Director
2025-2030 Low
Utility Pumping Facilities
Back-Up Power
Renton Public Works/Utility Systems
Director
2026 High
Volcanic Ash & Wildfire
Smoke Mitigation Strategy
Renton Emergency
Management/Emergency
Management Director
2025 and
ongoing
Low
Water System Risk
Assessment
Renton Public Works/Water Utility
Engineering Manager and Water
Maintenance Manager
2030–2031 Medium
Water Utility Seismic
Resilience
Renton Public Works/Water Utility
Engineering Manager and Water
Maintenance Manager
2026 High
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 30
Airport Seismic Mitigation
Lead POC
• Assistant Airport
Manager
• Airport Manager
• Airport Engineer
Partner Points of Contact
• Federal Aviation
Administration (FAA)
• Federal Emergency
Management
Administration
Hazards Mitigated
Earthquake, Landslide/
Sinkhole
Funding Sources/
Estimated Costs
FEMA grants;
FAA; AIP; local
budget CIP; Small
Airports Program.
$1.8M Retrofit cost;
$650,000 city cost.
Strategy Vision/Objective
Mitigate seismic impacts to the air traffic control tower in future events and repair current damage from the
past 1994 event(s). The tower is not currently rated for either Collapse Prevention, Life Safety or Immediate
Occupancy in case of a seismic event. Generally, an Immediate Occupancy performance level is assigned to a
building that is deemed an essential facility and is required to be functional shortly after the design-level
earthquake. The 2012 International Building Code (IBC) classifies aviation control towers and air traffic
control centers as essential facilities.
Mitigation Strategy
The Renton Municipal Airport’s air traffic control tower, built in the 1960s, does not meet current structural
code. Recent engineering studies identified the following deficiencies: excessive horizontal drift ratios,
inadequate beam connections to the weak axes of columns, inadequate panel zone shear capacities, lack of
beam bottom flange bracing, impacts of site liquefaction, and lack of connection between the timber piles and
the concrete pile caps to resist uplift forces due to an earthquake, which is of particular concern for a building
with the height-to-base width aspect ratio of a control tower. To remedy the tower to an ASCE 41-13, Retrofit
Standard BSE-2E, Tier III, Risk III, “Limited Safety Structural Performance, Non-Structural Performance not
considered” (Life Safety) rating, an exoskeleton and bracing could be fitted. As per the last official notice
Wiley Post Seaplane Base is considered a strategic asset according to the Puget Sound Transportations
Recovery Annex. Recent survey has identified the Seaplane Ramp is settling and developed significant cracking
due to a developed void underneath, the Airport needs to rebuild/reinforce ramp. Multiple conduits and water
mains are routed under the runway. Reinforcing this infrastructure to resist seismic activity would prevent loss
of air traffic control communication capabilities and hydraulic mining under the runway surface. This will
facilitate the safe operation of the Air Traffic Control Tower and Seaplane Base and the uninterrupted
transportation of goods/supplies and protect the city’s economic development.
2-Year Objectives
• Apply for FEMA PDM funding.
• Apply for FAA Funding, Master
Plan.
• Contingent on supplemental
funding approval, complete
retrofit of Tower Mitigation
Project.
5-Year Objectives
• Evaluate remaining life and
determine appropriateness of
complete replacement.
• Conduct siting study for new
tower.
• Relocate/fix Seaplane Base.
• Reinforce communication
conduit.
Long-Term Objectives
• Replace air traffic control
tower with new structure if
repair is not feasible.
• Maintain air traffic control
tower to a Critical
Infrastructure Standard,
Non-Structural to be
considered.
Implementation Plan/Actions
• Combine FEMA grants (PDM) and Airport funds for the Airport Tower Mitigation Project.
• Plan for future siting and building of new tower.
Performance Measures
• Successfully eliminate the structural seismic concern at the airport by retrofitting and/or building a
new facility.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 31
Cedar River Section 205 Flood Hazard Reduction Project – Operation and
Maintenance
Lead POC
• Surface Water
Engineering
Manager
Partner Points of
Contact
• King County Flood
Alerts
• Boeing
Hazards Mitigated
Dam Failure, Flood
Funding Sources/
Estimated Costs
Local budget Surface Water
Capital Improvement Program;
local budget Surface Water
Maintenance Fund; federal
disaster funding; US Army
Corps of Engineers; King
County Flood Control District.
Cost is dependent on specific
maintenance needs.
Strategy Vision/Objective
Following the construction of the Section 205 levees along the Cedar River from Williams Ave N to Lake
Washington, in cooperation with the US Army Corps of Engineers (USACE), obligations for operation and
maintenance were transferred to the City of Renton in accordance with the Operation and Maintenance
Manual (O&MM). Additionally, USACE conducts routine annual and 5-year periodic inspections of the levees
in order to determine maintenance needs and rate their acceptability and eligibility for flood response
assistance. The objective of this program is to operate and maintain the levees in accordance with the O&MM
and maintain a minimally acceptable rating following each USACE levee inspection. This would reduce the
risk of levee failure, maintain federal sponsorship of the Cedar River Section 205 levees and eligibility for
flood response assistance under PL84-99, and maintain the level of protection of the Cedar River Section 205
levees to, at minimum, the 100-year flow.
Mitigation Strategy
• Maintain close cooperation with USACE and Boeing.
• Adhere to the inspections, flood stage procedures, bridge operation, closure operation, and maintenance
requirements of the OM&M.
• Secure funding for routine repair projects.
2-Year Objectives
• Same as long-term
objectives.
5-Year Objectives
• Same as long-term
objectives.
Long-Term Objectives
• Prevent levee failure due to lack of maintenance or
improper operation.
• Maintain eligibility for federal flood response
assistance.
Implementation Plan/Actions
• Monitor flows on the Cedar River during major regional storm events.
• Initiate levee repair or vegetation management projects in a timely manner following the determination of
a deficiency.
• Conduct levee inspections with USACE and as required by the O&MM.
Performance Measures
• Obtain a minimally acceptable rating from USACE on an annual basis.
• Operate and maintain the Section 205 Levees in accordance with the O&MM.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 32
Cedar River Gravel Removal Project
Lead POC
• Surface Water
Engineering
Manager
Partner Points of Contact
• King County Flood
Control Zone District
• Boeing
Hazards Mitigated
Flood
Funding Sources/
Estimated Costs
Local budget Surface
Water Capital
Improvement Program;
King County Flood
Control Zone District
Capital Improvement
Program.
$ 10.5 Million
Strategy Vision/Objective
The USACE Section 205 project on the lower 1.25 miles of Cedar River requires periodic maintenance
dredging due to continuous sediment accumulation that gradually reduces the conveyance capacity of the river,
and level of flood protection offered by USACE Section 205 levees from Williams Ave S to Lake Washington.
The objective of this project is to periodically (every 12-18 years) dredge the bed of the Cedar River to reduce
the risk of flooding and protect adjacent properties. The periodic maintenance dredging is required as part of
the agreement with USACE for the initial construction of the Cedar River Section 205 Flood Hazard
Reduction Project levees and floodwalls.
Mitigation Strategy
The City of Renton monitors sediment accumulation on a yearly basis by performing cross section surveys
along the lower two miles of the river. When the riverbed reaches or significantly approaches the “warning
elevation,” defined as 1.5 ft below the “maximum bed elevation,” the city initiates the design and permitting
efforts of a maintenance dredging project. The “maximum bed elevation” is the riverbed elevation above
which the levees in Section 205 can no longer provide two feet of freeboard during the 100-year flood.
Typically, a maintenance dredging project also includes bank stabilization and outfall repairs needed to
maintain the structural stability of the levees.
2-Year Objectives
• Keep monitoring sediment
accumulation.
• Begin planning, permitting
and design of the next
gravel removal project.
5-Year Objectives
• Keep monitoring sediment
accumulation.
• Secure funding for the design,
permitting, construction and
mitigation requirements of the next
gravel removal Project.
• If required, initiate construction of the
next gravel removal project.
Long-Term Objectives
• Successfully dredge the
Cedar River and maintain
the flood protection
capacity of the USACE
Section 205 levees.
Implementation Plan/Actions
• Annual survey of sediment accumulation.
• Maintenance dredging of the Cedar River every 12-18 years.
Performance Measures
• Successful project execution is achieved when the Cedar River gets dredged before reaching the
“maximum bed elevation” in compliance with all permitting and mitigation requirements.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 33
Cedar River Section 205 Levee Certification Project
Lead POC
• Surface Water
Engineering
Manager
Partner Points of Contact
• USACE – Seattle District
• King County Flood
Control Zone District
• Boeing
• FEMA
Hazards Mitigated
Dam Failure, Flood
Funding Sources/
Estimated Costs
Local budget Surface Water
Capital Improvement
Program;
King County Flood Control
Zone District Capital
Improvement Program.
$ 5,000,000
Strategy Vision/Objective
The Cedar River USACE Section 205 levees are currently provisionally accredited levees, with final
accreditation contingent upon design and construction of levee improvements that were determined to be
needed in order to meet current FEMA accreditation standards and provide sufficient freeboard during the
100-year flood. If left uncertified, the levees would not be mapped by FEMA and adjacent properties would
be regulated as if they were in the floodplain. This mitigation strategy will work to protect Renton Municipal
Airport, the Boeing 737 production facility, city park, and adjacent commercial/residential properties from
flooding and being subjected to floodplain development regulations and flood insurance requirements.
Mitigation Strategy
Several sections of the levees and floodwalls need improvements in order to provide sufficient freeboard or
increase structural stability to meet current levee certification standards. The City of Renton is permitting,
designing and constructing these improvements.
2-Year Objectives
• Permit and design levee
improvements.
• Submit a new Conditional Letter
of Map Revision (CLOMR) input
to FEMA showing final design
drawings and demonstrating
Endangered Species Act
Compliance.
5-Year Objectives
• Construct levee
improvements.
• Submit a Letter of Map
Revision (LOMR) input to
FEMA with the final project
report and record drawing
and obtain accreditation.
Long-Term Objectives
• Maintain levee accreditation
with FEMA.
• Initiate a re-accreditation
project once the certification
issued by the consultant
expires.
Implementation Plan/Actions
• Use a phased approach (assessment, permitting, design, construction, final accreditation).
• Coordinate with USACE on Section 408 review and other agencies on required permits.
• Use an effective project management approach and closely monitor schedule.
Performance Measures
• Several milestones during the design of the levee improvements will serve as performance checkpoints.
• Successful accreditation relies on adequate project management and control, clear communication and
collaboration with the permitting agencies, and successful construction of the improvements.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 34
Civil Disturbance Mitigation
Lead POC
• Renton Police
Commander – Patrol
Partner Points of Contact
• Key community partners
determined situationally
relative to incidents.
Hazards Mitigated
Civil Disturbance
Funding Sources/
Estimated Costs
Staff time.
$0
Strategy Vision/Objective
To foster a united and resilient community in Renton where trust, understanding, and collaborative
relationships between residents, local government, and law enforcement prevent and mitigate civil
disturbances. To achieve this strategy, relationships between the community and the Renton Police
Department can be strengthened through dialogue, public outreach, and collaborative partnerships.
Mitigation Strategy
• Build and strengthen community partnerships to identify and address potential sources of tension or
dissatisfaction.
• In partnership with local organizations and community groups, address root causes of civil disturbances
through assessments that identify systemic issues such as economic disparities, social inequalities, and or
perceived lack of representation.
• Enhance communication and outreach through disseminated public outreach videos that highlight the
capabilities of local law enforcement and showcase the shared values and goals of the community.
2-Year Objectives
• Establish and maintain the
community partnerships.
• Complete an assessment of
systemic issues contributing to
civil disturbances and begin
addressing these areas.
• Launch community outreach
videos.
5-Year Objectives
• Develop and sustain programs
that continue to address
systemic issues.
• Expand community
partnerships and stakeholders
to support long-term
engagement.
• Continue community outreach
opportunities to reach more
groups.
Long-Term Objectives
• Foster a sustained culture of
trust and collaboration
reducing the incidences of
civil disturbances in the city.
Implementation Plan/Actions
• Host a community engagement meeting with local organizations and community groups to outline goals
and priorities and listen to concerns of the citizens.
• Conduct a community wide survey to identify concerns, perceptions, and receive suggestions regarding
local law enforcement and local government.
• Develop a communication plan for public outreach videos and social media campaigns.
• Continue fostering transparency by hosting regular meetings and listening sessions with the community.
• Roll out initiatives to address the systemic issues in collaboration with community partners.
• Monitor and evaluate the effectiveness of the mitigation efforts, adjusting strategies as needed.
• Continue to expand outreach efforts and strengthen partnerships to ensure ongoing trust and engagement.
Performance Measures
• Growth in attendance for community outreach events, meetings, and online engagement.
• Annual surveys to the community indicating increased satisfaction with law enforcement initiatives.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 35
Coal Mine Study Mitigation Strategy
Lead POC
• Planning Director
Partner Points of Contact
• US Office of Surface Mines
• Olympic Pipeline
• Bonneville Power
Administration
• Seattle City Light
• Puget Sound Energy
• Seattle Public Utilities
Hazards Mitigated
Earthquakes,
Landslides/Sinkholes
Funding Sources/
Estimated Costs
FEMA;
Match in staff time
through local
budget.
Total cost $100,000.
Strategy Vision/Objective
Update and verify historic maps of coal mine features, including mine shafts and coal mine seams, and overlay
these with vulnerable infrastructure including regional fuel pipelines, electrical transmission corridors, regional
water pipelines, sensitive receptors (schools, hospitals, etc.), and roadways to assist in identifying potential
hazards. Identify methods to stabilize areas where critical infrastructure is at risk from subsidence.
Mitigation Strategy
• Identify historic coal mine features that potentially conflict with critical infrastructure and sensitive
receptors.
• Identify mitigation measures to stabilize areas with high risk for subsidence.
• Avoid developing new critical infrastructure and/or sensitive receptors in areas with identified subsidence
risk from historic coal mining activities.
2-Year Objectives
• Review coal mine hazard
regulations for Best Available
Science compliance as part of
2024/2025 Critical Areas
Ordinance update
5-Year Objectives
• Fund study to verify location
and depth of abandoned and
closed historic coalmine
features and identify where
these features may threaten
critical infrastructure.
• Identify mitigation to stabilize
known areas of conflict.
Long-Term Objectives
• Coal mine maps are integrated
and maintained with other
hazard maps to gain a better
understanding of hazard
complexity to inform future
development and emergency
response and mitigation
decisions.
Implementation Plan/Actions
• Fund study no earlier than 2026 to verify locations and depths of abandoned and closed historic coalmines
and coal mining features. Overlay with critical infrastructure and develop mitigation to prevent subsidence
and threat to critical infrastructure and vulnerable sensitive receptors.
• Convene stakeholder meetings no earlier than late 2026 to share study findings and develop joint strategies
to develop mitigation measures.
Performance Measures
• Successfully identify potential hazards to determine current hazard risk and strategies to avoid impacts of
subsidence on critical infrastructure such as pipelines and roads, and vulnerable sensitive receptors such as
schools and hospitals.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 36
Cyber Incident Disaster Recovery Site
Lead POC
• IT Infrastructure
and Security
Manager
• IT Director
Partner Points of
Contact
• Cybersecurity and
Infrastructure
Security Agency,
Supervisory
Cybersecurity
Advisor
Hazards Mitigated
Cyber Incident
Funding Sources/
Estimated Costs
Local budget approved by
council and provided as part
of the Capital Improvement
Plan (CIP).
$1,400,000.
Strategy Vision/Objective
To provide for systems and/or data recovery in the event of detrimental infrastructure failure or cyber incident;
also providing for continuity of business in the event of the primary site becoming physically or virtually
inaccessible.
Mitigation Strategy
The city of Renton has over 150 virtual servers it relies on to provide critical services and applications. In the
event of a cyber incident that may compromise primary systems, a robust backup solution is required that can
safely store and protect immutable copies of our data for restoration after remediation. Adequate hardware
infrastructure is also required to support restoration in a timely manner along with failover capability if
necessary. To this end, the city has invested in new server hyperconverged infrastructure (HCI) in both our
primary and secondary data center locations, along with an industry-leading backup solution.
In the event of a cyber incident, the city references and follows our Incident Response Plan to remediate and
recover. If the secondary site is needed as a failover, necessary configuration changes will be made (IP, DNS,
etc.) and it will be brought online to allow for continuity of operation until the primary site is again available.
2-Year Objectives
• Purchase, install, configure, test
and go-live with new HCI
infrastructure and backup
solution.
5-Year Objectives
• Forklift secondary site to a
location geographically
separated from our primary
site to avoid losing both in the
event of natural disaster or loss
of physical access.
Long-Term Objectives
• Regularly monitor, test and
maintain backup and failover
capabilities.
Implementation Plan/Actions
• Have 3rd party perform disaster recovery assessment and suggest plan of action.
• Based on recommendations, gather quotes for necessary resources from partner value-added resellers
(VARs).
• Submit CIP request to Finance and City Council for approval.
• Acquire funding; procure, install, configure and test infrastructure in backup/disaster recovery site.
• Procure, install, configure and test infrastructure in primary site.
• Fine-tune backup service level agreements and business continuity/failover configurations.
• Fully test solution.
• Relocate secondary (disaster recovery and business continuity) site to an acceptably distant geographical
location.
• Test, verify, maintain.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 37
Performance Measures
• Restoration capabilities in line with established SLA’s.
• Adequate performance in failover state to second site.
Funding/Partnership Mitigation Strategy
Lead POC
• Emergency
Management
Director
Partner Points of Contact
• Washington State Military
Department Emergency
Management Division
Public Assistance Program
Coordinator
• FEMA Region 10 Senior
Stakeholder Relations
Specialist
Hazards
Mitigated
All
Funding Sources/
Estimated Costs
Staff time.
$0
Strategy Vision/Objective
Leverage community partnerships (public and private) and grant funding opportunities to address mitigation
priorities within the city.
Mitigation Strategy
• Reach out to community partners to determine shared concerns and priorities around hazard mitigation.
• Negotiate cost-share agreements for shared projects or allocate matching funds from city budget to meet
grant requirements.
2-Year Objectives
• Identify new partners for
mitigation projects where
appropriate.
• Submit grant applications when
opportunities arise.
5-Year Objectives
• Complete one project with partner
participation and/or grant funding.
Long-Term Objectives
• Continue to cultivate a
community culture that
participates in
mitigation investments.
Implementation Plan/Actions
• Introduce mitigation concepts in meetings with external stakeholders.
• Maintain grant documentation files and tracking system for applications.
Performance Measures
• Submit one grant application every two years.
• Complete one project with partner participation and/or grant funding.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 38
Hazardous Materials Public Education
Lead Points of
Contact
• Solid Waste
Program Manager
Partner Points of Contact
• King County Hazardous
Waste Management
Program, Educator
Consultant III
Hazards Mitigated
Hazardous Materials
Funding Sources/
Estimated Costs
King County Hazardous
Waste Management
Program grant.
$25,000
Strategy Vision/Objective
Increase the knowledge of Renton residents about potential chemical exposure risks from common household
products and provide them with alternative strategies to help reduce their exposure.
Mitigation Strategy
Expand the “Safer Cleaning” pilot program to educate all residents in mid-to-large sized multifamily
properties about safer cleaning product choices and strategies for alternative cleaning methods.
2-Year Objectives
• Host at least six in-person
workshops or tabling events on
safer cleaning.
• Build on previous and current
customer engagement to tailor
the workshops and tabling
events to resident needs.
5-Year Objectives
• Program is institutionalized. A
maintenance strategy keeps it
fresh and relevant to target
audiences.
Long-Term Objectives
• Reduce resident exposure
to toxic cleaning materials.
Implementation Plan/Actions
• In 2025, continue evaluating outcomes of “Safer Cleaning” pilot program.
• In 2026, adjust program based on pilot analysis recommendations.
• Expand offerings to include more in-person on-site workshops at multifamily properties and educational
tabling at events such as the city’s farmer’s market.
• Amplify messaging about safer cleaning via social media and monitor response in 2026 and beyond.
• Periodically evaluate program effectiveness.
Performance Measures
• Hold three workshops in 2026, and then annually.
• Participate in two tabling events in 2026, and then annually.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 39
Lower Cedar River Flood Risk Reduction Feasibility Study
Lead POC
• Surface Water
Engineering
Manager
Partner Points of Contact
• King County Flood
Control Zone District
• King County
• Boeing
Hazards Mitigated
Flood
Funding Sources/
Estimated Costs
Local budget Surface
Water Capital
Improvement Program;
King County Flood
Control Zone District
Capital Improvement
Program.
$ 500,000
Strategy Vision/Objective
Identify the most feasible level of flood protection along the lower 2 miles of the Cedar River and specific
improvement projects to implement in order to reach that level of protection. Reduce additional flood risk
beyond the 100-year level of flood protection. Identify future flood improvement projects along the lower two
miles of the Cedar River.
Mitigation Strategy
The Lower Cedar River traverses through a major commercial, industrial, recreational and residential area in
the City of Renton, vital to the local economy. The USACE Section 205 project, from Williams Ave N to Lake
Washington is protected from the 100-year flood by levees. However, overtopping could occur at locations
upstream of this reach and result in minor localized flooding of roadways. This study would explore measures
to prevent such localized flooding. Also, during floods larger than the 200-year flood event, extensive
overtopping of the left and right banks upstream of Logan Ave could occur. This study would explore
measures to reduce the flooding risks during such extreme events and the feasibility of achieving such a level
of protection.
2-Year Objectives
• Identify desired level of flood
protection requirement.
• Identify required flood improvement
projects.
5-Year Objectives
• Plan and identify funding needs
for proposed improvement
projects.
• Design and implement smaller
flood improvement projects.
Long-Term Objectives
• Design and
implement larger
flood improvement
projects.
• Improve overall
flood protection
along lower Cedar
River.
Implementation Plan/Actions
• Seek grants from the King County Flood Control District, FEMA, or Floodplains by Design to fund the
design and construction projects identified for improvement.
o Build on existing partnerships with environmental and community organizations to ensure that design
meets the needs of all stakeholders.
o Assess design to ensure that it meets estimated increased flows due to climate change.
• Construction of flood risk reduction improvements.
Performance Measures
• Successfully identify projects to reduce the risk of flooding, improve resiliency to climate change and
extreme weather events, protect private property, and preserve key economic assets.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 40
Maintenance Facility Standby Emergency Power
Lead POC
• Facilities
Director
Partner Points of
Contact
• N/A
Hazards Mitigated
Dam Failure, Earthquake,
Flood, Landslide, Severe
Weather, Volcano, Wildfire
Funding Sources/
Estimated Costs
Local budget,
FEMA HMGP.
$500,000;
Strategy Vision/Objective
Provide back-up emergency power generation at the City of Renton Maintenance Shop to allow for full
operation of the facility, which is the city’s Public Works Department Operations Center for responding to
any significant hazard that results in an emergency. The facility is used by the Street Maintenance, Surface
Water Utility Maintenance, Wastewater Maintenance, Fleet Services and Water Utility Maintenance sections.
All city departments rely on the facility for fueling and maintenance/repair of city vehicles. All public works
equipment that may be needed during an emergency is stored at the facility and city maintenance personnel are
dispatched from the facility when responding to hazards. The Supervisory Control and Data Acquisition
(SCADA) system controls for the Water Utility operation of the city’s water supply wells, reservoirs, pump
stations and treatment facilities are located at the facility along with the SCADA system for Wastewater Utility
and Surface Water Utility lift stations and pump stations. Standby emergency power can ensure full operation
of facility during power outages to allow response to hazards.
Mitigation Strategy
The maintenance facility currently only has back-up power generation that allow for partial operation, which
impacts the city’s ability to respond to hazards that result in power outages. The increased back-up power
generation would provide full power to the facility for hazard emergency response without a limitation due to
only partial power at the City of Renton Maintenance Shop.
2-Year Objectives
• Secure funding for design
• Hire consultant for design
• Start design and permitting
5-Year Objectives
• Secure funding for construction
• Complete final design, construction
plans, specifications and permitting
• Complete construction
Long-Term Objectives
• Maintain city
operations at the
facility during power
outages caused any
hazard event for
response to the event.
Implementation Plan/Actions
• Secure funding from possible funding sources, complete consultant selection process for design and
execute design contract.
• Complete design and permitting and secure funding for construction.
• Advertise for bids and award construction contract and complete construction.
• Implement maintenance of the back-up power generator and test periodically.
Performance Measures
• Back-up power generation is installed at the City of Renton Maintenance Shop facility to allow full
operation at the facility during a hazard that results in a power outage.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 41
Public Health Emergency Mitigation
Lead POC
• Emergency
Management
Director
• Communications
and Engagement
Director
• Risk Manager
Partner Points of Contact
• Public Health – Seattle &
King County
• Washington State Department
of Health
Hazards Mitigated
Public Health
Emergency
Funding Sources/
Estimated Costs
Staff time.
$0
Strategy Vision/Objective
Working in partnership with public health, contribute to protecting the public health, and maintaining a safe
and healthy community environment for our residents, businesses, and visitors.
Mitigation Strategy
Monitor urgent messages from public health at the county and state level. Amplify messages on social media
and the city web site in accordance with the City of Renton Crisis Communications Plan and Responses.
Amplify public health messages to city employees in accordance with risk management policies and practices.
Modify the Emergency Operations Center (EOC) Duty Officer Manual to include public health emergency
procedures in alignment with public health protocols and the crisis communications plan. By amplifying public
health messaging, officials are speaking with one voice, increasing public confidence and compliance to
mitigate the health issues that can be affected by human behavior. Employees are better protected in a public
health emergency, which preserves continuity of government and the provision of essential services to the
community.
2-Year Objectives
• Revise the EOC Duty
Officer Manual.
• Review the crisis
communications plan’s
public health emergency
section annually.
5-Year Objectives
• Review the EOC Duty Officer
Manual’s public health emergency
section annually.
• Review the crisis communications
plan’s public health emergency
section annually.
• Review risk management policies
for currency.
Long-Term Objectives
• Maintain accurate
information and
consistency in internal and
public messaging related to
public health emergencies.
Implementation Plan/Actions
• Revise the EOC Duty Officer Manual to include procedures related to public health emergencies.
• Provide training to new emergency management staff.
• Promulgate the crisis communication plan internally in the city and provide training on it to all personnel
with social media responsibilities.
• Establish an annual review cycle for both the EOC Duty Officer Manual and the City of Renton Crisis
Communications Plan and Responses.
Performance Measures
• EOC Duty Officer Manual is updated.
• Annual review of EOC Duty Manual is conducted.
• Annual review of City of Renton Crisis Communications Plan and Responses is conducted.
• Related risk management policies and procedures are reviewed every five years.
• Public health messages are consistently amplified through city media and internal employee channels.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 42
Regional Planning Mitigation Strategy
Lead POC
• Emergency
Management
Director
Partner Points of Contact
• King County Hazard
Mitigation Program
Coordinator
Hazards Mitigated
All
Funding Sources/
Estimated Costs
Staff time.
$ 0
Strategy Vision/Objective
As a partner in the development of the King County Regional Hazard Mitigation Plan, the city actively
engages in contributing to the county-wide initiatives that require stakeholder participation and support. This
includes participating in the plan maintenance strategy identified in the plan.
Mitigation Strategy
• Identify opportunities to support county-wide initiatives identified in the overall King County Regional
Hazard Mitigation Plan.
• Actively participate in the plan maintenance strategy identified in the plan.
2-Year Objectives
• Produce an annual review and
progress report
5-Year Objectives
• Produce a completely revised plan
Long-Term Objectives
• Maintain a current and
relevant Renton Annex
to the King County
Regional Hazard
Mitigation Plan
Implementation Plan/Actions
• Continue to conduct an annual plan review, to include a review of county-wide initiatives.
• Identify opportunities for Renton to contribute to county-wide initiatives and participate accordingly.
• Conduct a comprehensive plan revision in 5 years.
Performance Measures
• Annual review is completed and progress report produced.
• 5-year plan revision is completed and submitted to King County.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 43
Seiche Risk Awareness and Mitigation Strategy
Lead Points of Contact
• Community and
Economic
Development
Department Planning
Director and
• Long Range Planning
Manager
Partner Points of Contact
• Department of Ecology,
Shoreline Planner
• Department of Natural
Resources, Aquatic Lands
– King County Land
Manager
• Department of Fish and
Wildlife, Habitat Biologist
Hazards Mitigated
Tsunami/Seiche
Funding Sources/
Estimated Costs
Shoreline Master
Program Update
grants.
$1000
Strategy Vision/Objective
Decrease the potential for damages to property from a seiche.
Mitigation Strategy
Create awareness for property owners with properties vulnerable to seiches., and provide them with
resources and information on mitigation. Assess potential development regulations that could mitigate
damage to property and natural resource habitat.
2-Year Objectives
• Identify properties at risk of
seiche.
5-Year Objectives
• Outreach program to Lake
Washington and Cedar River
shoreline property during
Shoreline Master Program
update.
• Review Best Available Science
for potential development
regulations that mitigate risk
Long-Term Objectives
• Awareness of potential threat
and tools to protect if
warranted.
Implementation Plan/Actions
• Leverage grant funding availability during Shoreline Master Program update to include seiche
• risk awareness.
• Create separate outreach program related to seiches for property owners along the city’s
• shoreline designations
• Comprehensive review of risk and any potential development regulations meeting Best Available Science
to incorporate into master program.
• Master program update is due in 2029, however grant funding and planning work would likely begin three
(3) years prior.
Performance Measures
• Discussion of outreach methods and adoption (if necessary) of development regulations specific to seiches
within the master program.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 44
Terrorism Mitigation
Lead Points of
Contact
• Renton Police
Commander –
Administrative
Services
Partner Points of Contact
• Washington State Fusion
Center
• King County Sheriff’s Office
• Seattle Police Department
Hazards Mitigated
Terrorism
Funding Sources/
Estimated Costs
Staff time.
$0
Strategy Vision/Objective
To establish the City of Renton as a model of proactive terrorism prevention and response through seamless
collaboration with the Washington State Fusion Center (WSFC), leveraging intelligence, technology, and
community engagement to safeguard residents, critical infrastructure, and public spaces. The long-term
objective of this vision is to strengthen the City of Renton’s capacity to detect, prevent, and respond to
terrorism-related threats by fostering and maintaining a strong, collaborative relationship with the WSFC.
Mitigation Strategy
The WSFC serves as a vital resource for intelligence sharing and coordination between local, state, and federal
agencies. By leveraging WSFC’s capabilities, the City of Renton can enhance situational awareness, improve
response capabilities, and reduce vulnerability to terrorism. Maintain regular communication by designating a
primary liaison to maintain regular contact with WSFC personnel.
2-Year Objectives
• Establish communication
protocols, designate liaison role,
and initiate scheduled check-in
meetings with WSFC.
5-Year Objectives
• Integrate WSFC intelligence into
hazard and risk assessments.
• Develop protocols for
disseminating intelligence to
relevant departments and
agencies.
Long-Term Objectives
• Expand public awareness
campaigns and education
within the community.
Implementation Plan/Actions
• Designate and assign Renton role to liaise with WSFC.
• Initiate and schedule regular check-in meetings with WSFC.
• Conduct terrorism focused public awareness campaigns and community workshops.
• Use WSFC intelligence to update Renton’s Hazard Mitigation Plan and other risk assessments.
Performance Measures
• Number of joint meetings and intelligence exchanges conducted annually.
• Number of terrorism-focused public awareness campaigns and community workshops.
• Documented updates to hazard mitigation plan and risk assessments based on WSFC intelligence.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 45
Utility Pumping Facilities Back-Up Power
Lead POC
• Utility Systems
Director
Partner Points of Contact
• Renton RFA Fire Marshall
Hazards Mitigated
Earthquake, Flood,
Severe Weather
Funding Sources/
Estimated Costs
Local budget Capital
Improvement Programs:
$ 7M (water)
$ 1M (wastewater)
$ 1M (surface water)
Strategy Vision/Objective
Improve reliability at utility pumping facilities with on-site standby power systems. These projects could
prevent downtime of critical facilities during hazard events in order to maintain public health and safety.
Mitigation Strategy
Critical pumping facilities for the city include 11 domestic water booster pump stations, 20 wastewater lift
stations, and 2 stormwater pump stations. Not all of these facilities currently have back-up power. During
power outages, pumping facilities that lack back-up power 1) risk disruption to water and wastewater services;
2) reduce flood-control capabilities at stormwater pump stations; and 3) cause additional strain/wear to on-
line pumping facilities, which consequently decreases the equipment’s life expectancy. The city will evaluate
potential emergency standby power options, including installing on-site generators and increasing fuel storage,
to lessen the impact of future power outages at utility pumping facilities.
2-Year Objectives
• Construction of back-up
power improvement projects
in pre-design phase
• Identify additional back-up
power improvement projects
5-Year Objectives
• Plan and identify funding needs for
proposed improvement projects
• Design and implement priority back-
up power improvement projects
Long-Term Objectives
• Design and implement
remaining back-up
power improvement
projects
• Improve overall
reliability at critical
pumping facilities
Implementation Plan/Actions
• Complete construction of back-up power improvements at four wastewater lift stations.
• Complete final design and construction of back-up power improvements at two domestic water booster
pump stations that are currently in the 30 percent pre-design phase.
• Allocate capital funding to design and implement additional back-up power improvement projects.
Performance Measures
• Solutions maintain the continuity of operations, protect property, protect the environment, and protect
key economic assets.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 46
Volcanic Ash & Wildfire Smoke Mitigation Strategy
Lead POC
• Emergency
Management
Coordinator
Partner Points of Contact
• King County Public
Health
• Puget Sound Clean Air
Agency
Hazards Mitigated
Volcano, Wildfire
Funding Sources/
Estimated Costs
Staff time.
$0
Strategy Vision/Objective
The objective is to inform and prepare the community for the impacts of both volcanic ash deposits and
wildfire-caused ash. Since the likelihood of volcanic eruption is low and the wildfire ash impacts are sporadic,
the strategy will rely on public communication and outreach to ensure residents have an understanding of the
hazards affecting them, actions they can take, and what the city can provide.
Mitigation Strategy
Conduct an annual public education campaign for ash and wildfire smoke hazard awareness. Use May 18th, the
anniversary of Mt. St. Helen’s eruption, as an annual ash and wildfire smoke awareness campaign prompt.
Campaign may include social media and public communications on the risk to Renton residents and
appropriate actions if the hazard occurs. Connect building owners and business owners with air filtration
resources as requested. Provide information for individuals on personal preparedness measures (staying
indoors, use of appropriate masks), vehicle mitigation efforts (covering cars, avoid driving in limited visibility,
dangers to vehicle filtration systems), and methods of securing homes from air quality and ash impacts.
2-Year Objectives
• Community awareness of
impacts of volcanic or
wildfire caused ash hazards.
5-Year Objectives
• Normalize ash hazards and impacts as
part of wider air quality warnings, with
public safety actions known by the
community.
Long-Term Objectives
• Well-prepared community
members with baseline
awareness of possible ash
and smoke hazards and
protective actions they can
take.
Implementation Plan/Actions
• Design survey alongside partners to understand current levels of awareness.
• Design social media and public outreach campaign, including messaging and strategy.
• Implement plan during late spring – summer months.
Performance Measures
• Increase in awareness and engagement with post-campaign surveys of community.
• Increase in engagement with outreach efforts (for example, with online media campaign, in-person
outreach)
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 47
Water System Risk Assessment
Lead POC
• Water Utility
Engineering Manager
• Water Maintenance
Manager
Partner Points of
Contact
• Renton RFA
• Environmental
Protection Agency
• Local Emergency
Planning Committee
Chair
Hazards Mitigated
All
Funding
Sources/Estimated
Costs
Local budget Water
Capital
Improvement
Program.
$ 100,000
Strategy Vision/Objective
Develop a risk and resilience assessment that identifies the most significant malevolent acts and natural
hazards to the water utility’s critical assets, reduces vulnerabilities of these critical assets, prepares for the
threats that could occur, and mitigates the potential consequences of incidents that do occur.
Mitigation Strategy
The City of Renton is a community water system that provides supply, treatment, storage, and distribution of
dependable and safe water. The Water Utility is required under the 2018 America's Water Infrastructure Act
(AWIA) to assess the risks to, and resilience of, its water system. The risk assessment 1) inventories at-risk
water infrastructure that contribute to critical functionality of the water system; 2) evaluates the risk and
known vulnerabilities to significant threats and hazards; and 3) implements prevention, protection, and
mitigation activities for identified threats and hazards. The Water Utility may develop partnerships with local
emergency response and planning groups to foster hazard mitigation activities.
2-Year Objectives
• Develop risk assessment.
• Develop policy changes to
mitigate the risks to the
critical drinking water
infrastructure.
5-Year Objectives
• Assess the effectiveness of
efforts to secure and
strengthen the resilience of
critical drinking water
infrastructure.
• Update risk assessment.
Long-Term Objectives
• Increase drinking water
infrastructure resilience to
malevolent acts and natural
hazards.
• Update risk assessment every 5
years per AWIA regulations.
Implementation Plan/Actions
• Develop the water system risk assessment.
• Use as a prioritized plan for security upgrades, modifications of operational procedures, and policy
changes to mitigate risks.
Performance Measures
• Identifies potential improvements that serve multiple purposes to enhance operations and resilience of the
drinking water system.
AGENDA ITEM #1. c)
City of Renton Plan Annex to the 2025 King County Regional Hazard Mitigation Plan
Page 48
Water Utility Seismic Resilience
Lead POC
• Water Utility
Engineering
Manager
• Water
Maintenance
Manager
Partner Points of Contact
• Pacific Northwest Seismic
Network/Unites States
Geological Survey
• Renton RFA
• Department of Health
Hazards Mitigated
Earthquake
Funding Sources/
Estimated Costs
Local budget, Water
capital budgets;
Pre Disaster Mitigation
Grant.
$1.8M
Strategy Vision/Objective
Reduce potential damage/losses to critical water facilities from an earthquake by 1) installation of seismic
shut-off valves on water storage facilities; and 2) development of post-earthquake isolation and control
actions. These projects could improve the survivability of the municipal water supply system, reduce loss
following an earthquake, and potentially save lives.
Mitigation Strategy
Critical water facilities for the city include nine production wells, one spring, eleven booster pump stations,
and ten reservoirs. Because Washington State has one of the highest risks of expected casualties and economic
loss from earthquakes in the nation, the city needs water system infrastructure improvements for seismic
resiliency. The Water Utility will evaluate the feasibility of retrofitting six existing reservoirs with seismic valves
to automatically shutoff water flow at the tank to prevent complete water loss. The Water Utility may also
develop post-earthquake isolation and control protocols, which are needed to ensure adequate water storage
and distribution during an emergency.
2-Year Objectives
• Develop policies/protocols
for post-earthquake drinking
water isolation and control
actions.
5-Year Objectives
• Fund pre-design of seismic valve
retrofit.
• Allocate funding in the capital budget
to fund implementation of seismic
shut-off valve retrofit.
Long-Term Objectives
• Seismic valves on all
water tanks.
Implementation Plan/Actions
• Fund planning, pre-design, and construction of seismic valve retrofit on water reservoirs.
Performance Measures
• Solution maintains the continuity of operations and water service.
AGENDA ITEM #1. c)