HomeMy WebLinkAbout11/05/2025 - Agenda Packet
AGENDA
Planning Commission Meeting
6:00 PM - Wednesday, November 5, 2025
Council Chambers, 7th Floor, City Hall – 1055 S. Grady Way
1. CALL TO ORDER
2. ROLL CALL
3. CORRESPONDENCE RECEIVED
4. AUDIENCE COMMENT
1. Virtual Attendees
2. In-person Attendees
Those attending virtually (Call 253-215-8782, Zoom meeting ID: 880 3465 9736, password:
Weplan2024 or
https://us06web.zoom.us/j/88034659736?pwd=z1TyxJNsMEloal0MglAamlJkjbnLaR.1) will be
offered an opportunity to speak before the in-person (physical meeting at the City Hall, 7F
Council Chambers) comments are completed.
Please use your device to raise your (electronic) hand in order to be recognized by the
Recording Secretary.Each speaker will be provided three (3) minutes to address an item.
Groups or organizations may select a spokesperson to speak on a group’s behalf.
Alternatively, interested parties are encouraged to provide written comments to
planningcommission@rentonwa.gov.
Attendees will be muted and not audible to the Commission except during times they are
designated to speak.Public can use the “Raise Hand” option if attending through video.If there
are others calling in, you can be called upon by the last 4 digits of your telephone number.
Phone instructions: *6 to mute/unmute, *9 to raise hand.
5. COMMISSIONER COMMENTS
6. DIRECTOR'S REPORT
7. PUBLIC HEARING
a) Group 20B D-243: RMF-2 Rezone
b) Group 20B D-244: Contractor's Yards and Offices
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c) Group 20B D-245: Code Interpretations
d) Resource Center in the Valley
8. DELIBERATIONS AND RECOMMENDATIONS
a) Group 19B D-235: Critical Areas Ordinance Updates
9. COMMISSIONER COMMENTS
10. ADJOURNMENT
Hearing assistance devices for use in the Council Chambers are available upon request.
For more information please visit rentonwa.gov/planningcommission
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D-245: Administrative Code Interpretations Page 1 of 1
CITY OF RENTON
Community and Economic Development Department
D-245: Administrative Code Interpretations (2025 Docket 20 Group B)
Staff: Margarette Bravo, Planning Technician
Date: October 31, 2025
Applicant or Requestor: City Staff
SUPPLEMENTAL STAFF REPORT
SUMMARY
This Supplemental Staff Report documents the withdrawal of CI-164: Rental Registration
and Inspection Program from the list of Code Interpretations proposed for codification
under D-245. This withdrawal ensures that only active and applicable interpretations are
included in the current docket cycle.
GENERAL DESCRIPTION
Staff propose codifying adopted administrative interpretations that clarify ambiguous or
conflicting provisions within Title IV, Development Regulations. Topics include the
Residential Rental Program, transitional and supportive housing standards, definitions for
lot coverage, nonconforming dwelling alterations, public notice for vehicle permits, adult
family homes, fence permit thresholds, and parking stall dimensions. These interpretations
are already in effect and are now being formally incorporated for consistency and clarity.
Under this docket item, Staff initially proposed to advance eight (8) Code Interpretations for
codification. However, upon further review, it was determined that CI-164: Residential
Rental Registration and Inspection Program, effective February 23, 2021, had already been
codified through Renton City Ordinance No. 6052, adopted on December 13, 2021.
Specifically, the issue of ambiguity regarding the process referenced in RMC 4-5-125.F (“a
landlord shall have a certificate of inspection completed and submitted to the
Administrator”) has already been addressed through the enforcement provisions in RMC 4-
5-125.H, Penalties and Enforcement.
Accordingly, CI-164 has been withdrawn from the list of Code Interpretations initially
included in the current docket cycle.
AGENDA ITEM #7. c)
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CITY OF RENTON
Community and Economic Development Department
#D-235: Critical Areas Ordinance
Staff: Mariah Kerrihard, Associate Planner
Date: November 3, 2025
Applicant or Requestor: Staff
_____________________________________________________________________________________
General Description
The Critical Areas Ordinance (CAO) is a set of development regulations adopted and enforced by
cities and counties to protect environmentally sensitive areas and safeguard the public from
natural hazards. The ordinance is mandated under Washington’s Growth Management Act (GMA).
The purpose of the proposed code amendment is to align the City’s regulations with current state
law and “best available science” (BAS) by the State imposed end of the year deadline.
Background
The City of Renton last completed a comprehensive update to its CAO in 2015, following the
requirements of the Growth Management Act. Washington State law requires all jurisdictions to
periodically review and update development regulations to maintain compliance. This 2025 update
ensures the CAO continues to incorporate best available science, complies with state law,
addresses stakeholder input, and enhances public safety and environmental protection.
The City has received input from the Washington Department of Fish and Wildlife, the Department
of Ecology, the Department of Natural Resources, the Duwamish Tribal Historic Preservation, the
Master Builders Association, Puget Sound Energy, McCullough Hill LLC, and other stakeholders.
Draft amendments have been revised to address and align with the technical guidance and
recommendations provided by those agencies with the inclusion of public input.
Washington State law requires every city and county to protect critical areas by adopting
regulations that prevent any net loss of ecological functions or values. Under WAC 365-190-080,
when updating the Critical Areas Ordinance, jurisdictions must:
• Use definitions and guidelines provided in WAC when designating all critical areas and
developing regulations to protect their functions and values.
• Incorporate best available science, as outlined in chapter 365-195 WAC, into both the
designation of critical areas and in developing code policies and standards. This ensures
protection measures reflect new scientific information, with special attention given to
conserving or protecting anadromous fisheries and safeguarding both surface and
groundwater because of their importance to wetlands, streams, and lakes.
• Strive for coordinated, regional approaches by encouraging interjurisdictional cooperation,
incentives for voluntary protective measures, and consistent regulatory standards
wherever possible.
• Designate critical areas with a combination of mapping and performance standards. Maps
serve to improve public awareness and support permitting decisions. Regulatory
protections, however, are based on site-specific performance standards and not solely on
mapped features.
AGENDA ITEM #8. a)
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These principles make it necessary for Renton’s CAO update to:
• Integrate the most recent best available science into wetland buffers, stream and habitat
protections, and mitigation requirements.
• Strengthen and clarify performance-based standards in code sections regulating
development near or within mapped critical areas.
• Ensure all new policy language and code changes clearly state that mapped critical areas
are informative and not regulatory limits; site assessments and standards apply in site
specific permit reviews.
• By referencing these requirements from WAC 365-190-080, Renton's proposed CAO
amendments will clearly align with state guidance and demonstrate compliance with
current law and best practice. This ensures protection of critical ecological functions while
meeting community planning and permitting needs.
Key Procedures & Standards
• Maps & Mapping: Uses updated online mapping and GIS. Site-specific field verification
may override mapped boundaries if there is a conflict with actual conditions.
• Land Applicability: Expands critical areas regulations to explicitly include channel
migration zones, geologically hazardous areas, and fish and wildlife habitat conservation
areas, with revised definitions and clarified overlap with Shoreline Master Program
regulations.
• Wetland Buffers and Habitat Corridors: The 2025 update adopts guidance from
"Appendix C, Option 1"1 as the preferred implementation strategy for buffer standards.
Appendix C provides standardized buffer widths and vegetation requirements informed by
statewide ecological guidance. Option 1 aligns Renton’s buffer standards with Department
of Ecology recommendations, ensuring robust protection while maintaining consistency
across jurisdictions.
• Stream Buffers: Stream buffer widths may be determined by stream type, with wider
buffers for fish-bearing and ecologically significant streams. All buffers must be densely
planted with mostly native trees and shrubs. If the buffer lacks sufficient native vegetation,
it must be restored or the wider buffer standard must be applied. Buffer reductions are only
allowed if a professional study shows no loss of stream function, and any reduction must
be offset by enhancing the buffer area. Permanent protection of stream buffers with
signage or legal agreements is required to ensure long-term compliance. These rules help
maintain habitat, prevent erosion, and protect water quality.
• Studies & Submittal Requirements: Requires qualified professionals for all regulated
area studies, and outlines procedures for peer/independent review of submitted
geotechnical, stream, and wetland reports.
1 Appendix C, Option 1 refers to the standardized wetland buffer widths and vegetation management
measures detailed in the Washington State Department of Ecology's “Wetland Guidance for Critical Area
Ordinance (CAO) Updates” (Publication no. 22-06-014, May 2022). This technical guidance provides
recommended buffer standards and habitat corridor criteria based on the best available science for wetland
protection and management across Washington State. Jurisdictions are encouraged to adopt these
standards for consistency, regulatory clarity, and effective ecological protection.
AGENDA ITEM #8. a)
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• Exemptions & Administrative Waivers: Refines criteria and procedures for administrative
exemptions and for waiver of studies based on site conditions or existing data.
• Mitigation: Codifies performance standards, monitoring, and timing for all mitigation plans;
clarifies on- and off-site mitigation sequencing and surety requirements to ensure “no net
loss” of critical area functions.
Proposed Code Amendments
Staff is proposing changes to the following code section:
• RMC 4-3-050 CRITICAL AREAS REGULATIONS
• RMC 4-11-010 DEFINITIONS A
• RMC 4-11-040 DEFINITIONS D
• RMC 4-11-190 DEFINITIONS S
Proposed Amendments by Critical Area
Critical
Area / Topic
Current Code
Reference
(RMC 4-3-050)
Summary of Proposed Updates
Channel
Migration
Zones
B.1, G.7., D. 3
Inserts dedicated Channel Migration Zone (CMZ) language from
Shoreline Master Program. Bases CMZ regulations on updated
King County mapping and introduces a formal process for site-
specific reassessment or challenge of mapped boundaries
Streams G.7.e
Aligns performance standards for streams with a clear
“standard” and new “increased” buffer width - Buffers that do
not meet performance standards are assigned the increased
buffer - Mandates 80% native vegetated cover in stream
buffers; unvegetated or invasive buffers require restoration or
increased width - Incorporates mapping and removal of
salmonid migration barriers as a priority for mitigation
(consistent with WAC 365-196-830)
Wetlands G.7.d
Updates buffer width table using category, function, and new
alignment with Department of Ecology’s Appendix C Option 1
guidance - Standard buffer now bundled with vegetated
corridor - 80% native vegetation required in buffer; under-
vegetated buffers must be restored or widened - Clarifies
habitat corridor as part of the buffer, not added width -
Wetlands scoring 5 points or less do not need a corridor -
Further clarifies criteria for buffer averaging and reduction, and
formalizes mitigation
AGENDA ITEM #8. a)
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Critical
Area / Topic
Current Code
Reference
(RMC 4-3-050)
Summary of Proposed Updates
General C, E
Affirms that exempt activities must still comply with WAC 365-
196-830 and WAC 365-190-080 for no net loss; requires
mapping updates, qualified professional studies, maintains
field verification over mapped boundaries, and clarifies
mapping is for information and field data takes precedence;
adds explanations of land use intensity/impacts and qualified
professionals.
Proposed Wetland Buffer Widths
Wetland buffer widths are determined by wetland category and habitat score. Wider buffers are
required for wetlands with higher habitat scores.
Adoption of Appendix C, Option 1, means that Renton’s buffer widths and management protocols
are directly mapped to Ecology’s recommended framework. For both wetlands and streams, these
standards reflect best available science with improved habitat function, water quality protection,
and clearer permitting processes. Sites meeting Option 1 criteria will use standardized buffer
widths and corridor requirements, with increased buffers required for higher habitat/scoring
wetlands and fish-bearing streams.
Category & Habitat
Score
Current Low
Impact Use
Current All
Other Use
Proposed:
Standard Buffer
Proposed:
Increased Buffer
I – Bogs & Natural
Heritage (8-9)
175 ft 200 ft 225 ft 300 ft
I – All Others (8-9) 175 ft 200 ft 190 ft 250 ft
I – All Others (6-7) 125 ft 150 ft 110 ft 150 ft
I – All Others (3-4 or
3-5)
75 ft 115 ft 75 ft 100 ft
II (8-9) 150 ft 175 ft 225 ft 300 ft
II (5-7 or 6-7) 100 ft 150 ft 110 ft 150 ft
II (3-4 or 3-5) 75 ft 100 ft 75 ft 100 ft
III (8-9) 100 ft 125 ft 225 ft 300 ft
AGENDA ITEM #8. a)
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III (5-7 or 6-7) 75 ft 100 ft 110 ft 150 ft
III (3-4 or 3-5) 50 ft 75 ft 60 ft 80 ft
IV (>1,000 sq ft) 40 ft 50 ft 40 ft 50 ft
To apply the standard wetland buffer width shown in the table, a site must meet the defined
performance standards, vegetated buffer standards, and where applicable, the habitat corridor
requirement. Vegetated buffer standards for wetlands require buffers to be densely planted with
native trees, shrubs, and groundcover that provide at least 80% cover; if a buffer is bare, sparsely
vegetated, or dominated by invasive plants, it must either be restored with native vegetation or the
buffer must be widened until it achieves the level of protection necessary for the wetland.
In addition to meeting the vegetation and performance standards, the standard buffer must include a
relatively undisturbed vegetated corridor that is at least one hundred feet wide, extending from the
wetland to any nearby legally protected or high-quality natural areas. Examples include Priority Habitats,
designated wildlife refuges, select park lands, or sites with permanent conservation status. This corridor
is an integral part of the buffer, supporting ecological functions and connectivity for wildlife. These
requirements ensure that buffers and corridors work together to protect wetland functions and
connectivity for wildlife.
Proposed Stream Buffer Widths
Stream
Type
Current Buffer
Width
Structure Setback
Beyond Buffer
(Current)
Proposed:
Standard Buffer
Proposed:
Increased Buffer
Type F 115 ft 15 ft 115 ft 200 ft
Type
Np 75 ft 15 ft 75 ft 100 ft
Type Ns 50 ft 15 ft 50 ft 67 ft
To apply the standard buffer width, both the performance standards and vegetated buffer
standards must be met. Stream buffer vegetation standards require an average of 80% native cover
made up of trees, shrubs, and groundcover species appropriate for the ecoregion; if the buffer is
unvegetated, sparsely vegetated, or dominated by invasive species, it must be enhanced through
an approved mitigation plan or else the increased buffer width from the table will apply to maintain
adequate buffer functions.
The general performance standards include directing lights away from streams and stream buffers
while limiting necessary lighting to safety, placing noisy uses away from streams or using design to
minimize noise impacts, keeping toxic runoff from hard surfaces out of the stream, discharging
treated water into buffers only if it meets City standards and is located as far from the stream as
possible using low impact development methods where feasible, and requiring that subdivision
buffer edges are planted with dense native vegetation, fenced, and signed to reduce unwanted
AGENDA ITEM #8. a)
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access and disturbance. These combined standards are intended to minimize ecological impacts,
protect habitat and water quality, and support the long-term functional integrity of stream buffers.
Mitigation and Flexibility
The City of Renton’s current critical areas regulations provide several established mitigation
options for wetland and stream buffers. These existing provisions offer applicants flexibility to
address unavoidable impacts while ensuring continued environmental protection.
Wetland Buffers
• Option 1 from Appendix C specifies that buffer averaging and mitigation adjustments must
maintain no net loss of ecological function. Flexibility options, such as administrative
adjustments, follow the criteria and limitations outlined in Appendix C to ensure consistent
application with state guidance.
• Buffer Averaging: Applicants may request averaging of buffer widths as long as the total
buffer area remained equal to that required without averaging. The narrowest part of the
buffer had to be at least three-quarters of the required width, unless site constraints
required additional flexibility. Buffer averaging was typically accompanied by requirements
for enhancement or restoration to maintain wetland function.
• Compensatory Mitigation: Impacts to wetlands or their buffers may be mitigated by
creating, restoring, or enhancing wetlands and associated buffers on-site or off-site. The
compensatory mitigation had to provide equivalent or greater ecological function and
required critical area reports and approved plans.
• Mitigation Banks: Where permitted, mitigation banking may be used instead of on-site
mitigation, with required buffer widths at the mitigation site determined by the type of
wetland and the bank approval terms.
• Increase or Decrease of Buffers: The code previously allowed for administrative increase
or decrease of buffer widths based on site conditions, critical area studies, or specific
criteria (such as proximity to steep slopes or lack of existing vegetation).
• Enhancement as a Requirement: If existing buffers were not adequately vegetated, the
City could require buffer planting or enhancement, and could deny buffer averaging if
protection of wetland functions was not demonstrated.
Stream Buffers
• Averaging and Enhancement: Buffer averaging and enhancement options were also
available for stream and lake buffers, provided total area requirements and functional
protections are maintained. Buffer increases and reductions are made on a case-by-case
basis, documented by scientific studies and administrative review.
• Mitigation Sequencing: Mitigation planning is required for all buffer alterations, following
the familiar sequence: first avoid, then minimize, then compensate for any unavoidable
impacts. Enhancement and restoration of buffers are required to offset impacts, and all
work is subject to review and conditions imposed by the Administrator.
• Restoration after Exempt Activities: If an activity exempt from buffer regulations (such as
minor utility or maintenance work) caused temporary impacts to a buffer, restoration of the
disturbed area was required to meet or surpass its pre-disturbed function.
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These options, that are currently existing in the City’s critical areas regulations, demonstrate the
City’s established practice of allowing reasonable land use flexibility while maintaining standards
for buffer protection and ecological performance. The proposed amendments aim to clarify, align,
and update the requirements based on best available science and experience with
implementation.
Consultation and Agency Input
This Critical Areas Ordinance update was informed by a comprehensive review of best available
science and regulatory guidance from state and local agencies. Key documents reviewed include
best available science reports from King County (2004, 2023, 2024), technical manuals and
regulatory handbooks from the Washington State Department of Commerce and Department of
Ecology, and scientific syntheses and management recommendations from the Washington
Department of Fish and Wildlife.
Supporting documents include “Wetland Guidance for Critical Areas Ordinance Updates – Western
Washington (Ecology 2022),” “Riparian Management Zone Checklist for CAOs (WDFW 2023),” and
the “King County 2024 Comprehensive Plan Best Available Science Review”. Additional sources
include technical guidance from the Washington State Department of Ecology, Washington State
Department of Fish and Wildlife, the US Army Corps of Engineers, American Society of Civil
Engineers, and comparisons with local jurisdictions. Best available science guidance from
neighboring jurisdictions were also compared to ensure consistency and compliance with regional
expectations.
By adopting Appendix C, Option 1, Renton demonstrates its commitment to evidence-based
ecological management. This selection provides clarity for applicants, staff, and external agencies;
it streamlines review procedures and aligns the City’s standards with the Department of Ecology’s
recommendations.
Recommendation
Staff and the public are encouraged to access the City’s online resources for up-to-date critical
area maps and to review the full record of comments received during this review process. View the
City’s critical area maps and public comments at: Critical Areas Ordinance
Staff recommends that the Planning Commission review and discuss the substantive changes
outlined in this report. Adoption of the proposed amendments will ensure the City’s regulations are
aligned with Best Available Science and state law prior to the end of year deadline.
2 Link directs users to Renton’s critical areas maps and the full record of comments received. Field verification
remains required for regulatory compliance.
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DOCKET #235
CRITICAL AREAS ORDINANCE (CAO) UPDATE
Planning Commission Deliberations &
Recommendations
November 5, 2025
Presented by: Mariah Kerrihard, Associate Planner
425-430-7238
mkerrihard@rentonwa.gov
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Vision
A regionally vital and connected city fostering inclusivity, dynamic
economic growth, safety, environmental stewardship, and community,
enabling all residents to experience prosperity and quality of life.
Missions and how they relate to the CAO
1.Provide a safe, healthy and vibrant community
2.Support planned growth and influence decisions to foster
environmental sustainability
RENTON COMPREHENSIVE PLAN
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PURPOSE
Growth Management Act
Requirements
Satisfy State imposed
deadline
Respond to agency guidance
and community feedback
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PROCESS AND METHODOLOGY
Literature Review
Gap Analysis
Planning
Commission
Briefing
Planning &
Development
Committee Briefing
Community
Engagement
Draft Code
Amendments Public Hearing
Public Engagement
- Comments
Received
Deliberations and
Recommendations
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REGULATED CRITICAL AREAS
Flood Plain – Department of Ecology
https://ecology.wa.gov/water-shorelines/shoreline-coastal-
management/hazards/floods-floodplain-planning
Frequently flooded areas
Wetlands
Critical Aquifer Recharge Areas
Geologically Hazardous Areas
Fish and Wildlife Habitat
Conservation Areas
Chinook Salmon – U.S. Fish & Wildlife Service
https://www.fws.gov/media/chinook-salmon-mcallister-springs-wa-0
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PROPOSED AMENDMENTS TO THE CAO
1.Code Refinement:
•Updating terminology, clarifying document references, and
ensuring current standards use best available science
•The inclusion of Channel Migration Zones
2.Stream Buffers:
•The 2025 update adopts guidance from "Appendix C,
Option 1" as the preferred implementation strategy for buffer
standards.
•Appendix C provides standardized buffer widths and
vegetation requirements informed by statewide ecological
guidance. Option 1 aligns Renton’s buffer standards with
Department of Ecology recommendations, ensuring
robust protection while maintaining consistency across
jurisdictions
3.Wetland Buffers:
•Altering wetland buffers and replacement ratios may
increase due to best available science.
•Guidance from Appendix C. Buffer Approaches for Western
Washington Option 1 Wetland Guidance from Department of
Ecology as well as Jurisdictional Comparison
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WHAT IS A CHANNEL MIGRATION ZONE?
The area that a stream or river could be
expected to occupy in the future due to
lateral migration or channel avulsion.
•Often delineated into hazard areas
with regulations applied differently
•Moderate
•Severe
•Regulation is for the purpose of
prevention of loss of life and damage
to property or infrastructure
Cedar River – King County derived CMZ
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Category I
•Represent a unique or rare wetland type; or
•Are more sensitive to disturbance than most wetlands; or
•Are relatively undisturbed and contain ecological attributes that
are impossible to replace within a human lifetime; or
•Provide a very high level of functions
Category II
•Difficult, though not impossible, to replace, and provide high
levels of some functions.
•Occur more commonly than Category I wetlands, but still need a
relatively high level of protection
Category III
•Wetlands with a moderate level of functions
•Can often be adequately replaced with a well-planned
mitigation project
Category IV
•The lowest levels of functions and are often heavily disturbed
•These are wetlands that we should be able to replace, and in
some cases be able to improve
•May provide some important functions and need to be protected
City of Renton (COR) Maps – Wetland Layer
WETLAND CATEGORIZATION
Washington State Wetland Rating System – Department of Ecology - Hruby, Yahnke, 2023
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COMPARISON OF EXISTING VS. PROPOSED WETLAND BUFFER WIDTH
Category & Habitat Score Current Proposed: Standard
Buffer
Proposed: Increased
Buffer
I – Bogs & Natural
Heritage (8-9)200 ft 225 ft 300 ft
I – All Others (8-9)200 ft 190 ft 250 ft
I – All Others (6-7)150 ft 110 ft 150 ft
I – All Others (3-4 or 3-5)115 ft 75 ft 100 ft
II (8-9)175 ft 225 ft 300 ft
II (5-7 or 6-7)150 ft 110 ft 150 ft
II (3-4 or 3-5)100 ft 75 ft 100 ft
III (8-9)125 ft 225 ft 300 ft
III (5-7 or 6-7)100 ft 110 ft 150 ft
III (3-4 or 3-5)75 ft 60 ft 80 ft
IV (>1,000 sq ft)50 ft 40 ft 50 ft
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STREAM BUFFERS
•Type F:Waters that are known to be used
by fish or meet the physical criteria to be
potentially used by fish and that have
perennial (year-round) or seasonal flows.
•Type Np:Waters that do not contain fish
or fish habitat and that have perennial
(year-round) flows.
•Type Ns:Waters that do not contain fish
or fish habitat and have intermittent
flows.
Stream
Type Current Proposed
Standard
Proposed
Increased
Type F 115 ft 115 ft 200 ft
Type Np 75 ft 75 ft 100 ft
Type Ns 50 ft 50 ft 67 ft
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PERFORMANCE AND CORRIDOR STANDARDS
•80% native cover required for buffer
approval
•Non-compliant buffers must be restored or
widened
•Habitat corridor now included in buffer, not
added width
•Corridors connect wetlands/streams to
protected areas
Buffer
Habitat Corridor
Wetland
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General Purpose
•The typically required critical area buffers may be
reduced to no net loss of functions or values as
documented in a study prepared by a qualified
professional. Greater buffer width reductions
require review as a variance
Mitigation to Reduce Buffers
•Criteria for Reduction of Wetland Buffer Width
with Enhancement
•Criteria for Averaging of Wetland Buffer Width
Reasonable Use Variance
•No proposal shall result in a loss of critical area
functions or values.
•If the application of these provisions would deny
all reasonable use of the property, the applicant
may apply for a variance as identified in RMC 4-9-
250
Black River 2025
ALTERATIONS TO CRITICAL AREAS AND/OR BUFFERS
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General Purpose
•RMC 4-10-090, Critical Areas Regulations – Nonconforming
Activities and Structures
Existing Development
•Normal and routine maintenance and repair of any existing
public or private uses and facilities where no alteration of
the critical area and required buffer or additional fill
materials will be placed.
•In every case, critical area and required buffer impacts shall
be minimized and disturbed areas shall be restored during
and immediately after the use of construction equipment.
Proposed Development
•Prior to any development or alteration of a property
containing a critical area the owner or designee must obtain
a development permit, critical area permit, and/or letter of
exemption.
•No separate critical area permit is required for a
development proposal for which development permits are
required or that has received a letter of exemption.
May Creek 2025
LEGALLY NON-CONFORMING
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Development
•Existing or rebuilt accessory structures for residential
structures such as fences, gazebos, storage sheds, and
playhouses are exempt from critical areas review if
rebuilt in the same footprint.
•New accessory structures linked to residential
structures can be permitted in previously legally
altered areas, such as yards or portions of lots outside
designated critical areas and buffers.
•Routine repairs, maintenance, landscaping, and similar
activities outside mapped critical areas and buffers do
not require critical area permits or review.
•Construction and maintenance of pedestrian skybridge
structures at least 20 feet above the surface are also
exempt, if they do not require below-ground or ground-
disturbing work within the buffer or protected area.
EXEMPTIONS
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Comments Received
•Comments and agency technical input incorporated
Resources
•Online resource: interactive critical area maps
•View more information about the process and public
comments at yourvoice.rentonwa.gov/cao
Proposed Development
•Prior to any development or alteration of a property
containing a critical area the owner or designee must
obtain a development permit, critical area permit,
and/or letter of exemption.
•No separate critical area permit is required for a
development proposal for which development permits
are required or that has received a letter of exemption.
PUBLIC PROCESS AND ONLINE RESOURCES
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RECOMMENDATIONS
Staff recommends
Planning Commission
discussion and support for
proposed amendments
Updates align with Ecology
science, state law, and
regional standards
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Next Steps:
•Planning & Development Deliberations and Recommendations (11/10)
•Critical Areas Ordinance Adoption by the end of 2025
Presented by: Mariah Kerrihard, Associate Planner
425-430-7238
mkerrihard@rentonwa.gov
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