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HomeMy WebLinkAboutAPPROVED_Canopy PUD_TIR _220510
FINAL
TECHNICAL INFORMATION REPORT
FOR
CANOPY
CITY OF RENTON IN KING COUNTY, WASHINGTON
Project Manager: Gary Sharnbroich, P.E.
Prepared by: Sydney Stanton, EIT
Approved by: Holli Heavrin, P.E.
Date: February 17, 2021
Revised: July 16, 2021
February 7, 2022
April 15, 2022
Core No.: 18054
4/15/2022
SURFACE WATER UTILITY
JFarah 05/06/2022
DEVELOPMENT ENGINEERING
msippo 05/10/2022
Core Design, Inc. CANOPY i
Table of Contents
SECTION 1: PROJECT OVERVIEW ..................................................................................................... 1
SECTION 2: CONDITIONS AND REQUIREMENTS SUMMARY ........................................................... 3
2.1 Core Requirements ............................................................................................................... 4
2.1.1 Core Requirement #1: Discharge at the Natural Location ............................................ 4
2.1.2 Core Requirement #2: Offsite Analysis .......................................................................... 4
2.1.3 Core Requirement #3: Flow Control .............................................................................. 4
2.1.4 Core Requirement #4: Conveyance System .................................................................. 4
2.1.5 Core Requirements #5: Construction Stormwater Pollution Prevention ...................... 4
2.1.6 Core Requirement #6: Maintenance and Operations ................................................... 4
2.1.7 Core Requirement #7: Financial Guarantees and Liability ............................................ 4
2.1.8 Core Requirement #8: Water Quality ............................................................................ 4
2.1.9 Core Requirement #9: Flow Control BMPs .................................................................... 4
2.2 Special Requirements ............................................................................................................ 5
2.2.1 Special Requirement #1: Other Adopted Area-Specific Requirements ......................... 5
2.2.1.1 Master Drainage Plans ................................................................................................ 5
2.2.1.2 Basin Plans .................................................................................................................. 5
2.2.1.3 Salmon Conservation Plans ........................................................................................ 5
2.2.1.4 Lake Management Plans ............................................................................................. 5
2.2.1.5 Hazard Mitigation Plan ............................................................................................... 5
2.2.1.6 Shared Facility Drainage Plans .................................................................................... 5
2.2.2 Special Requirement #2: Flood Hazard Delineation ...................................................... 5
2.2.3 Special Requirement #3: Flood Protection Facilities ..................................................... 5
2.2.4 Special Requirement #4: Source Control ....................................................................... 5
2.2.5 Special Requirement #5: Oil Control ............................................................................. 5
2.2.6 Special Requirement #6: Aquifer Protection Area (APA)............................................... 5
SECTION 3: OFFSITE ANALYSIS ......................................................................................................... 6
TASK 1 Study Area Definition and Maps ..................................................................................... 6
TASK 2 Resource Review ............................................................................................................. 6
TASK 3 Field Investigation ........................................................................................................... 6
Core Design, Inc. CANOPY ii
TASK 4 Drainage System Description and Problem Description ................................................. 7
SECTION 4: FLOW CONTROL AND WATER QUALITY DESIGN .......................................................... 9
4.1 Performance Standards......................................................................................................... 9
4.2 Design Parameters .............................................................................................................. 11
4.3 Basin Modeling .................................................................................................................... 11
4.3.1 Existing Conditions ....................................................................................................... 11
4.3.2 Developed Conditions .................................................................................................. 14
4.4 BMP Requirements ............................................................................................................ 18
4.5 Detention Modeling ........................................................................................................... 20
4.6 Water Quality Calculations ................................................................................................. 21
SECTION 5: CONVEYANCE SYSTEM ANALYSIS AND DESIGN .......................................................... 23
SECTION 6: SPECIAL REPORTS AND STUDIES ................................................................................. 25
SECTION 7: OTHER PERMITS.......................................................................................................... 26
SECTION 8: CSWPP ANALYSIS AND DESIGN................................................................................... 27
8.1 ESC Plan Analysis and Design .............................................................................................. 27
8.2 SWPPS Plan Design .............................................................................................................. 27
9 BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT ...................... 28
9.1 Bond Quantities .................................................................................................................. 28
9.2 Facility Summaries .............................................................................................................. 28
9.3 Declaration of Covenant ..................................................................................................... 28
SECTION 10: OPERATIONS AND MAINTENANCE ........................................................................... 30
Appendix A – Parcel & Basin Information
King County Parcel Reports
Appendix B – Resource Review & Off-site Analysis Documentation
FEMA Map (53033C0664 F)
City Flood Hazard Areas Map
City Stream and Wetland Map
City Zoning Map
City Landslide Hazard Areas Map
Appendix C – MGS Flood Reports
Appendix C-1: Detention Vault Sizing
Core Design, Inc. CANOPY iii
Appendix C-2: Wetland Inflow Volume Calc
Appendix D – Special Reports and Studies
Core Design, Inc. Canopy Page 1
SECTION 1: PROJECT OVERVIEW
The Canopy project site consists of five parcels and is located east of the Lincoln Avenue NE and
north of NE 40th Street in the City of Renton. The site is bordered by single family residential to
the north, east and south. The project has a total area of 10.06 acres (before the right-of-way
dedication) and 9.96 acres (after the right-of-way dedication). The south property line is shared
with NE 40th Street and the east property line is shared with Lincoln Avenue NE. The project site
is zoned R-8 and will be developed in accordance with the applicable City of Renton code. See
Figure 1.1 at the end of this section for a vicinity map. The King County tax parcel ID numbers for
the parcels involved is included in Table 1.1 below. (Refer to the King County parcel reports
included in Appendix A).
Table 1.1 King County Parcel ID
KC Parcel # Parcel Area (SF)
3345700015 218,091
3345700016 40,430
3345700017 75,755
3345700018 75,698
3345700020 29,562
The project site is currently comprised of three vacant, unimproved parcels and two properties
each containing single family residences and associated structures. Trees and underbrush cover
most of the site. See the existing conditions exhibit at the end of this section.
The parcels generally slope from east to west. The proposed development of the property will
include the clearing and grading of the site for construction of 55 single family residences with
associated roadway, utilities, open space, stormwater detention and water quality facilities. The
project will require frontage half street improvements along Lincoln Avenue NE and NE 40th
Street. Lincoln Avenue NE is classified as a collector arterial street which requires a travel paved
width of 30 feet, 8-foot wide street parking lane on both sides, 0.5-foot wide curbs, 8-foot wide
planters, 8-foot wide sidewalk, 1- to 2-foot wide clear width back of sidewalk. Also required are
stormwater improvements and street lighting. NE 40th Street is classified as a residential street
with existing ROW width of approximately 60 feet which requires paved travel roadway width of
26 feet or paved width to match existing paved width along the corridor (the large number), 0.5-
foot wide curbs, 8-foot wide landscaped planters, 5-foot wide sidewalks, drainage improvements,
and streetlights.
The project will be designed using the guidelines and requirements established in the 2017 Renton
Surface Water Design Manual (RSWDM). The project will be adding more than 7,000 square feet
of new impervious area, so the project falls under Full Drainage Review and Conservation Flow
Control (Level 2). Water quality is required since the project will add more than 5,000 square feet
of pollution generating impervious surface (PGIS) that is not fully dispersed. The project is
required to provide basic water quality per the City of Renton. The drainage analysis for detention
Core Design, Inc. Canopy Page 2
sizing was modeled using MGS Flood, an approved continuous modeling software. The water
quality facility sizing calculations are based on the MGS Flood modeling of the site. Refer to section
4 of this report for more information.
Figure 1.1 Vicinity Map
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Civil Construction
2/18/2021; 07/16/2021;
02/04/2022
2/18/2021; 07/16/2021;
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Signed/Date
2/18/2021
Core Design, Inc. Canopy Page 3
SECTION 2: CONDITIONS AND REQUIREMENTS SUMMARY
The proposed project is classified as requiring “Full Drainage Review” Per the figure 1.1.2.A of the
2017 City of Renton Surface Water Design Manual (RSWDM). Therefore, all nine Core
Requirements and 6 Special Requirements will be addressed per section 1.1 of the 2017 RSWDM.
Core Design, Inc. Canopy Page 4
2.1 Core Requirements
2.1.1 Core Requirement #1: Discharge at the Natural Location
This project will match the two natural discharge locations in Lincoln Ave NE that converge
downstream.
2.1.2 Core Requirement #2: Offsite Analysis
This core requirement is addressed in Section 3 of this report.
2.1.3 Core Requirement #3: Flow Control
The project will meet the Flow Control Duration Standard for matching predeveloped (forested)
conditions. This requires that the developed condition discharge durations match the
predeveloped (forested) condition durations from 50% of the 2-year to the 50-year storm events
and that the developed 2-year and 10-year peak discharge rates do not exceed the predeveloped
(forested) 2-year and 10-year peak discharge rates, respectively. Refer to section 4 of this report
for a discussion and calculations.
2.1.4 Core Requirement #4: Conveyance System
See Section 5 of this report.
2.1.5 Core Requirements #5: Construction Stormwater Pollution Prevention
The proposed construction stormwater pollution prevention BMPs have been designed to meet
the requirements and design standards in Appendix D of the 2017 RSWDM. See Section 8 of this
report.
2.1.6 Core Requirement #6: Maintenance and Operations
See section 10 of this report.
2.1.7 Core Requirement #7: Financial Guarantees and Liability
A bond quantities worksheet is provided in section 9 of this report.
2.1.8 Core Requirement #8: Water Quality
The project is required to meet Basic water quality standards in the 2017 RSWDM. See section 4
of this report for further discussion.
2.1.9 Core Requirement #9: Flow Control BMPs
The project will implement flow control BMPs to mitigate the impact of storm and surface water
runoff from development. Refer to section 4.4 of this report for a discussion of the applicable
BMPs.
Core Design, Inc. Canopy Page 5
2.2 Special Requirements
2.2.1 Special Requirement #1: Other Adopted Area-Specific Requirements
No other area-specific requirements apply to this project.
2.2.1.1 Master Drainage Plans
Not applicable.
2.2.1.2 Basin Plans
Not applicable.
2.2.1.3 Salmon Conservation Plans
Not applicable.
2.2.1.4 Lake Management Plans
Not applicable.
2.2.1.5 Hazard Mitigation Plan
Not applicable.
2.2.1.6 Shared Facility Drainage Plans
Not applicable.
2.2.2 Special Requirement #2: Flood Hazard Delineation
The project is not within a flood hazard area as described in RMC 4-3-050. Refer to Appendix B of
this report for the applicable FIRM map, the City of Renton Flood Hazard Areas Map and site
location.
2.2.3 Special Requirement #3: Flood Protection Facilities
The project is not within a flood hazard area and will not be reliant on flood protection facilities.
Refer to Appendix B of this report for the applicable FIRM map, the City of Renton Flood Hazard
Areas Map and site location.
2.2.4 Special Requirement #4: Source Control
The proposed project is a single-family residential development and source control is not
applicable.
2.2.5 Special Requirement #5: Oil Control
The project is not a commercial development or high use site as defined in the 2017 RSDWM.
Therefore, oil control is not applicable to the project.
2.2.6 Special Requirement #6: Aquifer Protection Area (APA)
The project is not within an Aquifer Protection Areas Zones as defined in the Reference 15-B of
the 2017 RSDWM. Therefore, Aquifer Protection Area is not applicable to the project.
Core Design, Inc. Canopy Page 6
SECTION 3: OFFSITE ANALYSIS
TASK 1 Study Area Definition and Maps
The proposed project contains parcel numbers 3345700015, 3345700016, 3345700017, 3345700018 and
3345700020.
TASK 2 Resource Review
Basin Reconnaissance Summary Reports
No Basin Reconnaissance Summary Reports appear to be available for the area that is within a quarter
mile of this project site.
FEMA Maps
A FIRM map dated May 16, 1995 number 53033C0664 F was reviewed. The developable site is not located
within a floodplain as it is covered by “Zone X – Outside of 500-year floodplain”. The FEMA Map is included
in Appendix B.
Sensitive Areas Folio
The City of Renton Critical Areas Maps was reviewed to confirm whether or not the project site is located
within a wetland, stream, seismic, landslide, or erosion hazard area (Critical Area Maps is included in
Appendix B).
Downstream Drainage Complaints
Drainage complaints were researched within a quarter mile of the project site. Based on King County iMap
Drainage Complaints Map, only one of the complaints are located downstream of the project site which
was closed in 2017. See Drainage Complaint Exhibit at the end of this section, for location of nearby
drainage complaints.
TASK 3 Field Investigation
A field investigation was completed on May 22, 2018.
Tributary Area
The existing grade slopes moderately to steeply from the east to the west towards Lincoln Avenue NE. On
the northeast corner of the site there is a stream which flows to northwest throughout of the site. Just off
the southeast corner of the site, there is a stream running to southwest.
Upstream Tributary Analysis
The project site has significant upstream tributary area. Drainage from the forested areas east of the
project site runs on to the site.
Core Design, Inc. Canopy Page 7
TASK 4 Drainage System Description and Problem Description
A level one downstream analysis was performed during the field inspection. Stormwater onsite flows from
the east side of the property to the west towards Lincoln Avenue NE. The site is located in the East Lake
Washington-Bellevue South Drainage Basin.
For the purpose of this report, onsite flow basins will be classified as north and south.
North: As mentioned, on the northeast corner of the site, there is a stream running to northwest through
the site. Half of the northeast parcel stormwater flows to this stream. The remaining northern portion of
the site flows from east to west toward the wetland area at the northwest corner of the site. From this
wetland, runoff leaves the site flowing north along the east side of Lincoln Ave NE. Approximately 250
feet downstream of the project site, runoff from the wetland at the northwest corner of the site combines
with flow from the stream and flows into a 24-inch culvert. The 24-inch culvert flows west under Lincoln
Ave NE and discharges to the conveyance system on the south side of NE 43rd Street, continuing west.
Runoff from the north portion of the site combines with runoff from the south portion of the site in the
conveyance system along the south side of NE 43rd Street approximately at parcel number 3345700055.
The flows from the entire site combine at 0.07 miles downstream of northern discharge point from the
project site.
South: Stormwater runoff for the southern portion of the site flows from east to west. Some runoff
reaches the existing conveyance system along the east side of Lincoln Ave NE and flows north until
reaching the existing wetland on at the southwest corner of parcel 3345700015. The rest of the southern
portion of the site drains directly to this wetland. The wetland drains to a Type II catch basin and flows
west under Lincoln Ave NE through an 18-inch culvert. This culvert discharges to a stream on the west
side of Lincoln Ave NE flowing north. This stream continues north until reaching NE 43rd Street and
combining with flow from the northern portion of the site in the conveyance system on the south side of
NE 43rd Street. The flows from the entire site combine at 0.18 miles downstream of southern discharge
point from the project site.
Combined Flows: Once the stormwater flows have combined on the south side of NE 43rd Street, flow
continues west along the south side of NE 43rd Street until reaching the intersection with Jones Ave NE.
From here flows enter a culvert that conveys stormwater under NE 43rd Street to the north into a stream.
The stormwater continues north on east side of Lake Washington Blvd NE. The stormwater conveys to a
culvert under the NE 44th Street and runoff continues north in the stream. Shortly downstream of this
culvert runoff reaches the ¼ mile downstream point near parcel 3343301150.
Beyond ¼ mile downstream: Beyond ¼ mile downstream of the project site, runoff continues to flow
north and west, entering public conveyance systems and eventually flowing into Lake Washington.
See the downstream map and table provided on the following pages.
4,514752
Downstream Map
This map is a user generated static output from an Internet mapping site and is for
reference only. Data layers that appear on this map may or may not be accurate,
current, or otherwise reliable.
WGS_1984_Web_Mercator_Auxiliary_Sphere
Notes
None
2/7/2022
Legend
512 256
THIS MAP IS NOT TO BE USED FOR NAVIGATION
Feet512
Information Technology - GIS
0
RentonMapSupport@Rentonwa.gov
City and County Labels
Addresses
Parcels
City and County Boundary
<all other values>
Renton
Network Structures
Access Riser
Inlet
Manhole
Utility Vault
Clean Out
Unknown
Control Structure
Pump Station
Discharge Point
Water Quality
Detention Facilities
Pond
Tank
Vault
Bioswale
Wetland
Other
Surface Water Main
Culvert
Open Drains
Facility Outline
Private Network Structures
Access Riser
Inlet
Manhole
Clean Out
Utility Vault
Unknown
Private Control Structure
Private Pump Station
Private Discharge Point
Private Water Quality
Private Detention Facilities
Tank, No
Stormwater Wetland, No; Natural Wetland, No
Filter Strip, No
Infiltration Trench, No
Vault, No
Pond, No; Pond, Unknown
PROJECT
SITE
FLOWS FROM NORTH SIDE
OF SITE COMBINE HERE
RUNOFF LEAVES SITE
HERE
RUNOFF LEAVES SITE HERE
FLOWS FROM NORTH AND
SOUTH PORTIONS OF SITE
COMBINE HERE
FLOWS FROM SOUTH SIDE
OF SITE COMBINE HERE
PORTION OF SOUTH SIDE OF
SITE LEAVES SITE HERE AND
FLOWS TO EAST SIDE OF
LINCOLN AVE NE
1/4 MILE DOWNSTREAM
POINT
CITY OF RENTON SURFACE WATER DESIGN MANUAL
2017 City of Renton Surface Water Design Manual 12/12/2016 Ref 8-B-1
REFERENCE 8-B
OFF-SITE ANALYSIS DRAINAGE SYSTEM TABLE
CITY OF RENTON SURFACE WATER DESIGN MANUAL, CORE REQUIREMENT #2
Basin: Subbasin
Name:
Subbasin
Number:
Date
Symbol
Drainage Component
Type, Name, and Size
Drainage Component
Description Slope
Distance from
Site Discharge
Existing
Problems
Potential
Problems
Observations of Field
Inspector, Resource
Reviewer, or Resident
See map
Type: sheet flow, swale,
stream, channel, pipe,
pond, flow control/
treatment/on-site
BMP/facility
Size: diameter, surface
area
drainage basin,
vegetation, cover,
depth, type of sensitive
area, volume % ¼ ml = 1,320 ft.
Constrictions, under capacity, ponding,
overtopping, flooding, habitat or
organism destruction, scouring, bank
sloughing, sedimentation, incision,
other erosion
Tributary area, likelihood of
problem, overflow pathways,
potential impacts
NORTH: STREAM
NORTH: DITCH
NORTH: CULVERT
NORTH: DITCH
NORTH: CULVERT
SOUTH: STREAM
SOUTH: CULVERT
NORTH: DITCH
COMBINED: CULVERT
COMBINED: DITCH
COMBINED: CULVERT
COMBINED: STREAM
COMBINED: CULVERT
COMBINED: STREAM
LEAVING SITE
LEAVING SITE
UNDER LINCOLN AVE NE
SOUTH SIDE NE 43RD
SOUTH SIDE NE 43RD
FLOWING NORTH
UNDER LINCOLN AVE NE
SOUTH SIDE NE 43RD
SOUTH SIDE NE 43RD
SOUTH SIDE NE 43RD
UNDER NE 43RD
FLOWING NORTH
UNDER NE 44TH
FLOWING NORTH, END
OF ANALYSIS
410 FT
225 FT
75 FT
130 FT
25 FT
815 FT
140 FT
95 FT
50 FT
220 FT
60 FT
310 FT
120 FT
10 FT
CANOPY 2/7/2022
King County
Drainage Complaint Exhibit
Date: 5/24/2018
Notes:
±
Legend
Search Results: King
County Parcels
Override 1
Parcels
Drainage complaints
Compliant type: WQAI (Water Quality Audit)Problem: WQAI
The project will provide basic water quality treatment of the runoff through a wetvault. Therefore, the project should maintain or improve the runoff treatment from the site.
SITE
0.25 MILE
Core Design, Inc. Canopy Page 9
SECTION 4: FLOW CONTROL AND WATER QUALITY DESIGN
4.1 Performance Standards
All stormwater facilities will be designed using the guidelines and requirements established in the 2017
Renton Surface Water Design Manual (RSWDM). The project consists of ROW frontage improvements in
Lincoln Avenue NE, NE 40th Street and the onsite development. As discussed in Section 3 of this report
the ROW improvements and onsite work are within the same drainage basin. The performance
standards for the ROW Improvements and onsite development are discussed below.
Soils: Geotechnical Report Summary
The onsite soils were investigated by Terra Associates, Inc. The soil conditions consist of 2 to 24 inches of
topsoil overlaying medium dense to dense sandy silt and silty sand with varying gravel content (weathered
till) overlaying dense sandy silt, silt with sand, and silty sand with varying gravel content (glacial till).
Groundwater was encountered in seven of the nine test pits at depth ranging from one and one-half to
eight feet. The site is underlain by relatively impermeable glacial till soils and exhibited shallow perched
groundwater seepage. Therefore, the site would not be suitable for infiltration facilities and it is
recommended that the development stormwater be routed to a conventional storm system for disposal.
Refer to the full geotechnical report for additional detail (under separate cover).
Flow Control Duration Standard: Match Predeveloped (Forested) Conditions
The project is required to provide the Conservation Flow Control Standard, which requires maintaining
the durations of high flows at their pre-development levels for all flows greater than one-half of the 2-
year peak flow through the 50-year peak flow. The pre-development peak flow rates for the 2-year and
10-year runoff events must also be maintained under this requirement.
Onsite Flow Control
A detention facility is proposed for all target surfaces on site to meet the conservation flow control
standard. The impervious areas include the new proposed roadways, driveways, walkways and roofs. An
area summary table of impervious and pervious areas, along with corresponding MGS Flood hydrologic
analysis results are included in the following pages. The full MGS Flood Report is included in Appendix C
of this report.
Offsite Flow Control
The onsite detention facility will provide flow control for a portion of the target ROW area. A mitigation
trade at a 1:1 is proposed to mitigate target areas that will bypass the vault due to the existing topography.
The onsite detention facility will over-detain the onsite areas to meet the conservation flow control
standard.
Water Quality: Basic Water Quality
The proposed project is required to meet Basic water quality requirements Per the figure 6.1.A of the
2017 City of Renton Surface water Design Manual (RSWDM).
Core Design, Inc. Canopy Page 10
Core Design, Inc. Canopy Page 11
The Basic Water Quality Menu includes the following pollutant removal target:
· Basis: Total Suspended Solids (TSS) Removal= 80%
The project proposes to use sediment storage under the live storage in the detention facility. These
treatment facilities will provide all the required pollutant removal targets. Refer to section 4.5 of this
report for the water quality calculations, discussion, and proposed facility.
4.2 Design Parameters
Hydrologic Modeling
The project proposes to use MGS Flood, an approved continuous modeling program, to model the project
and flow control facilities. Refer to Appendix C for a full MGS Flood Report.
4.3 Basin Modeling
4.3.1 Existing Conditions
Existing Onsite Basin
The project site is approximately 9.95 acres in size (after ROW to the City). The parcels generally slope
from east to west. The project site is currently comprised of three vacant and unimproved parcels and
two properties each containing single family residences and associated structures. Trees and underbrush
cover most of the site. The project proposes to demolish the existing structures and construct a single-
family development consisting of 53 units. Historic site conditions are assumed for all existing areas per
Section 1.2.3.1 of the 2017 RSWDM (page 1-41).
ONSITE BASIN Total Area = 9.95 acres
GROUND COVER AREA(acres)
Till Forest 7.27
Undisturbed Area 2.68
Core Design, Inc. Canopy Page 12
Existing ROW (Offsite) Basin
The offsite project area consists of approximately 0.81 acres of ROW along Lincoln Avenue NE and 40th
Street. The ROW work will consist of frontage improvements and trenching for utility connections. Historic
site conditions are assumed for all existing areas per Section 1.2.3.1 of the 2017 RSWDM (page 1-41). See
the following area tables used to create the pre-developed peak flows. An existing conditions exhibit is
provided at the end of this section.
BYPASS Total Area = 0.36 acres
GROUND COVER AREA (acres)
Till Forest (Bypass) 0.36
NORTH VAULT Total Area = 0.45 acres
GROUND COVER AREA (acres)
Till Forest (Mitigation Trade) 0.45
Existing Wetland Basin
The existing basin that drains to the wetland consists of approximately 11.6 acres. This area was
determined using elevation contours from Lidar. The existing wetland basin includes flow from areas
both onsite and offsite.
WETLAND BASIN
(Tributary to Wetland) Total Area = 11.6 acres
GROUND COVER AREA (acres)
Till Forest 10.93
Impervious 0.67
112TH AVE SE (NOT OPEN)SE 80TH ST.LINCOLN AVE NENE 40TH STREET (NOT OPEN)PREDEVELOPED BASIN
EXHIBIT 1
IN COMPLIANCE WITH CITY OF RENTON STANDARDS
DESIGN
12100 NE 195th St, Suite 300 Bothell, Washington 98011 425.885.7877
CIVIL ENGINEERING
LANDSCAPE ARCHITECTURE
PLANNING
SURVEYING
CANOPY
4196 LINCOLN AVE NE, RENTON, WA 98056TED-XX-XXXXC: XX-XXXXXXLUA: XX-XXXXXXPR: XX-XXXXXXPREDEVELOPED ONSITE BASIN PREDEVELOPED OFFSITE BASIN (ROW)
112TH AVE SE (NOT OPEN)SE 80TH ST.LINCOLN AVE NENE 40TH STREET (NOT OPEN)NE 40TH STLINCOLN AVE NESE 80TH STALLEY2APRE-PROJECT WETLAND BASIN
EXHIBIT 1
IN COMPLIANCE WITH CITY OF RENTON STANDARDS
DESIGN
12100 NE 195th St, Suite 300 Bothell, Washington 98011 425.885.7877
CIVIL ENGINEERING
LANDSCAPE ARCHITECTURE
PLANNING
SURVEYING
CANOPY
4196 LINCOLN AVE NE, RENTON, WA 98056TED-XX-XXXXC: XX-XXXXXXLUA: XX-XXXXXXPR: XX-XXXXXXWETLAND EXISTING TRIBUTARY AREAS
Core Design, Inc. Canopy Page 14
4.3.2 Developed Conditions
Developed Onsite Basin
The developed site will consist of 53 single family residences with associated roadway, utility
improvements and stormwater facilities. The project proposes to implement BMPs onsite in order to meet
Core Requirement #9. The full MGS Flood report is located in Appendix C.
Onsite Basin
The impervious area per lot was determined using the criteria in the 2017 RSWDM page 3-24. The
impervious area will either be 4,000 square feet or the maximum impervious area permitted by code,
whichever is less. The maximum impervious surface allowed in the urban residential, R-8, zone in the City
of Renton, is 65%. A portion of the development will remove area that was tributary to wetland B.
DEVELOPED ONSITE BASIN
(Tributary to Vaults) Total Area = 7.28 acres
GROUND COVER AREA (acres)
Till Grass 3.63
Roof Impervious 1.55
Roadway Impervious 1.38
Driveway impervious 0.24
Sidewalks Impervious 0.42
Walkways Impervious 0.06
Total Impervious 3.65
Total Disturbed Area 7.28
Core Design, Inc. Canopy Page 15
ROW Basin
Due to existing topography, a portion of the frontage improvements along Lincoln Avenue NE and 40th
Street could not be collected and conveyed back on-site. Therefore, an impervious area equal to the
unmitigated area of Lincoln Avenue NE upstream of the site will be collected and treated in lieu of the
bypass area. Refer to the following table for a breakdown of the tributary ROW area.
OFFSITE MITIGATION TRADE
(Tributary to Vaults) Total Area = 0.45 acres
GROUND COVER AREA (acres)
Existing Impervious 0.30
Till Grass 0.15
OFFSITE BYPASS
(Tributary to Downstream) Total Area = 0.36 acres
GROUND COVER AREA (acres)
Impervious 0.30
Till Grass 0.06
Developed Wetland Basin
The developed wetland basin will consist of approximately 8.74 acres. The existing and predeveloped
wetland tributary areas were modeled in MGS Flood. Approximately 3.9 acres of tributary basin area to
the wetland will be removed due to the development. The project proposes to collect and route
approximately 1.09 acres of undisturbed upstream and onsite runoff not originally tributary to the
wetland. Therefore, the wetland will receive approximately 2.81 acres less. Since the developed basin
will consist of more till grass and impervious than forest, the runoff volumes the wetland will receive are
similar when accounting for daily and monthly variations per Ecology’s Wetland Protection Guidebook
#3. See the MGS Flood Flow summary below and full report, separate from the vaults located in
Appendix C.
WETLAND BASIN
(Tributary to Wetland) Total Area = 8.79 acres
GROUND COVER AREA (acres)
Till Forest 6.78
Till Grass 0.39
Impervious 1.62
Core Design, Inc. Canopy Page 16
112TH AVE SE (NOT OPEN)SE 80TH ST.LINCOLN AVE NENE 40TH STREET (NOT OPEN)CELL 4CELL 3CELL 2CELL 1CELL 3CELL 2CELL 1TRACT F
TRACT B
TRACT G
TRACT C
TR. K
TR. J
ROAD A
ALLEY 3
NE 40TH STALLEY 1
LINCOLN AVE NESE 80TH ST2 44
1
55 63
9
8
7
10 1615151413131211
5555
3435 31393237363833
5151
4647
22 23 2417 2518 261920 2721 28 29
50504948
53535252 5454
45 44 43 42
4041 30
TRACT H
TRACT A ALLEY2AVAULT ACCESS RD
VAULTACCESS RD
A
ALLEY 2
LINCOLN AVE NE NE 40TH STPLANT SCHEDULE
POSTDEVELOPED AREAS
EXHIBIT 1
IN COMPLIANCE WITH CITY OF RENTON STANDARDS
DESIGN
12100 NE 195th St, Suite 300 Bothell, Washington 98011 425.885.7877
CIVIL ENGINEERING
LANDSCAPE ARCHITECTURE
PLANNING
SURVEYING
CANOPY
4196 LINCOLN AVE NE, RENTON, WA 98056TED-XX-XXXXC: XX-XXXXXXLUA: XX-XXXXXXPR: XX-XXXXXXONSITE IMPERVIOUS AREAS OFFSITE IMPERVIOUS AREAS
CELL 4CELL 3CELL 2CELL 1CELL 3CELL 2CELL 1NE 40TH STLINCOLN AVE NESE 80TH STALLEY2ALINCOLN AVE NE NE 40TH STLINCOLN AVE NE NE 40TH STVAULT ACCESS
VAULT ACCESS AROAD AALLEY 1
ROAD A
ALLEY 2
ALLEY 2AALLEY 3
NE 40TH STPOST-PROJECT WETLAND BASIN
EXHIBIT 1
IN COMPLIANCE WITH CITY OF RENTON STANDARDS
DESIGN
12100 NE 195th St, Suite 300 Bothell, Washington 98011 425.885.7877
CIVIL ENGINEERING
LANDSCAPE ARCHITECTURE
PLANNING
SURVEYING
CANOPY
4196 LINCOLN AVE NE, RENTON, WA 98056TED-XX-XXXXC: XX-XXXXXXLUA: XX-XXXXXXPR: XX-XXXXXXWETLAND POSTDEVELOPED TRIBUTARY AREAS
Core Design, Inc. Canopy Page 18
4.4 BMP Requirements
Flow control BMPs are proposed for the project per Core Requirement #9. The project is greater than
22,000 square feet therefore, BMPs as specified in Section 1.2.9.2.2 of the 2017 RSWDM are required.
The following are responses to the BMP requirements for Large Lot BMPs.
1) The feasibility and applicability of full dispersion as detailed in Appendix C, Section C.2.1 must be
evaluated for all target impervious surfaces. If feasible and applicable for any such surface, then
full dispersion must be applied to that surface and implemented as part of the proposed project.
Typically, full dispersion will be applicable only on the largest sites/lots where there may be
enough forest area available within a threshold discharge area to meet the 15% ratio of fully
dispersed impervious area to native vegetated surface.
Response: The applicable flowpath segments are generally located upstream of the target
impervious surfaces onsite, Therefore, full dispersion is not feasible due to site constraints that do
not allow for 100 feet of native vegetative flow path.
2) Where full dispersion of target impervious roof areas is not feasible or applicable, or will cause
flooding or erosion impacts, the feasibility and applicability of full infiltration of roof runoff must
be evaluated in accordance with Appendix C, Section C.2.2, or Section 5.2, whichever is applicable
based on the type of project. If feasible and applicable, full infiltration of roof runoff must be
implemented as part of the proposed project.
Response: Per section 4.8 of the Geotech Report, the subsurface conditions are not suitable for
infiltration facilities. Therefore, full infiltration of roof runoff is not feasible.
3) All target impervious surfaces not mitigated by Requirements 1 and 2 above, must be mitigated
to the maximum extent feasible using one or more BMPs from the following list. Use of a given
BMP is subject to evaluation of its feasibility and applicability as detailed in Appendix C. Feasible
BMPs are required to be implemented. The BMPs listed below may be located anywhere on the
site/lot subject to the limitations and design specifications for each BMP. These BMPs must be
implemented as part of the proposed project.
Response: Per section 4.8 of the Geotech Report, the subsurface conditions are not suitable for
infiltration facilities. Therefore, full infiltration, limited infiltration and permeable pavement are
not feasible.
4) All target impervious surfaces not mitigated by Requirements 1,2 and 3 above, must be mitigated
to the maximum extent feasible using the Basic Dispersion BMP described below. Use of Basic
Dispersion is subject to evaluation of its feasibility and applicability as detailed in Appendix C.
Feasible BMPs are required to be implemented. Basic Dispersion BMPs may be located anywhere
on the site/lot subject the limitations and design specifications cited in Appendix C. The BMP must
be implemented as part of the proposed project.
Response: Most of the areas that could be used for the “vegetated flowpath segment” are not
located between potential dispersion devices and any downstream impervious surface or drainage
feature. Therefore, this BMP is infeasible for the project site.
5) BMPs must be implemented, at minimum, for impervious area amounts defined as follows.
· For projects that will result in an impervious surface coverage on the buildable portion of the
site/lot of less than 45%, flow control BMPs must be applied to 50% of target impervious
surfaces.
Core Design, Inc. Canopy Page 19
· For projects that will result in an impervious surface coverage 45-65% on the buildable portion
of the site/lot, flow control BMPs must be applied to 50% of target impervious surfaces
reduced by 1.5% for each 1% of impervious surface coverage above 45% (e.g. impervious
coverage of 55% results in a requirement of FCBMPs applied to 35% of target impervious
surfaces).
· For projects that will result in an impervious surface coverage greater than 65% on the
buildable portion of the site/lot, flow control BMPs must be applied to 20% of the target
impervious surfaces or to an impervious area equal to at least 10% of the site/lot, whichever
is less.
The buildable portion of the site/lot is the total area of the site/lot minus any critical areas and
minus 200 ft. buffer areas from a steep slope hazard, landslide hazard area, or erosion hazard
area. If these minimum areas are not mitigated using feasible BMPs from Requirements 1, 2, 3,
and 4 above, either a fee in lieu of the required minimum BMPs must be paid (requires that King
County Water and Land Resources Division has established a program for determining and
utilizing the fees for stormwater focused retrofit projects) OR one or more BMPs from the
following list are required to be implemented to achieve compliance. These BMPs must be
implemented as part of the proposed project.
Response: Reduced Impervious Surface Credit (Section C.2.9) has been evaluated for the project
site. This project cannot use wheel strip driveways (Section C.2.9.3) due to the proposed parking
layout, cannot implement a minimum disturbance foundation (Section C.2.9.4) due to the building
type, and open grid decking over pervious surface (Section C.2.9.5) is not applicable. Additionally,
the proposed improvements to the project create more than the threshold of 4,000 square feet or
4% of the total site area (whichever is greater) in impervious surface (Section C.2.9.2.2). Therefore,
minimum design requirement #1 (specified in Section C.2.9.1) cannot be met; hence, this BMP
cannot be claimed for the proposed site improvements.
Native Growth Retention Credit (Section C.2.10) has been evaluated for the project site. Any
potential area of target impervious surface to be credited as mitigated by this BMP must be
directed to vegetated pervious surfaces on the site or discharged through a perforated pipe
connection in accordance with Section C.2.11. It is not possible to direct stormwater runoff from
the potential target impervious surfaces to vegetated pervious surfaces due to the elevation
difference between the applicable areas. Therefore, minimum design requirement #4.b (specified
in Section C.2.10.1) cannot be met; hence, this BMP cannot be claimed for the proposed site
improvements.
6) The soil moisture holding capacity of new pervious surfaces (target pervious surfaces) must be
protected in accordance with the soil amendment BMP as detailed in Appendix C, Section C.2.13.
Response: The project will retain a portion of the native vegetation and forest near the northeast
and southwest corner and east side of the property. In addition, all landscaping will provide
compost amended soils per Reference 11-C to satisfy the requirements (Notes will be included on
the final landscape plans).
7) Any proposed connection of roof downspouts to the drainage system must be via a perforated
pipe connection as detailed in Appendix C, Section C.2.11.
Response: Feasibility of perforated pipe connections will be evaluated based on lot configuration
and will be determined at the time of building permit.
Core Design, Inc. Canopy Page 20
4.5 Detention Modeling
The project proposes to construct two detention vaults to detain the site runoff. Due to site topography
the two detention vaults will be at different elevations and connected in series. The south vault will route
the detained runoff into the north vault which will further detain the site flows to match the predeveloped
flows at the outfall. Refer to the developed conditions exhibit for a layout of the facility. See Appendix C-
1 for the full MGS Flood Report.
The two vaults in series were modeled with MGS Flood which was used to determine the required sizes.
The required live storage volume for the south vault was 80,640 cubic feet, while the north vault has a
required live storage volume of 24,440 cubic feet. The provided detention volumes for the south and
north vaults are 82,080 and 25,880 cubic feet respectively. Orifice and riser information is provided for
both vaults in the table below.
South Vault North Vault
Riser Geometry
Riser Structure Type : Circular
Riser Diameter (in) : 18.00
Common Length (ft) : 0.000
Riser Crest Elevation : 74.00 ft
Hydraulic Structure Geometry
Number of Devices: 4
---Device Number 1 ---
Device Type : Circular Orifice
Control Elevation (ft) : 64.00
Diameter (in) : 1.13
Orientation : Horizontal
Elbow : Yes
---Device Number 2 ---
Device Type : Circular Orifice
Control Elevation (ft) : 69.80
Diameter (in) : 1.00
Orientation : Horizontal
Elbow : Yes
---Device Number 3 ---
Device Type : Circular Orifice
Control Elevation (ft) : 71.00
Diameter (in) : 1.50
Orientation : Horizontal
Elbow : Yes
---Device Number 4 ---
Device Type : Circular Orifice
Control Elevation (ft) : 73.00
Diameter (in) : 2.00
Orientation : Horizontal
Elbow : Yes
Riser Geometry
Riser Structure Type : Circular
Riser Diameter (in) : 18.00
Common Length (ft) : 0.030
Riser Crest Elevation : 63.50 ft
Hydraulic Structure Geometry
Number of Devices: 3
---Device Number 1 ---
Device Type : Circular Orifice
Control Elevation (ft) : 58.50
Diameter (in) : 1.56
Orientation : Horizontal
Elbow : Yes
---Device Number 2 ---
Device Type : Circular Orifice
Control Elevation (ft) : 60.40
Diameter (in) : 1.75
Orientation : Horizontal
Elbow : Yes
---Device Number 3 ---
Device Type : Circular Orifice
Control Elevation (ft) : 61.90
Diameter (in) : 1.88
Orientation : Horizontal
Elbow : Yes
Core Design, Inc. Canopy Page 21
4.6 Water Quality Calculations
Onsite Water Quality
The project proposes a combined detention and wetvault. The north vault will provide all required water
quality. The treatment facility will provide the required pollutant removal target or 80% Total Suspended
Solids. The required wetvault volume was calculated using MGS Flood, the output of which is provided
below. The MGS Flood Report is also included in Appendix C-1.
********** Link: South Vault ********** ********** Link: North Vault **********
Basic Wet Pond Volume (91% Exceedance):
20273. cu-ft
Basic Wet Pond Volume (91% Exceedance):
6521. cu-ft
The total volume required is 26,794 cubic feet. The wetvault storage will be provided as 5.5 feet of dead
storage throughout the north vault which equates to 28,468 cubic feet.
112TH AVE SE (NOT OPEN)SE 80TH ST.LINCOLN AVE NENE 40TH STREET (NOT OPEN)CELL 4CELL 3CELL 2CELL 1CELL 3CELL 2CELL 1TRACT F
TRACT B
TRACT G
TRACT C
TR. K
TR. J
ROAD A
ALLEY 3
NE 40TH STALLEY 1
LINCOLN AVE NESE 80TH ST2 44
1
55 63
9
8
7
10 1615151413131211
5555
3435 31393237363833
5151
4647
22 23 2417 2518 261920 2721 28 29
50504948
53535252 5454
45 44 43 42
4041 30
TRACT H
TRACT A ALLEY2AVAULT ACCESS RD
VAULTACCESS RD
A
ALLEY 2
LINCOLN AVE NE NE 40TH STPLANT SCHEDULE
POSTDEVELOPED AREAS
EXHIBIT 1
IN COMPLIANCE WITH CITY OF RENTON STANDARDS
DESIGN
12100 NE 195th St, Suite 300 Bothell, Washington 98011 425.885.7877
CIVIL ENGINEERING
LANDSCAPE ARCHITECTURE
PLANNING
SURVEYING
CANOPY
4196 LINCOLN AVE NE, RENTON, WA 98056TED-XX-XXXXC: XX-XXXXXXLUA: XX-XXXXXXPR: XX-XXXXXXONSITE IMPERVIOUS AREAS OFFSITE IMPERVIOUS AREAS
TREATED BY WET
VAULT
Core Design, Inc. Canopy Page 23
SECTION 5: CONVEYANCE SYSTEM ANALYSIS AND DESIGN
All conveyance systems have been designed in accordance with the 2017 RSWDM. The conveyance system
has been designed to provide sufficient capacity to convey and contain, at a minimum, the 25-year peak
developed condition flows. Pipe system structures may overtop for runoff events that exceed the 25-year
design capacity provided that the 100-year runoff does not create a flooding or erosion problem. Peak
flows used in all hydraulic calculations have been determined using the rational method per section 3.2.1
of the 2017 RSWDM. Refer to the Conveyance Tributary Area Exhibit at the end of this section for a
breakdown of the tributary areas.
Rational Method
Q = CiA
Where:
Q = runoff (cfs)
C = runoff coefficient
I = average rainfall intensity (inches per hour)
A = drainage area (acres)
Composite Runoff Coefficient
= (+ )/= 0.58
Where:
Cc = composite runoff coefficient (cfs)
C1 = runoff coefficient 0.9 (Pavement and Roofs)
C2 = runoff coefficient 0.25 (Lawns)
A1, A2 = Area of land cover(acres)
At = Total area (acres)
A composite runoff coefficient was calculated for the basins. The composite coefficient was used in the
rational method calculations for conveyance.
Conveyance Calculation Results
All conveyance systems convey the 25-year and 100-year storm at 15-minute time steps without
overtopping. Refer to the Conveyance Capacity and Backwater Calculation spreadsheets are included at
the end of this section.
Outfall Sizing
The proposed energy dissipator for the outfall of the conveyance system was sized based on the velocity
the water would be traveling at if the pipe were to be flowing at full capacity. Using Manning’s Equation
and the specifications of the final pipe segment, it was found that the maximum velocity possible from
this final length of pipe is 3.52 feet per second. Per the specifications outlined in the 2017 RSWDM Section
4.2.2 and Table 4.2.2A, the required rock protection at the outfall is Rock Lining. The size of the rock lining
will be 1 foot thick by 7 feet wide by 8 feet long and extend 1 foot above the crown of the pipe outfall.
Project Description
18054 Conveyance Analysis (07-02-2021).SPF
Project Options
CFS
Elevation
Rational
User-Defined
Kinematic Wave
YES
NO
Analysis Options
Jul 02, 2021 00:00:00
Jul 03, 2021 00:00:00
Jul 02, 2021 00:00:00
0 days
0 01:00:00 days hh:mm:ss
0 00:05:00 days hh:mm:ss
0 00:05:00 days hh:mm:ss
30 seconds
Number of Elements
Qty
0
57
64
62
2
0
0
0
62
0
62
0
0
0
0
0
0
Rainfall Details
2.77 in/hr
Outlets .........................................................................
Pollutants ..............................................................................
Land Uses ............................................................................
Rainfall Intensity....................................................................
Links......................................................................................
Channels ......................................................................
Pipes ............................................................................
Pumps ..........................................................................
Orifices .........................................................................
Weirs ............................................................................
Nodes....................................................................................
Junctions ......................................................................
Outfalls .........................................................................
Flow Diversions ............................................................
Inlets ............................................................................
Storage Nodes .............................................................
Runoff (Dry Weather) Time Step ..........................................
Runoff (Wet Weather) Time Step .........................................
Reporting Time Step ............................................................
Routing Time Step ................................................................
Rain Gages ..........................................................................
Subbasins..............................................................................
Enable Overflow Ponding at Nodes .....................................
Skip Steady State Analysis Time Periods ............................
Start Analysis On ..................................................................
End Analysis On ...................................................................
Start Reporting On ...............................................................
Antecedent Dry Days ............................................................
File Name .............................................................................
Flow Units .............................................................................
Elevation Type ......................................................................
Hydrology Method ................................................................
Time of Concentration (TOC) Method ..................................
Link Routing Method .............................................................
18054 Canopy TIR Section 5
25-yr Conveyance Analysis
By: NRZ
Page 1 of 6
Subbasin Summary
Subbasin Area Weighted Total Total Total Peak Time of
ID Runoff Rainfall Runoff Runoff Runoff Concentration
Coefficient Volume
(ac) (in) (in) (ac-in) (cfs) (min)
Sub-10 0.04 0.58 0.29 0.17 0.01 0.06 6.2
Sub-10B 0.16 0.58 0.29 0.17 0.03 0.26 6.2
Sub-11 0.07 0.58 0.29 0.17 0.01 0.12 6.2
Sub-11B 0.29 0.58 0.29 0.17 0.05 0.46 6.2
Sub-12 0.03 0.58 0.29 0.17 0.00 0.04 6.2
Sub-12B 0.42 0.58 0.29 0.17 0.07 0.68 6.2
Sub-13 0.06 0.58 0.29 0.17 0.01 0.10 6.2
Sub-14 0.03 0.58 0.29 0.17 0.00 0.05 6.2
Sub-15 0.03 0.58 0.29 0.17 0.00 0.05 6.2
Sub-15A 0.03 0.58 0.29 0.17 0.00 0.04 6.2
Sub-16 0.08 0.58 0.29 0.17 0.01 0.14 6.2
Sub-16B 0.37 0.58 0.29 0.17 0.06 0.59 6.2
Sub-17 0.06 0.58 0.29 0.17 0.01 0.10 6.2
Sub-17B 0.26 0.58 0.29 0.17 0.04 0.42 6.2
Sub-18 0.04 0.58 0.29 0.17 0.01 0.06 6.2
Sub-19 0.16 0.58 0.29 0.17 0.03 0.26 6.2
Sub-2 0.02 0.58 0.29 0.17 0.00 0.04 6.2
Sub-20 0.20 0.58 0.29 0.17 0.03 0.32 6.2
Sub-21 0.06 0.58 0.29 0.17 0.01 0.09 6.2
Sub-22 0.08 0.58 0.29 0.17 0.01 0.13 6.2
Sub-23 0.16 0.58 0.29 0.17 0.03 0.26 6.2
Sub-24 0.15 0.58 0.29 0.17 0.03 0.24 6.2
Sub-25 0.21 0.58 0.29 0.17 0.04 0.34 6.2
Sub-26 0.25 0.58 0.29 0.17 0.04 0.41 6.2
Sub-29 0.48 0.58 0.29 0.17 0.08 0.77 6.2
Sub-2B 0.24 0.58 0.29 0.17 0.04 0.38 6.2
Sub-3 0.21 0.58 0.29 0.17 0.04 0.34 6.2
Sub-30 0.25 0.58 0.29 0.17 0.04 0.40 6.2
Sub-31 0.28 0.58 0.29 0.17 0.05 0.45 6.2
Sub-32 0.02 0.58 0.29 0.17 0.00 0.03 6.2
Sub-33 0.19 0.58 0.29 0.17 0.03 0.31 6.2
Sub-34 0.21 0.58 0.29 0.17 0.04 0.33 6.2
Sub-35 0.03 0.58 0.29 0.17 0.01 0.05 6.2
Sub-36 0.29 0.58 0.29 0.17 0.05 0.46 6.2
Sub-37 0.16 0.58 0.29 0.17 0.03 0.26 6.2
Sub-38 0.05 0.58 0.29 0.17 0.01 0.07 6.2
Sub-39 0.06 0.58 0.29 0.17 0.01 0.09 6.2
Sub-4 0.03 0.58 0.29 0.17 0.00 0.04 6.2
Sub-40 0.03 0.58 0.29 0.17 0.00 0.04 6.2
Sub-40B 0.14 0.58 0.29 0.17 0.02 0.23 6.2
Sub-41 0.50 0.58 0.29 0.17 0.08 0.80 6.2
Sub-45 0.00 0.58 0.29 0.17 0.00 0.01 6.2
Sub-46 0.00 0.58 0.29 0.17 0.00 0.01 6.2
Sub-47 0.08 0.58 0.29 0.17 0.01 0.12 6.2
Sub-48 0.04 0.58 0.29 0.17 0.01 0.07 6.2
Sub-49 0.10 0.58 0.29 0.17 0.02 0.15 6.2
Sub-4B 0.07 0.58 0.29 0.17 0.01 0.11 6.2
Sub-5 0.09 0.58 0.29 0.17 0.01 0.14 6.2
Sub-50 0.49 0.58 0.29 0.17 0.08 0.79 6.2
Sub-564 0.01 0.58 0.29 0.17 0.00 0.02 6.2
Sub-573 0.03 0.58 0.29 0.17 0.00 0.04 6.2
Sub-6 0.01 0.58 0.29 0.17 0.00 0.02 6.2
Sub-6B 0.09 0.58 0.29 0.17 0.01 0.14 6.2
Sub-7 0.01 0.58 0.29 0.17 0.00 0.02 6.2
Sub-8 0.01 0.58 0.29 0.17 0.00 0.02 6.2
Sub-8B 0.18 0.58 0.29 0.17 0.03 0.28 6.2
Sub-9 0.05 0.58 0.29 0.17 0.01 0.07 6.2
18054 Canopy TIR Section 5
25-yr Conveyance Analysis
By: NRZ
Page 2 of 6
Node SummaryCatch Basin Element Invert Ground/Rim Initial Surcharge Ponded Peak Max HGL Max MinNo Type Elevation (Max) Water Elevation Area Inflow Elevation Surcharge FreeboardElevation Elevation Attained Depth AttainedAttained(ft) (ft) (ft) (ft) (ft²) (cfs) (ft) (ft) (ft)1 Junction 54.82 57.91 54.82 57.91 0.00 10.81 55.96 0.00 1.9510B Junction 111.47 116.47 111.47 116.47 0.00 0.26 111.61 0.00 4.8611B Junction 117.00 120.09 117.00 120.09 0.00 0.46 117.14 0.00 2.9512B Junction 121.40 126.31 121.40 126.31 0.00 0.68 121.56 0.00 4.7515A Junction 142.59 146.82 142.59 146.82 0.00 1.26 142.82 0.00 4.0016B Junction 146.52 151.26 146.52 151.26 0.00 0.59 146.81 0.00 4.4517B Junction 151.02 155.73 151.02 155.73 0.00 0.42 151.24 0.00 4.492 Junction 56.02 59.88 56.02 59.88 0.00 10.88 57.17 0.00 2.713 Junction 72.09 76.09 72.09 76.09 0.00 9.16 73.23 0.00 2.864 Junction 73.52 78.37 73.52 78.37 0.00 8.53 74.18 0.00 4.195 Junction 79.00 82.72 79.00 82.72 0.00 8.40 79.71 0.00 3.016 Junction 85.25 91.32 85.25 91.32 0.00 7.04 85.88 0.00 5.457 Junction 91.59 96.39 91.59 96.39 0.00 6.90 92.01 0.00 4.388 Junction 96.00 102.24 96.00 102.24 0.00 6.88 96.95 0.00 5.289 Junction 102.38 107.18 102.38 107.18 0.00 6.62 102.89 0.00 4.2910 Junction 110.90 116.49 110.90 116.49 0.00 6.55 111.48 0.00 5.0111 Junction 115.13 120.11 115.13 120.11 0.00 6.27 115.84 0.00 4.2712 Junction 118.73 126.32 118.73 126.32 0.00 5.77 119.44 0.00 6.8813 Junction 121.88 129.56 121.88 129.56 0.00 4.29 122.59 0.00 6.9714 Junction 133.81 139.66 133.81 139.66 0.00 1.97 134.08 0.00 5.5815 Junction 138.11 141.52 138.11 141.52 0.00 1.93 138.38 0.00 3.1416 Junction 146.34 151.26 146.34 151.26 0.00 1.22 146.63 0.00 4.6317 Junction 150.77 155.73 150.77 155.73 0.00 0.52 150.99 0.00 4.7418 Junction 154.70 157.39 154.70 157.39 0.00 0.06 154.76 0.00 2.6319 Junction 153.80 155.86 153.80 155.86 0.00 0.32 153.92 0.00 1.9420 Junction 146.00 150.60 146.00 150.60 0.00 0.63 146.87 0.00 3.7421 Junction 145.76 150.67 145.76 150.67 0.00 0.71 146.01 0.00 4.6622 Junction 82.88 87.90 82.88 87.90 0.00 1.34 83.11 0.00 4.7823 Junction 87.81 91.66 87.81 91.66 0.00 1.21 88.04 0.00 3.6124 Junction 91.29 94.74 91.29 94.74 0.00 0.97 91.50 0.00 3.2425 Junction 95.02 97.82 95.02 97.82 0.00 0.73 95.20 0.00 2.6226 Junction 101.00 104.40 101.00 104.40 0.00 0.41 101.15 0.00 3.2629 Junction 123.00 126.04 123.00 126.04 0.00 2.38 123.73 0.00 2.312B Junction 76.76 82.76 76.76 82.76 0.00 0.38 76.90 0.00 5.8630 Junction 127.77 131.41 127.77 131.41 0.00 1.67 128.09 0.00 3.3231 Junction 134.46 138.22 134.46 138.22 0.00 1.31 134.73 0.00 3.4932 Junction 137.62 141.59 137.62 141.59 0.00 0.89 137.88 0.00 3.7133 Junction 139.60 143.20 139.60 143.20 0.00 0.64 139.80 0.00 3.4034 Junction 140.20 144.01 140.20 144.01 0.00 0.33 140.35 0.00 3.6735 Junction 137.30 148.33 137.30 148.33 0.00 0.81 137.65 0.00 10.6836 Junction 137.95 147.10 137.95 147.10 0.00 0.77 138.30 0.00 8.8037 Junction 138.39 145.35 138.39 145.35 0.00 0.33 138.61 0.00 6.7438 Junction 139.00 143.40 139.00 143.40 0.00 0.07 139.10 0.00 4.3039 Junction 63.73 67.04 63.73 67.04 0.00 1.15 63.99 0.00 3.0540 Junction 64.55 68.22 64.55 68.22 0.00 1.06 64.81 0.00 3.4140B Junction 65.99 68.68 65.99 68.68 0.00 0.23 66.10 0.00 2.5818054 Canopy TIR Section 525-yr Conveyance AnalysisBy: NRZPage 3 of 6
Node SummaryCatch Basin Element Invert Ground/Rim Initial Surcharge Ponded Peak Max HGL Max MinNo Type Elevation (Max) Water Elevation Area Inflow Elevation Surcharge FreeboardElevation Elevation Attained Depth AttainedAttained(ft) (ft) (ft) (ft) (ft²) (cfs) (ft) (ft) (ft)41 Junction 65.50 69.37 65.50 69.37 0.00 0.80 65.76 0.00 3.6145 Junction 97.04 100.48 97.04 100.48 0.00 0.25 97.24 0.00 3.2446 Junction 100.50 105.01 100.50 105.01 0.00 0.24 100.62 0.00 4.3947 Junction 104.16 108.66 104.16 108.66 0.00 0.23 104.26 0.00 4.4048 Junction 126.56 131.04 126.56 131.04 0.00 0.07 126.60 0.00 4.4449 Junction 142.29 145.54 142.29 145.54 0.00 0.86 142.48 0.00 3.064B Junction 74.35 78.35 74.35 78.35 0.00 0.10 74.43 0.00 3.9150 Junction 57.10 60.11 57.10 60.11 0.00 0.79 57.29 0.00 2.82367 Junction 142.50 145.87 142.50 145.87 0.00 0.00 142.50 0.00 3.37564 Junction 120.85 128.39 120.85 128.39 0.00 5.11 121.40 0.00 6.99569 Junction 55.82 57.98 55.82 57.98 0.00 0.00 55.82 0.00 2.16573 Junction 109.23 113.74 109.23 113.74 0.00 0.11 109.30 0.00 4.446B Junction 86.00 91.00 86.00 91.00 0.00 0.14 86.13 0.00 4.878B Junction 96.75 101.75 96.75 101.75 0.00 0.28 96.93 0.00 4.82NORTH_VAULT Junction 58.50 63.50 58.50 63.50 0.00 10.17 59.06 0.00 4.29SOUTH_VAULT Junction 64.00 74.00 64.00 74.00 0.00 9.16 72.85 0.00 1.75Out-1194 Outfall 96.800.25 97.00Out-1572 Outfall 48.8510.81 49.4018054 Canopy TIR Section 525-yr Conveyance AnalysisBy: NRZPage 4 of 6
Link Summary(UPSTR) (DNSTR) Pipe Length Inlet Outlet Average Diameter or Manning's Entrance Exit Peak Design Flow Peak Flow/ Peak Flow Peak Flow Peak FlowFROM TO Invert Invert Slope Height Roughness Losses Losses Flow Capacity Design Flow Velocity Depth Depth/CB CB Elevation ElevationRatio Total DepthRatio(ft) (ft) (ft) (%) (in) (cfs) (cfs) (ft/sec) (ft)48 573 93.41 126.56 109.23 18.55 12 0.012 0.50 0.50 0.06 16.62 0.00 5.08 0.05 0.05573 47 48.31 109.23 104.16 10.50 12 0.012 0.50 0.50 0.11 12.51 0.01 4.88 0.07 0.0747 46 41.32 104.16 100.50 8.86 12 0.012 0.50 0.50 0.23 11.49 0.02 5.73 0.10 0.1046 45 61.74 100.50 97.04 5.60 12 0.012 0.50 0.50 0.24 9.14 0.03 5.09 0.11 0.1145 Out-1194 47.17 97.04 96.80 0.50 12 0.012 0.50 0.50 0.25 2.73 0.09 2.24 0.20 0.2038 37 57.90 139.00 138.39 1.06 12 0.012 0.50 0.50 0.07 3.98 0.02 2.92 0.09 0.0937 36 70.23 138.39 137.95 0.62 12 0.012 0.50 0.50 0.33 3.04 0.11 2.55 0.22 0.2236 35 113.15 137.95 137.30 0.57 12 0.012 0.50 0.50 0.76 2.93 0.26 3.18 0.35 0.3535 564 107.93 137.30 120.85 15.24 12 0.012 0.50 0.50 0.81 15.07 0.05 10.23 0.16 0.16367 34 26.12 142.50 140.20 8.81 6 0.012 0.50 0.50 0.00 1.80 0.00 0.00 0.00 0.0034 33 17.47 140.20 139.60 3.43 12 0.012 0.50 0.50 0.33 7.15 0.05 4.66 0.15 0.1533 15 40.74 139.60 138.11 3.66 12 0.012 0.50 0.50 0.63 7.38 0.09 5.77 0.20 0.2018 19 24.51 154.70 153.80 3.67 12 0.012 0.50 0.50 0.06 7.40 0.01 2.83 0.06 0.0619 20 91.58 153.80 146.75 7.70 12 0.012 0.50 0.50 0.32 10.71 0.03 6.12 0.12 0.1220 21 18.10 146.00 145.76 1.35 12 0.012 0.50 0.50 0.63 4.48 0.14 4.02 0.25 0.2521 49 70.11 145.76 142.29 4.95 12 0.012 0.50 0.50 0.71 8.59 0.08 6.65 0.19 0.1949 32 40.59 142.29 137.62 11.50 12 0.012 0.50 0.50 0.86 13.09 0.07 9.38 0.17 0.1732 31 137.30 137.62 134.46 2.30 12 0.012 0.50 0.50 0.89 5.85 0.15 5.43 0.26 0.2631 30 143.92 134.46 127.77 4.65 12 0.012 0.50 0.50 1.30 8.32 0.16 7.76 0.27 0.2730 29 123.49 127.77 123.00 3.86 12 0.012 0.50 0.50 1.67 7.59 0.22 7.78 0.32 0.3229 13 224.49 123.01 121.88 0.50 12 0.012 0.50 0.50 2.34 2.74 0.86 4.08 0.71 0.7116B 16 24.50 146.52 146.34 0.74 12 0.012 0.50 0.50 0.58 3.32 0.18 3.50 0.28 0.2817B 17 24.50 151.02 150.77 1.00 12 0.012 0.50 0.50 0.42 3.86 0.11 3.52 0.22 0.2217 16 138.30 150.77 146.34 3.20 12 0.012 0.50 0.50 0.51 6.90 0.07 5.21 0.18 0.1816 15A 46.90 146.34 142.59 7.99 12 0.012 0.50 0.50 1.22 10.91 0.11 9.18 0.23 0.2315A 15 44.83 142.59 138.11 10.01 12 0.012 0.50 0.50 1.26 12.21 0.10 10.03 0.22 0.2215 14 46.19 138.11 133.81 9.30 12 0.012 0.50 0.50 1.93 11.77 0.16 11.05 0.27 0.2714 13 107.73 133.81 121.88 11.07 12 0.012 0.50 0.50 1.97 12.84 0.15 11.86 0.26 0.2613 564 20.67 121.88 120.85 4.98 12 0.012 0.50 0.50 4.29 8.62 0.50 10.95 0.50 0.50564 12 42.49 120.85 118.73 4.99 12 0.012 0.50 0.50 5.11 8.62 0.59 11.44 0.55 0.5512 11 118.46 118.73 115.13 3.04 12 0.012 0.50 0.50 5.76 6.73 0.86 9.66 0.71 0.7112B 12 23.60 121.40 118.73 11.31 12 0.012 0.50 0.50 0.68 12.98 0.05 8.74 0.16 0.1611B 11 23.60 117.00 115.13 7.92 12 0.012 0.50 0.50 0.46 10.86 0.04 6.90 0.14 0.1410B 10 23.60 111.47 110.90 2.42 12 0.012 0.50 0.50 0.26 6.00 0.04 3.88 0.14 0.148B 8 25.40 96.75 96.50 1.00 12 0.012 0.50 0.50 0.28 3.86 0.07 3.26 0.18 0.186B 6 25.40 86.00 85.75 1.00 12 0.012 0.50 0.50 0.14 3.86 0.04 2.74 0.13 0.1318054 Canopy TIR Section 525-yr Conveyance AnalysisBy: NRZPage 5 of 6
Link Summary(UPSTR) (DNSTR) Pipe Length Inlet Outlet Average Diameter or Manning's Entrance Exit Peak Design Flow Peak Flow/ Peak Flow Peak Flow Peak FlowFROM TO Invert Invert Slope Height Roughness Losses Losses Flow Capacity Design Flow Velocity Depth Depth/CB CB Elevation ElevationRatio Total DepthRatio(ft) (ft) (ft) (%) (in) (cfs) (cfs) (ft/sec) (ft)26 25 116.74 101.00 95.02 5.12 12 0.012 0.50 0.50 0.40 8.74 0.05 7.79 0.15 0.1525 24 53.13 95.02 91.29 7.02 12 0.012 0.50 0.50 0.73 10.23 0.07 7.58 0.18 0.1824 23 53.14 91.29 87.81 6.55 12 0.012 0.50 0.50 0.96 9.88 0.10 8.01 0.21 0.2123 22 70.20 87.81 82.88 7.02 12 0.012 0.50 0.50 1.21 10.23 0.12 8.75 0.23 0.2322 5 26.55 82.88 79.50 12.73 12 0.012 0.50 0.50 1.34 13.77 0.10 11.12 0.21 0.214B 4 23.60 74.35 73.52 3.51 12 0.012 0.50 0.50 0.10 7.23 0.01 3.31 0.08 0.0811 10 65.08 115.13 110.90 6.50 12 0.012 0.50 0.50 6.27 9.84 0.64 13.28 0.58 0.5810 9 77.12 110.90 102.38 11.05 12 0.012 0.50 0.50 6.55 12.83 0.51 16.42 0.51 0.519 8 35.93 102.38 96.50 16.36 12 0.012 0.50 0.50 6.62 15.61 0.42 19.06 0.45 0.458 7 35.49 96.00 91.59 12.43 18 0.012 0.50 0.50 6.88 40.11 0.17 16.96 0.42 0.287 6 35.49 91.59 85.25 17.86 18 0.012 0.50 0.50 6.90 48.10 0.14 19.32 0.38 0.266 5 57.25 85.25 79.00 10.92 18 0.012 0.50 0.50 7.04 37.60 0.19 16.30 0.44 0.295 4 33.86 79.00 73.52 16.18 18 0.012 0.50 0.50 8.40 45.78 0.18 19.72 0.44 0.294 3 64.14 73.52 72.09 2.23 24 0.012 0.50 0.50 8.53 36.61 0.23 9.51 0.66 0.333 SOUTH_VAULT 9.14 72.09 72.00 0.98 24 0.012 0.50 0.50 9.16 24.32 0.38 7.19 0.85 0.432B 3 68.79 76.76 73.09 5.34 12 0.012 0.50 0.50 0.38 8.92 0.04 6.94 0.14 0.1450 2 16.49 57.10 56.02 6.57 12 0.012 0.50 0.50 0.78 9.89 0.08 7.54 0.19 0.1941 40 47.12 65.50 64.55 2.02 12 0.012 0.50 0.50 0.79 5.48 0.15 5.72 0.26 0.2640B 40 24.71 65.99 64.55 5.83 12 0.012 0.50 0.50 0.23 9.32 0.02 4.83 0.11 0.1140 39 22.42 64.55 63.73 3.64 12 0.012 0.50 0.50 1.06 7.36 0.14 6.67 0.26 0.2639 NORTH_VAULT 34.23 63.73 57.50 18.21 18 0.012 0.50 0.50 1.15 48.56 0.02 11.08 0.16 0.11SOUTH_VAULT NORTH_VAULT 115.38 64.00 57.50 5.63 18 0.012 0.50 0.50 9.16 27.01 0.34 13.82 0.60 0.40NORTH_VAULT 2 41.25 58.50 56.02 6.01 18 0.012 0.50 0.50 10.17 27.90 0.36 14.54 0.63 0.422 1 239.79 56.02 54.82 0.50 24 0.012 0.50 0.50 10.81 17.34 0.62 5.91 1.14 0.57569 1 13.72 55.82 54.82 7.29 24 0.012 0.50 0.50 0.00 66.17 0.00 0.00 0.00 0.001 Outfall 82.22 54.82 48.85 7.26 24 0.012 0.50 0.50 10.81 66.04 0.16 15.50 0.55 0.2718054 Canopy TIR Section 525-yr Conveyance AnalysisBy: NRZPage 6 of 6
Core Design, Inc. Canopy Page 25
SECTION 6: SPECIAL REPORTS AND STUDIES
Special Reports and Studies provided in Appendix E.
Geotechnical Engineering Report (Under Separate Cover)
Prepared for: Blue Fern Development, LLC
Prepared by: Carolyn S. Decker, P.E
Dated: June 21, 2021
Terra Associates, Inc.
12220 113th Ave NE Ste. 130
Kirkland, WA 98034
Critical Areas Study and Conceptual Mitigation Plan
Prepared for: Blue Fern Development, LLC
Prepared by: Scott Brainard, PWS
Dated: February 26, 2021
Wetland Resources, Inc.
9505 19th Avenue SE, Suite 106
Everett, WA 98208
Core Design, Inc. Canopy Page 26
SECTION 7: OTHER PERMITS
Right of Way Use Permit
Building Permit
NPDES Permit
Separate building permits for any retaining wall higher than 4’, Utility Connections, Detention
Vaults, Pedestrian pathway stairs
Forest Practices Permit
Coal Creek Sewer and Water Approval
Core Design, Inc. Canopy Page 27
SECTION 8: CSWPP ANALYSIS AND DESIGN
8.1 ESC Plan Analysis and Design
The site will utilize Appendix D of the 2017 RSWDM for the erosion and sedimentation control design. The
project proposes to utilize a temporary construction entrance and sediment trap. Interceptor swales with
check dams will route runoff to the sediment traps and silt fence will delineate the project limits. The TESC
plans have been included in the approved plan set.
Sediment Pond calculations were completed in Appendix C of the SWPPP. The North Detention Vault will
be used as a temporary sediment pond. The required volume for the sediment pond is approximately
15,820 cubic feet and the provided volume is 27,828 cubic feet.
8.2 SWPPS Plan Design
A SWPPP has been prepared for this project and submitted under separate cover. The receiving
waterbody, Lake Washington, is 303(d) listed for bacteria. Proposed development of the site is not
anticipated to exacerbate this listing. All 13 elements will be maintained per the RSWDM. Temporary
and permanent measures will be implemented to ensure protection of downstream areas from
construction pollution and sediment runoff.
Core Design, Inc. Canopy Page 28
9 BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT
9.1 Bond Quantities
A Site Improvement Bond Quantity Worksheet is included at the end of this section.
9.2 Facility Summaries
Facility Summaries are required for the proposed vaults as they will be publicly owned and maintained.
Following approval of the plans, a “Flow Control and Water Quality Facility Summary Sheet and Sketch”
shall be submitted along with an 8-1/2” by 11” plan sketch for each facility proposed for construction. At
project completion, the Summary Sheet and Sketch shall be updated at the end of this section to reflect
the completed project.
9.3 Declaration of Covenant
A Declaration of Covenant is required to be submitted and approved by City Staff before permit issuance.
After the stormwater system has been constructed, as-built, inspected, and accepted, a signed and
notarized document will be recorded with the City and supplied to City Staff for reference.
Planning Division |1055 South Grady Way – 6 th Floor | Renton, WA 98057 (425) 430-7200
•
•
Section I: Project Information
•
•
•Section II: Bond Quantities Worksheets
•
•Section II.a EROSION CONTROL (Stabilization/Erosion Sediment Control (ESC))
•Section II.b TRANSPORTATION (Street and Site Improvements)
•Section II.c DRAINAGE (Drainage and Stormwater Facilities):
•Section II.d WATER - ONLY APPLICABLE IF WATER SERVICE IS PROVIDED BY CITY OF RENTON
•Section II.e SANITARY SEWER - ONLY APPLICABLE IF SEWER SERVICE IS PROVIDED BY CITY OF RENTON
•
•
•
•
•
•
Section III. Bond Worksheet
•This section calculates the required Permit Bond for construction permit issuance as well as the required Maintenance Bond for project close-out
submittals to release the permit bond on a project.
All unit prices include labor, equipment, materials, overhead and profit.
Complete the 'Quantity' columns for each of the appropriate section(s). Include existing Right-of-Way (ROW), Future Public Improvements and Private
Improvements.
The 'Quantity Remaining' column is only to be used when a project is under construction. The City allows one (1) bond reduction during the life of the
project with the exception of the maintenance period reduction.
Excel will auto-calculate and auto-populate the relevant fields and subtotals throughout the document. Only the 'Quantity' columns should need
completing.
Additional items not included in the lists can be added under the "write-in" sections. Provide a complete description, cost estimate and unit of measure
for each write-in item.
Note: Private improvements, with the exception of stormwater facilities, are not included in the bond amount calculation, but must be entered on the
form. Stormwater facilities (public and private) are required to be included in the bond amount.
BOND QUANTITY WORKSHEET INSTRUCTIONS
This worksheet is intended to be a "working" copy of the bond quantity worksheet, which will be used throughout all phases of the project, from initial
submittal to project close-out approval.
Submit this workbook, in its entirety, as follows:
The following forms are to be completed by the engineer/developer/applicant as applicable to the project:
The Bond Worksheet form will auto-calculate and auto-populate from the information provided in Section I and Section II.
This section includes all pertinent information for the project
Section II contains a separate spreadsheet TAB for each of the following specialties:
(1) electronic copy (.xlsx format) and (1) hard copy of the entire workbook for civil construction permit submittal. Hard copies are to be included as part
of the Technical Information Report (TIR).
(1) electronic copy (.xlsx format) and (1) hard copy of the entire workbook for final close-out submittal.
This section must be completed in its entirety
Information from this section auto-populates to all other relevant areas of the workbook
Page 1 of 1
Ref 8-H Bond Quantity Worksheet INSTRUCTIONS
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 2/17/2021
Planning Division |1055 South Grady Way – 6 th Floor | Renton, WA 98057 (425) 430-7200
Date Prepared:
Name:
PE Registration No:
Firm Name:
Firm Address:
Phone No.
Email Address:
Project Name: Project Owner:
CED Plan # (LUA):Phone:
CED Permit # (U):Address:
Site Address:
Street Intersection:Addt'l Project Owner:
Parcel #(s):Phone:
Address:
Clearing and grading greater than or equal to 5,000 board feet of timber?
Yes/No:NO Water Service Provided by:
If Yes, Provide Forest Practice Permit #:Sewer Service Provided by:
SITE IMPROVEMENT BOND QUANTITY WORKSHEET
PROJECT INFORMATION
CITY OF RENTON
COAL CREEK UTILITY DISTRICT
1 Select the current project status/phase from the following options:
For Approval - Preliminary Data Enclosed, pending approval from the City;
For Construction - Estimated Data Enclosed, Plans have been approved for contruction by the City;
Project Closeout - Final Costs and Quantities Enclosed for Project Close-out Submittal
Engineer Stamp Required
(all cost estimates must have original wet stamp and signature)
Clearing and Grading Utility Providers
N/A
Project Location and Description Project Owner Information
Canopy
Kirkland, WA 98033
3345700015
Glacial Venture II, LLC
19-000223 (360) 708-9130
2/12/2021
Prepared by:
FOR APPROVALProject Phase 1
HHH@coredesigninc.com
Holli Heavrin
53199
Core Design Inc.
12100 NE 195th St #300, Bothell, WA 98011
(425) 885-7877
4196 Lincoln Ave NE
1414 Market Street, Suite 200
N/A
19000397
Abbreviated Legal
Description:
See sheets for details
Page 1 of 1
Ref 8-H Bond Quantity Worksheet SECTION I PROJECT INFORMATION
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 2/17/2021
CED Permit #:19000397 UnitReference #Price Unit Quantity CostBackfill & compaction-embankment ESC-1 6.50$ CY Check dams, 4" minus rock ESC-2 SWDM 5.4.6.3 80.00$ Each 44 3,520.00Catch Basin Protection ESC-3 35.50$ Each 60 2,130.00Crushed surfacing 1 1/4" minus ESC-4 WSDOT 9-03.9(3)95.00$ CY Ditching ESC-5 9.00$ CY Excavation-bulk ESC-6 2.00$ CY Fence, silt ESC-7 SWDM 5.4.3.1 1.50$ LF 1674 2,511.00Fence, Temporary (NGPE)ESC-8 1.50$ LF Geotextile Fabric ESC-9 2.50$ SY Hay Bale Silt Trap ESC-10 0.50$ Each Hydroseeding ESC-11 SWDM 5.4.2.4 0.80$ SY 24733 19,786.40Interceptor Swale / Dike ESC-12 1.00$ LF 1789 1,789.00Jute Mesh ESC-13 SWDM 5.4.2.2 3.50$ SY Level Spreader ESC-14 1.75$ LF Mulch, by hand, straw, 3" deep ESC-15 SWDM 5.4.2.1 2.50$ SY Mulch, by machine, straw, 2" deep ESC-16 SWDM 5.4.2.1 2.00$ SY Piping, temporary, CPP, 6"ESC-17 12.00$ LF Piping, temporary, CPP, 8"ESC-18 14.00$ LF Piping, temporary, CPP, 12"ESC-19 18.00$ LF Plastic covering, 6mm thick, sandbagged ESC-20 SWDM 5.4.2.3 4.00$ SY Rip Rap, machine placed; slopes ESC-21 WSDOT 9-13.1(2)45.00$ CY Rock Construction Entrance, 50'x15'x1'ESC-22 SWDM 5.4.4.1 1,800.00$ Each Rock Construction Entrance, 100'x15'x1'ESC-23 SWDM 5.4.4.1 3,200.00$ Each 1 3,200.00Sediment pond riser assembly ESC-24 SWDM 5.4.5.2 2,200.00$ Each Sediment trap, 5' high berm ESC-25 SWDM 5.4.5.1 19.00$ LF Sed. trap, 5' high, riprapped spillway berm section ESC-26 SWDM 5.4.5.1 70.00$ LF Seeding, by hand ESC-27 SWDM 5.4.2.4 1.00$ SY Sodding, 1" deep, level ground ESC-28 SWDM 5.4.2.5 8.00$ SY Sodding, 1" deep, sloped ground ESC-29 SWDM 5.4.2.5 10.00$ SY TESC Supervisor ESC-30 110.00$ HR 80 8,800.00Water truck, dust control ESC-31 SWDM 5.4.7 140.00$ HR 40 5,600.00UnitReference #Price Unit Quantity Cost
EROSION/SEDIMENT SUBTOTAL:47,336.40SALES TAX @ 10%4,733.64EROSION/SEDIMENT TOTAL:52,070.04
(A)
SITE IMPROVEMENT BOND QUANTITY WORKSHEET
FOR EROSION & SEDIMENT CONTROL
Description No.(A)
WRITE-IN-ITEMS
Page 1 of 1
Ref 8-H Bond Quantity Worksheet SECTION II.a EROSION_CONTROL
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 2/17/2021
CED Permit #:19000397
Existing Future Public PrivateRight-of-Way Improvements Improvements
(D) (E)Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.CostGENERAL ITEMS Backfill & Compaction- embankment GI-1 6.00$ CYBackfill & Compaction- trench GI-2 9.00$ CY
Clear/Remove Brush, by hand (SY)GI-3 1.00$ SYBollards - fixed GI-4 240.74$ Each
Bollards - removable GI-5 452.34$ EachClearing/Grubbing/Tree Removal GI-6 10,000.00$ Acre 1.7 17,000.00 5.6 56,000.00Excavation - bulk GI-7 2.00$ CY 50990 101,980.00 23455 46,910.00Excavation - Trench GI-8 5.00$ CYFencing, cedar, 6' high GI-9 20.00$ LFFencing, chain link, 4'GI-10 38.31$ LFFencing, chain link, vinyl coated, 6' high GI-11 20.00$ LF
Fencing, chain link, gate, vinyl coated, 20' GI-12 1,400.00$ EachFill & compact - common barrow GI-13 25.00$ CY 4489 112,225.00 9994 249,850.00Fill & compact - gravel base GI-14 27.00$ CYFill & compact - screened topsoil GI-15 39.00$ CYGabion, 12" deep, stone filled mesh GI-16 65.00$ SYGabion, 18" deep, stone filled mesh GI-17 90.00$ SYGabion, 36" deep, stone filled mesh GI-18 150.00$ SY
Grading, fine, by hand GI-19 2.50$ SYGrading, fine, with grader GI-20 2.00$ SY
Monuments, 3' Long GI-21 250.00$ Each 3 750.00 9 2,250.00Sensitive Areas Sign GI-22 7.00$ EachSodding, 1" deep, sloped ground GI-23 8.00$ SYSurveying, line & grade GI-24 850.00$ Day 2 1,700.00 8 6,800.00 12 10,200.00Surveying, lot location/lines GI-25 1,800.00$ Acre 2 3,600.00 8 14,400.00 12 21,600.00Topsoil Type A (imported)GI-26 28.50$ CYTraffic control crew ( 2 flaggers )GI-27 120.00$ HR 40 4,800.00
Trail, 4" chipped wood GI-28 8.00$ SYTrail, 4" crushed cinder GI-29 9.00$ SY
Trail, 4" top course GI-30 12.00$ SYConduit, 2"GI-31 5.00$ LFWall, retaining, concrete GI-32 55.00$ SFWall, rockery GI-33 15.00$ SF 7173 107,595.00
SUBTOTAL THIS PAGE:10,850.00 254,655.00 492,155.00
(B)(C)(D)(E)
SITE IMPROVEMENT BOND QUANTITY WORKSHEET
FOR STREET AND SITE IMPROVEMENTS
Quantity Remaining
(Bond Reduction) (B)(C)
Page 1 of 3
Ref 8-H Bond Quantity Worksheet SECTION II.b TRANSPORTATION
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 2/17/2021
CED Permit #:19000397
Existing Future Public PrivateRight-of-Way Improvements Improvements
(D) (E)Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost
SITE IMPROVEMENT BOND QUANTITY WORKSHEET
FOR STREET AND SITE IMPROVEMENTS
Quantity Remaining
(Bond Reduction) (B)(C)
ROAD IMPROVEMENT/PAVEMENT/SURFACINGAC Grinding, 4' wide machine < 1000sy RI-1 30.00$ SYAC Grinding, 4' wide machine 1000-2000sy RI-2 16.00$ SY
AC Grinding, 4' wide machine > 2000sy RI-3 10.00$ SYAC Removal/Disposal RI-4 35.00$ SY
Barricade, Type III ( Permanent )RI-5 56.00$ LFGuard Rail RI-6 30.00$ LFCurb & Gutter, rolled RI-7 17.00$ LFCurb & Gutter, vertical RI-8 12.50$ LF 1479 18,487.50 2695 33,687.50Curb and Gutter, demolition and disposal RI-9 18.00$ LFCurb, extruded asphalt RI-10 5.50$ LFCurb, extruded concrete RI-11 7.00$ LF
Sawcut, asphalt, 3" depth RI-12 1.85$ LF 1047 1,936.95Sawcut, concrete, per 1" depth RI-13 3.00$ LFSealant, asphalt RI-14 2.00$ LFShoulder, gravel, 4" thick RI-15 15.00$ SYSidewalk, 4" thick RI-16 38.00$ SY 665 25,270.00 1647 62,586.00 269 10,222.00Sidewalk, 4" thick, demolition and disposal RI-17 32.00$ SYSidewalk, 5" thick RI-18 41.00$ SY
Sidewalk, 5" thick, demolition and disposal RI-19 40.00$ SYSign, Handicap RI-20 85.00$ Each
Striping, per stall RI-21 7.00$ EachStriping, thermoplastic, ( for crosswalk )RI-22 3.00$ SFStriping, 4" reflectorized line RI-23 0.50$ LFAdditional 2.5" Crushed Surfacing RI-24 3.60$ SYHMA 1/2" Overlay 1.5" RI-25 14.00$ SYHMA 1/2" Overlay 2"RI-26 18.00$ SYHMA Road, 2", 4" rock, First 2500 SY RI-27 28.00$ SY 933 26,124.00 2500 70,000.00 2500 70,000.00
HMA Road, 2", 4" rock, Qty. over 2500SY RI-28 21.00$ SY 1030 21,630.00 448 9,408.00HMA Road, 4", 6" rock, First 2500 SY RI-29 45.00$ SY
HMA Road, 4", 6" rock, Qty. over 2500 SY RI-30 37.00$ SYHMA Road, 4", 4.5" ATB RI-31 38.00$ SYGravel Road, 4" rock, First 2500 SY RI-32 15.00$ SYGravel Road, 4" rock, Qty. over 2500 SY RI-33 10.00$ SYThickened Edge RI-34 8.60$ LF
SUBTOTAL THIS PAGE:71,818.45 187,903.50 89,630.00
(B)(C)(D)(E)
Page 2 of 3
Ref 8-H Bond Quantity Worksheet SECTION II.b TRANSPORTATION
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 2/17/2021
CED Permit #:19000397
Existing Future Public PrivateRight-of-Way Improvements Improvements
(D) (E)Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost
SITE IMPROVEMENT BOND QUANTITY WORKSHEET
FOR STREET AND SITE IMPROVEMENTS
Quantity Remaining
(Bond Reduction) (B)(C)
PARKING LOT SURFACING No.2" AC, 2" top course rock & 4" borrow PL-1 21.00$ SY2" AC, 1.5" top course & 2.5" base course PL-2 28.00$ SY
4" select borrow PL-3 5.00$ SY1.5" top course rock & 2.5" base course PL-4 14.00$ SY
SUBTOTAL PARKING LOT SURFACING:
(B)(C)(D)(E)
LANDSCAPING & VEGETATION No.Street Trees LA-1Median Landscaping LA-2Right-of-Way Landscaping LA-3Wetland Landscaping LA-4
SUBTOTAL LANDSCAPING & VEGETATION:
(B)(C)(D)(E)
TRAFFIC & LIGHTING No.Signs TR-1 250.00$ Each 2 500.00 17 4,250.00
Street Light System ( # of Poles)TR-2 5,000.00$ Each 7 35,000.00 13 65,000.00Traffic Signal TR-3Traffic Signal Modification TR-4
SUBTOTAL TRAFFIC & LIGHTING:35,500.00 69,250.00
(B)(C)(D)(E)
WRITE-IN-ITEMS
SUBTOTAL WRITE-IN ITEMS:
STREET AND SITE IMPROVEMENTS SUBTOTAL:118,168.45 511,808.50 581,785.00
SALES TAX @ 10%11,816.85 51,180.85 58,178.50
STREET AND SITE IMPROVEMENTS TOTAL:129,985.30 562,989.35 639,963.50
(B)(C)(D)(E)
Page 3 of 3
Ref 8-H Bond Quantity Worksheet SECTION II.b TRANSPORTATION
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 2/17/2021
CED Permit #:19000397 Existing Future Public PrivateRight-of-Way Improvements Improvements(D) (E)Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.CostDRAINAGE (CPE = Corrugated Polyethylene Pipe, N12 or Equivalent) For Culvert prices, Average of 4' cover was assumed. Assume perforated PVC is same price as solid pipe.) Access Road, R/D D-1 26.00$ SY* (CBs include frame and lid)Beehive D-2 90.00$ EachThrough-curb Inlet Framework D-3 400.00$ EachCB Type I D-4 1,500.00$ Each 11 16,500.00 34 51,000.00CB Type IL D-5 1,750.00$ EachCB Type II, 48" diameter D-6 2,300.00$ Each 16 36,800.00
for additional depth over 4' D-7 480.00$ FTCB Type II, 54" diameter D-8 2,500.00$ Each for additional depth over 4'D-9 495.00$ FTCB Type II, 60" diameter D-10 2,800.00$ Each for additional depth over 4'D-11 600.00$ FTCB Type II, 72" diameter D-12 6,000.00$ Each
for additional depth over 4'D-13 850.00$ FTCB Type II, 96" diameter D-14 14,000.00$ Each for additional depth over 4'D-15 925.00$ FTTrash Rack, 12"D-16 350.00$ EachTrash Rack, 15"D-17 410.00$ EachTrash Rack, 18"D-18 480.00$ EachTrash Rack, 21"D-19 550.00$ EachCleanout, PVC, 4"D-20 150.00$ EachCleanout, PVC, 6"D-21 170.00$ Each 55 9,350.00Cleanout, PVC, 8"D-22 200.00$ EachCulvert, PVC, 4" D-23 10.00$ LFCulvert, PVC, 6" D-24 13.00$ LFCulvert, PVC, 8" D-25 15.00$ LFCulvert, PVC, 12" D-26 23.00$ LF 740 17,020.00 2745 63,135.00Culvert, PVC, 15" D-27 35.00$ LFCulvert, PVC, 18" D-28 41.00$ LFCulvert, PVC, 24"D-29 56.00$ LFCulvert, PVC, 30" D-30 78.00$ LFCulvert, PVC, 36" D-31 130.00$ LF
Culvert, CMP, 8"D-32 19.00$ LFCulvert, CMP, 12"D-33 29.00$ LF
SUBTOTAL THIS PAGE:33,520.00 150,935.00 9,350.00
(B)(C)(D)(E)
SITE IMPROVEMENT BOND QUANTITY WORKSHEET
FOR DRAINAGE AND STORMWATER FACILITIES
Quantity Remaining
(Bond Reduction) (B)(C)
Page 1 of 5
Ref 8-H Bond Quantity Worksheet SECTION II.c DRAINAGE
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 2/17/2021
CED Permit #:19000397 Existing Future Public PrivateRight-of-Way Improvements Improvements(D) (E)Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost
SITE IMPROVEMENT BOND QUANTITY WORKSHEET
FOR DRAINAGE AND STORMWATER FACILITIES
Quantity Remaining
(Bond Reduction) (B)(C)
DRAINAGE (Continued)Culvert, CMP, 15"D-34 35.00$ LFCulvert, CMP, 18"D-35 41.00$ LFCulvert, CMP, 24"D-36 56.00$ LFCulvert, CMP, 30"D-37 78.00$ LFCulvert, CMP, 36"D-38 130.00$ LFCulvert, CMP, 48"D-39 190.00$ LFCulvert, CMP, 60"D-40 270.00$ LFCulvert, CMP, 72"D-41 350.00$ LFCulvert, Concrete, 8"D-42 42.00$ LFCulvert, Concrete, 12"D-43 48.00$ LF
Culvert, Concrete, 15"D-44 78.00$ LFCulvert, Concrete, 18"D-45 48.00$ LFCulvert, Concrete, 24"D-46 78.00$ LFCulvert, Concrete, 30"D-47 125.00$ LFCulvert, Concrete, 36"D-48 150.00$ LFCulvert, Concrete, 42"D-49 175.00$ LF
Culvert, Concrete, 48"D-50 205.00$ LFCulvert, CPE Triple Wall, 6" D-51 14.00$ LFCulvert, CPE Triple Wall, 8" D-52 16.00$ LFCulvert, CPE Triple Wall, 12" D-53 24.00$ LFCulvert, CPE Triple Wall, 15" D-54 35.00$ LFCulvert, CPE Triple Wall, 18" D-55 41.00$ LFCulvert, CPE Triple Wall, 24" D-56 56.00$ LFCulvert, CPE Triple Wall, 30" D-57 78.00$ LFCulvert, CPE Triple Wall, 36" D-58 130.00$ LFCulvert, LCPE, 6"D-59 60.00$ LFCulvert, LCPE, 8"D-60 72.00$ LFCulvert, LCPE, 12"D-61 84.00$ LFCulvert, LCPE, 15"D-62 96.00$ LFCulvert, LCPE, 18"D-63 108.00$ LFCulvert, LCPE, 24"D-64 120.00$ LFCulvert, LCPE, 30"D-65 132.00$ LFCulvert, LCPE, 36"D-66 144.00$ LFCulvert, LCPE, 48"D-67 156.00$ LFCulvert, LCPE, 54"D-68 168.00$ LF
SUBTOTAL THIS PAGE:
(B)(C)(D)(E)
Page 2 of 5
Ref 8-H Bond Quantity Worksheet SECTION II.c DRAINAGE
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 2/17/2021
CED Permit #:19000397 Existing Future Public PrivateRight-of-Way Improvements Improvements(D) (E)Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost
SITE IMPROVEMENT BOND QUANTITY WORKSHEET
FOR DRAINAGE AND STORMWATER FACILITIES
Quantity Remaining
(Bond Reduction) (B)(C)
DRAINAGE (Continued)Culvert, LCPE, 60"D-69 180.00$ LFCulvert, LCPE, 72"D-70 192.00$ LFCulvert, HDPE, 6"D-71 42.00$ LFCulvert, HDPE, 8"D-72 42.00$ LFCulvert, HDPE, 12"D-73 74.00$ LFCulvert, HDPE, 15"D-74 106.00$ LFCulvert, HDPE, 18"D-75 138.00$ LFCulvert, HDPE, 24"D-76 221.00$ LFCulvert, HDPE, 30"D-77 276.00$ LFCulvert, HDPE, 36"D-78 331.00$ LFCulvert, HDPE, 48"D-79 386.00$ LFCulvert, HDPE, 54"D-80 441.00$ LFCulvert, HDPE, 60"D-81 496.00$ LF
Culvert, HDPE, 72"D-82 551.00$ LFPipe, Polypropylene, 6"D-83 84.00$ LFPipe, Polypropylene, 8"D-84 89.00$ LFPipe, Polypropylene, 12"D-85 95.00$ LFPipe, Polypropylene, 15"D-86 100.00$ LFPipe, Polypropylene, 18"D-87 106.00$ LF
Pipe, Polypropylene, 24"D-88 111.00$ LFPipe, Polypropylene, 30"D-89 119.00$ LFPipe, Polypropylene, 36"D-90 154.00$ LFPipe, Polypropylene, 48"D-91 226.00$ LFPipe, Polypropylene, 54"D-92 332.00$ LFPipe, Polypropylene, 60"D-93 439.00$ LF
Pipe, Polypropylene, 72"D-94 545.00$ LFCulvert, DI, 6"D-95 61.00$ LFCulvert, DI, 8"D-96 84.00$ LFCulvert, DI, 12"D-97 106.00$ LFCulvert, DI, 15"D-98 129.00$ LFCulvert, DI, 18"D-99 152.00$ LFCulvert, DI, 24"D-100 175.00$ LFCulvert, DI, 30"D-101 198.00$ LFCulvert, DI, 36"D-102 220.00$ LFCulvert, DI, 48"D-103 243.00$ LFCulvert, DI, 54"D-104 266.00$ LFCulvert, DI, 60"D-105 289.00$ LFCulvert, DI, 72"D-106 311.00$ LF
SUBTOTAL THIS PAGE:
(B)(C)(D)(E)
Page 3 of 5
Ref 8-H Bond Quantity Worksheet SECTION II.c DRAINAGE
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 2/17/2021
CED Permit #:19000397 Existing Future Public PrivateRight-of-Way Improvements Improvements(D) (E)Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost
SITE IMPROVEMENT BOND QUANTITY WORKSHEET
FOR DRAINAGE AND STORMWATER FACILITIES
Quantity Remaining
(Bond Reduction) (B)(C)
Specialty Drainage ItemsDitching SD-1 9.50$ CYFlow Dispersal Trench (1,436 base+)SD-3 28.00$ LF French Drain (3' depth)SD-4 26.00$ LFGeotextile, laid in trench, polypropylene SD-5 3.00$ SYMid-tank Access Riser, 48" dia, 6' deep SD-6 2,000.00$ EachPond Overflow Spillway SD-7 16.00$ SYRestrictor/Oil Separator, 12"SD-8 1,150.00$ EachRestrictor/Oil Separator, 15"SD-9 1,350.00$ EachRestrictor/Oil Separator, 18"SD-10 1,700.00$ Each 2 3,400.00Riprap, placed SD-11 42.00$ CY 5 210.00Tank End Reducer (36" diameter)SD-12 1,200.00$ EachInfiltration pond testing SD-13 125.00$ HRPermeable Pavement SD-14
Permeable Concrete Sidewalk SD-15Culvert, Box __ ft x __ ft SD-16
SUBTOTAL SPECIALTY DRAINAGE ITEMS:3,610.00
(B)(C)(D)(E)STORMWATER FACILITIES (Include Flow Control and Water Quality Facility Summary Sheet and Sketch)Detention Pond SF-1 Each Detention Tank SF-2 Each Detention Vault SF-3 350,000.00$ Each 2 700,000.00Infiltration Pond SF-4 Each Infiltration Tank SF-5 Each Infiltration Vault SF-6 Each
Infiltration Trenches SF-7 Each
Basic Biofiltration Swale SF-8 Each
Wet Biofiltration Swale SF-9 Each
Wetpond SF-10 Each
Wetvault SF-11 Each
Sand Filter SF-12 Each Sand Filter Vault SF-13 Each Linear Sand Filter SF-14 Each Proprietary Facility SF-15 Each Bioretention Facility SF-16 Each
SUBTOTAL STORMWATER FACILITIES:700,000.00
(B)(C)(D)(E)
Page 4 of 5
Ref 8-H Bond Quantity Worksheet SECTION II.c DRAINAGE
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 2/17/2021
CED Permit #:19000397 Existing Future Public PrivateRight-of-Way Improvements Improvements(D) (E)Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost
SITE IMPROVEMENT BOND QUANTITY WORKSHEET
FOR DRAINAGE AND STORMWATER FACILITIES
Quantity Remaining
(Bond Reduction) (B)(C)
WRITE-IN-ITEMS (INCLUDE ON-SITE BMPs)WI-1
WI-2
WI-3
WI-4
WI-5
WI-6WI-7WI-8WI-9WI-10WI-11WI-12WI-13WI-14WI-15
SUBTOTAL WRITE-IN ITEMS:
DRAINAGE AND STORMWATER FACILITIES SUBTOTAL:733,520.00 154,545.00 9,350.00
SALES TAX @ 10%73,352.00 15,454.50 935.00
DRAINAGE AND STORMWATER FACILITIES TOTAL:806,872.00 169,999.50 10,285.00
(B)(C)(D)(E)
Page 5 of 5
Ref 8-H Bond Quantity Worksheet SECTION II.c DRAINAGE
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 2/17/2021
CED Permit #:19000397
Existing Future Public Private
Right-of-Way Improvements Improvements
(D) (E)Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost
Connection to Existing Watermain W-1 2,000.00$ Each 2 4,000.00Ductile Iron Watermain, CL 52, 4 Inch Diameter W-2 50.00$ LFDuctile Iron Watermain, CL 52, 6 Inch Diameter W-3 56.00$ LFDuctile Iron Watermain, CL 52, 8 Inch Diameter W-4 60.00$ LF 404 24,240.00Ductile Iron Watermain, CL 52, 10 Inch Diameter W-5 70.00$ LF 1311 91,770.00Ductile Iron Watermain, CL 52, 12 Inch Diameter W-6 80.00$ LFGate Valve, 4 inch Diameter W-7 500.00$ EachGate Valve, 6 inch Diameter W-8 700.00$ Each 2 1,400.00
Gate Valve, 8 Inch Diameter W-9 800.00$ Each 5 4,000.00Gate Valve, 10 Inch Diameter W-10 1,000.00$ Each 4 4,000.00Gate Valve, 12 Inch Diameter W-11 1,200.00$ Each
Fire Hydrant Assembly W-12 4,000.00$ Each 2 8,000.00Permanent Blow-Off Assembly W-13 1,800.00$ Each 1 1,800.00Air-Vac Assembly, 2-Inch Diameter W-14 2,000.00$ EachAir-Vac Assembly, 1-Inch Diameter W-15 1,500.00$ EachCompound Meter Assembly 3-inch Diameter W-16 8,000.00$ EachCompound Meter Assembly 4-inch Diameter W-17 9,000.00$ EachCompound Meter Assembly 6-inch Diameter W-18 10,000.00$ EachPressure Reducing Valve Station 8-inch to 10-inch W-19 20,000.00$ Each
WATER SUBTOTAL:4,000.00 135,210.00
SALES TAX @ 10%400.00 13,521.00
WATER TOTAL:4,400.00 148,731.00
(B)(C)(D)(E)
SITE IMPROVEMENT BOND QUANTITY WORKSHEET
FOR WATER
Quantity Remaining
(Bond Reduction) (B)(C)
Page 1 of 1
Ref 8-H Bond Quantity Worksheet SECTION II.d WATER
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 2/17/2021
CED Permit #:19000397
Existing Future Public PrivateRight-of-Way Improvements Improvements
(D) (E)Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost
Clean Outs SS-1 1,000.00$ EachGrease Interceptor, 500 gallon SS-2 8,000.00$ EachGrease Interceptor, 1000 gallon SS-3 10,000.00$ EachGrease Interceptor, 1500 gallon SS-4 15,000.00$ EachSide Sewer Pipe, PVC. 4 Inch Diameter SS-5 80.00$ LF
Side Sewer Pipe, PVC. 6 Inch Diameter SS-6 95.00$ LFSewer Pipe, PVC, 8 inch Diameter SS-7 105.00$ LFSewer Pipe, PVC, 12 Inch Diameter SS-8 120.00$ LF
Sewer Pipe, DI, 8 inch Diameter SS-9 115.00$ LFSewer Pipe, DI, 12 Inch Diameter SS-10 130.00$ LFManhole, 48 Inch Diameter SS-11 6,000.00$ EachManhole, 54 Inch Diameter SS-13 6,500.00$ EachManhole, 60 Inch Diameter SS-15 7,500.00$ EachManhole, 72 Inch Diameter SS-17 8,500.00$ EachManhole, 96 Inch Diameter SS-19 14,000.00$ EachPipe, C-900, 12 Inch Diameter SS-21 180.00$ LFOutside Drop SS-24 1,500.00$ LSInside Drop SS-25 1,000.00$ LSSewer Pipe, PVC, ____ Inch Diameter SS-26Lift Station (Entire System)SS-27 LS
SANITARY SEWER SUBTOTAL:
SALES TAX @ 10%
SANITARY SEWER TOTAL:
(B)(C)(D)(E)
SITE IMPROVEMENT BOND QUANTITY WORKSHEET
FOR SANITARY SEWER
Quantity Remaining
(Bond Reduction) (B)(C)
Page 1 of 1
Ref 8-H Bond Quantity Worksheet SECTION II.e SANITARY SEWER
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 2/17/2021
Planning Division |1055 South Grady Way – 6 th Floor | Renton, WA 98057 (425) 430-7200
Date:
Name:Project Name:
PE Registration No:CED Plan # (LUA):
Firm Name:CED Permit # (U):
Firm Address:Site Address:
Phone No.Parcel #(s):
Email Address:Project Phase:
Site Restoration/Erosion Sediment Control Subtotal (a)
Existing Right-of-Way Improvements Subtotal (b)(b)134,385.30$
Future Public Improvements Subtotal (c)711,720.35$
Stormwater & Drainage Facilities (Public & Private) Subtotal (d)(d)987,156.50$
(e)
(f)
Site Restoration
Civil Construction Permit
Maintenance Bond 366,652.43$
Bond Reduction 2
Construction Permit Bond Amount 3
Minimum Bond Amount is $10,000.00
1 Estimate Only - May involve multiple and variable components, which will be established on an individual basis by Development Engineering.2 The City of Renton allows one request only for bond reduction prior to the maintenance period. Reduction of not more than 70% of the original bond amount, provided that the remaining 30% will
cover all remaining items to be constructed. 3 Required Bond Amounts are subject to review and modification by Development Engineering.* Note: The word BOND as used in this document means any financial guarantee acceptable to the City of Renton.** Note: All prices include labor, equipment, materials, overhead and profit.
(425) 885-7877
HHH@coredesigninc.com
Canopy
19-000223
4196 Lincoln Ave NE
3345700015
FOR APPROVAL
19000397
12100 NE 195th St #300, Bothell, WA 98011
1,240,804.48$
P
(a) x 100%
SITE IMPROVEMENT BOND QUANTITY WORKSHEET
BOND CALCULATIONS
2/12/2021
Holli Heavrin
53199
Core Design Inc.
R
((b x 150%) + (d x 100%))
S
(e) x 150% + (f) x 100%
Bond Reduction: Existing Right-of-Way Improvements (Quantity
Remaining)2
Bond Reduction: Stormwater & Drainage Facilities (Quantity
Remaining)2
T
(P +R - S)
Prepared by:Project Information
CONSTRUCTION BOND AMOUNT */**
(prior to permit issuance)
EST1
((b) + (c) + (d)) x 20%
-$
MAINTENANCE BOND */**
(after final acceptance of construction)
52,070.04$
134,385.30$
1,188,734.44$
52,070.04$
-$
987,156.50$
-$
Page 1 of 1
Ref 8-H Bond Quantity Worksheet SECTION III. BOND WORKSHEET
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 2/17/2021
Core Design, Inc. Canopy Page 30
SECTION 10: OPERATIONS AND MAINTENANCE
A general location and description of the stormwater management facilities are as follows.
See the following operation and maintenance manual for care of the permeable pavement areas. Excess
runoff from the road will be collected in the proposed conveyance system. In addition, all roof, sidewalk,
and landscaped area runoff will be collected by cleanouts, footing drains and catch basins. Some roof
cleanouts will be tight lined directly to the detention facility. The treated and detained stormwater is
tight lined to the existing public conveyance system in Lincoln Avenue NE. The operation and
maintenance of the facilities described above will be performed by the future Homeowners Association.
The proposed stormwater BMPs in the ROW will be inspected and maintained by the City of Renton.
Design of the storm drainage system is based on the City of Renton Surface Water Design Manual. The
operations and maintenance information for the proposed facilities are included at the end of this
section. It is a copy of Appendix A of the 2017 RSWDM.
APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS
12/12/2016 2017 City of Renton Surface Water Design Manual A-8
NO. 4 – CONTROL STRUCTURE/FLOW RESTRICTOR
MAINTENANCE
COMPONENT
DEFECT OR
PROBLEM
CONDITION WHEN MAINTENANCE
IS NEEDED
RESULTS EXPECTED WHEN
MAINTENANCE IS PERFORMED
Structure Trash and debris Trash or debris of more than ½ cubic foot which is located immediately in front of the structure opening or is blocking capacity of the structure by more than 10%.
No Trash or debris blocking or potentially blocking entrance to structure.
Trash or debris in the structure that exceeds 1/3 the depth from the bottom of basin to invert the lowest pipe into or out of the basin.
No trash or debris in the structure.
Deposits of garbage exceeding 1 cubic foot in volume. No condition present which would attract or support the breeding of insects or rodents.
Sediment accumulation Sediment exceeds 60% of the depth from the bottom of the structure to the invert of the lowest pipe into or out of the structure or the bottom of the FROP-T section or is
within 6 inches of the invert of the lowest pipe into or out of the structure or the bottom of the FROP-T section.
Sump of structure contains no sediment.
Damage to frame and/or top slab Corner of frame extends more than ¾ inch past curb face into the street (If applicable).
Frame is even with curb.
Top slab has holes larger than 2 square inches or cracks wider than ¼ inch. Top slab is free of holes and cracks.
Frame not sitting flush on top slab, i.e., separation of more than ¾ inch of the frame from the top slab.
Frame is sitting flush on top slab.
Cracks in walls or bottom Cracks wider than ½ inch and longer than 3 feet, any evidence of soil particles entering structure through cracks, or maintenance person judges that structure is unsound.
Structure is sealed and structurally sound.
Cracks wider than ½ inch and longer than 1 foot at the joint of any inlet/outlet pipe or
any evidence of soil particles entering structure through cracks.
No cracks more than 1/4 inch wide at the joint of inlet/outlet pipe.
Settlement/ misalignment Structure has settled more than 1 inch or has rotated more than 2 inches out of alignment.
Basin replaced or repaired to design standards.
Damaged pipe joints Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering the structure at the joint of the inlet/outlet pipes.
No cracks more than ¼-inch wide at the joint of inlet/outlet pipes.
Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint.
Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film.
Ladder rungs missing or unsafe Ladder is unsafe due to missing rungs, misalignment, rust, cracks, or sharp edges. Ladder meets design standards and allows maintenance person safe access.
FROP-T Section Damaged FROP-T T section is not securely attached to
structure wall and outlet pipe structure should support at least 1,000 lbs of up or down pressure.
T section securely attached to wall and
outlet pipe.
Structure is not in upright position (allow up to 10% from plumb). Structure in correct position.
APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS
2017 City of Renton Surface Water Design Manual 12/12/2016 A-9
NO. 4 – CONTROL STRUCTURE/FLOW RESTRICTOR
MAINTENANCE
COMPONENT
DEFECT OR
PROBLEM
CONDITION WHEN MAINTENANCE
IS NEEDED
RESULTS EXPECTED WHEN
MAINTENANCE IS PERFORMED
FROP-T Section (cont.) Damaged FROP-T (cont.) Connections to outlet pipe are not watertight or show signs of deteriorated grout.
Connections to outlet pipe are water tight; structure repaired or replaced and works as designed.
Any holes—other than designed holes—in
the structure.
Structure has no holes other than designed
holes.
Cleanout Gate Damaged or missing cleanout gate Cleanout gate is missing. Replace cleanout gate.
Cleanout gate is not watertight. Gate is watertight and works as designed.
Gate cannot be moved up and down by one maintenance person. Gate moves up and down easily and is watertight.
Chain/rod leading to gate is missing or damaged. Chain is in place and works as designed.
Orifice Plate Damaged or missing
orifice plate
Control device is not working properly due
to missing, out of place, or bent orifice plate.
Plate is in place and works as designed.
Obstructions to orifice plate Any trash, debris, sediment, or vegetation blocking the plate. Plate is free of all obstructions and works as designed.
Overflow Pipe Obstructions to
overflow pipe
Any trash or debris blocking (or having the
potential of blocking) the overflow pipe.
Pipe is free of all obstructions and works
as designed.
Deformed or damaged lip of overflow pipe
Lip of overflow pipe is bent or deformed. Overflow pipe does not allow overflow at an elevation lower than design
Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment.
Trash and debris Trash and debris accumulated in
inlet/outlet pipes (includes floatables and non-floatables).
No trash or debris in pipes.
Damaged inlet/outlet
pipe
Cracks wider than ½-inch at the joint of the
inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes.
No cracks more than ¼-inch wide at the
joint of the inlet/outlet pipe.
Metal Grates (If applicable) Unsafe grate opening Grate with opening wider than 7/8 inch. Grate opening meets design standards.
Trash and debris Trash and debris that is blocking more
than 20% of grate surface.
Grate free of trash and debris. footnote to
guidelines for disposal
Damaged or missing grate Grate missing or broken member(s) of the grate. Grate is in place and meets design standards.
Manhole Cover/Lid Cover/lid not in place Cover/lid is missing or only partially in place. Any open structure requires urgent maintenance.
Cover/lid protects opening to structure.
Locking mechanism
not working
Mechanism cannot be opened by one
maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work.
Mechanism opens with proper tools.
Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs. of lift. Cover/lid can be removed and reinstalled by one maintenance person.
APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS
12/12/2016 2017 City of Renton Surface Water Design Manual A-10
NO. 5 – CATCH BASINS AND MANHOLES
MAINTENANCE
COMPONENT
DEFECT OR
PROBLEM
CONDITION WHEN MAINTENANCE
IS NEEDED
RESULTS EXPECTED WHEN
MAINTENANCE IS PERFORMED
Structure Sediment accumulation Sediment exceeds 60% of the depth from the bottom of the catch basin to the invert of the lowest pipe into or out of the catch basin or is within 6 inches of the invert of the lowest pipe into or out of the catch basin.
Sump of catch basin contains no sediment.
Trash and debris Trash or debris of more than ½ cubic foot which is located immediately in front of the catch basin opening or is blocking capacity of the catch basin by more than 10%.
No Trash or debris blocking or potentially blocking entrance to catch basin.
Trash or debris in the catch basin that exceeds 1/3 the depth from the bottom of basin to invert the lowest pipe into or out of the basin.
No trash or debris in the catch basin.
Dead animals or vegetation that could generate odors that could cause complaints or dangerous gases (e.g., methane).
No dead animals or vegetation present within catch basin.
Deposits of garbage exceeding 1 cubic foot in volume. No condition present which would attract or support the breeding of insects or rodents.
Damage to frame and/or top slab Corner of frame extends more than ¾ inch past curb face into the street (If applicable).
Frame is even with curb.
Top slab has holes larger than 2 square inches or cracks wider than ¼ inch. Top slab is free of holes and cracks.
Frame not sitting flush on top slab, i.e., separation of more than ¾ inch of the frame from the top slab.
Frame is sitting flush on top slab.
Cracks in walls or bottom Cracks wider than ½ inch and longer than 3 feet, any evidence of soil particles entering catch basin through cracks, or maintenance person judges that catch
basin is unsound.
Catch basin is sealed and is structurally sound.
Cracks wider than ½ inch and longer than 1 foot at the joint of any inlet/outlet pipe or any evidence of soil particles entering catch basin through cracks.
No cracks more than 1/4 inch wide at the joint of inlet/outlet pipe.
Settlement/ misalignment Catch basin has settled more than 1 inch or has rotated more than 2 inches out of alignment.
Basin replaced or repaired to design standards.
Damaged pipe joints Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering the catch basin at the joint of the inlet/outlet pipes.
No cracks more than ¼-inch wide at the joint of inlet/outlet pipes.
Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint.
Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film.
Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment.
Trash and debris Trash and debris accumulated in
inlet/outlet pipes (includes floatables and non-floatables).
No trash or debris in pipes.
APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS
2017 City of Renton Surface Water Design Manual 12/12/2016 A-11
NO. 5 – CATCH BASINS AND MANHOLES
MAINTENANCE
COMPONENT
DEFECT OR
PROBLEM
CONDITION WHEN MAINTENANCE
IS NEEDED
RESULTS EXPECTED WHEN
MAINTENANCE IS PERFORMED
Inlet/Outlet Pipe (cont.) Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes.
No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe.
Metal Grates (Catch Basins) Unsafe grate opening Grate with opening wider than 7/8 inch. Grate opening meets design standards.
Trash and debris Trash and debris that is blocking more than 20% of grate surface. Grate free of trash and debris. footnote to guidelines for disposal
Damaged or missing grate Grate missing or broken member(s) of the grate. Any open structure requires urgent maintenance.
Grate is in place and meets design standards.
Manhole Cover/Lid Cover/lid not in place Cover/lid is missing or only partially in place. Any open structure requires urgent maintenance.
Cover/lid protects opening to structure.
Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work.
Mechanism opens with proper tools.
Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs. of lift. Cover/lid can be removed and reinstalled by one maintenance person.
APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS
2017 City of Renton Surface Water Design Manual 12/12/2016 A-15
NO. 9 – FENCING
MAINTENANCE
COMPONENT
DEFECT OR
PROBLEM
CONDITIONS WHEN
MAINTENANCE IS NEEDED
RESULTS EXPECTED WHEN
MAINTENANCE IS PERFORMED
Site Erosion or holes under fence Erosion or holes more than 4 inches high and 12-18 inches wide permitting access through an opening under a fence.
No access under the fence.
Wood Posts, Boards
and Cross Members
Missing or damaged
parts
Missing or broken boards, post out of
plumb by more than 6 inches or cross members broken
No gaps on fence due to missing or broken
boards, post plumb to within 1½ inches, cross members sound.
Weakened by rotting
or insects
Any part showing structural deterioration
due to rotting or insect damage
All parts of fence are structurally sound.
Damaged or failed
post foundation
Concrete or metal attachments
deteriorated or unable to support posts.
Post foundation capable of supporting
posts even in strong wind.
Metal Posts, Rails and Fabric Damaged parts Post out of plumb more than 6 inches. Post plumb to within 1½ inches.
Top rails bent more than 6 inches. Top rail free of bends greater than 1 inch.
Any part of fence (including post, top rails, and fabric) more than 1 foot out of design alignment.
Fence is aligned and meets design standards.
Missing or loose tension wire. Tension wire in place and holding fabric.
Deteriorated paint or protective coating Part or parts that have a rusting or scaling condition that has affected structural adequacy.
Structurally adequate posts or parts with a uniform protective coating.
Openings in fabric Openings in fabric are such that an 8-inch diameter ball could fit through. Fabric mesh openings within 50% of grid size.
APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS
12/12/2016 2017 City of Renton Surface Water Design Manual A-16
NO. 10 – GATES/BOLLARDS/ACCESS BARRIERS
MAINTENANCE
COMPONENT
DEFECT OR
PROBLEM
CONDITIONS WHEN
MAINTENANCE IS NEEDED
RESULTS EXPECTED WHEN
MAINTENANCE IS PERFORMED
Chain Link Fencing Gate Damaged or missing members Missing gate. Gates in place.
Broken or missing hinges such that gate cannot be easily opened and closed by a maintenance person.
Hinges intact and lubed. Gate is working freely.
Gate is out of plumb more than 6 inches and more than 1 foot out of design alignment.
Gate is aligned and vertical.
Missing stretcher bar, stretcher bands, and ties. Stretcher bar, bands, and ties in place.
Locking mechanism does not lock gate Locking device missing, no-functioning or does not link to all parts. Locking mechanism prevents opening of gate.
Openings in fabric Openings in fabric are such that an 8-inch diameter ball could fit through. Fabric mesh openings within 50% of grid size.
Bar Gate Damaged or missing cross bar Cross bar does not swing open or closed, is missing or is bent to where it does not prevent vehicle access.
Cross bar swings fully open and closed and prevents vehicle access.
Locking mechanism does not lock gate Locking device missing, no-functioning or does not link to all parts. Locking mechanism prevents opening of gate.
Support post damaged Support post does not hold cross bar up. Cross bar held up preventing vehicle access into facility.
Bollards Damaged or missing bollards Bollard broken, missing, does not fit into support hole or hinge broken or missing. No access for motorized vehicles to get into facility.
Bollards do not lock Locking assembly or lock missing or cannot be attached to lock bollard in place. No access for motorized vehicles to get into facility.
Boulders Dislodged boulders Boulders not located to prevent motorized vehicle access. No access for motorized vehicles to get into facility.
Evidence of vehicles
circumventing boulders
Motorized vehicles going around or
between boulders.
No access for motorized vehicles to get
into facility.
APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS
2017 City of Renton Surface Water Design Manual 12/12/2016 A-17
NO. 11 – GROUNDS (LANDSCAPING)
MAINTENANCE
COMPONENT
DEFECT OR
PROBLEM
CONDITIONS WHEN
MAINTENANCE IS NEEDED
RESULTS EXPECTED WHEN
MAINTENANCE IS PERFORMED
Site Trash and debris Any trash and debris which exceed 1 cubic foot per 1,000 square feet (this is about equal to the amount of trash it would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping.
Trash and debris cleared from site.
Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public.
Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where City personnel or the public might normally be.
Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint.
Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film.
Excessive growth of grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches.
Trees and Shrubs Hazard tree identified Any tree or limb of a tree identified as having a potential to fall and cause property damage or threaten human life. A hazard tree identified by a qualified arborist must be removed as soon as possible.
No hazard trees in facility.
Damaged tree or
shrub identified
Limbs or parts of trees or shrubs that are
split or broken which affect more than 25% of the total foliage of the tree or shrub.
Trees and shrubs with less than 5% of total
foliage with split or broken limbs.
Trees or shrubs that have been blown
down or knocked over.
No blown down vegetation or knocked over
vegetation. Trees or shrubs free of injury.
Trees or shrubs which are not adequately supported or are leaning over, causing exposure of the roots.
Tree or shrub in place and adequately supported; dead or diseased trees removed.
APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS
12/12/2016 2017 City of Renton Surface Water Design Manual A-18
NO. 12 – ACCESS ROADS
MAINTENANCE
COMPONENT
DEFECT OR
PROBLEM
CONDITION WHEN MAINTENANCE
IS NEEDED
RESULTS EXPECTED WHEN
MAINTENANCE IS PERFORMED
Site Trash and debris Trash and debris exceeds 1 cubic foot per 1,000 square feet (i.e., trash and debris would fill up one standards size garbage can).
Roadway drivable by maintenance vehicles.
Debris which could damage vehicle tires or prohibit use of road. Roadway drivable by maintenance vehicles.
Contaminants and
pollution
Any evidence of contaminants or pollution
such as oil, gasoline, concrete slurries or paint.
Materials removed and disposed of
according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film.
Blocked roadway Any obstruction which reduces clearance above road surface to less than 14 feet. Roadway overhead clear to 14 feet high.
Any obstruction restricting the access to a 10- to 12 foot width for a distance of more than 12 feet or any point restricting access to less than a 10 foot width.
At least 12-foot of width on access road.
Road Surface Erosion, settlement, potholes, soft spots,
ruts
Any surface defect which hinders or prevents maintenance access. Road drivable by maintenance vehicles.
Vegetation on road surface Trees or other vegetation prevent access to facility by maintenance vehicles. Maintenance vehicles can access facility.
Shoulders and Ditches Erosion Erosion within 1 foot of the roadway more than 8 inches wide and 6 inches deep. Shoulder free of erosion and matching the surrounding road.
Weeds and brush Weeds and brush exceed 18 inches in height or hinder maintenance access. Weeds and brush cut to 2 inches in height or cleared in such a way as to allow maintenance access.
Modular Grid Pavement Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or
paint.
Materials removed and disposed of according to applicable regulations. Source
control BMPs implemented if appropriate. No contaminants present other than a surface oil film.
Damaged or missing blocks/grids Access surface compacted because of broken on missing modular block. Access road surface restored so road infiltrates.
APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS
12/12/2016 2017 City of Renton Surface Water Design Manual A-12
NO. 6 – CONVEYANCE PIPES AND DITCHES
MAINTENANCE
COMPONENT
DEFECT OR
PROBLEM
CONDITIONS WHEN
MAINTENANCE IS NEEDED
RESULTS EXPECTED WHEN
MAINTENANCE IS PERFORMED
Pipes Sediment & debris accumulation Accumulated sediment or debris that exceeds 20% of the diameter of the pipe. Water flows freely through pipes.
Vegetation/root growth in pipe Vegetation/roots that reduce free movement of water through pipes. Water flows freely through pipes.
Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint.
Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate.
No contaminants present other than a surface oil film.
Damage to protective coating or corrosion Protective coating is damaged; rust or corrosion is weakening the structural integrity of any part of pipe.
Pipe repaired or replaced.
Damaged pipes Any dent that decreases the cross section area of pipe by more than 20% or is determined to have weakened structural integrity of the pipe.
Pipe repaired or replaced.
Ditches Trash and debris Trash and debris exceeds 1 cubic foot per 1,000 square feet of ditch and slopes. Trash and debris cleared from ditches.
Sediment accumulation Accumulated sediment that exceeds 20% of the design depth. Ditch cleaned/flushed of all sediment and debris so that it matches design.
Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public.
Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where City personnel or the public might normally be.
Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint.
Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film.
Excessive vegetation growth Vegetation that reduces free movement of water through ditches. Water flows freely through ditches.
Erosion damage to
slopes
Any erosion observed on a ditch slope. Slopes are not eroding.
Rock lining out of place or missing (If applicable)
One layer or less of rock exists above native soil area 5 square feet or more, any exposed native soil.
Replace rocks to design standards.
APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS
12/12/2016 2017 City of Renton Surface Water Design Manual A-24
NO. 17 – WETVAULT
MAINTENANCE
COMPONENT
DEFECT OR
PROBLEM
CONDITION WHEN MAINTENANCE
IS NEEDED
RESULTS EXPECTED WHEN
MAINTENANCE IS PERFORMED
Site Trash and debris Trash and debris accumulated on facility site. Trash and debris removed from facility site.
Treatment Area Trash and debris Any trash and debris accumulated in vault (includes floatables and non-floatables). No trash or debris in vault.
Sediment accumulation Sediment accumulation in vault bottom exceeds the depth of the sediment zone plus 6 inches.
No sediment in vault.
Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint.
Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film.
Vault Structure Damage to wall, frame, bottom, and/or top slab
Cracks wider than ½-inch, any evidence of soil entering the structure through cracks, vault does not retain water or qualified inspection personnel determines that the vault is not structurally sound.
Vault is sealed and structurally sound.
Baffles damaged Baffles corroding, cracking, warping and/or showing signs of failure or baffle cannot be removed.
Repair or replace baffles or walls to specifications.
Ventilation area blocked/plugged Ventilation area blocked or plugged. No reduction of ventilation area exists.
Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment.
Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables).
No trash or debris in pipes.
Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet
pipes.
No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe.
Gravity Drain Inoperable valve Valve will not open and close. Valve opens and closes normally.
Valve won’t seal Valve does not seal completely. Valve completely seals closed.
Access Manhole Access cover/lid damaged or difficult to open
Access cover/lid cannot be easily opened by one person. Corrosion/deformation of cover/lid.
Access cover/lid can be opened by one person.
Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work.
Mechanism opens with proper tools.
Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs of lift. Cover/lid can be removed and reinstalled by one maintenance person.
Access doors/plate has gaps, doesn't cover completely
Large access doors not flat and/or access opening not completely covered. Doors close flat; covers access opening completely.
Lifting rings missing, rusted Lifting rings not capable of lifting weight of door or plate. Lifting rings sufficient to lift or remove door or plate.
Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access.
APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS
12/12/2016 2017 City of Renton Surface Water Design Manual A-48
NO. 39 – RETAINED TREES
MAINTENANCE
COMPONENT
DEFECT OR
PROBLEM
CONDITIONS WHEN MAINTENANCE
IS NEEDED
RESULTS EXPECTED WHEN
MAINTENANCE IS PERFORMED
Tree Dead or declining Dead, damaged, or declining Tree replaced per planting plan or acceptable substitute
NO. 40 – FILTERRA SYSTEM
MAINTENANCE
COMPONENT
DEFECT OR
PROBLEM
CONDITION WHEN MAINTENANCE
IS NEEDED
RESULTS EXPECTED WHEN
MAINTENANCE IS PERFORMED
In addition to the specific maintenance criteria provided below, all manufacturer’s requirements shall be followed.
Facility – General Requirements Life cycle Once per year, except mulch and trash removal twice per year Facility is re-inspected and any needed maintenance performed
Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries, or paint
Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate.
No contaminants present other than a surface oil film.
Inlet Excessive sediment or trash accumulation Accumulated sediments or trash impair free flow of water into system Inlet should be free of obstructions allowing free distributed flow of water into system
Mulch Cover Trash and floatable debris accumulation Excessive trash and/or debris accumulation Minimal trash or other debris on mulch cover. Mulch cover raked level.
“Ponding” of water on mulch cover “Ponding” in unit could be indicative of clogging due to excessive fine sediment accumulation or spill of petroleum oils
Stormwater should drain freely and evenly through mulch cover
Proprietary Filter Media/ Vegetation Substrate
“Ponding” of water on mulch cover after mulch cover has been maintained
Excessive fine sediment passes the mulch cover and clogs the filter media/vegetative substrate
Stormwater should drain freely and evenly through mulch cover. Replace substrate and vegetation when needed
Vegetation Plants not growing or in poor condition Soil/mulch too wet, evidence of spill, incorrect plant selection, pest infestation,
and/or vandalism to plants
Plants should be healthy and pest free
Media/mulch too dry Irrigation is required
Plants absent Plants absent Appropriate plants are present
Excessive plant growth Excessive plant growth inhibits facility function or becomes a hazard for pedestrian and vehicular circulation and safety
Pruning and/or thinning vegetation maintains proper plant density. Appropriate plants are present.
Structure Structure has visible cracks Cracks wider than ½ inch
Evidence of soil particles entering the structure through the cracks
Structure is sealed and structurally sound
Appendix A
Parcel & Basin Information
Fair, Equitable, and Understandable Property Valuations
You're in: Assessor >> Look up Property Info >> eReal Property
Departmentof
Assessments
500 FourthAvenue,Suite ADM-
AS-0708,Seattle, WA98104
Office Hours:
Mon - Fri 8:30 a.m. to4:30 p.m.
TEL: 206-
296-7300FAX: 206-296-5107TTY: 206-296-7888
Send usmail
ADVERTISEMENT
New Search Property Tax Bill Map This Property Glossary of Terms Area Report Property Detail
PARCEL
ParcelNumber 334570-0015
Name GOODWIN DC LLC
SiteAddress
Legal HILLMANS LK WN GARDEN OF EDEN # 7 LOT 3 LESS S 75 FT OF W 211 FT TGW W 50 FT OF TR 4 &POR OF S 135 FT OF TR 4 LY E OF SD W 50 FT ALL OF TR 5 & TR 6 LESS N 155 FT OF W 211 FT LESS
RD
BUILDING 1
Year Built
Total Square Footage
Number Of Bedrooms
Number Of Baths
Grade
Condition
Lot Size 218091
Views No
Waterfront
TOTAL LEVY RATE DISTRIBUTION
Tax Year: 2018 Levy Code: 2151 Total Levy Rate: $12.51853 Total Senior Rate: $6.80724
49.70% Voter Approved
Click here to see levy distribution comparison by year.
TAX ROLL HISTORY
ValuedYear TaxYear Appraised LandValue ($)Appraised ImpsValue ($)AppraisedTotal ($)Taxable LandValue ($)Taxable ImpsValue ($)TaxableTotal ($)
2017 2018 657,000 0 657,000 657,000 0 657,000
2016 2017 587,000 0 587,000 587,000 0 587,000
2015 2016 554,000 0 554,000 554,000 0 554,000
2014 2015 455,000 0 455,000 455,000 0 455,000
2013 2014 407,000 0 407,000 407,000 0 407,000
2012 2013 379,000 0 379,000 379,000 0 379,000
2011 2012 388,000 0 388,000 388,000 0 388,000
2010 2011 416,000 0 416,000 416,000 0 416,000
2009 2010 400,000 0 400,000 400,000 0 400,000
2008 2009 500,000 0 500,000 500,000 0 500,000
2007 2008 449,000 0 449,000 449,000 0 449,000
2006 2007 391,000 0 391,000 391,000 0 391,000
2005 2006 340,000 0 340,000 340,000 0 340,000
2004 2005 318,000 0 318,000 318,000 0 318,000
2003 2004 306,000 0 306,000 306,000 0 306,000
2002 2003 295,000 0 295,000 295,000 0 295,000
2001 2002 231,000 0 231,000 231,000 0 231,000
2000 2001 210,000 0 210,000 210,000 0 210,000
1999 2000 183,000 0 183,000 183,000 0 183,000
1998 1999 167,000 0 167,000 167,000 0 167,000
1997 1998 0 0 0 147,000 0 147,000
ADVERTISEMENT
ReferenceLinks:
King County TaxingDistricts Codes andLevies (.PDF)
King County Tax
Links
Property Tax Advisor
Washington State
Department of
Revenue (External
link)
Washington StateBoard of TaxAppeals (Externallink)
Board of
Appeals/Equalization
Districts Report
iMap
Recorder's Office
Scanned images ofsurveys and othermap documents
Scanned images ofplats
Search Kingcounty.gov
Home How do I... Services About King County Departments
King County Department of Assessments
Information for...
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© King County, WA 2018 Privacy Accessibility Terms of use
1996 1997 0 0 0 147,000 0 147,000
1994 1995 0 0 0 114,700 0 114,700
1992 1993 0 0 0 96,500 0 96,500
1990 1991 0 0 0 91,900 0 91,900
1988 1989 0 0 0 71,200 0 71,200
1986 1987 0 0 0 71,200 0 71,200
1984 1985 0 0 0 79,100 0 79,100
1982 1983 0 0 0 79,100 0 79,100
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Updated: March 17, 2016 Share Tweet Email Print
Information for...Do more online
Get help
Fair, Equitable, and Understandable Property Valuations
You're in: Assessor >> Look up Property Info >> eReal Property
Departmentof
Assessments
500 FourthAvenue,Suite ADM-
AS-0708,Seattle, WA98104
Office Hours:
Mon - Fri 8:30 a.m. to4:30 p.m.
TEL: 206-
296-7300FAX: 206-296-5107TTY: 206-296-7888
Send usmail
ADVERTISEMENT
New Search Property Tax Bill Map This Property Glossary of Terms Area Report Property Detail
PARCEL
ParcelNumber 334570-0016
Name GOODWIN DC LLC
SiteAddress
Legal HILLMANS LK WN GARDEN OF EDEN # 7 W 211 FT OF S 75 FT OF 3 & 6 LESS S 100 FT LESS E 85FT OF N 155 FT & LESS CO RD
BUILDING 1
Year Built
Total Square Footage
Number Of Bedrooms
Number Of Baths
Grade
Condition
Lot Size 40430
Views No
Waterfront
TOTAL LEVY RATE DISTRIBUTION
Tax Year: 2018 Levy Code: 2151 Total Levy Rate: $12.51853 Total Senior Rate: $6.80724
49.70% Voter Approved
Click here to see levy distribution comparison by year.
TAX ROLL HISTORY
ValuedYear TaxYear Appraised LandValue ($)Appraised ImpsValue ($)AppraisedTotal ($)Taxable LandValue ($)Taxable ImpsValue ($)TaxableTotal ($)
2017 2018 244,000 0 244,000 244,000 0 244,000
2016 2017 218,000 0 218,000 218,000 0 218,000
2015 2016 206,000 0 206,000 206,000 0 206,000
2014 2015 211,000 10,000 221,000 211,000 10,000 221,000
2013 2014 189,000 10,000 199,000 189,000 10,000 199,000
2012 2013 176,000 10,000 186,000 176,000 10,000 186,000
2011 2012 181,000 10,000 191,000 181,000 10,000 191,000
2010 2011 194,000 9,000 203,000 194,000 9,000 203,000
2009 2010 187,000 9,000 196,000 187,000 9,000 196,000
2008 2009 218,000 50,000 268,000 218,000 50,000 268,000
2007 2008 196,000 50,000 246,000 196,000 50,000 246,000
2006 2007 171,000 50,000 221,000 171,000 50,000 221,000
2005 2006 149,000 50,000 199,000 149,000 50,000 199,000
2004 2005 140,000 50,000 190,000 140,000 50,000 190,000
2003 2004 135,000 50,000 185,000 135,000 50,000 185,000
2002 2003 130,000 50,000 180,000 130,000 50,000 180,000
2001 2002 106,000 67,000 173,000 106,000 67,000 173,000
ADVERTISEMENT
ReferenceLinks:
King County TaxingDistricts Codes andLevies (.PDF)
King County Tax
Links
Property Tax Advisor
Washington State
Department of
Revenue (External
link)
Washington StateBoard of TaxAppeals (Externallink)
Board of
Appeals/Equalization
Districts Report
iMap
Recorder's Office
Scanned images ofsurveys and othermap documents
Scanned images ofplats
Search Kingcounty.gov
Home How do I... Services About King County Departments
King County Department of Assessments
Information for...
Residents
Businesses
Job seekers
Volunteers
King County employees
Do more online
Trip Planner
Property tax information & payment
Jail inmate look up
Parcel viewer or iMap
Public records
More online tools...
Get help
Contact us
Customer service
Phone list
Employee directory
Subscribe to alerts
Stay connected! View King County social media
© King County, WA 2018 Privacy Accessibility Terms of use
2000 2001 97,000 35,000 132,000 97,000 35,000 132,000
1999 2000 85,000 35,000 120,000 85,000 35,000 120,000
1998 1999 78,000 29,000 107,000 78,000 29,000 107,000
1997 1998 0 0 0 68,500 26,000 94,500
1996 1997 0 0 0 68,500 26,000 94,500
1994 1995 0 0 0 56,000 54,800 110,800
1992 1993 0 0 0 34,200 54,800 89,000
1990 1991 0 0 0 32,600 52,200 84,800
1988 1989 0 0 0 25,200 30,900 56,100
1986 1987 0 0 0 25,200 22,500 47,700
1984 1985 0 0 0 26,000 24,200 50,200
1982 1983 0 0 0 26,000 27,800 53,800
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500 FourthAvenue,Suite ADM-
AS-0708,Seattle, WA98104
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PARCEL
Parcel Number 334570-0017
Name OGREN DAVID M JR
Site Address 8314 110TH PL SE 98056
Legal HILLMANS LK WN GARDEN OF EDEN #7 PP ACT 39901012 MOBILE HOME
BUILDING 1
Year Built 1989
Total Square Footage 900
Number Of Bedrooms 1
Number Of Baths 1.00
Grade 6 Low Average
Condition Average
Lot Size 75755
Views No
Waterfront
TOTAL LEVY RATE DISTRIBUTION
Tax Year: 2018 Levy Code: 2151 Total Levy Rate: $12.51853 Total Senior Rate: $6.80724
49.70% Voter Approved
Click here to see levy distribution comparison by year.
TAX ROLL HISTORY
ValuedYear TaxYear Appraised LandValue ($)Appraised ImpsValue ($)AppraisedTotal ($)Taxable LandValue ($)Taxable ImpsValue ($)TaxableTotal ($)
2017 2018 333,000 167,000 500,000 333,000 167,000 500,000
2016 2017 298,000 130,000 428,000 298,000 130,000 428,000
2015 2016 282,000 123,000 405,000 282,000 123,000 405,000
2014 2015 294,000 110,000 404,000 294,000 110,000 404,000
2013 2014 263,000 87,000 350,000 263,000 87,000 350,000
2012 2013 245,000 102,000 347,000 245,000 102,000 347,000
2011 2012 251,000 105,000 356,000 251,000 105,000 356,000
2010 2011 269,000 110,000 379,000 269,000 110,000 379,000
2009 2010 259,000 107,000 366,000 259,000 107,000 366,000
2008 2009 277,000 297,000 574,000 277,000 297,000 574,000
2007 2008 249,000 266,000 515,000 249,000 266,000 515,000
2006 2007 217,000 223,000 440,000 217,000 223,000 440,000
2005 2006 189,000 193,000 382,000 189,000 193,000 382,000
2004 2005 177,000 182,000 359,000 177,000 182,000 359,000
2003 2004 171,000 171,000 342,000 171,000 171,000 342,000
2002 2003 165,000 139,000 304,000 165,000 139,000 304,000
2001 2002 132,000 232,000 364,000 132,000 232,000 364,000
2000 2001 120,000 194,000 314,000 120,000 194,000 314,000
1999 2000 105,000 167,000 272,000 105,000 167,000 272,000
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ReferenceLinks:
King County TaxingDistricts Codes andLevies (.PDF)
King County Tax
Links
Property Tax Advisor
Washington State
Department of
Revenue (External
link)
Washington StateBoard of TaxAppeals (Externallink)
Board of
Appeals/Equalization
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1998 1999 96,000 147,000 243,000 96,000 147,000 243,000
1997 1998 0 0 0 85,000 129,000 214,000
1996 1997 0 0 0 85,000 129,000 214,000
1995 1996 0 0 0 66,400 102,600 169,000
1994 1995 0 0 0 66,400 95,436 161,836
1992 1993 0 0 0 44,000 95,436 139,436
1991 1992 0 0 0 41,900 88,276 130,176
1990 1991 0 0 0 41,900 88,276 130,176
1989 1990 0 0 0 32,400 70,992 103,392
1988 1989 0 0 0 32,400 39,292 71,692
1987 1988 0 0 0 32,400 36,991 69,391
1986 1987 0 0 0 32,400 34,176 66,576
1985 1986 0 0 0 8,400 32,860 41,260
1984 1985 0 0 0 8,400 0 8,400
1982 1983 0 0 0 8,400 0 8,400
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Fair, Equitable, and Understandable Property Valuations
You're in: Assessor >> Look up Property Info >> eReal Property
Departmentof
Assessments
500 FourthAvenue,Suite ADM-
AS-0708,Seattle, WA98104
Office Hours:
Mon - Fri 8:30 a.m. to4:30 p.m.
TEL: 206-
296-7300FAX: 206-296-5107TTY: 206-296-7888
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New Search Property Tax Bill Map This Property Glossary of Terms Area Report Property Detail
PARCEL
Parcel Number 334570-0018
Name LUND JEFF & JONI
Site Address 4130 LINCOLN AVE NE 98056
Legal HILLMANS LK WN GARDEN OF EDEN #7
BUILDING 1
Year Built 1982
Total Square Footage 2580
Number Of Bedrooms 3
Number Of Baths 2.00
Grade 8 Good
Condition Average
Lot Size 75698
Views No
Waterfront
TOTAL LEVY RATE DISTRIBUTION
Tax Year: 2018 Levy Code: 2151 Total Levy Rate: $12.51853 Total Senior Rate: $6.80724
49.70% Voter Approved
Click here to see levy distribution comparison by year.
TAX ROLL HISTORY
ValuedYear TaxYear Appraised LandValue ($)Appraised ImpsValue ($)AppraisedTotal ($)Taxable LandValue ($)Taxable ImpsValue ($)TaxableTotal ($)
2017 2018 292,000 353,000 645,000 292,000 353,000 645,000
2016 2017 261,000 291,000 552,000 261,000 291,000 552,000
2015 2016 247,000 275,000 522,000 247,000 275,000 522,000
2014 2015 255,000 219,000 474,000 255,000 219,000 474,000
2013 2014 228,000 182,000 410,000 228,000 182,000 410,000
2012 2013 213,000 166,000 379,000 213,000 166,000 379,000
2011 2012 219,000 169,000 388,000 219,000 169,000 388,000
2010 2011 235,000 178,000 413,000 235,000 178,000 413,000
2009 2010 226,000 172,000 398,000 226,000 172,000 398,000
2008 2009 235,000 384,000 619,000 235,000 384,000 619,000
2007 2008 211,000 345,000 556,000 211,000 345,000 556,000
2006 2007 184,000 291,000 475,000 184,000 291,000 475,000
2005 2006 160,000 278,000 438,000 160,000 278,000 438,000
2004 2005 150,000 261,000 411,000 150,000 261,000 411,000
2003 2004 145,000 246,000 391,000 145,000 246,000 391,000
2002 2003 140,000 235,000 375,000 140,000 235,000 375,000
2001 2002 132,000 223,000 355,000 132,000 223,000 355,000
2000 2001 120,000 201,000 321,000 120,000 201,000 321,000
1999 2000 105,000 187,000 292,000 105,000 187,000 292,000
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ReferenceLinks:
King County TaxingDistricts Codes andLevies (.PDF)
King County Tax
Links
Property Tax Advisor
Washington State
Department of
Revenue (External
link)
Washington StateBoard of TaxAppeals (Externallink)
Board of
Appeals/Equalization
Districts Report
iMap
Recorder's Office
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© King County, WA 2018 Privacy Accessibility Terms of use
1998 1999 96,000 174,000 270,000 96,000 174,000 270,000
1997 1998 0 0 0 85,000 153,000 238,000
1996 1997 0 0 0 85,000 153,000 238,000
1994 1995 0 0 0 66,400 147,600 214,000
1992 1993 0 0 0 42,000 147,600 189,600
1990 1991 0 0 0 40,000 140,600 180,600
1988 1989 0 0 0 31,000 97,300 128,300
1986 1987 0 0 0 31,000 91,000 122,000
1984 1985 0 0 0 34,400 89,400 123,800
1983 1984 0 0 0 34,400 49,300 83,700
1982 1983 0 0 0 34,400 64,600 99,000
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Updated: March 17, 2016
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Fair, Equitable, and Understandable Property Valuations
You're in: Assessor >> Look up Property Info >> eReal Property
Departmentof
Assessments
500 FourthAvenue,Suite ADM-
AS-0708,Seattle, WA98104
Office Hours:
Mon - Fri 8:30 a.m. to4:30 p.m.
TEL: 206-
296-7300FAX: 206-296-5107TTY: 206-296-7888
Send usmail
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New Search Property Tax Bill Map This Property Glossary of Terms Area Report Property Detail
PARCEL
Parcel Number 334570-0020
Name GOODWIN DC LLC
Site Address
Legal HILLMANS LK WN GARDEN OF EDEN # 7 N 120 FT LESS W 50 FT OF 4
BUILDING 1
Year Built
Total Square Footage
Number Of Bedrooms
Number Of Baths
Grade
Condition
Lot Size 29562
Views No
Waterfront
TOTAL LEVY RATE DISTRIBUTION
Tax Year: 2018 Levy Code: 2151 Total Levy Rate: $12.51853 Total Senior Rate: $6.80724
49.70% Voter Approved
Click here to see levy distribution comparison by year.
TAX ROLL HISTORY
Valued
Year
Tax
Year
Appraised Land
Value ($)
Appraised Imps
Value ($)
Appraised
Total ($)
Taxable Land
Value ($)
Taxable Imps
Value ($)
Taxable
Total ($)
2017 2018 215,000 0 215,000 215,000 0 215,000
2016 2017 192,000 0 192,000 192,000 0 192,000
2015 2016 182,000 0 182,000 182,000 0 182,000
2014 2015 181,000 0 181,000 181,000 0 181,000
2013 2014 162,000 0 162,000 162,000 0 162,000
2012 2013 151,000 0 151,000 151,000 0 151,000
2011 2012 155,000 0 155,000 155,000 0 155,000
2010 2011 166,000 0 166,000 166,000 0 166,000
2009 2010 160,000 0 160,000 160,000 0 160,000
2008 2009 183,000 0 183,000 183,000 0 183,000
2007 2008 165,000 0 165,000 165,000 0 165,000
2006 2007 144,000 0 144,000 144,000 0 144,000
2005 2006 126,000 0 126,000 126,000 0 126,000
2004 2005 118,000 0 118,000 118,000 0 118,000
2003 2004 114,000 0 114,000 114,000 0 114,000
2002 2003 110,000 0 110,000 110,000 0 110,000
2001 2002 80,000 0 80,000 80,000 0 80,000
2000 2001 73,000 0 73,000 73,000 0 73,000
1999 2000 64,000 0 64,000 64,000 0 64,000
1998 1999 59,000 0 59,000 59,000 0 59,000
1997 1998 0 0 0 52,000 0 52,000
1996 1997 0 0 0 52,000 0 52,000
1994 1995 0 0 0 41,700 0 41,700
1992 1993 0 0 0 30,500 0 30,500
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ReferenceLinks:
King County TaxingDistricts Codes andLevies (.PDF)
King County Tax
Links
Property Tax Advisor
Washington State
Department of
Revenue (External
link)
Washington StateBoard of TaxAppeals (Externallink)
Board of
Appeals/Equalization
Districts Report
iMap
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© King County, WA 2018 Privacy Accessibility Terms of use
1990 1991 0 0 0 29,000 0 29,000
1988 1989 0 0 0 22,500 0 22,500
1986 1987 0 0 0 22,500 0 22,500
1984 1985 0 0 0 8,800 0 8,800
1982 1983 0 0 0 8,800 0 8,800
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Appendix B
Resource Review & Off-site Analysis Documentation
SITE
9,0281505Flood Hazard Areas MapThis map is a user generated static output from an Internet mapping site and is forreference only. Data layers that appear on this map may or may not be accurate,current, or otherwise reliable.WGS_1984_Web_Mercator_Auxiliary_SphereNotesNone5/24/2018Legend1023 512THIS MAP IS NOT TO BE USED FOR NAVIGATIONFeet1023Information Technology - GIS0RentonMapSupport@Rentonwa.govCity and County BoundaryParcelsFloodwaySpecial Flood Hazard Areas (100 year flood)Other Flood Areas (Zone X - 500 year flood)SITE
9,0281505Streams and Wetlands MapThis map is a user generated static output from an Internet mapping site and is forreference only. Data layers that appear on this map may or may not be accurate,current, or otherwise reliable.WGS_1984_Web_Mercator_Auxiliary_SphereNotesNone5/24/2018Legend1023 512THIS MAP IS NOT TO BE USED FOR NAVIGATIONFeet1023Information Technology - GIS0RentonMapSupport@Rentonwa.govCity and County BoundaryParcelsStreams (Classified)Type SType FType NpType NsWetlandsSITE
9,0281505City of Renton Print map TemplateThis map is a user generated static output from an Internet mapping site and is forreference only. Data layers that appear on this map may or may not be accurate,current, or otherwise reliable.WGS_1984_Web_Mercator_Auxiliary_SphereNotesNone5/24/2018Legend1023 512THIS MAP IS NOT TO BE USED FOR NAVIGATIONFeet1023Information Technology - GIS0RentonMapSupport@Rentonwa.govCity and County BoundaryParcelsZoningRC-Resource ConservationR1-Residential 1 du/acR4-Residential 4 du/acR6-Residential - 6 DU/ACR8-Residential 8 du/acR10-Residential 10 du/acR14-Residential 14 du/acRMF-Residential Multi-FamilyRMH-Residential Manufactured HomesCN-Commercial NeighborhoodCV-Center VillageCA-Commercial ArterialUC-Urban CenterCD-Center DowntownAuto Mall AAuto Mall BAuto Mall CEmployment Area ValleyCity Center Sign Regulation AreaUrban Design District AUrban Design District BUrban Design District CUrban Design District DUrban SeparatorDowntown Business DistrictSITE
9,0281505Landslide Hazard Areas MapThis map is a user generated static output from an Internet mapping site and is forreference only. Data layers that appear on this map may or may not be accurate,current, or otherwise reliable.WGS_1984_Web_Mercator_Auxiliary_SphereNotesNone5/24/2018Legend1023 512THIS MAP IS NOT TO BE USED FOR NAVIGATIONFeet1023Information Technology - GIS0RentonMapSupport@Rentonwa.govCity and County BoundaryParcelsLandslideVERY HIGHHIGHMODERATEUNCLASSIFEDSITE
Appendix C
MGS Flood Reports
Appendix C-1
Detention Vault Sizing
—————————————————————————————————
MGS FLOOD
PROJECT REPORT
Program Version: MGSFlood 4.56
Program License Number: 200210008
Project Simulation Performed on: 04/05/2022 1:32 PM
Report Generation Date: 04/05/2022 1:34 PM
—————————————————————————————————
Input File Name: 18054 Vault Sizing.FLD
Project Name: 18054
Analysis Title:
Comments:
———————————————— PRECIPITATION INPUT ————————————————
Computational Time Step (Minutes): 15
Extended Precipitation Time Series Selected
Climatic Region Number: 15
Full Period of Record Available used for Routing
Precipitation Station : 96004005 Puget East 40 in_5min 10/01/1939-10/01/2097
Evaporation Station : 961040 Puget East 40 in MAP
Evaporation Scale Factor : 0.750
HSPF Parameter Region Number: 3
HSPF Parameter Region Name : USGS Default
********** Default HSPF Parameters Used (Not Modified by User) ***************
********************** WATERSHED DEFINITION ***********************
Predevelopment/Post Development Tributary Area Summary
Predeveloped Post Developed
Total Subbasin Area (acres) 7.580 7.580
Area of Links that Include Precip/Evap (acres) 0.000 0.000
Total (acres) 7.580 7.580
----------------------SCENARIO: PREDEVELOPED
Number of Subbasins: 2
---------- Subbasin : Existing Onsite Basin ----------
-------Area (Acres) --------
Till Forest 7.280
----------------------------------------------
Subbasin Total 7.280
---------- Subbasin : Existing Offsite Basin ----------
-------Area (Acres) --------
Till Forest 0.300
----------------------------------------------
Subbasin Total 0.300
----------------------SCENARIO: POSTDEVELOPED
Number of Subbasins: 2
---------- Subbasin : South Vault Onsite basin ----------
-------Area (Acres) --------
Till Grass 3.630
Impervious 3.650
----------------------------------------------
Subbasin Total 7.280
---------- Subbasin : North Vault Basin ----------
-------Area (Acres) --------
Impervious 0.300
----------------------------------------------
Subbasin Total 0.300
************************* LINK DATA *******************************
----------------------SCENARIO: PREDEVELOPED
Number of Links: 1
------------------------------------------
Link Name: New Copy Lnk1
Link Type: Copy
Downstream Link: None
************************* LINK DATA *******************************
----------------------SCENARIO: POSTDEVELOPED
Number of Links: 2
------------------------------------------
Link Name: South Vault
Link Type: Structure
Downstream Link Name: North Vault
Prismatic Pond Option Used
Pond Floor Elevation (ft) : 64.00
Riser Crest Elevation (ft) : 74.00
Max Pond Elevation (ft) : 75.00
Storage Depth (ft) : 10.00
Pond Bottom Length (ft) : 126.0
Pond Bottom Width (ft) : 64.0
Pond Side Slopes (ft/ft) : Z1= 0.00 Z2= 0.00 Z3= 0.00 Z4= 0.00
Bottom Area (sq-ft) : 8064.
Area at Riser Crest El (sq-ft) : 8,064.
(acres) : 0.185
Volume at Riser Crest (cu-ft): 80,640.
(ac-ft) : 1.851
Area at Max Elevation (sq-ft) : 8064.
(acres) : 0.185
Vol at Max Elevation (cu-ft): 88,704.
(ac-ft) : 2.036
Hydraulic Conductivity (in/hr) : 0.00
Massmann Regression Used to Estimate Hydralic Gradient
Depth to Water Table (ft) : 100.00
Bio-Fouling Potential : Low
Maintenance : Average or Better
Riser Geometry
Riser Structure Type : Circular
Riser Diameter (in) : 18.00
Common Length (ft) : 0.000
Riser Crest Elevation : 74.00 ft
Hydraulic Structure Geometry
Number of Devices: 4
---Device Number 1 ---
Device Type : Circular Orifice
Control Elevation (ft) : 64.00
Diameter (in) : 1.13
Orientation : Horizontal
Elbow : Yes
---Device Number 2 ---
Device Type : Circular Orifice
Control Elevation (ft) : 69.80
Diameter (in) : 1.00
Orientation : Horizontal
Elbow : Yes
---Device Number 3 ---
Device Type : Circular Orifice
Control Elevation (ft) : 71.00
Diameter (in) : 1.50
Orientation : Horizontal
Elbow : Yes
---Device Number 4 ---
Device Type : Circular Orifice
Control Elevation (ft) : 73.00
Diameter (in) : 2.00
Orientation : Horizontal
Elbow : Yes
------------------------------------------
Link Name: North Vault
Link Type: Structure
Downstream Link: None
Prismatic Pond Option Used
Pond Floor Elevation (ft) : 58.50
Riser Crest Elevation (ft) : 63.50
Max Pond Elevation (ft) : 64.00
Storage Depth (ft) : 5.00
Pond Bottom Length (ft) : 94.0
Pond Bottom Width (ft) : 52.0
Pond Side Slopes (ft/ft) : Z1= 0.00 Z2= 0.00 Z3= 0.00 Z4= 0.00
Bottom Area (sq-ft) : 4888.
Area at Riser Crest El (sq-ft) : 4,888.
(acres) : 0.112
Volume at Riser Crest (cu-ft): 24,440.
(ac-ft) : 0.561
Area at Max Elevation (sq-ft) : 4888.
(acres) : 0.112
Vol at Max Elevation (cu-ft): 26,884.
(ac-ft) : 0.617
Hydraulic Conductivity (in/hr) : 0.00
Massmann Regression Used to Estimate Hydralic Gradient
Depth to Water Table (ft) : 100.00
Bio-Fouling Potential : Low
Maintenance : Average or Better
Riser Geometry
Riser Structure Type : Circular
Riser Diameter (in) : 18.00
Common Length (ft) : 0.030
Riser Crest Elevation : 63.50 ft
Hydraulic Structure Geometry
Number of Devices: 3
---Device Number 1 ---
Device Type : Circular Orifice
Control Elevation (ft) : 58.50
Diameter (in) : 1.56
Orientation : Horizontal
Elbow : Yes
---Device Number 2 ---
Device Type : Circular Orifice
Control Elevation (ft) : 60.40
Diameter (in) : 1.75
Orientation : Horizontal
Elbow : Yes
---Device Number 3 ---
Device Type : Circular Orifice
Control Elevation (ft) : 61.90
Diameter (in) : 1.88
Orientation : Horizontal
Elbow : Yes
**********************FLOOD FREQUENCY AND DURATION STATISTICS*******************
----------------------SCENARIO: PREDEVELOPED
Number of Subbasins: 2
Number of Links: 1
----------------------SCENARIO: POSTDEVELOPED
Number of Subbasins: 2
Number of Links: 2
********** Link: North Vault ********** Link WSEL Stats
WSEL Frequency Data(ft)
(Recurrence Interval Computed Using Gringorten Plotting Position)
Tr (yrs) WSEL Peak (ft)
======================================
1.05-Year 59.352
1.11-Year 59.449
1.25-Year 59.599
2.00-Year 60.171
3.33-Year 60.486
5-Year 60.947
10-Year 61.629
25-Year 62.406
50-Year 62.700
100-Year 63.267
***********Groundwater Recharge Summary *************
Recharge is computed as input to Perlnd Groundwater Plus Infiltration in Structures
Total Predeveloped Recharge During Simulation
Model Element Recharge Amount (ac-ft)
-----------------------------------------------------------------------------------------------
Subbasin: Existing Onsite Basi 1255.283
Subbasin: Existing Offsite Bas 51.729
Link: New Copy Lnk1 0.000
_____________________________________
Total: 1307.011
Total Post Developed Recharge During Simulation
Model Element Recharge Amount (ac-ft)
-----------------------------------------------------------------------------------------------
Subbasin: South Vault Onsite b 443.625
Subbasin: North Vault Basin 0.000
Link: South Vault Not Computed
Link: North Vault 0.000
_____________________________________
Total: 443.625
Total Predevelopment Recharge is Greater than Post Developed
Average Recharge Per Year, (Number of Years= 158)
Predeveloped: 8.272 ac-ft/year, Post Developed: 2.808 ac-ft/year
***********Water Quality Facility Data *************
----------------------SCENARIO: PREDEVELOPED
Number of Links: 1
********** Link: New Copy Lnk1 **********
2-Year Discharge Rate : 0.162 cfs
15-Minute Timestep, Water Quality Treatment Design Discharge
On-line Design Discharge Rate (91% Exceedance): 0.13 cfs
Off-line Design Discharge Rate (91% Exceedance): 0.07 cfs
Infiltration/Filtration Statistics--------------------
Inflow Volume (ac-ft): 689.91
Inflow Volume Including PPT-Evap (ac-ft): 689.91
Total Runoff Infiltrated (ac-ft): 0.00, 0.00%
Total Runoff Filtered (ac-ft): 0.00, 0.00%
Primary Outflow To Downstream System (ac-ft): 689.91
Secondary Outflow To Downstream System (ac-ft): 0.00
Volume Lost to ET (ac-ft): 0.00
Percent Treated (Infiltrated+Filtered+ET)/Total Volume: 0.00%
----------------------SCENARIO: POSTDEVELOPED
Number of Links: 2
********** Link: North Vault **********
Basic Wet Pond Volume (91% Exceedance): 6521. cu-ft
Computed Large Wet Pond Volume, 1.5*Basic Volume: 9782. cu-ft
2-Year Discharge Rate : 0.080 cfs
15-Minute Timestep, Water Quality Treatment Design Discharge
On-line Design Discharge Rate (91% Exceedance): 999.00 cfs
Off-line Design Discharge Rate (91% Exceedance): 999.00 cfs
Infiltration/Filtration Statistics--------------------
Inflow Volume (ac-ft): 2500.61
Inflow Volume Including PPT-Evap (ac-ft): 2500.61
Total Runoff Infiltrated (ac-ft): 0.00, 0.00%
Total Runoff Filtered (ac-ft): 0.00, 0.00%
Primary Outflow To Downstream System (ac-ft): 2500.55
Secondary Outflow To Downstream System (ac-ft): 0.00
Volume Lost to ET (ac-ft): 0.00
Percent Treated (Infiltrated+Filtered+ET)/Total Volume: 0.00%
***********Compliance Point Results *************
Scenario Predeveloped Compliance Link: New Copy Lnk1
Scenario Postdeveloped Compliance Link: North Vault
*** Point of Compliance Flow Frequency Data ***
Recurrence Interval Computed Using Gringorten Plotting Position
Predevelopment Runoff Postdevelopment Runoff
Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs)
----------------------------------------------------------------------------------------------------------------------
2-Year 0.162 2-Year 8.006E-02
5-Year 0.263 5-Year 0.154
10-Year 0.355 10-Year 0.196
25-Year 0.450 25-Year 0.296
50-Year 0.574 50-Year 0.324
100-Year 0.622 100-Year 0.371
200-Year 0.968 200-Year 0.525
500-Year 1.433 500-Year 0.732
** Record too Short to Compute Peak Discharge for These Recurrence Intervals
**** Flow Duration Performance ****
Excursion at Predeveloped 50%Q2 (Must be Less Than or Equal to 0%): -0.2% PASS
Maximum Excursion from 50%Q2 to Q2 (Must be Less Than or Equal to 0%): 0.0% PASS
Maximum Excursion from Q2 to Q50 (Must be less than 10%): -0.8% PASS
Percent Excursion from Q2 to Q50 (Must be less than 50%): 0.0% PASS
-------------------------------------------------------------------------------------------------
MEETS ALL FLOW DURATION DESIGN CRITERIA: PASS
-------------------------------------------------------------------------------------------------
Appendix C-2
Wetland Inflow Volume Calculation
—————————————————————————————————
MGS FLOOD
PROJECT REPORT
Program Version: MGSFlood 4.52
Program License Number: 200210008
Project Simulation Performed on: 02/09/2021 1:51 PM
Report Generation Date: 02/09/2021 1:52 PM
—————————————————————————————————
Input File Name: 18054 Wetland.fld
Project Name: 18054 Wetland
Analysis Title:
Comments:
———————————————— PRECIPITATION INPUT ————————————————
Computational Time Step (Minutes): 15
Extended Precipitation Time Series Selected
Climatic Region Number: 15
Full Period of Record Available used for Routing
Precipitation Station : 96004005 Puget East 40 in_5min 10/01/1939-10/01/2097
Evaporation Station : 961040 Puget East 40 in MAP
Evaporation Scale Factor : 0.750
HSPF Parameter Region Number: 1
HSPF Parameter Region Name : USGS Default
********** Default HSPF Parameters Used (Not Modified by User) ***************
********************** WATERSHED DEFINITION ***********************
Predevelopment/Post Development Tributary Area Summary
Predeveloped Post Developed
Total Subbasin Area (acres) 11.460 8.870
Area of Links that Include Precip/Evap (acres) 0.000 0.000
Total (acres) 11.460 8.870
----------------------SCENARIO: PREDEVELOPED
Number of Subbasins: 1
---------- Subbasin : Existing Wetland ----------
-------Area (Acres) --------
Till Forest 8.810
Till Grass 1.200
Impervious 1.450
----------------------------------------------
Subbasin Total 11.460
----------------------SCENARIO: POSTDEVELOPED
Number of Subbasins: 1
---------- Subbasin : Developed Wetland ----------
-------Area (Acres) --------
Till Forest 5.830
Till Grass 1.920
Impervious 1.120
----------------------------------------------
Subbasin Total 8.870
************************* LINK DATA *******************************
----------------------SCENARIO: PREDEVELOPED
Number of Links: 0
************************* LINK DATA *******************************
----------------------SCENARIO: POSTDEVELOPED
Number of Links: 0
**********************FLOOD FREQUENCY AND DURATION STATISTICS*******************
----------------------SCENARIO: PREDEVELOPED
Number of Subbasins: 1
Number of Links: 0
----------------------SCENARIO: POSTDEVELOPED
Number of Subbasins: 1
Number of Links: 0
***********Groundwater Recharge Summary *************
Recharge is computed as input to Perlnd Groundwater Plus Infiltration in Structures
Total Predeveloped Recharge During Simulation
Model Element Recharge Amount (ac-ft)
-----------------------------------------------------------------------------------------------
Subbasin: Existing Wetland 1665.752
_____________________________________
Total: 1665.752
Total Post Developed Recharge During Simulation
Model Element Recharge Amount (ac-ft)
-----------------------------------------------------------------------------------------------
Subbasin: Developed Wetland 1239.905
_____________________________________
Total: 1239.905
Total Predevelopment Recharge is Greater than Post Developed
Average Recharge Per Year, (Number of Years= 158)
Predeveloped: 10.543 ac-ft/year, Post Developed: 7.848 ac-ft/year
***********Water Quality Facility Data *************
----------------------SCENARIO: PREDEVELOPED
Number of Links: 0
----------------------SCENARIO: POSTDEVELOPED
Number of Links: 0
***********Compliance Point Results *************
Scenario Predeveloped Compliance Subbasin: Existing Wetland
Scenario Postdeveloped Compliance Subbasin: Developed Wetland
*** Point of Compliance Flow Frequency Data ***
Recurrence Interval Computed Using Gringorten Plotting Position
Predevelopment Runoff Postdevelopment Runoff
Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs)
----------------------------------------------------------------------------------------------------------------------
2-Year 0.751 2-Year 0.660
5-Year 1.041 5-Year 0.938
10-Year 1.297 10-Year 1.210
25-Year 1.859 25-Year 1.740
50-Year 2.169 50-Year 2.081
100-Year 2.260 100-Year 2.314
200-Year 2.727 200-Year 2.537
500-Year 3.354 500-Year 2.832
** Record too Short to Compute Peak Discharge for These Recurrence Intervals
**** Flow Duration Performance ****
Excursion at Predeveloped 50%Q2 (Must be Less Than or Equal to 0%): -57.5% PASS
Maximum Excursion from 50%Q2 to Q2 (Must be Less Than or Equal to 0%): -50.8% PASS
Maximum Excursion from Q2 to Q50 (Must be less than 10%): -11.8% PASS
Percent Excursion from Q2 to Q50 (Must be less than 50%): 0.0% PASS
-------------------------------------------------------------------------------------------------
MEETS ALL FLOW DURATION DESIGN CRITERIA: PASS
-------------------------------------------------------------------------------------------------
**** LID Duration Performance ****
Excursion at Predeveloped 8%Q2 (Must be Less Than 0%): -21.3% PASS
Maximum Excursion from 8%Q2 to 50%Q2 (Must be Less Than 0%): -25.1% PASS
-------------------------------------------------------------------------------------------------
MEETS ALL LID DURATION DESIGN CRITERIA: PASS
-------------------------------------------------------------------------------------------------
Appendix D
Special Reports and Studies
GEOTECHNICAL REPORT
Canopy
4130 Lincoln Avenue Northeast
Renton, Washington
Project No. T-7886
Prepared for:
Blue Fern Development, LLC
Kirkland, Washington
March 19, 2019
7th Revision June 21, 2021
6-21-2021
TABLE OF CONTENTS
Page No.
1.0 Project Description .......................................................................................................... 1
2.0 Scope of Work ................................................................................................................. 1
3.0 Site Conditions ................................................................................................................ 2
3.1 Surface ................................................................................................................ 2
3.2 Subsurface .......................................................................................................... 2
3.3 Groundwater ....................................................................................................... 3
3.4 Geologic Hazards ............................................................................................... 3
3.4.1 Steep Slopes ............................................................................................. 3
3.4.2 Erosion Hazard Areas ............................................................................... 4
3.4.3 Landslide Hazard Areas ........................................................................... 5
3.4.4 Coal Mine Hazard Areas .......................................................................... 6
3.4.5 Seismic Hazard Areas ............................................................................... 7
4.0 Discussion and Recommendations .................................................................................. 7
4.1 General ............................................................................................................... 7
4.2 Site Preparation and Grading .............................................................................. 8
4.3 Excavation .......................................................................................................... 9
4.4 Slopes and Embankments ................................................................................... 9
4.5 Foundation Support .......................................................................................... 10
4.6 Floor Slab-on-Grade ......................................................................................... 10
4.7 Lateral Earth Pressures for Wall Design .......................................................... 11
4.8 Infiltration Feasibility ....................................................................................... 11
4.9 Rockeries .......................................................................................................... 12
4.10 Drainage ........................................................................................................... 12
4.11 Utilities ............................................................................................................. 12
4.12 Pavement .......................................................................................................... 13
5.0 Additional Services ....................................................................................................... 13
6.0 Limitations ..................................................................................................................... 13
Figures
Vicinity Map ......................................................................................................................... Figure 1
Exploration Location Plan .................................................................................................... Figure 2
Typical Slope Key and Bench Detail ................................................................................... Figure 3
Typical Wall Drainage Detail ............................................................................................... Figure 4
Appendices
Field Exploration and Laboratory Testing ........................................................................ Appendix A
SLIDE 2 Graphical Output ............................................................................................... Appendix B
Geotechnical Report Canopy 4130 Lincoln Avenue Northeast Renton, Washington
1.0 PROJECT DESCRIPTION
The project consists of developing 5 adjoining tax parcels totaling approximately 10.1 acres with 53 single-family
homes, stormwater facilities, and associated access and utilities. Based on review of the conceptual site plan,
prepared by CORE Design dated February 15, 2021, grading to achieve the building lot and roadway elevations
will consist of cuts and fills from 1 to 16 feet. Vertical grade transitions along the perimeter of the site will be
supported with maximum 10 foot tall, reinforced fill rockery walls, Redi-Rock walls, or cut rockery walls. Interior
grade transitions will be supported with 2:1 (Horizontal: Vertical) slopes.
We anticipate that the structures will be two- to three-story, wood-framed, and constructed either at grade or over a
crawl space with relatively light structural loading. We expect that bearing walls will carry loads of 1 to 3 kips per
foot and isolated columns will carry maximum loads of 30 to 60 kips.
The recommendations in the following sections of this report are based on our understanding of the preceding design
features. We should review final design drawings as they become available to verify that our recommendations
have been properly interpreted and to supplement them, if required.
2.0 SCOPE OF WORK
We completed our site exploration on April 9, 2018, by observing soil and groundwater conditions at 9 test pits
excavated to maximum depths of about 11 feet below existing site grades. On April 4, 2019, we supplemented this
data by excavating 5 additional test pits to maximum depths of approximately 12 feet below existing site grades.
On April 10, 2019, and April 11, 2019, we further supplemented the data by drilling 4 test borings to depths of 30
to 35 feet below current site grades. Using the information obtained from the subsurface exploration and laboratory
testing, we performed analyses to develop geotechnical recommendations for project design and construction.
Specifically, this report addresses the following:
Soil and groundwater conditions.
Geologic Hazards per the City of Renton Municipal Code.
Seismic Site Class per the 2015 International Building Code (IBC).
Site preparation and grading.
Slopes and embankments.
Excavation.
Foundation support.
Slab-on-grade floors.
Infiltration feasibility per 2016 King County Surface Water Design Manual.
Rockeries.
Drainage.
Utilities.
Pavements.
March 19, 2019
7th Revision June 21, 2021
Project No. T-7886
Page No. 2
It should be noted that recommendations outlined in this report regarding drainage are associated with soil strength,
design earth pressures, erosion, and stability. Design and performance issues with respect to moisture as it relates
to the structure environment are beyond Terra Associates’ Inc’s purview. A building envelope specialist or
contractor should be consulted to address these issues, as needed.
3.0 SITE CONDITIONS
3.1 Surface
The project site consists of an assemblage of 5 tax parcels totaling approximately 10.1 acres located east of Lincoln
Avenue Northeast and north of Northeast 40th Street in Renton, Washington. However, our site investigation was
limited to the parcel located at 4130 Lincoln Avenue Northeast and the large parcel located immediately to the
north. The approximate site location is shown on Figure 1.
The site area explored currently supports a single-family home and a couple of small outbuildings in its southern
corner. The remainder of the site is undeveloped and supports a combination of densely forested areas and
unforested brush covered areas. Trees at the site consist of a combination of mature coniferous and broadleaf trees.
Topography at the site generally falls moderately to steeply from east to west with overall site relief on the order of
145 feet.
3.2 Subsurface
In general, the soil conditions observed in the test pits excavated in 2018 and 2019 consisted of 2 to 24 inches of
topsoil overlying medium dense to dense sandy silt and silty sand with varying gravel content (weathered till)
overlying dense sandy silt, silt with sand, and silty sand with varying gravel content (glacial till) to the terminus of
the test pits. There were three exceptions to this general condition. At Test Pits TP-2 and TP-7, we observed two
to two- and one-half feet of loose to medium dense inorganic fill overlying the native till soils. At Test Pit TP-8,
we observed dense sand to sand with silt underlying the upper approximately six feet of glacial till. At Test Pit TP-
1, underlying the upper topsoil horizon, we observed medium dense to dense sand and sand with silt to the terminus
of the test pit.
The upper soil conditions observed in the test borings completed at the site were consistent with those observed in
the test pits. Underlying the weathered and unweathered till materials, we observed very stiff to hard silt to the
termination of the test borings. The till material was observed to depths of 18 to 23 feet below current site grades
in Test Borings B-2, B-3, and B-4. Test Boring B-1 did not extend through the till material into the hard silt.
The Geologic Map of Surficial Deposits in the Seattle 30’ by 60’ Quadrangle, Washington by J.C. Yount, J.P.
Minard, and G.R. Dembroff (1993) indicates that the majority of the site is underlain by Vashon till (Qvt) with Pre-
Fraser deposits undifferentiated (Qpf) underlying the western-most margin of the site near its frontage with Lincoln
Avenue Northeast. The soils observed at depth in our test pits are consistent with the Vashon till mapped unit with
the hard silt observed in the test borings consistent with the pre-fraser deposit unit.
March 19, 2019
7th Revision June 21, 2021
Project No. T-7886
Page No. 3
The preceding discussion is intended to be a general review of the soil conditions encountered. For more detailed
descriptions, please refer to the Test Pit and Test Boring Logs in Appendix A.
3.3 Groundwater
We observed light to moderate, perched groundwater seepage in 10 of the 14 test pits at depths ranging from 1.5 to
9 feet below current site grades. The groundwater seepage was generally noted to flow near the contact between
the upper weathered and existing fill soils and the dense to very dense native glacial till. This is typical for sites
underlain by glacial till and occurs as a result of rainfall that infiltrates through the upper weathered soil zone and
becomes perched on the underlying dense till. The dense till soils have a relatively low permeability that impedes
the continued downward migration of the infiltrated rainfall. As a result, groundwater seepage will develop and
tend to flow laterally along the contact. Locally, such seepage is referred to as interflow. Scattered across much of
the eastern half of the property, we observed areas where groundwater was seeping from the ground surface. In our
opinion, these ground seeps are the result of shallow interflow encountering impermeable layers near the ground
surface.
The occurrence of interflow will fluctuate seasonally with the highest seepage levels occurring during the normally
wet winter to late spring months (November to May). Based on the time of year of our exploration, the groundwater
observed is likely near the seasonal high levels.
3.4 Geologic Hazards
3.4.1 Steep Slopes
Title IV, Chapter 3, Section 4-3-050(G)(5)(a) of the Renton Municipal Code (RMC) defines steep slopes in the
following two categories:
“i. Sensitive Slopes: A hillside, or portion thereof, characterized by: (a) an average slope of 25 percent
to less than 40 percent as identified in the City of Renton Steep Slope Atlas or in a method approved by
the City; or (b) an average slope of 40 percent or greater with a vertical rise of less than 15 feet as
identified in the City of Renton Steep Slope Atlas or in a method approved by the City; (c) abutting an
average slope of 25 percent to 40 percent as identified in the City of Renton Steep Slope Atlas or in a
method approved by the City. This definition excludes engineered retaining walls.
ii. Protected Slopes: A hillside, or portion thereof, characterized by an average slope of 40 percent or
greater grade and having a minimum vertical rise of 15 feet as identified in the City of Renton Steep
Slope Atlas or in a method approved by the City.”
Based on a topographic site plan prepared by CORE Design, there are isolated areas across the site where slope
gradients exceed 40 percent over a vertical rise of 15 feet. Therefore, the site does contain protected slopes as
defined in item (ii) above. Per the RMC, a building setback of 15 feet must be established between any structures
associated with the development and these protected slope areas. A map showing these locations is shown on Figure
3.
March 19, 2019
7th Revision June 21, 2021
Project No. T-7886
Page No. 4
3.4.2 Erosion Hazard Areas
Title IV, Chapter 3, Section 4-3-050(G)(5)(c) of the RMC defines erosion hazards in the following two categories:
“i. Low Erosion Hazard (EL): Areas with soils characterized by the Natural Resource Conservation Service
(formerly U.S. Soil Conservation Service) as having slight or moderate erosion potential, and a slope less
than 15 percent.
ii. High Erosion Hazard (EH): Areas with soils characterized by the Natural Resource Conservation Service
(formerly U.S. Soil Conservation Service) as having severe or very severe erosion potential, and a slope
more than 15 percent.”
The soils observed within the proposed development area are classified as Alderwood gravelly sandy loam, 8 to 30
percent slopes, Everett very gravelly sandy loam, 8 to 15 percent slopes, Ragnar-Indianola association, sloping and
Ragnar-Indianola association, moderately steep by the United States Department of Agriculture Natural Resources
Conservation Service (NRCS). With the existing slope gradients, these soils will have a moderate to severe potential
for erosion when exposed. Therefore, the site does contain a high erosion hazard area as defined by the RMC.
Implementation of temporary and permanent Best Management Practices (BMPs) for preventing and controlling
erosion will be required and will mitigate the erosion hazard. As a minimum, we recommend implementing the
following erosion and sediment control BMPs prior to, during, and immediately following construction activities
at the site.
Prevention
Limit site clearing and grading activities to the relatively dry months (typically May through September).
Limit disturbance to areas where construction is imminent.
Locate temporary stockpiles of excavated soils no closer than ten feet from the crest of the slope.
Provide temporary cover for cut slopes and soil stockpiles during periods of inactivity. Temporary cover
may consist of durable plastic sheeting that is securely anchored to the ground surface or straw mulch.
Establish permanent cover over exposed areas that will not be disturbed for a period of 30 days or more by
seeding, in conjunction with a mulch cover or appropriate hydroseeding.
Containment
Install a silt fence along site margins and downslope of areas that will be disturbed. The silt fence should
be in place before clearing and grading is initiated.
Intercept surface water flow and route the flow away from the slope to a stabilized discharge point. Surface
water must not discharge at the top or onto the face of the steep slope.
Provide onsite sediment retention for collected runoff.
The contractor should perform daily review and maintenance of all erosion and sedimentation control measures at
the site.
March 19, 2019
7th Revision June 21, 2021
Project No. T-7886
Page No. 5
3.4.3 Landslide Hazard Areas
Title IV, Chapter 3, Section 4-3-050(G)(5)(b) of the RMC defines landslide hazards in the following four categories:
“i. Low Landslide Hazard (LL): Areas with slopes less than 15 percent.
ii. Medium Landslide Hazard (LM): Areas with slopes between 15 percent and 40 percent and underlain
by soils that consist largely of sand, gravel, or glacial till.
iii. High Landslide Hazards (LH): Areas with slopes greater than 40 percent, and areas with slopes
between 15 percent and 40 percent and underlain by soils consisting largely of silt and clay.
iv. Very High Landslide Hazards (LV): Areas of known mapped or identified landslide deposits.”
The site does contain slopes inclined at greater than 40 percent but does not contain any mapped or identified
landslide deposits. Therefore, portions of the site would be considered a High Landslide Hazard (LH) per the RMC.
However, during our site reconnaissance, we did not observe evidence of current or historic slope instability such
as uniformly back tilted trees, tension cracks, or headscarps. We did observe several areas where groundwater was
seeping out of the ground surface. However, in our opinion, these seeps are the result of perched interflow
mounding on shallow impermeable obstructions and not indicative of a more significant static groundwater table.
Relative Slope Stability
In addition to reconnoitering the slope, we completed a slope stability analysis in order to determine if the existing
slopes on the site were unstable and to assess the impact of the proposed development. The analyses were performed
at locations designated as Cross-Section A-A’, Cross Section B-B’, and Cross Section C-C’ using the computer
program Slide 2. The approximate cross-section locations are shown on Figure 2.
Our analysis considered both static and the pseudostatic (seismic) conditions. A horizontal acceleration of 0.3g was
used in the pseudostatic analysis to simulate slope performance under earthquake loading. This represents one-half
of the Peak Ground Acceleration (PGA) for the site.
Based on our field exploration, laboratory testing, and previous experience with similar soil types, we chose the
following parameters for our analysis:
Table 1 – Slope Stability Analysis Soil Parameters
Soil Type Unit Weight (pcf) Friction Angle
(degrees) Cohesion (psf)
New structural fill 120 34 0 – 50
Medium dense silty SAND with
gravel (weathered till) 125 34 0 – 50
Dense to very dense silty SAND
with gravel (unweathered till) 125 40 150
Very stiff to hard SILT 110 28 750
March 19, 2019
7th Revision June 21, 2021
Project No. T-7886
Page No. 6
The results of our slope stability analysis, as shown by the lowest safety factors for each condition, are presented in
the following table:
Table 2 – Slope Stability Analysis Results
Based on our analysis, although the slope fits the code criteria of a High Landslide Hazard, the result of our study
indicates that they are not at risk of a deep-seated failure in their current state. As such, it is our opinion that the
site can be developed as planned as the post construction factors of safety are over the generally required 1.5 for
static and 1.1 for seismic. Results of our analysis are attached in Appendix B.
Cross Section B-B’ was completed in the area where there is a proposed retaining wall that will regrade a portion
of the protected slope in this area and was revised to reflect the additional lot depth on Building Lot 30. Based on
the results of our analysis, the proposed regrading is acceptable from a geotechnical standpoint.
3.4.4 Coal Mine Hazard Areas
Title IV, Chapter 3, Section 4-3-050(G)(5)(e) of the RMC defines coal mine hazards in the following three
categories:
“i. Low Coal Mine Hazards (CL): Areas with no known mine workings and no predicted subsidence.
While no mines are known in these areas, undocumented mining is known to have occurred.
ii. Medium Coal Mine Hazards (CM): Areas where mine workings are deeper than 200 feet for steeply
dipping seams, or deeper than 15 times the thickness of the seam or workings for gently dipping seams.
These areas may be affected by subsidence.
iii. High Coal Mine Hazard (CH): Areas with abandoned and improperly sealed mine openings and areas
underlain by mine workings shallower than 200 feet in depth for steeply dipping seams, or shallower than
15 times the thickness of the seam or workings for gently dipping seams. These areas may be affected by
collapse or other subsidence.”
Based on the City of Renton Sensitive Areas: Coal Mine Hazards Map the site is not located near any coal mine
hazards. Therefore, the site would not be classified as a coal mine hazard area per the RMC.
Cross Section Minimum Safety Factors
Existing Conditions Post Construction
A-A’ 2.63
(Seismic FS = 1.18)
1.95
(Seismic FS = 1.12)
B-B’ 2.47
(Seismic FS = 1.35)
1.92
(Seismic FS = 1.12)
C-C’ N/A 1.87
(Seismic FS = 1.40)
March 19, 2019
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Project No. T-7886
Page No. 7
3.4.5 Seismic Hazard Areas
Title IV, Chapter 3, Section 4-3-050(G)(5)(d) of the RMC defines seismic hazards in the following two categories:
“i. Low Seismic Hazard (SL): Areas underlain by dense soils or bedrock. These soils generally have site
classifications of A through D, as defined in the International Building Code, 2012.
ii. High Seismic Hazard (SH): Areas underlain by soft or loose, saturated soils. These soils generally have
Site Classifications E or F, as defined in the International Building Code, 2012.”
Liquefaction is a phenomenon where there is a reduction or complete loss of soil strength due to an increase in
water pressure induced by vibrations. Liquefaction mainly affects geologically recent deposits of fine grained sand
that are below the groundwater table. Soils of this nature derive their strength from intergranular friction. The
generated water pressure or pore pressure essentially separates the soil grains and eliminates this intergranular
friction; thus, eliminating the soil’s strength.
Based on the soil and groundwater conditions observed, in our opinion, the potential for soil liquefaction and
seismically induced settlement within the native soils is negligible. Therefore, the site would be classified as a Low
Seismic Hazard (SL) per the RMC.
Based on soil conditions observed in the test pits and our knowledge of the area geology, per Chapter 16 of the
2015 International Building Code (IBC), Site Class D should be used in structural design.
4.0 DISCUSSION AND RECOMMENDATIONS
4.1 General
Based on our study, there are no geotechnical conditions that would preclude the planned development. Buildings
can be supported on conventional spread footings bearing on competent native soils underlying organic topsoil or
on structural fill placed on the competent native soils. Floor slabs and pavements can be similarly supported.
We would note that the loose fill material with nested boulders observed at Test Pit TP-2 will be unsuitable for
support of new site improvements and should be removed below all structures and pavements. Following removal
of the unsuitable fill material, the residential structures can be supported on conventional spread footings bearing
on competent native or competent existing fill soils or on structural fill placed and compacted above these competent
soils. Pavement and floor slabs can be similarly supported.
Most of the native and existing fill soils encountered at the site contain a significant amount of fines and will be
difficult to compact as structural fill when too wet. The ability to use native and existing fill soil from site
excavations as structural fill will depend on its moisture content and the prevailing weather conditions at the time
of construction. If grading activities will take place during winter, the owner should be prepared to import clean
granular material for use as structural fill and backfill.
The following sections provide detailed recommendations regarding the preceding issues and other geotechnical
design considerations. These recommendations should be incorporated into the final design drawings and
construction specifications.
March 19, 2019
7th Revision June 21, 2021
Project No. T-7886
Page No. 8
4.2 Site Preparation and Grading
To prepare the site for construction, all vegetation, organic surface soils, and other deleterious material should be
stripped and removed from the site. Surface stripping depths of up to 24 inches should be expected to remove the
organic surface soils. In the developed portions of the site, demolition of existing structures should include removal
of existing foundations, floor slabs, underground septic systems, and other buried utilities. Abandoned utility pipes
that fall outside of new building areas can be left in place provided they are sealed to prevent intrusion of
groundwater seepage and soil. Organic topsoil will not be suitable for use as structural fill but may be used for
limited depths in nonstructural areas.
As mentioned above, the upper approximately two feet of loose fill material mixed with nested boulders observed
at Test Pit TP-2 will need to be removed prior to foundation or pavement construction. We recommend that this
material be removed to expose competent native soils and that grade be restored with new structural fill. The fill
was noted to be relatively free of organics and would be suitable for reuse as structural fill provided the boulders
are removed prior to placement. Removal depths of about two feet should be planned for; however, the actual depth
and lateral extents of the unsuitable soils will need to be determined in the field at the time of construction.
Once clearing and excavation operations are complete, cut and fill operations can be initiated to establish desired
grades. Prior to placing fill, all exposed bearing surfaces should be observed by a representative of Terra Associates,
Inc. to verify soil conditions are as expected and suitable for support of new fill. Our representative may request a
proofroll using heavy rubber-tired equipment to determine if any isolated soft and yielding areas are present. If
excessively yielding areas are observed, and they cannot be stabilized in place by compaction, the affected soils
should be excavated and removed to firm bearing and grade restored with new structural fill. Beneath embankment
fills or roadway subgrade if the depth of excavation to remove unstable soils is excessive, the use of geotextile
fabrics, such as Mirafi 500X, or an equivalent fabric, can be used in conjunction with clean granular structural fill.
Our experience has shown that, in general, a minimum of 18 inches of a clean, granular structural fill placed and
compacted over the geotextile fabric should establish a stable bearing surface.
The native soils encountered at the site contain a sufficient amount of soil fines that will make them difficult to
compact as structural fill when too wet or too dry. The ability to use soils from site excavations as structural fill
will depend on its moisture content and the prevailing weather conditions at the time of construction. If wet soils
are encountered, the contractor will need to dry the soils by aeration during dry weather conditions. Alternatively,
the use of an additive such as Portland cement or lime to stabilize the soil moisture can be considered. If the soil is
amended, additional Best Management Practices (BMPs) addressing the potential for elevated pH levels will need
to be included in the Storm Water Pollution Prevention Program (SWPPP) prepared with the Temporary Erosion
and Sedimentation Control (TESC) plan.
If grading activities are planned during the wet winter months, or if they are initiated during the summer and extend
into fall and winter, the owner should be prepared to import wet weather structural fill. For this purpose, we
recommend importing a granular soil that meets the following grading requirements:
U.S. Sieve Size Percent Passing
6 inches 100
No. 4 75 maximum
No. 200 5 maximum*
* Based on the 3/4-inch fraction.
Prior to use, Terra Associates, Inc. should examine and test all materials imported to the site for use as structural
fill.
March 19, 2019
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Project No. T-7886
Page No. 9
Structural fill should be placed in uniform loose layers not exceeding 12 inches and compacted to a minimum of 95
percent of the soil’s maximum dry density, as determined by American Society for Testing and Materials (ASTM)
Test Designation D-698 (Standard Proctor). The moisture content of the soil at the time of compaction should be
within minus one to plus three percent of its optimum, as determined by this ASTM standard. In nonstructural
areas, the degree of compaction can be reduced to 90 percent.
4.3 Excavation
All excavations at the site associated with confined spaces, such as utility trenches, must be completed in accordance
with local, state, and federal requirements. Based on regulations outlined in the Washington Industrial Safety and
Health Act (WISHA), the loose to dense existing fill, sand, and weathered till soils observed at the site would be
classified as Type C soils. The dense unweathered glacial till soil would be classified as Type A soil.
Accordingly, temporary excavations in Type C soils should have their slopes laid back at an inclination of 1.5:1
(Horizontal: Vertical) or flatter, from the toe to the crest of the slope. Side slopes in Type A soils can be laid back
at a slope inclination of 0.75:1 or flatter. For temporary excavation slopes less than 8 feet in height in Type A soils,
the lower 3.5 feet can be cut to a vertical condition, with a 0.75:1 slope graded above. For temporary excavation
slopes greater than 8 feet in height up to a maximum height of 12 feet, the slope above the 3.5-foot vertical portion
will need to be laid back at a minimum slope inclination of 1:1. No vertical cut with a backslope immediately above
is allowed for excavation depths that exceed 12 feet. In this case, a four-foot vertical cut with an equivalent
horizontal bench to the cut slope toe is required. All exposed temporary slope faces that will remain open for an
extended period of time should be covered with a durable reinforced plastic membrane during construction to
prevent slope raveling and rutting during periods of precipitation.
Shallow groundwater seepage may be encountered within excavations particularly during the winter and spring
months. In our opinion, the volume of water and rate of flow into the excavation should be relatively minor to
moderate and would not be expected to impact the stability of the excavations when completed as described above.
Conventional sump pumping procedures along with a system of collection trenches, if necessary, should be capable
of maintaining a relatively dry excavation for construction purposes.
The above information is provided solely for the benefit of the owner and other design consultants and should not
be construed to imply that Terra Associates, Inc. assumes responsibility for job site safety. It is understood that job
site safety is the sole responsibility of the project general contractor.
4.4 Slopes and Embankments
All permanent cut and fill slopes should be graded with a finished inclination of no greater than 2:1 (Horizontal:
Vertical). Upon completion of grading, the slope face should be appropriately vegetated or provided with other
physical means to guard against erosion. Final grades at the top of the slope must promote surface drainage away
from the slope crest. Water must not be allowed to flow uncontrolled over the slope face. If surface runoff must
be directed towards the slope, the runoff should be controlled at the top of the slope, piped in a closed conduit
installed on the slope face, and taken to an appropriate point of discharge beyond the toe.
March 19, 2019
7th Revision June 21, 2021
Project No. T-7886
Page No. 10
All fill placed for embankment construction should meet the structural fill requirements in Section 4.2 of this report.
In addition, if the new fills will be placed over existing slopes of 20 percent or greater, the structural fill should be
keyed and benched into competent native slope soils. Figure 4 presents a typical slope key and bench configuration.
At minimum, a toe drain should be installed in the key cut as shown on Figure 4. Depending on seepage conditions,
drains may also be required along individual benches excavated on the slope face. The need for drains along the
upper benches will be best determined in the field at the time of construction.
4.5 Foundation Support
The buildings can be supported on conventional spread footing foundations bearing on competent native soils or on
structural fills placed above competent native soils. As noted above, the existing loose fill material observed in
Test Pit TP-2 would not be suitable for support of building foundations. Foundation subgrade should be prepared
as recommended in Section 4.2 of this report. Perimeter foundations exposed to the weather should bear a minimum
depth of 1.5 feet below final exterior grades for frost protection. Interior foundations can be constructed at any
convenient depth below the floor slab.
The native soils that will be exposed at the expected foundation elevations are moisture sensitive and will be easily
disturbed by normal construction activity when wet. As a measure to protect the soils from disturbance during
construction, consideration should be given to placing a four-inch-thick layer of clean crushed rock or lean mix
concrete over the foundation subgrade to serve as a working surface.
Foundations obtaining support on competent native soil or on new structural fill can be dimensioned for a net
allowable bearing capacity of 2,500 pounds per square foot (psf). For short-term loads, such as wind and seismic,
a one-third increase in this allowable capacity can be used. With structural loading as anticipated and this bearing
stress applied, estimated total and differential settlements are expected to be less than one-half inch.
For designing foundations to resist lateral loads, a base friction coefficient of 0.35 can be used. Passive earth
pressures acting on the side of the footing can also be considered. We recommend calculating this lateral resistance
using an equivalent fluid weight of 350 pcf. We recommend not including the upper 12 inches of soil in this
computation because they can be affected by weather or disturbed by future grading activity. This value assumes
the foundation will be constructed neat against competent native soil or backfilled with structural fill as described
in Section 4.2 of this report. The values recommended include a safety factor of 1.5.
4.6 Floor Slab-on-Grade
Slab-on-grade floors may be supported on subgrade prepared as recommended in Section 4.2 of this report.
Immediately below the floor slab, we recommend placing a four-inch-thick capillary break layer composed of clean,
coarse sand or fine gravel that has less than three percent passing the No. 200 sieve. This material will reduce the
potential for upward capillary movement of water through the underlying soil and subsequent wetting of the floor
slab.
March 19, 2019
7th Revision June 21, 2021
Project No. T-7886
Page No. 11
The capillary break layer will not prevent moisture intrusion through the slab caused by water vapor transmission.
Where moisture by vapor transmission is undesirable, such as covered floor areas, a common practice is to place a
durable plastic membrane on the capillary break layer and then cover the membrane with a layer of clean sand or
fine gravel to protect it from damage during construction, and to aid in uniform curing of the concrete slab. It
should be noted that if the sand or gravel layer overlying the membrane is saturated prior to pouring the slab, it will
not be effective in assisting uniform curing of the slab and can actually serve as a water supply for moisture bleeding
through the slab, potentially affecting floor coverings. Therefore, in our opinion, covering the membrane with a
layer of sand or gravel should be avoided if floor slab construction occurs during the wet winter months and the
layer cannot be effectively drained. We recommend floor designers and contractors refer to the current American
Concrete Institute (ACI) Manual of Concrete Practice for further information regarding vapor barrier installation
below slab-on-grade floors.
4.7 Lateral Earth Pressures for Wall Design
The magnitude of earth pressures developing on below-grade walls and retaining walls will depend on the quality
and compaction of the wall backfill. We recommend placing and compacting wall backfill as structural fill, as
described in Section 4.2 of this report. To prevent overstressing the walls during backfilling, heavy construction
machinery should not be operated within five feet of the back of the wall. Wall backfill in this zone should be
compacted with hand-operated equipment. To prevent hydrostatic pressure development, wall drainage must also
be installed. A typical wall drainage detail is shown on Figure 5. All drains should be routed to the storm sewer
system or other approved point of controlled discharge.
With drainage properly installed, we recommend designing unrestrained walls for an active earth pressure
equivalent to a fluid weighing 35 pounds per cubic foot (pcf). For restrained walls, an additional uniform load of
100 psf should be added to the 35 pcf. To account for typical traffic surcharge loading, the walls can be designed
for an additional imaginary height of two feet (two-foot soil surcharge). For evaluation of wall performance under
seismic loading, a uniform pressure equivalent to 8H psf, where H is the height of the below-grade portion of the
wall should be applied in addition to the static lateral earth pressure. These values assume a horizontal backfill
condition and that no other surcharge loading, sloping embankments, or adjacent buildings will act on the wall. If
such conditions exist, then the imposed loading must be included in the wall design. Friction at the base of
foundations and passive earth pressure will provide resistance to these lateral loads. Values for these parameters
are provided in Section 4.5 of this report.
4.8 Infiltration Feasibility
In our opinion, the native soils observed at the site would not be suitable for support infiltration facilities. The site
is underlain by relatively impermeable glacial till soils and exhibited shallow perched groundwater seepage. These
are all indicators of a poorly drained soil formation. Therefore, we recommend that development stormwater be
routed to a conventional storm system for disposal.
March 19, 2019
7th Revision June 21, 2021
Project No. T-7886
Page No. 12
4.9 Rockeries
As noted above, some of the vertical grade transitions may be supported using rockery walls. A rockery is not
intended to function as an engineered structure to resist lateral earth pressures as a conventional retaining wall
system does. Rockeries should only be used to face soil formations that are inherently stable and can stand in a
near-vertical exposure without lateral support. The primary function of the rockery is to cover the stable exposed
soil face to reduce the potential for erosion.
We recommend limiting cut rockeries to a height of ten feet when placed again competent native soils and limiting
fill rockeries to a height of four feet where placed against unreinforced structural fill. Where buildings will be
constructed above and adjacent to all rockery construction, the foundations should be lowered to prevent surcharge
loading on the rockery. Foundation depths should provide for a theoretical 1:1 influence line extending from the
footing edge to pass beneath the rockery base. The structural fill should be overbuilt and then cut back prior to
constructing the rockery. This will provide a more competent and stable soil face behind the rockery.
Where buildings or roadways will be constructed above the rockeries, the rockeries should be constructed using
geotextile reinforcing. We can complete the designs for a reinforced rockery wall, if requested.
A rockery design has been completed and is in a separate design package.
4.10 Drainage
Surface
Final exterior grades should promote free and positive drainage away from the site at all times. Water must not be
allowed to pond or collect adjacent to foundations or within the immediate building areas. We recommend
providing a positive drainage gradient away from the building perimeters. If this gradient cannot be provided,
surface water should be collected adjacent to the structures and disposed to appropriate storm facilities.
Subsurface
We recommend installing perimeter foundation drains adjacent to shallow foundations. The drains can be laid to
grade at an invert elevation equivalent to the bottom of footing grade. The drains can consist of four-inch diameter
perforated PVC pipe that is enveloped in washed pea gravel-sized drainage aggregate. The aggregate should extend
six inches above and to the sides of the pipe. Roof and foundation drains should be tightlined separately to the
storm drains. All drains should be provided with cleanouts at easily accessible locations.
4.11 Utilities
Utility pipes should be bedded and backfilled in accordance with American Public Works Association (APWA) or
the local jurisdiction specifications. As a minimum, trench backfill should be placed and compacted as structural
fill, as described in Section 4.2 of this report. As noted, depending on the soil moisture when excavated most
inorganic native soils on the site should be suitable for use as backfill material during dry weather conditions.
However, if utility construction takes place during the wet winter months, it will likely be necessary to import
suitable wet weather fill for utility trench backfilling.
March 19, 2019
7th Revision June 21, 2021
Project No. T-7886
Page No. 13
4.12 Pavement
Pavement subgrade should be prepared as described in the Section 4.2 of this report. Regardless of the degree of
relative compaction achieved, the subgrade must be firm and relatively unyielding before paving. The subgrade
should be proofrolled with heavy rubber-tire construction equipment such as a loaded 10-yard dump truck to verify
this condition.
The pavement design section is dependent upon the supporting capability of the subgrade soils and the traffic
conditions to which it will be subjected. For the parking areas, with traffic consisting mainly of light passenger
vehicles with only occasional heavy traffic, and with a stable subgrade prepared as recommended, we recommend
the following pavement sections:
Two inches of hot mix asphalt (HMA) over four inches of crushed rock base (CRB).
Three- and one-half inches full depth HMA.
The paving materials used should conform to the Washington State Department of Transportation (WSDOT)
specifications for ½-inch class HMA and CRB.
Long-term pavement performance will depend on surface drainage. A poorly-drained pavement section will be
subject to premature failure as a result of surface water infiltrating into the subgrade soils and reducing their
supporting capability. For optimum pavement performance, we recommend surface drainage gradients of at least
two percent. Some degree of longitudinal and transverse cracking of the pavement surface should be expected over
time. Regular maintenance should be planned to seal cracks when they occur.
5.0 ADDITIONAL SERVICES
Terra Associates, Inc. should review the final design drawings and specifications in order to verify that earthwork
and foundation recommendations have been properly interpreted and implemented in project design. We should
also provide geotechnical service during construction to observe compliance with our design concepts,
specifications, and recommendations. This will allow for design changes if subsurface conditions differ from those
anticipated prior to the start of construction.
6.0 LIMITATIONS
We prepared this report in accordance with generally accepted geotechnical engineering practices. No other
warranty, expressed or implied, is made. This report is the copyrighted property of Terra Associates, Inc. and is
intended for specific application to the Canopy project in Renton, Washington. This report is for the exclusive use
of Blue Fern Development, LLC, and its authorized representatives.
The analyses and recommendations present in this report are based on data obtained from the subsurface exploration
conducted on-site. Variations in soil conditions can occur, the nature and extent of which may not become evident
until construction. If variations appear evident, Terra Associates, Inc. should be requested to reevaluate the
recommendations in this report prior to proceeding with construction.
© 2018 Microsoft Corporation © 2018 HERE
SITE
Environmental Earth Sciences
Terra
Associates, Inc.
Consultants in Geotechnical Engineering
Geology and Figure 1
VICINITY MAP
0 2000 4000
APPROXIMATE SCALE IN FEET
REFERENCE: https://www.bing.com/maps ACCESSED 4/19/18
Proj.No. T-7886 Date:JUNE 2021
RENTON, WASHINGTON
CANOPY
TP-1TP-2TP-3TP-4TP-5TP-6TP-7TP-8TP-9A
A'B-1TP-101TP-102TP-103TP-104TP-105B-2B-3B-4C'
C
B'BREFERENCE:REFERENCE ONLY AND SHOULD NOT BE USED FORDESIGN OR CONSTRUCTION PURPOSES.DIMENSIONS ARE APPROXIMATE. IT IS INTENDED FORNOTE:THIS SITE PLAN IS SCHEMATIC. ALL LOCATIONS ANDConsultants in Geotechnical EngineeringTerraAssociates, Inc.Geology andEnvironmental Earth SciencesEXPLORATION LOCATION PLANFigure 2LEGEND:080160APPROXIMATE SCALE IN FEETSITE PLAN PROVIDED BY CORE.APPROXIMATE TEST PIT LOCATIONProj.No. T-7886Date:JUNE 2021RENTON, WASHINGTONCANOPY(TERRA ASSOCIATES 4/2018)APPROXIMATE TEST PIT LOCATION(TERRA ASSOCIATES 4/2019)APPROXIMATE TEST BORING LOCATION(TERRA ASSOCIATES 4/2019)
REFERENCE:REFERENCE ONLY AND SHOULD NOT BE USED FORDESIGN OR CONSTRUCTION PURPOSES.DIMENSIONS ARE APPROXIMATE. IT IS INTENDED FORNOTE:THIS SITE PLAN IS SCHEMATIC. ALL LOCATIONS ANDConsultants in Geotechnical EngineeringTerraAssociates, Inc.Geology andEnvironmental Earth SciencesPROTECTED SLOPE LAYOUTFigure 3080160APPROXIMATE SCALE IN FEETSITE PLAN PROVIDED BY CORE.Proj.No. T-7886Date:JUNE 2021RENTON, WASHINGTONCANOPY
Proj.No. T-7886 Date:JUNE 2021
RENTON, WASHINGTON
CANOPY
Environmental Earth Sciences
Terra
Associates, Inc.
Consultants in Geotechnical Engineering
Geology and
TYPICAL SLOPE KEY AND BENCH DETAIL
Figure 4
NOT TO SCALE
6' (MIN.)
2
1
EXISTING
SLOPE TOE
NOTES:
1)STRUCTURAL FILL SHALL BE COMPACTED TO A MINIMUM OF 95%
OF ASTM D 698 MAXIMUM DRY DENSITY VALUE.
TOE OF NEW
FILL EMBANKMENT
KEYWAY
6' (MIN.)
2' (MIN.)
1
1
STRUCTURAL FILL
(SEE NOTE 1)
TYPICAL SLOPE BENCH
CLEARED AND STRIPPED
NATIVE GROUND
1
1
2)DRAINS SHALL CONSIST OF 6" DIA. PERFORATED PVC PIPE ENVELOPED
IN 1 cu ft OF 3/4" WASHED GRAVEL. DRAIN PIPE SHALL BE DIRECTED TO
KEYWAY DRAIN
(SEE NOTE 2)
THE STORM DRAIN SYSTEM OR APPROVED POINT OF DISCHARGE.
(SEE NOTE 3)
3)ADDITIONAL BENCHES AND BENCH DRAINS MAY BE REQUIRED
BASED ON FIELD EVALUATION BY THE GEOTECHNICAL ENGINEER.
12"
COMPACTED
STRUCTURAL FILL
EXCAVATED SLOPE
(SEE REPORT TEXT
FOR APPROPRIATE
INCLINATIONS)
SLOPE TO DRAIN
12" MINIMUM 3/4"
MINUS WASHED
GRAVEL
3" BELOW PIPE
12" OVER PIPE
4" DIAMETER PERFORATED PVC PIPE
SEE NOTE
6"(MIN.)
NOT TO SCALE
NOTE:
MIRADRAIN G100N PREFABRICATED DRAINAGE PANELS OR SIMILAR
PRODUCT CAN BE SUBSTITUTED FOR THE 12-INCH WIDE GRAVEL
DRAIN BEHIND WALL. DRAINAGE PANELS SHOULD EXTEND A MINIMUM
OF SIX INCHES INTO 12-INCH THICK DRAINAGE GRAVEL LAYER
OVER PERFORATED DRAIN PIPE.
Environmental Earth Sciences
Terra
Associates, Inc.
Consultants in Geotechnical Engineering
Geology and
TYPICAL WALL DRAINAGE DETAIL
Figure 5Proj.No. T-7886 Date:JUNE 2021
RENTON, WASHINGTON
CANOPY
APPENDIX A
FIELD EXPLORATION AND LABORATORY TESTING
Canopy
Renton, Washington
On April 9, 2018, we completed our site exploration by observing soil conditions at 9 test pits. On April 4, 2019,
we supplemented this data by observing soil conditions at 5 additional test pits. On April 10, 2019, and April 11,
2019, we supplemented this data by observing soil conditions at 4 test borings drilled to depths of 31.5 to 36.5 feet
below current site grades. The test pits were excavated using a track-mounted mini-excavator and trackhoe to
maximum depths of about 12 feet below existing site grades. Test Pit and Test Boring locations were determined
in the field by measurements from existing site features and with a handheld GPS using coordinates obtained from
Google Earth. The approximate locations of the test pits and test borings are shown on the attached Exploration
Location Plan, Figure 2. Test Pit and Test Boring Logs are attached as Figures A-2 through A-19.
A geotechnical engineer from our office conducted the field exploration. Our representative classified the soil
conditions encountered, maintained a log of each test pit, obtained representative soil samples, and recorded water
levels observed during excavation. During drilling, soil samples were obtained in general accordance with ASTM
Test Designation D-1586. Using this procedure, a 2-inch (outside diameter) split barrel sampler is driven into the
ground 18 inches using a 140-pound hammer free falling a height of 30 inches. The number of blows required to
drive the sampler 12 inches after an initial 6-inch set is referred to as the Standard Penetration Resistance value or
N value. This is an index related to the consistency of cohesive soils and relative density of cohesionless materials.
N values obtained for each sampling interval are recorded on the Boring Logs, Figures A-16 through A-19. All soil
samples were visually classified in accordance with the Unified Soil Classification System (USCS) described on
Figure A-1.
Representative soil samples obtained from the test pits were placed in closed containers and taken to our laboratory
for further examination and testing. The moisture content of each sample was measured and is reported on the
individual Test Pit Logs. Grain size analyses were performed on selected samples. The results of the grain size
analyses are shown on Figures A-20 and A-21.
Environmental Earth Sciences
Terra
Associates, Inc.
Consultants in Geotechnical Engineering
Geology and
MAJOR DIVISIONS LETTER
SYMBOL TYPICAL DESCRIPTION
GRAVELS
More than 50%
of coarse fraction
is larger than No.
4 sieve
Clean
Gravels (less
than 5%
fines)
GW Well-graded gravels, gravel-sand mixtures, little or no fines.
GP Poorly-graded gravels, gravel-sand mixtures, little or no fines.
Gravels with
fines
GM Silty gravels, gravel-sand-silt mixtures, non-plastic fines.
GC Clayey gravels, gravel-sand-clay mixtures, plastic fines.
SANDS
More than 50%
of coarse fraction
is smaller than
No. 4 sieve
Clean Sands
(less than
5% fines)
SW Well-graded sands, sands with gravel, little or no fines.
SP Poorly-graded sands, sands with gravel, little or no fines.
Sands with
fines
SM Silty sands, sand-silt mixtures, non-plastic fines.
SC Clayey sands, sand-clay mixtures, plastic fines.
SILTS AND CLAYS
Liquid Limit is less than 50%
ML Inorganic silts, rock flour, clayey silts with slight plasticity.
CL Inorganic clays of low to medium plasticity. (Lean clay)
OL Organic silts and organic clays of low plasticity.
SILTS AND CLAYS
Liquid Limit is greater than 50%
MH Inorganic silts, elastic.
CH Inorganic clays of high plasticity. (Fat clay)
OH Organic clays of high plasticity.
HIGHLY ORGANIC SOILS PT Peat.COARSE GRAINED SOILSMore than 50% material largerthan No. 200 sieve sizeFINE GRAINED SOILSMore than 50% material smallerthan No. 200 sieve sizeDEFINITION OF TERMS AND SYMBOLS
COHESIONLESSCOHESIVE Standard Penetration
Density Resistance in Blows/Foot
Very Loose 0-4
Loose 4-10
Medium Dense 10-30
Dense 30-50
Very Dense >50
Standard Penetration
Consistancy Resistance in Blows/Foot
Very Soft 0-2
Soft 2-4
Medium Stiff 4-8
Stiff 8-16
Very Stiff 16-32
Hard >32
2" OUTSIDE DIAMETER SPILT SPOON SAMPLER
2.4" INSIDE DIAMETER RING SAMPLER OR
SHELBY TUBE SAMPLER
WATER LEVEL (Date)
Tr TORVANE READINGS, tsf
Pp PENETROMETER READING, tsf
DD DRY DENSITY, pounds per cubic foot
LL LIQUID LIMIT, percent
PI PLASTIC INDEX
N STANDARD PENETRATION, blows per foot
UNIFIED SOIL CLASSIFICATION SYSTEM
Figure A-1Proj.No. T-7886 Date:JUNE 2021
RENTON, WASHINGTON
CANOPY
Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY:
LOCATION:
DATE LOGGED:
APPROX. ELEV:
DEPTH TO CAVING:
FIGURE
DEPTH TO GROUNDWATER:
SURFACE CONDITIONS:
Description Consistency/
Relative Density W (%)interpreted as being indicative of other locations at the site.NOTE: This subsurface information pertains only to this test pit location and should not be
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
A-2
T-7886 AJD
Renton, Washington Grass
April 9, 2018
Goodwin Assemblage
LOG OF TEST PIT NO. TP-1
78 Feet
8 Feet N/A
1
2
3
Dark brown silty SAND, fine to medium, moist, frequent organics. (SM) (TOPSOIL)
Brown grading to tan SAND with silt, fine to medium, moist. (SP-SM)
Gray-brown SAND, fine to medium, moist becoming wet below 8 feet, interbedded with scattered
gravel layers, occasional boulder to 18 inches in diameter. (SP)
Test pit terminated at approximately 10.5 feet.
Light groundwater seepage observed at 8 feet.
Loose
Medium Dense
Medium Dense
to Dense
7.6
8.6
19.1
Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY:
LOCATION:
DATE LOGGED:
APPROX. ELEV:
DEPTH TO CAVING:
FIGURE
DEPTH TO GROUNDWATER:
SURFACE CONDITIONS:
Description Consistency/
Relative Density W (%)interpreted as being indicative of other locations at the site.NOTE: This subsurface information pertains only to this test pit location and should not be
0
1
2
3
4
5
6
7
8
9
10
A-3
T-7886 AJD
Renton, Washington Grass
April 9, 2018
Goodwin Assemblage
LOG OF TEST PIT NO. TP-2
124 Feet
2 Feet N/A
1
2
FILL: Brown silty SAND with gravel mixed with boulders, fine to coarse sand, fine to coarse gravel,moist. (SM)
Brown silty SAND, fine to medium, moist, weakly cemented in places, mottled.
(SM) (Weathered Till)
Gray silty SAND with gravel, fine to coarse sand, fine to coarse gravel, moist, moderately
cemented. (SM) (Glacial Till)
Test pit terminated at approximately 8 feet.
Light perched groundwater seepage observed at 2 feet.
Loose
Medium Dense
Dense
20.5
11.9
Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY:
LOCATION:
DATE LOGGED:
APPROX. ELEV:
DEPTH TO CAVING:
FIGURE
DEPTH TO GROUNDWATER:
SURFACE CONDITIONS:
Description Consistency/
Relative Density W (%)interpreted as being indicative of other locations at the site.NOTE: This subsurface information pertains only to this test pit location and should not be
0
1
2
3
4
5
6
7
8
9
10
A-4
T-7886 AJD
Renton, Washington Blackberries
April 9, 2018
Goodwin Assemblage
LOG OF TEST PIT NO. TP-3
162 Feet
2 Feet N/A
1
2
Dark brown silty SAND, fine to medium, moist, frequent organics. (SM) (TOPSOIL)
Brown silty SAND to silty SAND with gravel, fine to medium sand, fine gravel, wet.
(SM) (Weathered Till)
Gray silty SAND with gravel, fine to coarse sand, fine to coarse gravel, moist, moderately
cemented. (SM) (Glacial Till)
Test pit terminated at approximately 9 feet.
Light perched groundwater seepage observed at 2 feet.
Medium Dense
Dense
15.5
13.2
Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY:
LOCATION:
DATE LOGGED:
APPROX. ELEV:
DEPTH TO CAVING:
FIGURE
DEPTH TO GROUNDWATER:
SURFACE CONDITIONS:
Description Consistency/
Relative Density W (%)interpreted as being indicative of other locations at the site.NOTE: This subsurface information pertains only to this test pit location and should not be
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
A-5
T-7886 AJD
Renton, Washington Blackberries
April 9, 2018
Goodwin Assemblage
LOG OF TEST PIT NO. TP-4
190 Feet
2 Feet N/A
1
2
3
4
Dark brown silty SAND, fine to medium, wet, frequent organics. (SM) (TOPSOIL)
Brown silty SAND to sandy SILT, fine to medium sand, wet becoming moist below 2.5 feet,
mottled. (SM/ML) (Weathered Till)
Gray and brown SILT with sand, fine to medium sand, moist. (MH) (Glacial Till)
Test pit terminated at approximately 10 feet.
Light perched groundwater seepage observed at 2 feet.
Loose
Medium Dense
Stiff
Very Stiff
14.7
26.7
38.2
33.7
Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY:
LOCATION:
DATE LOGGED:
APPROX. ELEV:
DEPTH TO CAVING:
FIGURE
DEPTH TO GROUNDWATER:
SURFACE CONDITIONS:
Description Consistency/
Relative Density W (%)interpreted as being indicative of other locations at the site.NOTE: This subsurface information pertains only to this test pit location and should not be
0
1
2
3
4
5
6
7
8
9
10
A-6
T-7886 AJD
Renton, Washington Blackberries
April 9, 2018
Goodwin Assemblage
LOG OF TEST PIT NO. TP-5
158 Feet
6 Feet N/A
1
2
(4 inches of ORGANIC TOPSOIL)
Red-brown grading to tan silty SAND with gravel, fine to coarse sand, fine to coarse gravel, moist,
interbedded with scattered sand seams, weakly cemented in places, mottled.
(SM) (Weathered Till)
Gray silty SAND to sandy SILT, fine to medium sand, moist, moderately cemented.
(SM/ML) (Glacial Till)
Test pit terminated at approximately 8.5 feet.
Light perched groundwater seepage observed at 6 feet.
Medium Dense
Dense
15.2
12.5
Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY:
LOCATION:
DATE LOGGED:
APPROX. ELEV:
DEPTH TO CAVING:
FIGURE
DEPTH TO GROUNDWATER:
SURFACE CONDITIONS:
Description Consistency/
Relative Density W (%)interpreted as being indicative of other locations at the site.NOTE: This subsurface information pertains only to this test pit location and should not be
0
1
2
3
4
5
6
7
8
9
10
A-7
T-7886 AJD
Renton, Washington Grass
Forest Duff
Goodwin Assemblage
LOG OF TEST PIT NO. TP-6
124 Feet
N/A N/A
1
(10 inches of ORGANIC TOPSOIL)
Brown and gray silty SAND, fine to coarse, moist, moderately cemented. (SM) (Glacial Till)
Test pit terminated at approximately 8 feet.
No groundwater seepage observed.
Dense
18.7
Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY:
LOCATION:
DATE LOGGED:
APPROX. ELEV:
DEPTH TO CAVING:
FIGURE
DEPTH TO GROUNDWATER:
SURFACE CONDITIONS:
Description Consistency/
Relative Density W (%)interpreted as being indicative of other locations at the site.NOTE: This subsurface information pertains only to this test pit location and should not be
0
1
2
3
4
5
6
7
8
9
10
A-8
T-7886 AJD
Renton, Washington Grass
April 9, 2018
Goodwin Assemblage
LOG OF TEST PIT NO. TP-7
130 Feet
N/A N/A
1
2
3
(4 inches of ORGANIC TOPSOIL)
FILL: Brown silty SAND with gravel, fine to coarse sand, fine to coarse gravel, moist, trace
organics. (SM)
Tan and gray silty SAND with gravel, fine to coarse sand, fine to coarse gravel, moist to wet.
(SM) (Weathered Till)
Gray silty SAND with gravel, fine to coarse sand, fine to coarse gravel, moist, moderately
cemented. (SM) (Glacial Till)
Test pit terminated at approximately 8.5 feet.
No groundwater seepage observed.
Medium Dense
Dense
23.5
15.4
15.4
Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY:
LOCATION:
DATE LOGGED:
APPROX. ELEV:
DEPTH TO CAVING:
FIGURE
DEPTH TO GROUNDWATER:
SURFACE CONDITIONS:
Description Consistency/
Relative Density W (%)interpreted as being indicative of other locations at the site.NOTE: This subsurface information pertains only to this test pit location and should not be
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
A-9
T-7886 AJD
Renton, Washington Brush
April 9, 2018
Goodwin Assemblage
LOG OF TEST PIT NO. TP-8
192 Feet
6.5 Feet N/A
1
2
Dark brown silty SAND, fine to medium, wet, frequent organics. (SM) (TOPSOIL)
Gray silty SAND with gravel, fine to coarse sand, fine to coarse gravel, moist, mottled.
(SM) (Glacial Till)
Gray SAND with silt, fine to medium, scattered gravel, wet. (SP-SM)
Test pit terminated at approximately 11 feet.
Light to moderate perched groundwater seepage observed at 6.5 feet.
Loose
Dense
12.8
18.4
Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY:
LOCATION:
DATE LOGGED:
APPROX. ELEV:
DEPTH TO CAVING:
FIGURE
DEPTH TO GROUNDWATER:
SURFACE CONDITIONS:
Description Consistency/
Relative Density W (%)interpreted as being indicative of other locations at the site.NOTE: This subsurface information pertains only to this test pit location and should not be
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
A-10
T-7886 AJD
Renton, Washington Brush
April 9, 2018
Goodwin Assemblage
LOG OF TEST PIT NO. TP-9
194 Feet
1.5 Feet N/A
1
2
(10 inches of ORGANIC TOPSOIL)
Brown silty SAND, fine to coarse, moist to wet, mottled, weakly cemented in places below 2 feet.
(SM) (Weathered Till)
Gray-brown silty SAND to sandy SILT, fine to medium sand, moist, scattered fine gravel, weakly
cemented. (SM/ML) (Glacial Till)
Test pit terminated at approximately 10 feet.
Light perched groundwater seepage observed at 1.5 feet.
Medium Dense
Dense
21.4
12.9
Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY:
LOCATION:
DATE LOGGED:
APPROX. ELEV:
DEPTH TO CAVING:
FIGURE
DEPTH TO GROUNDWATER:
SURFACE CONDITIONS:
Description Consistency/
Relative Density W (%)interpreted as being indicative of other locations at the site.NOTE: This subsurface information pertains only to this test pit location and should not be
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
A-11
T-7886 MJX
Renton, Washington Grass & brush
April 4, 2019
Canopy
LOG OF TEST PIT NO. TP-101
N/A
4.5 Feet N/A
Black silty SAND with gravel, fine sand, fine to coarse gravel, moist, numerous organics, scatteredcobbles. (SM) (Organic TOPSOIL)
Reddish-brown SAND with silt and gravel, fine to medium sand, fine to coarse gravel, moist,
scattered roots, scattered rootlets, trace cobbles. (SM)
Gray sandy SILT with gravel, fine to medium sand, fine to coarse gravel, moist, mottled,
interbedded sand with silt seams. (ML)
Gray silty SAND with gravel, fine to medium sand, fine to coarse gravel, moist, trace cobbles,
occasional boulder, weak cementation. (SM)
Bluish-gray silty SAND, fine to coarse sand, moist, trace gravel, stratified silt and sand with siltlayers. (SM)
Test pit terminated at approximately 12 feet.
Light perched groundwater seepage observed at approximately 4.5 feet.
No caving observed.
Loose to Medium
Dense
Medium Dense
Stiff
Dense to Very
Dense
Dense
Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY:
LOCATION:
DATE LOGGED:
APPROX. ELEV:
DEPTH TO CAVING:
FIGURE
DEPTH TO GROUNDWATER:
SURFACE CONDITIONS:
Description Consistency/
Relative Density W (%)interpreted as being indicative of other locations at the site.NOTE: This subsurface information pertains only to this test pit location and should not be
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
A-12
T-7886 MJX
Renton, Washington Grass
April 4, 2019
Canopy
LOG OF TEST PIT NO. TP-102
N/A
4 & 9 Feet 3 to 5 Feet
(10 inches ORGANIC TOPSOIL)
Gray sandy SILT with gravel, fine to coarse sand, fine to coarse gravel, moist to wet, mottled, trace
cobbles. (ML)
*6-inch layer of grayish-brown SAND with silt.
Gray silty SAND with gravel, fine to coarse sand, fine to coarse gravel, moist to wet, slightly
mottled, trace cobbles, occasional rootlet, weak to moderate cementation. (SM)
*6-inch layer of gray SAND with silt observed.
Test pit terminated at approximately 11 feet.
Light perched groundwater seepage observed at approximately 4 and 9 feet.
Minor caving observed from approximately 3 to 5 feet.
Medium Stiff
Dense
Very Dense
Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY:
LOCATION:
DATE LOGGED:
APPROX. ELEV:
DEPTH TO CAVING:
FIGURE
DEPTH TO GROUNDWATER:
SURFACE CONDITIONS:
Description Consistency/
Relative Density W (%)interpreted as being indicative of other locations at the site.NOTE: This subsurface information pertains only to this test pit location and should not be
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
A-13
T-7886 MJX
Renton, Washington Blackberries
April 4, 2019
Canopy
LOG OF TEST PIT NO. TP-103
N/A
N/A N/A
(8 inches ORGANIC TOPSOIL)
Gray silty SAND with gravel, fine to coarse sand, fine to coarse gravel, moist, scattered rootlets,
trace roots, trace cobbles, occasional sand inclusion, weak to moderate cementation. (SM)
Test pit terminated at approximately 10 feet.
No groundwater seepage observed.
No caving observed.
Dense
Very Dense
Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY:
LOCATION:
DATE LOGGED:
APPROX. ELEV:
DEPTH TO CAVING:
FIGURE
DEPTH TO GROUNDWATER:
SURFACE CONDITIONS:
Description Consistency/
Relative Density W (%)interpreted as being indicative of other locations at the site.NOTE: This subsurface information pertains only to this test pit location and should not be
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
A-14
T-7886 MJX
Renton, Washington Brush
April 4, 2019
Canopy
LOG OF TEST PIT NO. TP-104
NA
1 & 6 Feet 1 to 7 Feet
Black silty SAND with gravel, fine sand, fine to coarse gravel, moist to wet, numerous organics,scattered cobbles. (SM) (Organic TOPSOIL)
Gray sandy SILT with gravel, fine to medium sand, fine to coarse gravel, moist, mottled, trace
rootlets, trace cobbles. (ML)
*1-foot layer of gray SILT observed.
Gray SAND with silt to silty SAND, fine to medium sand, moist to wet. (SP-SM/SM)
Gray silty SAND with gravel, fine to coarse sand, fine to coarse gravel, moist, trace cobbles, weak
to moderate cementation. (SM)
Test pit terminated at approximately 10 feet.
Light perched groundwater seepage observed at approximately 1 feet.
Moderate perched groundwater seepage observed at approximately 6 feet.
Moderate caving observed from approximately 1 to 7 feet.
Loose to Medium
Dense
Medium Stiff
Medium Dense
Dense to VeryDense
Sample No.Depth (ft)PROJECT NAME: PROJ. NO: LOGGED BY:
LOCATION:
DATE LOGGED:
APPROX. ELEV:
DEPTH TO CAVING:
FIGURE
DEPTH TO GROUNDWATER:
SURFACE CONDITIONS:
Description Consistency/
Relative Density W (%)interpreted as being indicative of other locations at the site.NOTE: This subsurface information pertains only to this test pit location and should not be
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
A-15
T-7886 MJX
Renton, Washington Grass
April 4, 2019
Canopy
LOG OF TEST PIT NO. TP-105
N/A
N/A N/A
(10 inches ORGANIC TOPSOIL)
Brown silty SAND with gravel, fine to medium sand, fine to coarse gravel, moist, scattered roots,
trace cobbles. (SM)
Gray sandy SILT, fine to medium sand, moist, mottled, trace gravel, trace cobbles. (ML)
Gray silty SAND with gravel, fine to coarse sand, fine to coarse gravel, moist, trace cobbles, weak
to moderate cementation. (SM)
Test pit terminated at approximately 10 feet.
No groundwater seepage observed.
No caving observed.
Medium Dense
Stiff
Very Dense
Dense
Figure No.
Project:Project No:
Logged By:Driller:
Location:Approx. Elev:
Client:
Relative Density
Consistency/
Soil Description
SPT (N)
Blows/foot
10 30 50
Date Drilled:
Depth to Groundwater:Sample IntervalDepth (ft)MoistureContent (%)pertains only to this boring location and should not be interpeted as being indicative ofNOTE: This borehole log has been prepared for geotechnical purposes. This information
other areas of the site
0
5
10
15
20
25
30
35
40
A-16LOG OF BORING NO. B-1
Canopy T-7886 4/10/19
BSBoreTecBlue Fern Development
Renton, Washington 90 Feet25 Feet
19
50/5"
50/4"
77
45
69
Medium Dense
Very Dense
Dense
Very Dense
(8 inches TOPSOIL)Tan silty SAND with gravel, fine to medium sand, fine to coarse
gravel, moist. (SM)
Gray/tan silty SAND with gravel, fine to medium sand, fine to coarse
gravel, mosit to wet. (SM)
*At 20 feet observed interbedded coarse sand layers.
*At 25 feet becomes fine sand and fine gravel.
Test boring terminated at 31.5 feet.
Groundwater observed at 25 feet.
18.2
16.9
21.7
21.6
18.0
Figure No.
Project:Project No:
Logged By:Driller:
Location:Approx. Elev:
Client:
Relative Density
Consistency/
Soil Description
SPT (N)
Blows/foot
10 30 50
Date Drilled:
Depth to Groundwater:Sample IntervalDepth (ft)MoistureContent (%)pertains only to this boring location and should not be interpeted as being indicative ofNOTE: This borehole log has been prepared for geotechnical purposes. This information
other areas of the site
0
5
10
15
20
25
30
35
40
A-17LOG OF BORING NO. B-2
Canopy T-7886 4/11/19
BSBoreTecBlue Fern Development
Renton, Washington 150 FeetN/A
27
68
63
34
20
34
Medium Dense
Very Dense
Very Stiff
(12 inches TOPSOIL)Tan/brown silty SAND with gravel, fine to medium sand, fine to
coarse gravel, moist. (SM)
Tan silty SAND with gravel, fine to medium sand, fine to coarse
gravel, moist to wet. (SM)
Gray SILT, moist. (ML)
Test boring terminated at 31.5 feet.
No groundwater seepage observed.
14.1
12.5
17.3
16.1
24.6
23.5
Figure No.
Project:Project No:
Logged By:Driller:
Location:Approx. Elev:
Client:
Relative Density
Consistency/
Soil Description
SPT (N)
Blows/foot
10 30 50
Date Drilled:
Depth to Groundwater:Sample IntervalDepth (ft)MoistureContent (%)pertains only to this boring location and should not be interpeted as being indicative ofNOTE: This borehole log has been prepared for geotechnical purposes. This information
other areas of the site
0
5
10
15
20
25
30
35
40
A-18LOG OF BORING NO. B-3
Canopy T-7886 4/11/19
BSBoreTecBlue Fern Development
Renton, Washington 168 FeetN/A
47
73
78
47
32
25
27
Dense
Very Dense
Very Stiff to Hard
(12 inches TOPSOIL)
Gray/tan silty SAND with gravel, fine to medium sand, fine to coarse
gravel, moist. (SM)
Gray SILT, moist. (ML)
Test boring terminated at 36.5 feet.
No groundwater seepage observed.
9.9
12.7
17.3
18
21.8
22.5
21.1
Figure No.
Project:Project No:
Logged By:Driller:
Location:Approx. Elev:
Client:
Relative Density
Consistency/
Soil Description
SPT (N)
Blows/foot
10 30 50
Date Drilled:
Depth to Groundwater:Sample IntervalDepth (ft)MoistureContent (%)pertains only to this boring location and should not be interpeted as being indicative ofNOTE: This borehole log has been prepared for geotechnical purposes. This information
other areas of the site
0
5
10
15
20
25
30
35
40
A-19LOG OF BORING NO. B-4
Canopy T-7886 4/11/19
BSBoreTecBlue Fern Development
Renton, Washington 174 FeetN/A
14
50/5"
23
5
73
38
Medium Dense
Very Dense
Very Stiff
Medium Stiff
Hard
(12 inches TOPSOIL)
Gray/tan silty SAND with gravel, fine to medium sand, fine to coarse
gravel, moist. (SM)
Gray sandy SILT, fine sand, moist, interbedded with some coarse
sand, some gravel. (ML)
Gray SILT, moist. (ML)
Test boring terminated at 31.5 feet.
No groundwater seepage observed.
15.0
14.4
12.6
18.3
17.7
22.5
APPENDIX B
SLIDE 2 GRAPHICAL OUTPUT
2.6282.62812.6282.628Material NameColorUnit Weight(lbs/Ō3)Strength TypeCohesion(psf)Phi(deg)Unweathered Glacial Till125Mohr‐Coulomb15040Weathered Glacial Till125Mohr‐Coulomb5034Silt110Mohr‐Coulomb750282502001501005050100150200250300350Analysis DescriptionCross Section A-A' - Existing ConditionsCompanyTerra Associates, Inc.Scale1:448Drawn ByC. DeckerFile NameCross Section A-A' Geo.slmdDateMay 13, 2019ProjectCanopySLIDEINTERPRET 8.029
1.1801.1801.1801.180Material NameColorUnit Weight(lbs/Ō3)Strength TypeCohesion(psf)Phi(deg)Unweathered Glacial Till125Mohr‐Coulomb15040Weathered Glacial Till125Mohr‐Coulomb5034Silt110Mohr‐Coulomb75028 0.312001000800600400200-1000-800-600-400-20002004006008001000Analysis DescriptionCross Section A-A' - Existing Conditions - SeismicCompanyTerra Associates, Inc.Scale1:2513Drawn ByC. DeckerFile NameCross Section A-A' Geo.slmdDateMay 13, 2019ProjectCanopySLIDEINTERPRET 8.029
1.9481.948121.9481.948Material NameColorUnit Weight(lbs/Ō3)Strength TypeCohesion(psf)Phi(deg)Unweathered Glacial Till125Mohr‐Coulomb15040New Structural Fill120Mohr‐Coulomb5034Rockery Rocks110Infinite strengthWeathered Glacial Till 2125Mohr‐Coulomb034Silt110Mohr‐Coulomb75028200150100500050100150200250300350400Analysis DescriptionCross Section A-A' - Post ConstructionCompanyTerra Associates, Inc.Scale1:498Drawn ByC. DeckerFile NameCross Section A-A' Geo.slmdDateMay 13, 2019ProjectCanopySLIDEINTERPRET 8.029
1.1171.1171.1171.117Material NameColorUnit Weight(lbs/Ō3)Strength TypeCohesion(psf)Phi(deg)Unweathered Glacial Till125Mohr‐Coulomb15040Weathered Glacial Till125Mohr‐Coulomb5034New Structural Fill120Mohr‐Coulomb5034Rockery Rocks110Infinite strengthSilt110Mohr‐Coulomb75028 0.325020015010050050100150200250300350400Analysis DescriptionCross Section A-A' - Post Construction - SeismicCompanyTerra Associates, Inc.Scale1:498Drawn ByC. DeckerFile NameCross Section A-A' Geo.slmdDateMay 13, 2019ProjectCanopySLIDEINTERPRET 8.029
2.4722.47212.4722.472Material NameColorUnit Weight(lbs/Ō3)Strength TypeCohesion(psf)Phi(deg)WaterSurfaceRuUnweathered Glacial Till125Mohr‐Coulomb15040None0Silt110Mohr‐Coulomb75028PiezometriLine 1140120100806040-60-40-20020406080100120Analysis DescriptionCross Section B-B' - Existing ConditionsCompanyTerra Associates, Inc.Scale1:234Drawn ByC. DeckerFile NameCross Section A-A' Geo.slmdDate8/22/2019, 11:46:04 AMProjectCanopySLIDEINTERPRET 8.029
1.3461.3461.3461.346Material NameColorUnit Weight(lbs/Ō3)Strength TypeCohesion(psf)Phi(deg)WaterSurfaceRuUnweathered Glacial Till125Mohr‐Coulomb15040None0Silt110Mohr‐Coulomb75028None0 0.31751501251007550-120-100-80-60-40-20020406080100120Analysis DescriptionCross Section B-B' - Existing Conditions - SeismicCompanyTerra Associates, Inc.Scale1:304Drawn ByC. DeckerFile NameCross Section A-A' Geo.slmdDate8/22/2019, 11:46:04 AMProjectCanopySLIDEINTERPRET 8.029
1.9151.91511.9151.915RuWater SurfaceAllow SlidingPhi (deg)Cohesion (psf)Strength TypeUnit Weight (lbs/ft3)ColorMaterial Name0None40150Mohr‐Coulomb125Unweathered Glacial TillPiezometric Line 128750Mohr‐Coulomb110Silt0NoneYesInfinite strength120Redi‐Rock Wall1009080706050400102030405060708090100ScenarioMaster ScenarioGroupCross Section B-B' - Post Construction - Redi-RockCompanyTerra Associates, Inc.Drawn ByC. DeckerFile NameCanopy Cross Sections June 2021.slmdDate2/19/2020 rv 6/21/2021ProjectCanopySLIDEINTERPRET 9.008
1.1191.1191.1191.119RuWater SurfaceAllow SlidingPhi (deg)Cohesion (psf)Strength TypeUnit Weight (lbs/ft3)ColorMaterial Name0None40150Mohr‐Coulomb125Unweathered Glacial Till0None28750Mohr‐Coulomb110Silt0NoneYesInfinite strength120Redi‐Rock Wall 0.32001751501251007550-80-60-40-20020406080100120140160ScenarioSeismicGroupCross Section B-B' - Post Construction - Redi-RockCompanyTerra Associates, Inc.Drawn ByC. DeckerFile NameCanopy Cross Sections June 2021.slmdDate2/19/2020 rv 6/21/2021ProjectCanopySLIDEINTERPRET 9.008
1.8701.87011.8701.870Material NameColorUnit Weight(lbs/Ō3)Strength TypeCohesion(psf)Phi(deg)Water SurfaceRuUnweathered Glacial Till125Mohr‐Coulomb15040None0Silt110Mohr‐Coulomb75028Piezometric Line 110080604020020406080100120Analysis DescriptionCross Section C-C' - Post ConstructionCompanyTerra Associates, Inc. Scale1:174Drawn ByC. DeckerFile NameCross Section A-A' Geo.slmdDate2/19/2020, 9:57:24 AMProjectCanopySLIDEINTERPRET 8.029
1.3991.3991.3991.399Material NameColorUnit Weight(lbs/Ō3)Strength TypeCohesion(psf)Phi(deg)Water SurfaceRuUnweathered Glacial Till125Mohr‐Coulomb15040None0Silt110Mohr‐Coulomb75028None0 0.3150125100755025-60-40-20020406080100120140160Analysis DescriptionCross Section C-C' - Post Construction - SeismicCompanyTerra Associates, Inc. Scale1:291Drawn ByC. DeckerFile NameCross Section A-A' Geo.slmdDate2/19/2020, 9:57:24 AMProjectCanopySLIDEINTERPRET 8.029
CRITICAL AREAS STUDY & CONCEPTUAL
MITIGATION PLAN
FOR
BLUE FERN DEVELOPMENT – CANOPY
CITY OF RENTON, WA
Wetland Resources, Inc. Project #18158
Prepared By
Wetland Resources, Inc.
9505 19th Avenue SE, Suite 106
Everett, WA 98208
(425) 337-3174
Prepared For
Blue Fern Development, LLC
Attn: Evan Mann
11232 120th Ave NE, Suite 204
Renton, WA 98033
July 9, 2018
Revision #2 February 16, 2021
Revision #3: July 14, 2021
ii
THIS PAGE IS INTENTIONALLY LEFT BLANK
iii
TABLE OF CONTENTS
1.0 INTRODUCTION .........................................................................................................................1
1.1 SITE DESCRIPTION ..............................................................................................................................1
1.2 PROJECT DESCRIPTION ......................................................................................................................2
2.0 CRITICAL AREAS DETERMINATION REPORT ............................................................................3
2.1 PUBLICLY AVAILABLE DATA ...............................................................................................................3
2.2 WETLAND & STREAM DETERMINATION METHODOLOGY ...............................................................4
2.3 WETLAND & STREAM BOUNDARY DETERMINATION FINDINGS ......................................................5
3.0 GEOLOGIC HAZARDS .................................................................................................................8
4.0 WETLAND & STREAM BUFFER AVERAGING ...............................................................................9
4.1 STREAM BUFFER AVERAGING ............................................................................................................9
4.2 WETLAND BUFFER AVERAGING .......................................................................................................10
5.0 PROPOSED IMPACTS .................................................................................................................12
5.1 WETLAND IMPACTS ...........................................................................................................................12
5.2 BUFFER IMPACTS ...............................................................................................................................13
6.0 PROPOSED PEDESTRIAN TRAIL ................................................................................................14
7.0 MITIGATION SEQUENCING ......................................................................................................15
8.0 MITIGATION PLAN ...................................................................................................................17
8.1 WETLAND ENHANCEMENT ...............................................................................................................17
8.2 BUFFER ENHANCEMENT ...................................................................................................................18
9.0 FUNCTIONS AND VALUES ASSESSMENT ...................................................................................20
9.1 EXISTING WETLAND CONDITIONS ..................................................................................................21
9.2 POST CONSTRUCTION WETLAND FUNCTIONS AND VALUES .........................................................22
10.0 PROJECT NOTES .....................................................................................................................22
11.0 PLANTING NOTES ...................................................................................................................23
12.0 PROJECT MONITORING PROGRAM ........................................................................................26
12.1 REQUIREMENTS FOR MONITORING PROJECT: ..............................................................................26
12.2 MONITORING REPORT CONTENTS ...............................................................................................26
13.0 PROJECT SUCCESS & COMPLIANCE .......................................................................................27
13.1 CRITERIA FOR SUCCESS .................................................................................................................27
13.2 DEFINITION OF SUCCESS ................................................................................................................27
14.0 MAINTENANCE .......................................................................................................................28
15.0 CONTINGENCY PLAN .............................................................................................................29
16.0 FENCING & SIGNAGE ..............................................................................................................29
17.0 COST ESTIMATE & SURETY DEVICE ......................................................................................30
18.0 USE OF THIS REPORT ............................................................................................................31
19.0 REFERENCES ..........................................................................................................................14
iv
LIST OF FIGURES
FIGURE 1 - AERIAL VIEW OF THE SUBJECT PARCEL. .........................................................................1
LIST OF TABLES
TABLE 1 - SUMMARY OF STREAM S BUFFER WIDTH AVERAGING ..................................................10
TABLE 2 - SUMMARY OF WETLAND BUFFER WIDTH AVERAGING ...................................................11
LIST OF APPENDICES
APPENDIX A: U.S. CORPS OF ENGINEERS WETLAND DETERMINATION DATA FORMS
APPENDIX B: DEPARTMENT OF ECOLOGY WETLAND RATING FORMS
APPENDIX C: CRITICAL AREAS STUDY AND CONCEPTUAL MITIGATION MAPS (SHEETS 1-3/3)
APPENDIX D: SLOPE ANALYSIS FIGURES (SHEET 1/1)
Critical Area Study & Conceptual Mitigation Plan Wetland Resources, Inc. #18158
Blue Fern Development – Canopy 1 Revision 3: July 14, 2021
1.0 INTRODUCTION
Wetland Resources, Inc. (WRI) conducted site investigations on May 23 and 24, 2018 to locate
wetlands and streams on and in the vicinity of the investigation area, which is composed of five
King County tax parcels (3345700015, 3345700016, 3345700017, 3345700018, 3345700020).
The site is approximately 10.1-acres, located at and adjacent to 8314 110th Pl SE and 4130 Lincoln
Ave NE in the City of Renton, Washington (Section 32, Township 24N, Range 5E, W.M.). Access
is via a driveway from Lincoln Ave NE. The body of this report presents finding regarding the
wetlands and streams on-site. The Geotechnical Report included in Appendix E.
1.1 SITE DESCRIPTION
The investigation area is located within the May Creek sub-basin of the Cedar River/Lake
Washington Watershed (WRIA 8). Lake Washington is approximately 3,000 feet west of the
subject property. Surrounding land use is mixed, including residential, commercial, and industrial
uses; with I-405 approximately 1,100 feet to the west. The site is partially developed; in the south,
there are multiple single-family residences and associated infrastructure, while the northern portion
contains naturally vegetated pasture and forested areas. Topography slopes steeply to the west,
and, according to King County iMap, is underlain by high erosion hazard areas, with slopes in
excess of 20 percent.
- Aerial view of the subject parcel.
Four wetlands (Wetlands A through D) and one stream (Stream S) were identified within the
investigation area.
Critical Area Study & Conceptual Mitigation Plan Wetland Resources, Inc. #18158
Blue Fern Development – Canopy 2 Revision 3: July 14, 2021
Pursuant to Renton Municipal Code (RMC), on-site wetlands were classified under the Washington
State Wetland Rating System for Western Washington: 2014 Update (Hruby 2014). Wetlands A through D
are classified as Category IV wetlands. Per RMC (7)(a) Stream S was classified based on the WAC
222-16-030. As such, Stream S is classified as a Type Np Stream. Per 4-3-050(G)(2), Category IV
wetlands typically receive 50-foot buffers (when adjacent to non-low impact land uses) and Type
Np streams typically receive 75-foot buffers.
In addition, geological hazards were identified on-site by the geotechnical engineer, Terra Associates,
Inc. Geological hazards identified include protected slopes, high erosion hazard area, and low
seismic hazard area. Per RMC 4-3-050G(2), protected slopes require a 15 foot structure setback.
1.2 PROJECT DESCRIPTION
The applicant is proposing to develop a 56-lot residential development and associated
infrastructure. To accommodate this development, the applicant will do a combination of buffer
width averaging and wetland/buffer impacts, to be mitigated for on-site. As a result of required
frontage improvements and stormwater infrastructure, the applicant will permanently impact the
entirety of Wetland A (and a portion of an associated ditch), totaling 1,585 square feet, and a small
portion (240 square feet) of Wetland B’s buffer. In addition, the applicant will utilize buffer
averaging to accommodate the proposed development adjacent to Wetland B, Wetland D, and
Stream S.
As mitigation for the impacts, the applicant is proposing a combination of on-site and off-site
mitigation. A portion of the compensation (meeting City of Renton requirements) for Wetland A
impacts will be provided by enhancing the entirety of the on-site portions of Wetlands B and D
(totaling 4,865 square feet). This exceeds the 3:1 (enhancement to impact) ratio for Category IV
wetlands, per RMC 4-3-050(J)(4)(c).
The aforementioned impact to the buffer of Wetland B will be mitigated for via enhancement of
700 square feet of buffer located between Wetland B and Lincoln Ave NE (exceeding the 1:1
mitigation to impact ratio required by RMC 4-3-050(J)(4)(d)). To accommodate Stream S buffer
width averaging, the applicant proposes to enhance a 6,788 square feet of stream buffer, per RMC
4-3-050(I)(2)(b)(v).
As part of the proposed development the City of Renton is requiring an on-site and off-site trail to
connect the development to the City of Newcastle’s pedestrian trail located along the NE 43rd
Street right-of-way, north of the subject property. The off-site portion of the trail will be located
within the unopened right-of-way of 112th Avenue SE, that parallels the eastern property
boundary. The trail shall be 5 feet wide, with the majority consisting of wood chips underlain with
filter fabric, and will be field fit to avoid trees. The trail will cross portions of wetland, stream, and
buffer. Per RMC 4-3-050C(3) and RMC 4-3-050C(4), trails are exempt and allowed within critical
areas and their associated buffers as long as they meet certain requirements. The portion of trail
crossing the wetland will consist of a boardwalk and supported by pin piles. The slatted decking of
the boardwalk and grated top of the dock will allow precipitation to move through the structure.
This design minimizes impacts to the wetland and aquatic area and avoids any fill or grading within
the wetland. Disturbance within the wetland will be limited to vegetation impacted for boardwalk
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installation. This portion of the trail will impact approximately 134 square feet of vegetation
associated with Wetland D. To mitigate for any temporal loss of vegetation from installation of the
boardwalk, buffer enhancement of a portion of Wetland D’s on-site buffer is proposed at a 3:1
enhancement to impact ratio. The bridge proposed over Stream S will be approximately 6 feet
wide and will consist of concrete slabs and metal railings. The crossing will be consistent with
WDFW stream crossing guidelines.
2.0 CRITICAL AREAS DETERMINATION REPORT
2.1 PUBLICLY AVAILABLE DATA
Prior to conducting the site investigation, public resource information was reviewed to gather
background information on the subject parcels and the surrounding area in regards to wetlands,
streams, and other critical areas. These sources included the following:
• USDA/NRCS Web Soil Survey shows 2 soil units underlying the subject property: Ragnar-
Indianola association, (moderately steep, sloping) and Alderwood gravelly sandy loam (8-
15 percent slopes, 15-30 percent slopes).
• WDFW SalmonScape Interactive Mapping System does not show any hydrologic features on the
subject property. The closest mapped feature is May Creek, shown approximately 1,500
feet to the west.
• USFWS National Wetlands Inventory (NWI) does not show any features on the subject property.
The closest mapped feature is May Creek, shown in the same location shown by
SalmonScape.
• WDFW Priority Habitat and Species (PHS) Interactive Map does not show any priority species or
habitats on the subject parcel or in the near vicinity.
• King County iMap shows steep slopes encumbering the majority of the subject properties. No
other critical areas are mapped on-site. May Creek is shown approximately 1,800 feet off-
site to the south.
• City of Renton Maps of Your Community (CRM) shows a wetland in the central region of the
subject property, as well as an unnamed, Type F stream off-site to the north of the subject
property (originating in the mapped wetland). A stormwater ditch is mapped in
approximately the same location as Stream S. It appears that this stormwater ditch (Stream
S) originates off-site, west of the development located near the intersection of SE 80th St
and 115th Ave SE. The stormwater ditch (Stream S) then flows through the mapped
wetland, eventually meeting the off-site Type F stream. Off-site, multiple wetlands are
shown to the west of Lincoln Ave NE and May Creek is mapped over 1,000 feet to the west
of the site.
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2.2 WETLAND & STREAM DETERMINATION METHODOLOGY
The OHWM of streams in the investigation area were identified using the methodologies described
in the Washington State Department of Ecology (DOE), Determining the Ordinary High Water Mark for
Shoreline Management Act Compliance in Washington State (Anderson et al. 2016). The Washington State
Shoreline Management Act (SMA) defines ordinary high water mark as,
“…that mark that will be found by examining the bed and banks and ascertaining where the presence and
action of waters are so common and usual, and so long continued in all ordinary years, as to mark upon the
soil a character distinct from that of the abutting upland, in respect to vegetation as that condition exists on
June 1, 1971, as it may naturally change thereafter, or as it may change thereafter in accordance with
permits issued by a local government or the department: PROVIDED, that in any area where the ordinary
high water mark cannot be found, the ordinary high water mark adjoining salt water shall be the line of
mean higher high tide and the ordinary high water mark adjoining fresh water shall be the line of mean high
water.”
Wetland boundaries were determined using the routine approach described in the Corps of
Engineers Wetlands Delineation Manual (Environmental Laboratory 1987) and the Regional
Supplement to the Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys,
and Coast Region (Version 2.0) (U.S. Army Corps of Engineers 2010). Under the routine
methodology, the process for making a wetland determination is based on three steps:
1.) Examination of the site for hydrophytic vegetation (species present and percent cover);
2.) Examination of the site for hydric soils;
3.) Determining the presence of wetland hydrology
The following criteria must be met in order to make a positive wetland determination:
2.2.1 Hydrophytic Vegetation Criteria
The Corps Manual and 2010 Regional Supplement define hydrophytic vegetation as “the
assemblage of macrophytes that occurs in areas where inundation or soil saturation is either
permanent or of sufficient frequency and duration to influence plant occurrence.” Field indicators
are used to determine whether the hydrophytic vegetation criteria have been met. Examples of
these indicators include, but are not limited to, the rapid test for hydrophytic vegetation, a
dominance test result of greater than 50%, and/or a prevalence index score less than or equal to
3.0.
2.2.2 Soils Criteria and Mapped Description
The 2010 Regional Supplement (per the National Technical Committee for Hydric Soils) defines
hydric soils as soils “that formed under conditions of saturation, flooding, or ponding long enough
during the growing season to develop anaerobic conditions in the upper part.” Field indicators are
used to determine whether a given soil meets the definition for hydric soils. Indicators are
numerous and include, but are not limited to, presence of a histosol or histic epipedon, a sandy
gleyed matrix, depleted matrix, and redoximorphic depressions.
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According to the NRCS Web Soil Survey, 2 soil map units are predicted to occur on the subject
property: Ragnar-Indianola association (moderately steep, sloping) and Alderwood gravelly sandy
loam (8-15, 15-30 percent slopes).
Ragnar-Indianola series (moderately steep, sloping) is described as moderately well drained
on outwash plains. The surface layer is typically a dark brown fine sandy loam about two inches
thick. The upper part of the subsoil is dark brown and brown sandy loam about 22 inches thick.
Included in this unit are areas of Everett, Indianola, Pastik and Wilson soils on terraces and
outwash plains. Other small inclusions may be areas of Everett, Indianola, and Ragnar soils on
terraces and outwash plains.
Alderwood Gravelly Sandy Loam (8-15 percent slopes, 15-30 percent slopes), is described as
a moderately well drained soil on till plains. It is moderately deep over a hardpan. This soil formed
in glacial till. Typically, the surface layer is very dark grayish brown gravelly sandy loam about 7
inches thick. The upper part of the subsoil is dark yellowish brown and dark brown very gravelly
sandy loam about 23 inches thick. Included in this unit are small areas of soils that have a stony
or bouldery surface layer and areas of McKenna soils, Norma soils, and Terric Medisaprists in
drainageways on plains. Also included are small areas of Everett, Indianola, and Ragnar soils on
terraces and outwash plains. Included areas make up about 15 percent of the total acreage.
Permeability of this soil is moderately rapid above the hardpan and very slow through it. Available
water capacity is low.
2.2.3 Hydrology Criteria
The 2010 Regional Supplement defines wetland hydrology as “areas that are inundated (flooded
or ponded) or the water table is less than or equal to 12 inches below the soil surface for 14 or more
consecutive days during the growing season at a minimum frequency of 5 years in 10.” During the
early growing season, wetland hydrology determinations are made based on physical observation
of surface water, a high water table, or saturation in the upper 12 inches. Outside of the early
growing season, wetland hydrology determinations are made based on physical evidence of recent
inundation or saturation (i.e. water marks, surface soil cracks, water-stained leaves).
2.3 WETLAND & STREAM BOUNDARY DETERMINATION FINDINGS
2.3.1 Wetland A
Cowardin Classification: Palustrine, Forested, Broad-leaved Deciduous, Saturated Only.
City of Renton Classification: Category IV (low wildlife function)
City of Renton Buffer: 50-feet
Wetland A is a slope wetland located in the northwestern corner of the investigation area, along
the western boundary of the subject property. Dominant vegetation within the wetland includes:
red alder (Alnus rubra; FAC), Himalayan blackberry (Rubus armeniacus; FAC), and reed canarygrass
(Phalaris arundinacea; FACW). The majority of the dominant species rate “facultative” or wetter,
indicating that a hydrophytic vegetative community is present. Typical soils in Wetland A
extending from 0 to 16 inches below the surface are generally a black (7.5YR 2.5/1) with a loam
texture. At the time of the May 2018 investigation, soils were saturated to the surface with a water
table observed at 9 inches below the soil surface. In addition, secondary indicators of wetland
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hydrology Geomorphic Position (D2) and FAC-Neutral Test (D5) were observed. Despite the lack
of visible indicators, the soils within Wetland A are considered hydric due to presence of
hydrophytic plant community and strong presence of hydrology, and it is possible that the soils
meet the Thick Dark Surface (A12) indicator. This determination is based on best professional
judgment.
Given the hydrophytic community, hydric soils, and presence of hydrology, the area mapped as
off-site Wetland A meets the criteria for a wetland.
Wetland A is associated with a ditch that does not meet the characteristics of a stream, per WAC
222-16-030, as it lacks a defined bed or bank and is densely vegetated by reed canarygrass. The
originates within Wetland A, traveling off-site (south to north), east of Lincoln Ave NE. It is
conveyed beneath Lincoln Ave NE to the west via a culvert (WDFW Site ID #934106).
2.3.2 Wetland B
Cowardin Classification: Palustrine, Forested, Broad-leaved Deciduous, Saturated.
City of Renton Classification: Category IV (low wildlife function)
City of Renton Buffer: 50-feet
Wetland B is a slope wetland located in the west-central region of the investigation area, along the
western boundary of the subject property. Dominant vegetation within the wetland includes: red
alder (Alnus rubra; FAC), black cottonwood (Populus balsamifera; FAC) Himalayan blackberry (Rubus
armeniacus; FAC), giant horsetail (Equisetum telmateia; FACW), and lady fern (Athyrium filix-femina;
FAC). The majority of the dominant species rate “facultative” or wetter, indicating that a
hydrophytic vegetative community is present. Within the wetland, from 0 to 8 inches below the
surface, soils are generally a black (10YR 2/1) and a sandy loam texture. The sublayer is a very
dark gray (10YR 3/1) with dark yellowish brown (10YR 4/4) redoximorphic features and a sandy
loam texture. These soils meet the Redox Dark Surface (F6) hydric soil indicator. At the time of
the May 2018 investigation, soils were saturated at 9 inches below the soil surface. Secondary
indicator of wetland hydrology, Geomorphic Position (D2), was also observed.
Given the hydrophytic community, hydric soils, and presence of hydrology, the area mapped as
off-site Wetland B meets the criteria for a wetland.
2.3.3 Wetland C
Cowardin Classification: Palustrine, Scrub-Shrub, Broad-leaved Deciduous, Saturated.
City of Renton Classification: Category IV (moderate wildlife function)
City of Renton Buffer: 50-feet
Wetland C is a slope wetland located in the northeastern corner of the investigation area and
associated with Stream S (Type Np). Dominant vegetation within the wetland includes: Himalayan
blackberry (Rubus armeniacus; FAC), salmonberry (Rubus spectabilis; FAC), skunk cabbage (Lysichton
americanus; OBL), and giant horsetail (Equisetum telmateia; FACW). The majority of the dominant
species rate “facultative” or wetter, indicating that a hydrophytic vegetative community is present.
Within the wetland, from 0 to 9 inches below the surface, soils are generally a very dark gray (2.5Y
3/1) and a sandy loam texture. The sublayer is a black (Gley 1 4/N) with olive brown (2.5Y 4/4)
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redoximorphic features and a sandy loam texture. These soils meet the Depleted Below Dark
Surface (A11) and Loamy Gleyed Matrix (F2) hydric soil indicators. At the time of the May 2018
investigation, soils were saturated to the surface with a water table visible at 9 inches below the soil
surface. Secondary indicator of wetland hydrology, FAC-Neutral Test (D5), was also observed.
Given the hydrophytic community, hydric soils, and presence of hydrology, the area mapped as
off-site Wetland C meets the criteria for a wetland.
2.3.4 Wetland D
Cowardin Classification: Palustrine, Scrub-Shrub, Broad-leaved Deciduous, Saturated Only.
City of Renton Classification: Category IV (low wildlife function)
City of Renton Buffer: 50-feet
Wetland D is a slope wetland located in the east-central region of the investigation area, along the
eastern boundary. Wetland D extends off-site to the east. Dominant vegetation within the wetland
includes: red alder (Alnus rubra; FAC), a variety of prunus (Prunus sp.), Himalayan blackberry (Rubus
armeniacus; FAC), Sitka willow (Salix sitchensis; FACW), and fowl manna grass (Glyceria striata;
OBL). The majority of the dominant species rate “facultative” or wetter, indicating that a
hydrophytic vegetative community is present. Within the wetland, from 0 to 8 inches below the
surface, soils are generally a very dark brown (10YR 2/2) and a clay loam texture. From 8 to 11
inches, soils are a very dark grayish brown (10YR 3/2) with very dark brown (7.5YR 2.5/3)
redoximorphic features and a clay loam texture. The bottommost layer sampled, from 11 to 17
inches depth, is a dark grayish brown (10YR 4/2) with very dark brown (7.5YR 2.5/3)
redoximorphic features and a clay loam texture. These soils meet the Depleted Below Dark Surface
(A11) hydric soil indicator. At the time of the May 2018 investigation, soils were saturated at 8
inches below the soil surface. In addition, secondary indicator, FAC-neutral Test (D5), was
observed.
Given the hydrophytic community, hydric soils, and presence of hydrology, the area mapped as
off-site Wetland D meets the criteria for a wetland.
2.3.5 Non-wetland Areas
In non-wetland areas, vegetation includes: red alder (Alnus rubra; FAC), bigleaf maple (Acer
macrophyllum; FACU), beaked hazelnut (Corylus cornuta; FACU), Himalayan blackberry (Rubus
armeniacus; FAC), English holly (Ilex aquifolium; FACU), bracken fern (Pteridium aquilinum), giant
horsetail (Equisetum telmateia; FACW), reed canarygrass (Phalaris arundinacea; FACW), and sword fern
(Polystichum munitum; FACU). Typical soils from soils in areas mapped as upland were a very dark
brown (10YR 3/2) with a sandy loam texture in the upper layer. In the sublayer, soils were
generally dark brown to dark yellowish brown (10YR 3/3, 10YR 4/3) and a sandy loam texture.
Soils in area mapped as non-wetland were dry at the time of the May 2018 site investigation. This
typical soil profile does not meet any hydric soil indicators.
No hydrological indicators were observed in the non-wetland areas adjacent to the on-site
wetlands. Given the lack of a hydrophytic vegetation community, wetland hydrology, and hydric
soils, the areas mapped as non-wetland do not meet the criteria for wetlands.
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2.3.6 Stream S
Cowardin Classification: Riverine, Upper Perennial, Unconsolidated Bottom, Cobble-Gravel.
City of Renton Classification: Type Np
City of Renton Buffer: 75-feet
Stream S is located in the northeastern region of the investigation area, associated with Wetland
C. At the time of the May 2018 site investigation, Stream S was flowing, had an average width
greater than 2 feet, and exhibited bed and bank characteristics. Based on precipitation preceding
the site investigations, WRI believes that Stream S is a perennial feature.
Stream S originates off-site to the east of the subject property and is mapped as a stormwater ditch.
City of Renton Maps of Your Community (CRM) shows Stream S starting west of the residential
development located around the intersection of SE 80th St and 115th Ave SE. Once on-site, Stream
S flows northeast to southwest, exiting the subject property to the north, where it meets an
unnamed, Type F stream. This Type F stream travels east to west, both aboveground and via
multiple pipes, until discharging to Lake Washington (known fish/salmonid habitat). Salmonscape
indicates that a total fish passage barrier (dam) exists between the aforementioned Type F stream
and Lincoln Ave NE, on King County Tax Identification Parcel 3345700005.
CRM indicates that Stream S is underlain by high erosion hazard area (soils having severe erosion
potential and slope greater than 15 percent). WRI’s slope analysis (see Appendix D) shows that
multiple segments of Stream S (downstream of Wetland C) flow down steep slopes (greater than 20
percent).
Based on information gathered from publicly available resources, on-site observations, and WRI’s
slope analysis, WRI concludes that Stream S is a perennial feature that does not contain fish or fish
habitat. As such, Stream S is classified as a Type Np stream, consistent with RMC and WAC 222-
16-030. Please see Appendix D for further stream typing justification. This determination was
confirmed by WDFW.
3.0 GEOLOGIC HAZARDS
A Geotechnical Report has been provided by Terra Associates, Inc. (TAI), dated March 29, 2019.
This report indicates that the project site contains protected slopes (requiring a 15-foot structure
setback), moderate to severe potential erosion hazard areas (to be prevented and controlled using
Best Management Practices (BMPs)), high landslide hazard (LH) areas (deemed not at risk of a
deep-seated failure in its current state). Additionally, TAI has classified the site as a Low Seismic
Hazard (SL) per RMC. TAI maintains that, “there are no geotechnical conditions that would preclude the
planned development.”
Please see the Geotechnical Report (included as a part of this submittal package), by TAI, for
detailed information regarding these recommendations, which include a 15-foot building setback
from protected slopes, as designated by RMC 4-3-050(G)(2).
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4.0 WETLAND & STREAM BUFFER AVERAGING
4.1 STREAM BUFFER AVERAGING
The applicant proposes utilization of stream buffer width averaging to accommodate Lots 48-49
and grading associated with the proposed access road. The area buffer reduction totals 2,635
square feet, resulting in a minimum buffer width of 52 feet. A buffer addition area of 2,695 square
feet (~1:1 addition to reduction ratio) is proposed east of the reduction area. Per RMC 4-3-
050(I)(2)(b)(v), the applicant will enhance 6,788 square feet of stream buffer that is currently
composed of Himalayan blackberry and an old road grade.
RMC 4-3-050(I)(2)(b) states that stream buffer width averaging may be allowed when the applicant
demonstrates the following criteria. All RMC citations relevant to stream buffer width averaging
criteria are presented below in italics, followed by applicant responses in standard text.
i. There are existing physical improvements in or near the water body and associated riparian area; and
An existing dam and multiple downstream culverts are located within Stream S, downstream of
the subject site. In addition, multiple disturbances are present within the buffer of the stream,
including: maintained landscaping, structures, roads and driveway. The dam and culverts within
the stream channel as well and the disturbances within the buffer represent existing physical
improvement within the waterbody. Thus, stream buffer averaging is allowed.
ii. Buffer width averaging will result in no net loss of stream/lake/riparian ecological function; and
Along with providing higher quality buffer area, the proposed stream buffer averaging plan will
result in a 60 square foot net gain of buffer area and will include enhancement of 6,788 square feet
of buffer. The proposed plan will improve the functions and values of the stream buffer because
over time, the buffer area currently overrun by Himalayan blackberry, grasses, and road grade will
progress to a native scrub-shrub and eventually forested condition. The installed enhancement
plantings will provide replacement forage and cover opportunities for wildlife, as well as protection
from erosion, and sequestration of excess sediments and nutrients. Furthermore, a structurally
diverse plant community will slow the rate of overland flow.
iii. The total area contained within the buffer after averaging is no less than that contained within the
required standard buffer width prior to averaging; and
The proposed stream buffer width averaging plan will result in a net gain of 60 square feet of
wetland buffer area. See summary of buffer width averaging below:
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Critical Area Buffer Reduction
(SF)
Buffer Addition
(SF)
Net Gain in Buffer Area
(SF)
Stream S 2,635 2,695 60
Total: 60
Table 1 - Summary of Stream S buffer width averaging
iv. The proposed buffer standard is based on consideration of the best available science as described in
WAC 365-195-905; and
Best available science indicates that the functions provided by wetland and stream buffers are:
removing sediment, excess nutrients, and toxics from surface water, influencing the microclimate,
maintaining adjacent habitat critical for the life needs of many species that use wetlands, screening
adjacent disturbances, and maintaining habitat connectivity (Sheldon, et al. 2005).
Stream S is a Type Np stream, that lacks fish habitat. As such the buffer area surrounding Stream
S is not critical in providing resources for salmonids/fish. However, Stream S does contribute to
Lake Washington (which contains salmonids) downstream, thus maintaining this features water
quality contributes to health of aquatic life downstream.
Given the increase of 60 square feet in overall buffer area, in combination with the limited
reduction in overall width (the buffer width will be reduced by a maximum of 23 feet), and the
associated stream buffer enhancement (see response to 4-3-050(I)(2)(b)(v) below), the proposed
buffer width averaging plan is expected to deliver a modest lift in the functions and values of the
on-site buffer. In addition, buffer width averaging of Stream S, in combination with Wetland D
buffer width averaging, will result in habitat connectivity between Stream S, Wetland C, and
Wetland D, which previously did not exist. This habitat connectivity is to be protected in
perpetuity.
v. Where the buffer width is reduced by averaging pursuant to this subsection, buffer enhancement shall be
required.
The applicant will enhance 6,788 square feet of stream buffer that is currently composed of
Himalayan blackberry and an old road grade (covered by grasses). Enhancement will involve
removing all invasive/non-native species from this area, soil decompaction and amendment as
necessary, and the planting of native trees and shrubs. Please see Section 9.3.2, Stream S Buffer
Enhancement Plan, for more details.
4.2 WETLAND BUFFER AVERAGING
The buffers of Wetlands B and D will be averaged in order to accommodate Lot 7 and Lots 43-
44, respectively. The Wetland B buffer reduction totals 1,032 square feet, resulting in a minimum
buffer width of 37.5 feet (75 percent of the standard 50-foot buffer). A buffer addition area of 1,092
square feet (1.05:1 buffer addition to reduction ratio) is proposed southeast of the reduction area.
The Wetland D buffer reduction totals 2,095 square feet, resulting in a minimum buffer width of
37.5-feet (75 percent of the standard 50-foot buffer). A buffer addition area of 2,305 square feet
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(1.1:1 addition to reduction ratio) is proposed north and south of the reduction area, resulting in a
contiguous vegetated corridor between Stream S, Wetland C, and Wetland D, to be protected in
perpetuity.
Critical
Area
Buffer
Reduction (SF)
Buffer
Addition (SF)
Net Gain in Buffer
Area (SF)
Mitigation
to Impact
Ratio
Wetland B 1,032 1,092 60 1.05:1
Wetland D 2,095 2,305 210 1.1:1
Total: 270
Table 2 - Summary of wetland buffer width averaging
Per RMC 4-3-050(I)(3)(b), wetland buffer width averaging may be allowed when the applicant
demonstrates the following criteria. All RMC citations relevant to wetland buffer width averaging
criteria are presented below in italics, followed by applicant responses in standard text.
i. There are existing physical improvements in or near the wetland and buffer; and
Lincoln Ave NE and its associated right of way (ROW) is located immediately adjacent to Wetland
B. This maintained city road and ROW is a clear existing physical improvement immediately
adjacent to the wetland. Thus, wetland buffer averaging is allowed.
ii. That buffer width averaging will not adversely impact the wetland function and values; and
The buffer reduction areas of Wetlands B and D are composed of forested and scrub-shrub
vegetation. Similarly, the areas proposed for buffer addition are also composed of forested and
scrub-shrub vegetation. Therefore, direct compensation of functions and values will be addressed
by providing additional buffer of a similar composition to the reduction areas at a >1:1 buffer
addition to reduction ratio. No impacts to existing functions and values of the wetland areas are
expected to occur because of the proposed buffer averaging activity.
iii. That the total area contained within the wetland buffer after averaging is no less than that contained
within the required standard buffer prior to averaging; and
The wetland buffer width averaging plan will result in a net gain of 270 square feet of wetland
buffer area (see Table 2, above).
iv. A site-specific evaluation and documentation of buffer adequacy based upon Wetlands in Washington
State, Volume 1: A Synthesis of the Science (Ecology Publication No. 05-06-006, March 2005) and
Wetlands in Washington State, Volume 2: Managing and Protecting Wetlands (Ecology Publication
No. 04-06-008, April 2005), or similar approaches have been conducted. The proposed buffer
standard is based on consideration of the best available science as described in WAC 365-195-905; and
Best available science indicates that the functions provided by wetland and stream buffers are:
removing sediment, excess nutrients, and toxics from surface water, influencing the microclimate,
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maintaining adjacent habitat critical for the life needs of many species that use wetlands, screening
adjacent disturbances, and maintaining habitat connectivity (Sheldon, et al. 2005).
Considering the areas of buffer addition are of the similar species composition to the areas of
reduction and that the buffer width averaging plan will result in a net gain of 270 square feet of
buffer, the proposed buffer averaging activity is expected to deliver a modest lift in the functions
and values of the on-site buffer. In addition, buffer width averaging of Wetland D, in combination
with Stream S buffer width averaging, will result in habitat connectivity between Stream S,
Wetland C, and Wetland D, which previously did not exist. This habitat connectivity is to be
protected in perpetuity.
v. In no instance shall the buffer width be reduced by more than seventy five percent (75%) of the standard
buffer. Greater buffer width reductions require review as a variance pursuant to RMC 4-9-250B; and
In no instance are the buffers of Wetlands B and D reduced by more than 75 percent (37.5-feet) of
the standard buffer (50-feet) as a result of buffer averaging.
vi. Buffer enhancement in the areas where the buffer is reduced shall be required on a case-by-case basis
where appropriate to site conditions, wetland sensitivity, and proposed land development characteristics.
Given the existing condition of the buffer, no buffer enhancement is proposed as a part of the
proposed wetland buffer width averaging plan.
5.0 PROPOSED IMPACTS
5.1 WETLAND IMPACTS
Required frontage improvements create the need to fill of 797 square feet of Wetland A, which is
approximately 50 percent of the wetland. Based on site restrictions, including frontage
improvements, access, on-site wetlands and streams, and topography, the northwest corner of the
site is most suitable to locate stormwater facilities. Given this, the applicant is proposing to fill the
entirety of Wetland A (1,585 square feet). Per RMC 4-3-050(J)(4), wetland alterations may only be
authorized after the City makes a written finding that the proposal is consistent with the following
criteria. RMC wetland alteration criteria are presented below in italics, followed by applicant
responses in standard text.
a. No Net Loss: Activities that adversely affect wetlands and/or wetland buffers shall include mitigation
sufficient to achieve no net loss of wetland function and acreage and to achieve, where practicable, a net
resource gain in wetlands over present conditions. The concept of “no net loss” means to create, restore
and/or enhance a wetland so that there is no reduction to total wetland acreage and/or function.
Mitigation for the fill of Wetland A will be provided through on-site wetland enhancement of
Wetlands B and D, provided at a >3:1 mitigation to impact ratio. The proposed wetland
enhancement plan will increase diversity and density of native plants within Wetlands B and D,
while providing increased opportunities for wildlife habitat. The proposed enhancement plan will
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allow the remaining on-site wetlands and buffer area to provide a greater level of functions and
values post development than they currently provide.
b. Compensation for wetland alternations shall occur in the following order of preference:
i. Re-establishing wetlands on upland sites that were formerly wetlands.
Based on publicly available resources, aerial imagery, and the site investigations, it does not appear
that the subject property contains upland area that was formerly wetland.
ii. Rehabilitating wetlands for the purposes of repairing or restoring natural and/or historic functions.
Based on publicly available resources, aerial imagery, and the site investigations, it does not appear
that rehabilitation to natural and/or historic functions applies to wetlands on-site.
iii. Creating wetlands on disturbed upland sites such as those consisting primarily of nonnative, invasive
plant species.
The majority of the subject property is situated on a slope; thus, it would be difficult for wetland
creation to be successful due to hydrologic input requirements.
iv. Enhancing significantly degraded wetlands.
Wetlands B and D can be enhanced, as they are composed of a mix of native and non-native
species, including Himalayan blackberry (Rubus armeniacus), English ivy (Hedera helix), and reed
canarygrass (Phalaris arundinacea).
v. Preserving Category I or II wetlands that are under imminent threat; provided, that preservation shall
only be allowed in combination with other forms of mitigation and when the Administrator determines
that the overall mitigation package fully replaces the functions and values lost due to development.
No Category I or II wetlands exist on-site. The on-site wetlands (Wetlands A-D) are Category IV
wetlands.
vi. Cooperative compensation to mitigation banks or in-lieu fee programs, as indicated in subsection G9e
of this Section.
Not applicable. Compensatory mitigation for the proposed impacts will be provided on-site via the
enhancement of Wetlands B and D.
5.2 BUFFER IMPACTS
The applicant proposes minor impacts, totaling 240 square feet, to the buffer of Wetland B due to
required frontage improvements. Per RMC 4-3-050(C)(3)(e)(iii), Utilities, Traffic Control, Walkways,
Bikeways Within Existing, Improved Right-of-Way or easements, are exempt activities within wetlands and
wetland buffer. The proposed impacts are located within an existing improved right-of-way and
are therefore allowed. The applicant will mitigate via enhancement of a 700 square feet of Wetland
B buffer (~3:1 mitigation to impact ratio), abutting Lincoln Ave NE. This is consistent with RMC
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4-3-050(J)(4)(d), which states, compensation for wetland buffer impacts shall occur at a minimum one to one
(1:1) ratio. Please see Section 8 for mitigation plan details.
6.0 PROPOSED PEDESTRIAN TRAIL
The City of Renton is requiring a trail connection between the proposed development and the
City of Newcastle’s pedestrian trail located along the right-of-way of NE 43rd Street. Trails through
critical areas and their associated buffers are exempt per RMC 4-3-050C(3) and 4-3-050C(4), as
long as they meet specific requirements and provided a letter of exemption has been issued. RMC
requirements are presented below in italics, followed by applicant responses in standard text.
RMC 4-3-050C(3) Footnote #14:
Normal and routine maintenance, operation and repair of existing parks, trails, streets, roads, rights-of-way and
associated appurtenances, facilities and utilities where no alteration or additional fill materials will be placed other
than the minimum alteration and/or fill needed to restore those facilities or to construct new trails to meet established
safety standards. The use of heavy construction equipment shall be limited to utilities and public agencies that require
this type of equipment for normal and routine maintenance and repair of existing utility structures and rights-of-way.
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.
Impacts to critical areas will be minimized to the furthest extent possible when installing the new
trail. Any disturbed critical areas outside of the proposed mitigation plan will be restored to pre-
construction conditions immediately after installation.
RMC 4-3-050C(4) Footnote #1:
1.Walkways and trails, and associated open space in critical area buffers located on public property, or where
easements or agreements have been granted for such purposes on private property. All of the following criteria shall be
met:
a. The trail, walkway, and associated open space shall be consistent with the Parks, Recreation, and Natural
Areas Plan. The City may allow private trails as part of the approval of a site plan, subdivision or other land
use permit approvals.
The on-site and off-site trail is a requirement of the City of Renton and will connect to the
City of Newcastle’s pedestrian trail located along NE 43rd Street right-of-way.
b. Trails and walkways shall be located in the outer twenty five percent (25%) of the buffer, i.e., the portion
of the buffer that is farther away from the critical area. Exceptions to this requirement may be made for:
i. Trail segments connecting to existing trails where an alternate alignment is not practical.
ii. Public access points to water bodies spaced periodically along the trail.
Due to constraints within the right-of-way and connection to an existing trail, the trail
alignment cannot be located within the outside 25% of the buffer and has to cross a portion
of Wetland D and Stream S.
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c. Enhancement of the buffer area is required where trails are located in the buffer. Where enhancement of the
buffer area abutting a trail is not feasible due to existing high quality vegetation, additional buffer area or other
mitigation may be required.
Enhancement of a portion of Wetland D (1,356 square feet) and Stream S’s buffer (781 square
feet) is proposed on-site. Enhancement abutting the trail is not feasible due to the location of
the trail within the right-of-way.
d. Trail widths shall be a maximum width of twelve feet (12'). Trails shall be constructed of permeable
materials which protect water quality, allow adequate surface water and ground water movements, do not
contribute to erosion, are located where they do not disturb nesting, breeding, and rearing areas, and designed
to avoid or reduce the removal of trees. Impervious materials may be allowed if pavement is required for
handicapped or emergency access, or safety, or is a designated nonmotorized transportation route or makes a
connection to an already dedicated trail, or reduces potential for other environmental impacts.
The off-site portion of the trail that crosses wetland, stream, and buffer will be 5 feet wide.
The portions of the trail through buffer will consist of wood chips underlain with filter fabric
and will be field fit to avoid trees. The portion of trail crossing the wetland will consist of a
boardwalk and supported by pin piles. The slatted decking of the boardwalk and grated top
of the dock will allow precipitation to move through the structure. This design minimizes
impacts to the wetland and aquatic area and avoids any fill or grading within the wetland.
The proposed bridge crossing Stream S will be 6 feet wide, include concrete decking, and
meets WDFW stream crossing guidelines.
e. Any crossing over a stream or wetland shall be generally perpendicular to the critical area and shall be
accomplished by bridging or other technique designed to minimize critical area disturbance. It shall also be the
minimum width necessary to accommodate the intended function or objective.
Both the stream and wetland crossing structures have been designed to minimize impacts to
critical areas to the furthest extent possible. The wetland crossing will be located over the
shortest distance of wetland possible given the right-of-way constraints. The stream crossing
will be perpendicular to Stream S.
7.0 MITIGATION SEQUENCING
The applicant is proposing to fill the entirety of Wetland A in order to accommodate frontage
improvements and the proposed stormwater infrastructure. RMC 4-3-050(L)(1)(b) posits that, “If
alterations to critical areas are proposed for a non-exempt activity, the applicant shall evaluate alternative methods of
developing the property using the following criteria in this order and provide reasons why a less intrusive method of
development is not feasible. In determining whether to grant permit approval pursuant to RMC 4-3-050C, a
determination shall be made as to whether the feasibility of less intrusive methods of development has been adequately
evaluated and that less intrusive methods of development are not feasible.”
RMC 4-3-050(L)(1)(b)(i)-(vii) mitigation sequencing provisions are presented below in italics,
followed by applicant responses in standard text.
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i. Avoiding the impact altogether by not taking a certain action or parts of an action (usually by
either finding another site or changing the location on the site).
Required frontage improvements create the need to fill of 797 square feet of Wetland A, which is
approximately 50 percent of the wetland. Based on site restrictions, including frontage
improvements, access, on-site wetlands and streams, and topography, the northwest corner of the
site is most suitable to locate stormwater facilities. Given this, the applicant is proposing to fill the
entirety of Wetland A (1,585 square feet).
ii. Minimizing adverse impacts by limiting the magnitude of the action and its implementation,
by using appropriate technology, or by taking affirmative steps, such as project redesign,
relocation, or timing, to avoid or reduce impacts.
Other than the proposed permanent impacts to Wetland A and minor impacts to Wetland B (both
to be mitigated for on-site), no other impacts to critical areas on-site are proposed.
iii. Rectifying adverse impacts to wetlands, Wellhead Protection Areas, flood hazard areas, and
habitat conservation areas by repairing, rehabilitating, or restoring the affected environment to
the historical conditions or the conditions existing at the time of the initiation of the project.
Mitigation for the fill of Wetland A will be provided through on-site wetland enhancement,
provided at a >3:1 mitigation to impact ratio.
iv. Minimizing or eliminating the hazard by restoring or stabilizing the hazard area through
engineered or other methods.
Best Management Practices (BMPs), and temporary erosion and sediment control (TESC) plans,
and retaining walls will be utilized to minimize the risks associated with steep slope hazard areas
on-site.
v. Reducing or eliminating the adverse impacts or hazard over time by preservation and
maintenance operations over the life of the action.
See response to 4-3-050(L)(1)(b)(iv), above.
vi. Compensating for adverse impacts to wetlands, Wellhead Protection Areas, flood hazard areas,
and habitat conservation areas by replacing, enhancing, or providing substitute resources or
environments.
See response to 4-3-050(L)(1)(b)(iii), above.
vii. Monitoring the hazard or other required mitigation and taking remedial action when necessary.
Not applicable.
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8.0 MITIGATION PLAN
8.1 WETLAND ENHANCEMENT
Due to required frontage improvements and stormwater infrastructure, the applicant is proposing
to fill the entirety of Wetland A (1,585 square feet). Mitigation for the fill of Wetland A will be
provided through on-site wetland enhancement of Wetlands B and D, totaling 4,865 square feet.
The proposed wetland enhancement plantings and large woody debris will increase diversity and
density of native plants within Wetlands B and D, while providing increased opportunities for
wildlife habitat.
8.1.1 Wetland B Enhancement Plan
Prior to planting, invasive woody species including (but not limited to) Himalayan blackberry
(Rubus armeniacus), English holly (Ilex aquifolium), and English ivy (Hedera helix) will be removed from
the wetland. Any existing native plants within the wetlands shall be retained and protected. Only
shrubs will be planted within Wetland B, as a dense native overstory and moderate native
understory currently exist. In order to provide dense vegetative cover to compete with potentially
encroaching Himalayan blackberry (Rubus armeniacus), spacing of shrubs is at 5 feet on-center. This
will allow the thicket forming species (twinberry, rose, and salmonberry) to outcompete non-native
species.
Wetland B Enhancement Plan (1,765 square feet)
Common Name Latin Name Size Spacing Quantity
Twinberry Lonicera involucrata 1 gallon 5’ 12
Pacific ninebark Physocarpus capitatus 1 gallon 5’ 12
Red-osier dogwood Cornus sericea 1 gallon 5’ 12
Nootka rose Rosa nutkana 1 gallon 5’ 12
Salmonberry Rubus spectabilis 1 gallon 5’ 12
8.1.2 Wetland D Enhancement Plan
Prior to planting, invasive woody species including (but not limited to) Himalayan blackberry
(Rubus armeniacus) will be removed from the wetland. Any existing native plants within the wetlands
shall be retained and protected. In order to provide dense vegetative cover to compete with
potentially encroaching Himalayan blackberry (Rubus armeniacus), spacing trees at 10 feet on-center
and shrubs at 5 feet on-center. This will allow the thicket forming species (twinberry, rose, and
salmonberry) to outcompete non-native species.
Wetland D Enhancement Plan (3,100 square feet)
Common Name Latin Name Size Spacing Quantity
Sitka spruce Picea sitchensis 1 gallon 10’ 15
Red alder Alnus rubra 1 gallon 10’ 15
Sitka willow Salix sitchensis 1 gallon 5’ 23
Twinberry Lonicera involucrata 1 gallon 5’ 23
Nootka rose Rosa nutkana 1 gallon 5’ 23
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Salmonberry Rubus spectabilis 1 gallon 5’ 23
8.1.3 Large Woody Debris
In addition to the enhancement plantings, a minimum of two (2) pieces of woody debris (per
wetland) will be added to Wetlands B and D. If possible, material removed from the site for
development will be salvaged for use as woody debris within the buffer enhancement area. Woody
debris shall consist of coniferous logs or root wads. Minimum size of the woody debris will be 10-
inch diameter and 15 feet in length, or 10-foot diameter root-wads.
8.2 BUFFER ENHANCEMENT
To compensate for minor impacts (240 square feet) to the buffer of Wetland B associated with
frontage improvements, a total of 700 square feet of buffer located between Lincoln Ave NE and
Wetland B will be enhanced with a variety of native vegetation and large woody debris. In order
to utilize buffer averaging for the buffer of Stream S, the applicant proposes to enhance 6,788
square feet of stream buffer, which is comprised of an old road grade and dominated by Himalayan
blackberry (Rubus armeniacus) and grasses.
To compensate for minor impacts to Wetland D (134 square feet), Wetland D’s buffer (954 square
feet), and Streams S’s buffer (781 square feet) for installation of the pedestrian trail, a total of 2,137
square feet of buffer will be enhanced. This includes 781 square feet of Stream S buffer and 1,356
square feet of Wetland D buffer.
The proposed buffer enhancement plantings and large woody debris will increase diversity and
density of native plants within Wetlands B and D, while providing increased opportunities for
wildlife habitat.
8.2.1 Wetland B Buffer Enhancement
Prior to planting, invasive woody species including (but not limited to) Himalayan blackberry
(Rubus armeniacus) and English holly (Ilex aquifolium) will be removed from the buffer enhancement
area. Any existing native plants within the buffer shall be retained and protected. As the overstory
of Wetland B and surrounding buffer is dense with red alder and black cottonwood, a variety of
native shrubs and herbaceous species will be planted in the understory. The following native shrubs
and groundcover will be planted in the buffer enhancement area and any disturbed areas will be
seeded with the buffer grass seed mix specified below:
Wetland B Buffer Enhancement (700 square feet)
Common Name Latin Name Size Spacing Quantity
Vine maple Acer circinatum 2” cal. (7-8’ tall) 6’ 8
Salmonberry Rubus spectabilis 1 gallon 6’ 8
Salal Gaultheria shallon 1 gallon 6’ 8
Snowberry Symphoricarpos albus 1 gallon 6’ 8
Sword fern Polystichum munitum 1 gallon 4’ 10
Low Oregon grape Mahonia nervosa 1 gallon 4’ 10
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Buffer Grass Seed Mixture
Common Name Latin Name lbs./1,000 SF
Tall fescue Festuca arundinacea 0.4
Colonial bentgrass Agrostis tenuis 0.4
Annual ryegrass Lolium multiflorum 0.5
Red clover Trifolium repens 0.2
8.2.2 Wetland D Buffer Enhancement
Prior to planting, invasive woody species including (but not limited to) Himalayan blackberry
(Rubus armeniacus) and English holly (Ilex aquifolium) will be removed from the buffer enhancement
area. Any existing native plants within the buffer shall be retained and protected. The following
native trees, shrubs, and groundcover will be planted in the buffer enhancement area and any
disturbed areas will be seeded with the buffer grass seed mix specified below:
Wetland D Buffer Enhancement (1,356 square feet)
Common Name Latin Name Size Spacing Quantity
Big-leaf maple Acer macrophyllum 1 gallon 9’ 8
Grand fir Abies grandis 1 gallon 9’ 8
Vine maple Acer circinatum 1 gallon 6’ 6
Salmonberry Rubus spectabilis 1 gallon 6’ 5
Salal Gaultheria shallon 1 gallon 6’ 5
Snowberry Symphoricarpos albus 1 gallon 6’ 5
Sword fern Polystichum munitum 1 gallon 4’ 24
Low Oregon grape Mahonia nervosa 1 gallon 4’ 23
Buffer Grass Seed Mixture
Common Name Latin Name lbs./1,000 SF
Tall fescue Festuca arundinacea 0.4
Colonial bentgrass Agrostis tenuis 0.4
Annual ryegrass Lolium multiflorum 0.5
Red clover Trifolium repens 0.2
8.2.3 Stream S Buffer Enhancement Plan
If soils associated with the old road grade are compacted, site preparation including soil
decompaction and amendment will occur prior to planting. If necessary, soils will be decompacted
and 3 inches of premium topsoil shall be tilled into the top 6 inches of existing soil. The topsoil
amendment shall have at least 15 percent organic content.
Prior to planting, invasive woody species including (but not limited to) Himalayan blackberry
(Rubus armeniacus) will be removed from the buffer enhancement area. Any existing native plants
within the buffer shall be retained and protected. The following native trees and shrubs will be
planted in the buffer enhancement area and any disturbed areas will be seeded with the buffer
grass seed mix specified below:
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Stream S Buffer Enhancement Area A (6,788 square feet)
Common Name Latin Name Size Spacing Quantity
Western hemlock Tsuga heterophylla ≥6’ tall 9’ 27
Big-leaf maple Acer macrophyllum 2" cal. 9’ 27
Red alder Alnus rubra 2” cal. 6’ 42
Osoberry Oemleria cerasiformis 1 gallon 6’ 42
Snowberry Symphoricarpos albus 1 gallon 6’ 42
Salal Gaultheria shallon 1 gallon 6’ 42
Low Oregon grape Mahonia nervosa 1 gallon 6’ 42
Stream S Buffer Enhancement Area B (781 square feet)
Common Name Latin Name Size Spacing Quantity
Western hemlock Tsuga heterophylla ≥6’ tall 9’ 5
Big-leaf maple Acer macrophyllum 2" cal. 9’ 4
Red alder Alnus rubra 2” cal. 6’ 3
Osoberry Oemleria cerasiformis 1 gallon 6’ 3
Snowberry Symphoricarpos albus 1 gallon 6’ 2
Salal Gaultheria shallon 1 gallon 6’ 2
Low Oregon grape Mahonia nervosa 1 gallon 6’ 2
Buffer Grass Seed Mixture
Common Name Latin Name lbs./1,000 SF
Tall fescue Festuca arundinacea 0.4
Colonial bentgrass Agrostis tenuis 0.4
Annual ryegrass Lolium multiflorum 0.5
Red clover Trifolium repens 0.2
8.2.4 Large Woody Debris
In addition to the enhancement plantings, a minimum of one (1) piece of woody debris will be
added to the Wetland B enhancement area and any trees measuring four or more inches in
diameter that are removed within 200-feet of Stream S, during the clearing and grading process,
will be added to the Stream S buffer enhancement area. A minimum of one (1) piece of large woody
debris (LWD) will be placed within the stream channel. Minimum size of this LWD will be 10-inch
diameter and at least 8-feet in length. This LWD should be an evergreen species preferably cedar,
hemlock, or fir, as they have relatively slower decay rates than deciduous species and have complex
root systems. In-channel LWD shall be buried with a minimum of two-thirds of its length into
the graded stream bank at an approximate 60-degree angle with its root-wad in contact with
the stream and facing upstream.
9.0 FUNCTIONS AND VALUES ASSESSMENT
Wetlands and streams in Western Washington perform a variety of ecosystem functions. Included
among the most important functions provided by wetlands are stormwater control, water quality
improvement, fish and wildlife habitat, aesthetic value, recreational opportunities and education.
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The most commonly assessed functions and their descriptions are listed below. Assessments of
these functions for the project site are provided in the “Analysis” section of this report.
Hydrologic Functions
Wetlands often function as natural water storage areas during periods of precipitation and flooding.
By storing water that otherwise might be channeled into open flow systems, wetlands can attenuate
or modify potentially damaging effects of storm events, reducing erosion and peak flows to
downstream systems. Additionally, the soils underlying wetlands are often less permeable,
providing long-term storage of stormwater or floodflow and controlling baseflows of downstream
systems. Stormwater storage capacity and floodflow attenuation are generally a function of the
size of the wetland and their topographic characteristics.
Water Quality
Surface water quality improvement is another important function provided by wetlands. Surface
runoff during periods of precipitation increases the potential for sediments and pollutants to enter
surface water. Wetlands improve water quality by acting as filters as water passes through them,
trapping sediments and pollutants from surface water. Ponded areas within depressional wetlands
also allow sediments to drop out of suspension, thereby increasing water quality
Wildlife Habitat
Wetlands have potential to provide diverse habitat for aquatic, terrestrial, and avian species for
nesting, rearing, resting, cover, and foraging. Wildlife species are commonly dependent upon a
variety of intermingled habitat types, including: wetlands, adjacent uplands, large bodies of water,
and movement corridors between them. Human intrusion, including development within and
adjacent to wetlands, and impacts to movement corridors are the most limiting factors for wildlife
habitat functions.
9.1 EXISTING WETLAND CONDITIONS
Wetland A is a slope wetland with an overstory of red alder and an understory dominated by
Himalayan blackberry (Rubus armeniacus) and reed canarygrass (Phalaris arundinacea). This wetland
provides some hydrologic functions by slowing water velocity, especially during periods of high
flows. Vegetation within the wetland assists in filtration of sediments and pollutants. The
hydrological and water quality functions of this wetland are limited by the low residence time of
water within the wetland. This wetland provides low habitat value, due to limited structural
diversity, interspersion of habitats, special habitat features, and low landscape potential to support
habitat functions on-site. Overall, this wetland provides a low to moderate level of functions.
Wetland B is a slope wetland with a canopy of red alder (Alnus rubra) and black cottonwood (Populus
balsamifera), and understory dominated by Himalayan blackberry (Rubus armeniacus) and giant
horsetail (Equisetum telmateia). This wetland provides some hydrologic functions by slowing water
velocity, especially during periods of high flows. Vegetation within the wetland assists in filtration
of sediments and pollutants. The hydrological and water quality functions of this wetland are
limited by the low volume of storage capacity and the lack of persistent vegetation. Similar to
Wetland A, this wetland provides low habitat value, due to limited structural diversity,
interspersion of habitats, special habitat features, and low landscape potential to support habitat
functions on-site. Overall, this wetland provides a low to moderate level of functions.
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Wetland C is a slope wetland dominated by Himalayan blackberry (Phalaris arundinacea) and skunk
cabbage (Lysichiton americanus). This wetland provides some hydrologic functions by slowing water
velocity, especially during periods of high flows. Vegetation within the wetland assists in filtration
of sediments and pollutants. The hydrological and water quality functions of this wetland are
limited by the low residence time of water within the wetland. This wetland does provide moderate
habitat value, partially attributed to its association with Stream S. Overall, this wetland provides a
moderate level of functions.
Wetland D is a slope wetland with a sparse canopy of red alder (Alnus rubra), and a moderately
dense understory dominated by Himalayan blackberry (Rubus armeniacus) and fowl mannagrass
(Glyceria striata). This wetland provides some hydrologic functions by slowing water velocity,
especially during periods of high flows. Vegetation within the wetland assists in filtration of
sediments and pollutants. The hydrological and water quality functions of this wetland are limited
by the low residence time of water within the wetland. This wetland provides low habitat value,
due to limited site and landscape potential to support habitat functions. Overall, this wetland
provides a low to moderate level of functions.
9.2 POST CONSTRUCTION WETLAND FUNCTIONS AND VALUES
As mitigation for the proposed development on this property, the applicant is proposing to enhance
the on-site portions of Wetlands B and D, as well as portions of Stream S, Wetland B, and Wetland
D’s buffer. The proposed wetland and buffer enhancement plantings and installation of large
woody debris will provide a greater diversity of vegetation, facilitating more opportunities for
wildlife to find refuge. Additional native, fruit bearing shrubs will provide an increase in food
sources for wildlife in the area. This is a vital uplift of habitat functions on-site, as Wetland A, B,
and D currently provide low habitat value.
The enhancement plantings on the slopes within the buffer will increase density of woody
vegetation in that area, providing a higher level of velocity reduction and water filtration. The
increased variety and quantity of vegetation within the wetlands will slow stormwater flows as they
move through the site and toward the off-site stream. Additionally, buffer enhancement will
provide screening and protection to Wetland B, Wetland D, and Stream S. The enhancement
plantings will allow the remaining on-site wetlands and buffer area to provide a greater level of
functions and values post development than they currently provide, to be protected in perpetuity.
10.0 PROJECT NOTES
Pre-Construction Meeting
Mitigation projects are typically more complex to install than to describe in plans. Careful
monitoring by a wetland professional for all portions of this project is strongly recommended.
Construction timing and sequencing is important to the success of this type of project. There will
be a pre-construction meeting on this site between the Permittee, the consulting wetland
professional, and laborers. The objective will be to verify the location of erosion control facilities,
verify the location of mitigation areas, and to discuss project sequencing.
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Inspections
A wetland professional shall be contracted to periodically inspect the mitigation installation
described in this plan. Minor adjustments to the original design may be necessary prior to and
during construction due to unusual or hidden site conditions. A City of Renton representative
and/or the consulting professional will make these decisions during construction.
11.0 PLANTING NOTES
Plant in the early spring or late fall and obtain all plants from a reputable nursery. Care and
handling of all plant materials is extremely important to the overall success of the project. The
origin of all plant materials specified in this plan shall be native plants, nursery grown in the Puget
Sound region of Washington. Some limited species substitution may be allowed, only with the
agreement of the landscape designer, wetland professional, and/or City staff.
Pre-Planting Meeting
Prior to control of invasive species or installation of mitigation plantings, a site meeting between
the contracted landscaper and the consulting wetland professional shall occur to resolve any
questions that may arise. During this meeting a discussion regarding plant spacing and locations
of plant species including wetland verses buffer species shall occur between the landscape
contractor and the consulting wetland professional.
Handling
Plants shall be handled so as to avoid all damage, including: breaking, bruising, root damage,
sunburn, drying, freezing or other injury. Plants must be covered during transport. Plants shall
not be bound with wire or rope in a manner that could damage branches. Protect plant roots with
shade and wet soil in the time period between delivery and installation. Do not lift container stock
by trunks, stems, or tops. Do not remove from containers until ready to plant. Water all plants as
necessary to keep moisture levels appropriate to the species horticultural requirements. Plants shall
not be allowed to dry out. All plants shall be watered thoroughly immediately upon installation.
Soak all containerized plants thoroughly prior to installation.
Storage
Plants stored by the Permittee for longer than one month prior to planting shall be planted in
nursery rows and treated in a manner suitable to those species’ horticultural requirements. Plants
must be re-inspected by the wetland professional and/or landscape designer prior to installation.
Damaged plants
Damaged, dried out, or otherwise mishandled plants will be rejected at installation inspection. All
rejected plants shall be immediately removed from the site.
Plant Names
Plant names shall comply with those generally accepted in the native plant nursery trade. Any
question regarding plant species or variety shall be referred to the landscape designer, wetland
professional, or City staff. All plant materials shall be true to species and variety and legibly tagged.
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Quality and condition
Plants shall be normal in pattern of growth, healthy, well-branched, vigorous, with well-developed
root systems, and free of pests and diseases. Damaged, diseased, pest-infested, scraped, bruised,
dried out, burned, broken, or defective plants will be rejected. Plants with pruning wounds over
1-inch in diameter will be rejected.
Roots
All plants shall be balled and burlapped (B &B) or containerized, unless explicitly authorized by
the landscape designer and/or wetland professional. Rootbound plants or B&B plants with
damaged, cracked, or loose rootballs (major damage) will be rejected. Immediately before
installation, plants with minor root damage (some broken and/or twisted roots) must be root-
pruned. Matted or circling roots of containerized plantings must be pruned or straightened and
the sides of the root ball must be roughened from top to bottom to a depth of approximately half
an inch in two to four places. Bare root plantings of woody material are allowed only with
permission from the landscape designer, wetland professional and/or City staff.
Sizes
Plant sizes shall be the size indicated in the plant schedule in approved plans. Larger stock may
be acceptable provided that it has not been cut back to the size specified, and that the root ball is
proportionate to the size of the plant. Smaller stock may be acceptable, and preferable under
some circumstances, based on site-specific conditions. Measurements, caliper, branching, and
balling and burlapping shall conform to the American Standard of Nursery Stock by the American
Association of Nurserymen (latest edition).
Form
Evergreen trees shall have single trunks and symmetrical, well-developed form. Deciduous trees
shall be single trunked unless specified as multi-stem in the plant schedule. Shrubs shall have
multiple stems and be well-branched.
Timing of Planting
Unless otherwise approved by City staff, all planting shall occur between November 1 and March
1. Overall, the earlier plants go into the ground during the dormant period, the more time they
have to adapt to the site and extend their root systems before the water demands of spring and
summer.
Weeding
Existing and exotic vegetation in the mitigation areas will be hand-weeded from around all newly
installed plants at the time of installation and on a routine basis throughout the monitoring period.
No chemical control of vegetation on any portion of the site is recommended.
Site conditions
The contractor shall immediately notify the landscape designer and/or wetland professional of
drainage or soil conditions likely to be detrimental to the growth or survival of plants. Planting
operations shall not be conducted under the following conditions: freezing weather, when the
ground is frozen, excessively wet weather, excessively windy weather, or in excessive heat.
Critical Area Study & Conceptual Mitigation Plan Wetland Resources, Inc. #18158
Blue Fern Development – Canopy 25 Revision 3: July 14, 2021
Planting Pits
Planting pits shall be circular or square with vertical sides, and shall be 6” deeper and 12” larger
in diameter than the root ball of the plant. Break up the sides of the pit in compacted soils. Set
plants upright in pits. Burlap shall be removed from the planting pit. Backfill shall be worked back
into holes such that air pockets are removed without adversely compacting down soils.
Fertilizer
Slow release fertilizer may be used if pre-approved by City of Renton staff. Fertilizers shall be
applied only at the base of plantings underneath the required covering of mulch (that does not
make contact with stems of the plants). No soil amendment or fertilizers will be placed in planting
holes.
Staking
Most shrubs and many trees DO NOT require any staking. If the plant can stand alone without
staking in a moderate wind, do not use a stake. If the plant needs support, then strapping or
webbing should be used as low as possible on the trunk to loosely brace the tree with two stakes.
Do not brace the tree tightly or too high on the trunk. If the tree is unable to sway, it will further
lose the ability to support itself. Do not use wire in a rubber hose for strapping as it exerts too much
pressure on the bark. As soon as supporting the plant becomes unnecessary, remove the stakes. All
stakes must be removed within two (2) years of installation.
Plant Location
Colored surveyors ribbon or other appropriate marking shall be attached to the installed plants to
assist in locating the plants while removing the competing non-native vegetation and during the
monitoring period.
Arrangement and Spacing
The plants shall be arranged in a pattern with the appropriate numbers, sizes, species, and
distribution that are required in accordance with the approved plans. The actual placement of
individual plants shall mimic natural, asymmetric vegetation patterns found on similar undisturbed
sites in the area. Spacing of the plantings may be adjusted to maintain existing vegetation with the
agreement of the landscape designer, wetland professional, and/or City staff.
Inspection(s)
A wetland professional shall be present on site to inspect the plants prior to planting. Minor
adjustments to the original design may be required prior to and during construction.
Woodchip Mulch
All landscaped areas denuded of vegetation and soil surface surrounding all planting pit areas shall
receive no less than 2 to 4 inches of certified woodchip mulch after planting. A layer of woodchip
mulch will be placed around the base of each plant in a 3-foot radius and at a depth of 2 to 4
inches. The woodchip mulch shall not be allowed to contact plant stems in order to avoid plant
decay and rot.
Critical Area Study & Conceptual Mitigation Plan Wetland Resources, Inc. #18158
Blue Fern Development – Canopy 26 Revision 3: July 14, 2021
12.0 PROJECT MONITORING PROGRAM
12.1 REQUIREMENTS FOR MONITORING PROJECT:
1. Initial compliance/as-built report
2. Site inspection (twice per year) for five years
3. Annual reports (one report submitted during each monitored year)
Purpose for Monitoring
The purpose for monitoring this mitigation project shall be to evaluate its success. Success will be
determined if monitoring shows at the end of five years that the definitions of success stated below
are met. The property owner shall grant access to the mitigation area for inspection and
maintenance to the contracted landscape and/or wetland specialist and City of Renton during the
monitoring period or until the project is evaluated as successful.
Monitoring
Monitoring shall be conducted twice annually for five years in accordance with the approved
Mitigation Plan. The monitoring period will begin once the City receives written notification
confirming the mitigation plan has been implemented and City staff inspects the site and issues
approval of the installation.
Vegetation Monitoring
Sampling points or transects will be established for vegetation monitoring and photo points will be
established from which photos will be taken throughout the monitoring period. Permanent
sampling points must be identified on the mitigation site plans in the first monitoring report (they
may be drawn on approved plans by hand). Each sampling point shall detail herbaceous, shrub,
and tree coverage. Monitoring of vegetation sampling points shall occur once per monitored year.
Wetland Hydrology Monitoring
To ensure that wetland hydrology is not impacted by the development, the wetland boundaries
will be reviewed during the spring monitoring visit of each monitored year. If it appears that any
existing wetland areas are no longer saturated or inundated for sufficient duration to support
wetland conditions, those areas will be demarcated in the field and depicted on a map. Additional
mitigation may need to be provided, as described in the contingency plan in Section 15, below.
Photo points
No less than four permanent photo points will be established within the mitigation areas.
Photographs will be taken from these points to visually record condition of the mitigation areas.
Photos shall be taken annually between May 15 and September 30 (prior to leaf drop), unless
otherwise specified.
12.2 MONITORING REPORT CONTENTS
Monitoring reports shall be submitted by December 31 of each year during the monitoring period.
As applicable, monitoring reports must include descriptions / data for:
1. Site plan and vicinity map
Critical Area Study & Conceptual Mitigation Plan Wetland Resources, Inc. #18158
Blue Fern Development – Canopy 27 Revision 3: July 14, 2021
2. Historic description of project, including date of installation, current year of monitoring,
restatement of mitigation / restoration goals, and performance standards
3. Plant survival, vigor, and areal coverage for every plant community (transect or sampling
point data), and explanation of monitoring methodology in the context of assessing
performance standards
4. Wetland and buffer conditions, e.g., surrounding land use, use by humans, and/or wild
and domestic creatures
5. Observed wildlife, including amphibians, avians, and others
6. Assessment of nuisance / exotic biota and recommendations for management
7. Color photographs taken from permanent photo-points that shall be depicted on the
monitoring report map
13.0 PROJECT SUCCESS & COMPLIANCE
13.1 CRITERIA FOR SUCCESS
Upon completion of the proposed mitigation project, an inspection by a qualified biologist will be
made to determine plan compliance. A compliance report will be supplied to the City of Renton
within 30 days after the completion of planting. A landscape professional or wetland professional
will perform condition monitoring of the plantings in the spring and fall of each monitored year.
A written report describing the monitoring results will be submitted to the City after each site
inspection of each monitored year. Final inspection will occur five years after completion of this
project. The contracted consultant will prepare a report as to the success of the project.
13.2 DEFINITION OF SUCCESS
The planting areas shall meet the following performance standards:
a) End of Year 1
• 100 percent survival of newly planted species and
• Less than 10 percent cover of weedy/invasive species
b) End of Year 2
• 80 percent survival of newly planted species
• Less than 10 percent cover of weedy/invasive species
c) End of Year 3
• At least 50 percent native vegetation coverage within the mitigation areas*
• Less than 10 percent cover of weedy/invasive species
d) End of Year 5
• At least 80 percent aerial cover of native woody plant species*,
• Less than 10 percent cover of weedy/invasive species.
*Volunteering native species may be included in the aerial cover calculations.
The species mix should resemble that proposed in the planting plans, but strict adherence to
obtaining all of the species shall not be a criterion for success.
Critical Area Study & Conceptual Mitigation Plan Wetland Resources, Inc. #18158
Blue Fern Development – Canopy 28 Revision 3: July 14, 2021
14.0 MAINTENANCE
The mitigation areas will require periodic maintenance to remove undesirable species and replace
vegetation mortality. Maintenance shall occur in accordance with the approved plans. Chemical
control, only if approved by City staff, shall be applied by a licensed applicator following all label
instructions.
Duration and Extent
In order to achieve performance standards, the permittee shall have the mitigation area maintained
for the duration of the five-year monitoring period. Maintenance will include: watering, weeding
around the base of installed plants, pruning, replacement, re-staking, removal of all classes of
noxious weeds (see Washington State Noxious Weeds List, WAC 16-750-005) as well as Himalayan
blackberry, and any other measures needed to ensure plant survival. The landscape designer
and/or wetland professional shall direct all maintenance.
Survival
The permittee shall be responsible for the health of 100% of all newly installed plants for one growing
season after installation has been accepted by the City of Renton. A growing season for these
purposes is defined as occurring from spring to spring (March 15 to March 15 of the following
year). For fall installation (often required), the growing season will begin the following spring. The
permittee shall replace any plants that are: failing, weak, defective in manner of growth, or dead
during this growing season, as directed by the landscape designer, wetland professional, and/or
City of Renton staff.
Installation Timing for Replacement Plants
Replacement plants shall be installed between September 15 and January 15, unless otherwise
determined by the landscape designer, wetland professional, and/or City of Renton staff.
Standards for Replacement Plants
Replacement plants shall meet the same standards for size and type as those specified for the
original installation, unless otherwise directed by the landscape designer, wetland professional,
and/or City of Renton staff.
Replanting
Plants that have settled in their planting pits too deep, too shallow, loose, or crooked shall be
replanted as directed by the landscape designer, wetland professional, and/or City of Renton staff.
Herbicides / Pesticides
In general, chemical controls shall not be used in the mitigation area, sensitive areas, or their
buffers. However, limited use of herbicides may be approved depending on site-specific conditions,
only if approved by City of Renton staff.
Irrigation / Watering
Water shall be provided during the dry season (July 1 through October 15) for the first two years
after installation to ensure plant survival and establishment. A temporary above ground irrigation
system shall be installed within the Stream S buffer enhancement area and Wetland B buffer
enhancement area to provide water. Water shall be applied at a rate of 1” of water twice per week
Critical Area Study & Conceptual Mitigation Plan Wetland Resources, Inc. #18158
Blue Fern Development – Canopy 29 Revision 3: July 14, 2021
for year one and 1” per week during year two. If the mitigation plantings meet 80 percent survival
at the end of year two, the system may be removed.
General
The permittee shall include in general maintenance activities the replacement of any vandalized
or damaged signs, habitat features, fences, or other structural components of this mitigation site.
15.0 CONTINGENCY PLAN
If 20% of the plants are severely stressed during any of the inspections, or it appears 20 percent
may not survive, additional plantings of the same species may be added to the planting area.
Elements of a contingency plan may include, but will not be limited to: more aggressive weed
control, pest control, mulching, replanting with larger plant material, species substitution,
fertilization, soil amendments, and/or irrigation.
16.0 FENCING & SIGNAGE
Per RMC 4-3-050(G)(3)(f)-(h) outlines fencing and signage requirements. Prior to construction, the
outer extent of the approved critical area buffer and areas not to be disturbed shall be marked with
high visibility orange construction fencing and silt fencing. Subsequently, permanent fencing of the
native growth protection area containing critical area shall be installed, along with permanent signs
(made of wood or metal, adhered to treated or metal posts). Sign locations and size specifications
shall be approved by the city. RMC 4-3-050(G)(3)(h) recommends the following wording for signs,
“Protection of this natural area is in your care. Alteration or disturbance is
prohibited by law.”
Critical Area Study & Conceptual Mitigation Plan Wetland Resources, Inc. #18158
Blue Fern Development – Canopy 30 Revision 3: July 14, 2021
17.0 COST ESTIMATE & SURETY DEVICE
A surety device shall be provided to the City of Renton for the period of five years from the
completion of the project, in the amount of equal to the estimated cost for plant material and labor.
The City of Renton shall release this bond at the end of the five years, upon successful
determination for all portions of this mitigation project. This does not represent a bid to install.
The total estimated project cost is as follows:
517 1-gallon Plantings (including installation, @ $11.50/each) $5,945.50
84 2” cal. Plantings (including installation, @ $36.00/each) $3,024.00
Decompacting 33.26 Till/ Hardpan to 6” depth ($1.57/CY) $52.22
0.22-Acres of Temporary Irrigation ($3,000/AC) $660.00
6 Pieces of LWD ($245.00/Each) $1,470.00*
1,210 LF of Silt Fencing ($1.60/LF) $1,936.00
Woodchip Mulch, 2” Deep (By Hand) ($3.25/SY) $52.00
Topsoil, delivered and Spread ($35.73/CY) $594.19
1,210 LF of Split Rail Fencing, 3’ High (2-rail) ($10.54/LF) $12,753.40
12 Permanent Signs ($28.50/Each) $342.00
Maintenance (Twice/Year) $4,500.00
Monitoring for 5 Years $9,000.00
Total Estimated Project Cost $38,859.31
*If possible, material removed from the site will be salvaged for use as large woody debris
Critical Area Study & Conceptual Mitigation Plan Wetland Resources, Inc. #18158
Blue Fern Development – Canopy 31 Revision 3: July 14, 2021
18.0 USE OF THIS REPORT
This Critical Area Study & Conceptual Mitigation Plan is supplied to Blue Fern Development,
LLC as a means of determining on-site critical area conditions, as required by the City of Renton
during the permitting process. This report is based largely on readily observable conditions and,
to a lesser extent, on readily ascertainable conditions. No attempt has been made to determine
hidden or concealed conditions.
The laws applicable to wetlands are subject to varying interpretations and may be changed at any
time by the courts or legislative bodies. This report is intended to provide information deemed
relevant in the applicant's attempt to comply with the laws now in effect.
The work for this report has conformed to the standard of care employed by wetland ecologists.
No other representation or warranty is made concerning the work or this report, and any implied
representation or warranty is disclaimed.
Wetland Resources, Inc.
Scott Brainard, PWS
Principal Wetland Ecologist
Alia Richardson
Associate Ecologist & Wildlife Biologist
Critical Area Study & Conceptual Mitigation Plan Wetland Resources, Inc. #18158
Blue Fern Development – Canopy 14 Revision 3: July 14, 2021
19.0 REFERENCES
Anderson et al. 2016. Determining the Ordinary High Water Mark for Shoreline Management
Act Compliance in Washington State. WA Department of Ecology. Publication #16-06-
029.
Brinson, M.M. 1993. A Hydrogeomorphic Classification for Wetlands. Technical Report WRPDE-4. US
Army Engineers Waterways Experiment Station, Vicksburg, MS.
Cowardin, et al., 1979. Classification of Wetlands and Deepwater Habitats of the United States. U.S.
Department of the Interior. FWS/OBS-79/31. December 1979.
Ecology, Department of. Shoreline Master Programs Handbook (SMP Handbook). Washington State
Department of Ecology. Publication #11-06-010. Olympia, WA.
Lichvar, Tobert W. and J.T. Kartesz, 2014. National Wetland Plant List, Version 3.0. U.S. Army
Corps of Engineers Engineer Research and Development Center Cold Regions Research
and Engineering Laboratory, Hanover NH and BONAP, Chapel Hill, NC.
http://wetland_plants.usace.army.mil
Hruby, T. 2014. Washington State Wetland Rating System for Western Washington: 2014 Update.
Publication #14-06-029. Washington Department of Ecology. Olympia, WA.
King County. 2019. iMap Interactive Mapping Tool.
http://www.kingcounty.gov/operations/GIS/Maps/iMAP.aspx.
Munsell Color. 2012. Munsell Soil Color Book. Munsell Color, Grand Rapids, MI.
NRCS. 2018. Web Soil Survey. United States Department of Agriculture.
http://websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx.
Sheldon, D., T. Hruby, P. Johnson, K. Harper, A. McMillan, T. Granger, S. Stanley, and E.
Stockdale. March 2005. Wetlands in Washington State - Volume 1: A Synthesis of the Science.
Washington State Department of Ecology. Publication #05-06-006. Olympia, WA.
Renton, City of. Renton Municipal Code. 4-3-050 Critical Areas Regulations (current through
Ordinance 5921, passed February 11, 2019).
Renton, City of. City of Renton Maps of Your Community.
http://rp.rentonwa.gov/HTML5Public/Index.HTML?viewer=CORMaps
US Army COE. 2010. Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Western
Mountains, Valleys, and Coast Region (Version 2.0). Vicksburg, MS
USFWS. 2019. National Wetlands Inventory (NWI) Online Mapper.
http://www.fws.gov/wetlands/Data/Mapper.html.
Critical Area Study & Conceptual Mitigation Plan Wetland Resources, Inc. #18158
Blue Fern Development – Canopy 15 Revision 3: July 14, 2021
WDFW. 2019. Priority Habitat and Species (PHS) Interactive Map.
http://apps.wdfw.wa.gov/phsontheweb/.
WDFW. 2019. SalmonScape Online Mapping Application.
http://apps.wdfw.wa.gov/salmonscape/map.html.
APPENDIX A
WETLAND DETERMINATION
DATA FORMS
THIS PAGE IS INTENTIONALLY LEFT BLANK
US Army Corps of Engineers Western Mountains, Valleys, and Coast – Version 2.0
WETLAND DETERMINATION DATA FORM – Western Mountains, Valleys, and Coast Region
Project/Site:
City/County:
Sampling Date:
Applicant/Owner:
State:
Sampling Point:
Investigator(s):
Section, Township, Range:
Landform (hillslope, terrace, etc.):
Local relief (concave, convex, none):
Slope (%):
Subregion (LRR):
Lat:
Long:
Datum:
Soil Map Unit Name:
NWI classification:
Are climatic / hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.)
Are Vegetation
, Soil
, or Hydrology
significantly disturbed? Are “Normal Circumstances” present? Yes No
Are Vegetation
, Soil
, or Hydrology
naturally problematic? (If needed, explain any answers in Remarks.)
SUMMARY OF FINDINGS – Attach site map showing sampling point locations, transects, important features, etc.
Hydrophytic Vegetation Present? Yes No
Hydric Soil Present? Yes No
Wetland Hydrology Present? Yes No
Is the Sampled Area
within a Wetland? Yes No
Remarks:
VEGETATION – Use scientific names of plants.
Absolute Dominant Indicator
Tree Stratum (Plot size:
) % Cover Species? Status
1.
2.
3.
4.
= Total Cover Sapling/Shrub Stratum (Plot size:
)
1.
2.
3.
4.
5.
= Total Cover
Herb Stratum (Plot size:
)
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
= Total Cover
Woody Vine Stratum (Plot size:
)
1.
2.
= Total Cover
% Bare Ground in Herb Stratum
Dominance Test worksheet:
Number of Dominant Species
That Are OBL, FACW, or FAC:
(A)
Total Number of Dominant
Species Across All Strata:
(B)
Percent of Dominant Species
That Are OBL, FACW, or FAC:
(A/B)
Prevalence Index worksheet:
Total % Cover of: Multiply by:
OBL species
x 1 =
FACW species
x 2 =
FAC species
x 3 =
FACU species
x 4 =
UPL species
x 5 =
Column Totals:
(A)
(B)
Prevalence Index = B/A =
Hydrophytic Vegetation Indicators:
Rapid Test for Hydrophytic Vegetation
Dominance Test is >50%
Prevalence Index is ≤3.01
Morphological Adaptations1 (Provide supporting
data in Remarks or on a separate sheet)
Wetland Non-Vascular Plants1
Problematic Hydrophytic Vegetation1 (Explain)
1Indicators of hydric soil and wetland hydrology must
be present, unless disturbed or problematic.
Hydrophytic
Vegetation
Present? Yes No
Remarks:
Blue Fern Development - Vino Veritas Vista City of Renton/King Co.5/23/2018
Blue Fern Development, LLC WA S1 (Wet. C)
J. Rothwell, T. Amen S32, T24N, R05E, W.M.
Hillslope None 8%
LRR-A 47.529 -122.180 NAD83
Alderwood gravelly sandy loam, 8 to 15 percent slopes PSS
4
4
4
4
4 4
Inside Wetland C
5m^2
Alnus rubra*50 Y FAC
Pseudotsuga menziesii*15 Y FACU
Acer macrophyllum*10 N FACU
75
3m^2
Rubus armneiacus 40 Y FAC
Corylus cornuta*20 Y FACU
Rubus spectabilis 15 Y FAC
75
1m^2
Lysichiton americanus 50 Y OBL
Equisetum telmateia 10 Y FAC
60
3m^2
0
40
4
7
71%
0
0
0
0
0
0 0
4
4
* = Not rooted in wetland
US Army Corps of Engineers Western Mountains, Valleys, and Coast – Version 2.0
SOIL Sampling Point:
Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.)
Depth Matrix Redox Features
(inches) Color (moist) % Color (moist) % Type1 Loc2 Texture Remarks
1Type: C=Concentration, D=Depletion, RM=Reduced Matrix, CS=Covered or Coated Sand Grains. 2Location: PL=Pore Lining, M=Matrix.
Hydric Soil Indicators: (Applicable to all LRRs, unless otherwise noted.) Indicators for Problematic Hydric Soils3:
Histosol (A1) Sandy Redox (S5) 2 cm Muck (A10)
Histic Epipedon (A2) Stripped Matrix (S6) Red Parent Material (TF2)
Black Histic (A3) Loamy Mucky Mineral (F1) (except MLRA 1) Very Shallow Dark Surface (TF12)
Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Other (Explain in Remarks)
Depleted Below Dark Surface (A11) Depleted Matrix (F3)
Thick Dark Surface (A12) Redox Dark Surface (F6) 3Indicators of hydrophytic vegetation and
Sandy Mucky Mineral (S1) Depleted Dark Surface (F7) wetland hydrology must be present,
Sandy Gleyed Matrix (S4) Redox Depressions (F8) unless disturbed or problematic.
Restrictive Layer (if present):
Type:________________________________
Depth (inches):________________________
Hydric Soil Present? Yes No
Remarks:
HYDROLOGY
Wetland Hydrology Indicators:
Primary Indicators (minimum of one required; check all that apply) Secondary Indicators (2 or more required)
Surface Water (A1) Water-Stained Leaves (B9) (except MLRA Water-Stained Leaves (B9) (MLRA 1, 2,
High Water Table (A2) 1, 2, 4A, and 4B) 4A, and 4B)
Saturation (A3) Salt Crust (B11) Drainage Patterns (B10)
Water Marks (B1) Aquatic Invertebrates (B13) Dry-Season Water Table (C2)
Sediment Deposits (B2) Hydrogen Sulfide Odor (C1) Saturation Visible on Aerial Imagery (C9)
Drift Deposits (B3) Oxidized Rhizospheres along Living Roots (C3) Geomorphic Position (D2)
Algal Mat or Crust (B4) Presence of Reduced Iron (C4) Shallow Aquitard (D3)
Iron Deposits (B5) Recent Iron Reduction in Tilled Soils (C6) FAC-Neutral Test (D5)
Surface Soil Cracks (B6) Stunted or Stressed Plants (D1) (LRR A) Raised Ant Mounds (D6) (LRR A)
Inundation Visible on Aerial Imagery (B7) Other (Explain in Remarks) Frost-Heave Hummocks (D7)
Sparsely Vegetated Concave Surface (B8)
Field Observations:
Surface Water Present? Yes No Depth (inches):
Water Table Present? Yes No Depth (inches):
Saturation Present? Yes No Depth (inches):
(includes capillary fringe)
Wetland Hydrology Present? Yes No
Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available:
Remarks:
S1 (Wet. C)
0-9 2.5Y 3/1 100 Sandy Loam
9-16 Gley 1 4/N 80 2.5Y 4/6 20 C M Sandy Loam
4
4
4
4
4
4
4
4 9"
4 Surface 4
US Army Corps of Engineers Western Mountains, Valleys, and Coast – Version 2.0
WETLAND DETERMINATION DATA FORM – Western Mountains, Valleys, and Coast Region
Project/Site:
City/County:
Sampling Date:
Applicant/Owner:
State:
Sampling Point:
Investigator(s):
Section, Township, Range:
Landform (hillslope, terrace, etc.):
Local relief (concave, convex, none):
Slope (%):
Subregion (LRR):
Lat:
Long:
Datum:
Soil Map Unit Name:
NWI classification:
Are climatic / hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.)
Are Vegetation
, Soil
, or Hydrology
significantly disturbed? Are “Normal Circumstances” present? Yes No
Are Vegetation
, Soil
, or Hydrology
naturally problematic? (If needed, explain any answers in Remarks.)
SUMMARY OF FINDINGS – Attach site map showing sampling point locations, transects, important features, etc.
Hydrophytic Vegetation Present? Yes No
Hydric Soil Present? Yes No
Wetland Hydrology Present? Yes No
Is the Sampled Area
within a Wetland? Yes No
Remarks:
VEGETATION – Use scientific names of plants.
Absolute Dominant Indicator
Tree Stratum (Plot size:
) % Cover Species? Status
1.
2.
3.
4.
= Total Cover Sapling/Shrub Stratum (Plot size:
)
1.
2.
3.
4.
5.
= Total Cover
Herb Stratum (Plot size:
)
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
= Total Cover
Woody Vine Stratum (Plot size:
)
1.
2.
= Total Cover
% Bare Ground in Herb Stratum
Dominance Test worksheet:
Number of Dominant Species
That Are OBL, FACW, or FAC:
(A)
Total Number of Dominant
Species Across All Strata:
(B)
Percent of Dominant Species
That Are OBL, FACW, or FAC:
(A/B)
Prevalence Index worksheet:
Total % Cover of: Multiply by:
OBL species
x 1 =
FACW species
x 2 =
FAC species
x 3 =
FACU species
x 4 =
UPL species
x 5 =
Column Totals:
(A)
(B)
Prevalence Index = B/A =
Hydrophytic Vegetation Indicators:
Rapid Test for Hydrophytic Vegetation
Dominance Test is >50%
Prevalence Index is ≤3.01
Morphological Adaptations1 (Provide supporting
data in Remarks or on a separate sheet)
Wetland Non-Vascular Plants1
Problematic Hydrophytic Vegetation1 (Explain)
1Indicators of hydric soil and wetland hydrology must
be present, unless disturbed or problematic.
Hydrophytic
Vegetation
Present? Yes No
Remarks:
Blue Fern Development - Vino Veritas Vista City of Renton 5/23/2018
Blue Fern Development, LLC WA S2
J. Rothwell, T. Amen S32, T24N, R05E, W.M.
Hillslope None 8%
LRR-A 47.529 -122.180 NAD83
Alderwood gravelly sandy loam, 8 to 15 percent slopes N/A
4
4
4
4
4 4
Outside Wetland C
5m^2
Alnus rubra 100 Y FAC
100
3m^2
Rubus armeniacus 80 Y FAC
Ilex aquifolium 25 Y FACU
Crataegus monogyna 5 N FACU
110
1m^2
Pteridium aquilinum 10 Y FACU
Equisetum telmateia 5 Y FACW
15
3m^2
0
85
3
5
60%
0
0
0
0
0
0 0
4
4
US Army Corps of Engineers Western Mountains, Valleys, and Coast – Version 2.0
SOIL Sampling Point:
Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.)
Depth Matrix Redox Features
(inches) Color (moist) % Color (moist) % Type1 Loc2 Texture Remarks
1Type: C=Concentration, D=Depletion, RM=Reduced Matrix, CS=Covered or Coated Sand Grains. 2Location: PL=Pore Lining, M=Matrix.
Hydric Soil Indicators: (Applicable to all LRRs, unless otherwise noted.) Indicators for Problematic Hydric Soils3:
Histosol (A1) Sandy Redox (S5) 2 cm Muck (A10)
Histic Epipedon (A2) Stripped Matrix (S6) Red Parent Material (TF2)
Black Histic (A3) Loamy Mucky Mineral (F1) (except MLRA 1) Very Shallow Dark Surface (TF12)
Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Other (Explain in Remarks)
Depleted Below Dark Surface (A11) Depleted Matrix (F3)
Thick Dark Surface (A12) Redox Dark Surface (F6) 3Indicators of hydrophytic vegetation and
Sandy Mucky Mineral (S1) Depleted Dark Surface (F7) wetland hydrology must be present,
Sandy Gleyed Matrix (S4) Redox Depressions (F8) unless disturbed or problematic.
Restrictive Layer (if present):
Type:________________________________
Depth (inches):________________________
Hydric Soil Present? Yes No
Remarks:
HYDROLOGY
Wetland Hydrology Indicators:
Primary Indicators (minimum of one required; check all that apply) Secondary Indicators (2 or more required)
Surface Water (A1) Water-Stained Leaves (B9) (except MLRA Water-Stained Leaves (B9) (MLRA 1, 2,
High Water Table (A2) 1, 2, 4A, and 4B) 4A, and 4B)
Saturation (A3) Salt Crust (B11) Drainage Patterns (B10)
Water Marks (B1) Aquatic Invertebrates (B13) Dry-Season Water Table (C2)
Sediment Deposits (B2) Hydrogen Sulfide Odor (C1) Saturation Visible on Aerial Imagery (C9)
Drift Deposits (B3) Oxidized Rhizospheres along Living Roots (C3) Geomorphic Position (D2)
Algal Mat or Crust (B4) Presence of Reduced Iron (C4) Shallow Aquitard (D3)
Iron Deposits (B5) Recent Iron Reduction in Tilled Soils (C6) FAC-Neutral Test (D5)
Surface Soil Cracks (B6) Stunted or Stressed Plants (D1) (LRR A) Raised Ant Mounds (D6) (LRR A)
Inundation Visible on Aerial Imagery (B7) Other (Explain in Remarks) Frost-Heave Hummocks (D7)
Sparsely Vegetated Concave Surface (B8)
Field Observations:
Surface Water Present? Yes No Depth (inches):
Water Table Present? Yes No Depth (inches):
Saturation Present? Yes No Depth (inches):
(includes capillary fringe)
Wetland Hydrology Present? Yes No
Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available:
Remarks:
S2
0-14 10YR 3/2 100 Sandy Loam
14-17 2.5Y 4/3 100 Sandy Loam
4
4
4
4
4 4
US Army Corps of Engineers Western Mountains, Valleys, and Coast – Version 2.0
WETLAND DETERMINATION DATA FORM – Western Mountains, Valleys, and Coast Region
Project/Site: City/County: Sampling Date:
Applicant/Owner: State: Sampling Point:
Investigator(s): Section, Township, Range:
Landform (hillslope, terrace, etc.): Local relief (concave, convex, none): Slope (%):
Subregion (LRR): Lat: Long: Datum:
Soil Map Unit Name: NWI classification:
Are climatic / hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.)
Are Vegetation , Soil , or Hydrology significantly disturbed? Are “Normal Circumstances” present? Yes No
Are Vegetation , Soil , or Hydrology naturally problematic? (If needed, explain any answers in Remarks.)
SUMMARY OF FINDINGS – Attach site map showing sampling point locations, transects, important features, etc.
Hydrophytic Vegetation Present? Yes No
Hydric Soil Present? Yes No
Wetland Hydrology Present? Yes No
Is the Sampled Area
within a Wetland? Yes No
Remarks:
VEGETATION – Use scientific names of plants.
Absolute Dominant Indicator
Tree Stratum (Plot size: ) % Cover Species? Status
1.
2.
3.
4.
= Total Cover Sapling/Shrub Stratum (Plot size: )
1.
2.
3.
4.
5.
= Total Cover
Herb Stratum (Plot size: )
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
= Total Cover
Woody Vine Stratum (Plot size: )
1.
2.
= Total Cover
% Bare Ground in Herb Stratum
Dominance Test worksheet:
Number of Dominant Species
That Are OBL, FACW, or FAC: (A)
Total Number of Dominant
Species Across All Strata: (B)
Percent of Dominant Species
That Are OBL, FACW, or FAC: (A/B)
Prevalence Index worksheet:
Total % Cover of: Multiply by:
OBL species x 1 =
FACW species x 2 =
FAC species x 3 =
FACU species x 4 =
UPL species x 5 =
Column Totals: (A)(B)
Prevalence Index = B/A =
Hydrophytic Vegetation Indicators:
Rapid Test for Hydrophytic Vegetation
Dominance Test is >50%
Prevalence Index is ≤3.01
Morphological Adaptations1 (Provide supporting
data in Remarks or on a separate sheet)
Wetland Non-Vascular Plants1
Problematic Hydrophytic Vegetation1 (Explain)
1Indicators of hydric soil and wetland hydrology must
be present, unless disturbed or problematic.
Hydrophytic
Vegetation
Present? Yes No
Remarks:
Blue Fern Development - Vino Veritas Vista City of Renton 5/23/2018
Blue Fern Development, LLC WA S3
J. Rothwell, T. Amen S32, T24N, R05E, W.M.
Upland hillslope Concave 10%
LRR-A 47.529 -122.180 NAD83
Alderwood gravelly sandy loam, 8 to 15 percent slopes None
4
4
4
4
4 4
Upland - small depression on hillside
5m^2
Alnus rubra 100 Y FAC
100
3m^2
Rubus armeniacus 100 Y FAC
Salix sitchensis 30 Y FACW
130
1m^2
Equisetum telmateia 10 Y FACW
Polystichum munitum 5 Y FACU
15
3m^2
0
85
4
5
80%
0
0
0
0
0
0 0
4
4
US Army Corps of Engineers Western Mountains, Valleys, and Coast – Version 2.0
SOIL Sampling Point:
Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.)
Depth Matrix Redox Features
(inches) Color (moist) % Color (moist) % Type1 Loc2 Texture Remarks
1Type: C=Concentration, D=Depletion, RM=Reduced Matrix, CS=Covered or Coated Sand Grains. 2Location: PL=Pore Lining, M=Matrix.
Hydric Soil Indicators: (Applicable to all LRRs, unless otherwise noted.) Indicators for Problematic Hydric Soils3:
Histosol (A1) Sandy Redox (S5) 2 cm Muck (A10)
Histic Epipedon (A2) Stripped Matrix (S6) Red Parent Material (TF2)
Black Histic (A3) Loamy Mucky Mineral (F1) (except MLRA 1) Very Shallow Dark Surface (TF12)
Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Other (Explain in Remarks)
Depleted Below Dark Surface (A11) Depleted Matrix (F3)
Thick Dark Surface (A12) Redox Dark Surface (F6) 3Indicators of hydrophytic vegetation and
Sandy Mucky Mineral (S1) Depleted Dark Surface (F7) wetland hydrology must be present,
Sandy Gleyed Matrix (S4) Redox Depressions (F8) unless disturbed or problematic.
Restrictive Layer (if present):
Type:________________________________
Depth (inches):________________________
Hydric Soil Present? Yes No
Remarks:
HYDROLOGY
Wetland Hydrology Indicators:
Primary Indicators (minimum of one required; check all that apply) Secondary Indicators (2 or more required)
Surface Water (A1) Water-Stained Leaves (B9) (except MLRA Water-Stained Leaves (B9) (MLRA 1, 2,
High Water Table (A2) 1, 2, 4A, and 4B) 4A, and 4B)
Saturation (A3) Salt Crust (B11) Drainage Patterns (B10)
Water Marks (B1) Aquatic Invertebrates (B13) Dry-Season Water Table (C2)
Sediment Deposits (B2) Hydrogen Sulfide Odor (C1) Saturation Visible on Aerial Imagery (C9)
Drift Deposits (B3) Oxidized Rhizospheres along Living Roots (C3) Geomorphic Position (D2)
Algal Mat or Crust (B4) Presence of Reduced Iron (C4) Shallow Aquitard (D3)
Iron Deposits (B5) Recent Iron Reduction in Tilled Soils (C6) FAC-Neutral Test (D5)
Surface Soil Cracks (B6) Stunted or Stressed Plants (D1) (LRR A) Raised Ant Mounds (D6) (LRR A)
Inundation Visible on Aerial Imagery (B7) Other (Explain in Remarks) Frost-Heave Hummocks (D7)
Sparsely Vegetated Concave Surface (B8)
Field Observations:
Surface Water Present? Yes No Depth (inches):
Water Table Present? Yes No Depth (inches):
Saturation Present? Yes No Depth (inches):
(includes capillary fringe)
Wetland Hydrology Present? Yes No
Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available:
Remarks:
S3
0-6 10YR 2/2 100 Sandy Clay Loam
6-9 2.5Y 3/2 85 7.5YR 3/4 15 C M Sandy Loam
9-17 2.5Y 4/3 90 7.5YR 3/4 10 C M Sandy Loam
4
4
4
4
4
4 6"4
US Army Corps of Engineers Western Mountains, Valleys, and Coast – Version 2.0
WETLAND DETERMINATION DATA FORM – Western Mountains, Valleys, and Coast Region
Project/Site:
City/County:
Sampling Date:
Applicant/Owner:
State:
Sampling Point:
Investigator(s):
Section, Township, Range:
Landform (hillslope, terrace, etc.):
Local relief (concave, convex, none):
Slope (%):
Subregion (LRR):
Lat:
Long:
Datum:
Soil Map Unit Name:
NWI classification:
Are climatic / hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.)
Are Vegetation
, Soil
, or Hydrology
significantly disturbed? Are “Normal Circumstances” present? Yes No
Are Vegetation
, Soil
, or Hydrology
naturally problematic? (If needed, explain any answers in Remarks.)
SUMMARY OF FINDINGS – Attach site map showing sampling point locations, transects, important features, etc.
Hydrophytic Vegetation Present? Yes No
Hydric Soil Present? Yes No
Wetland Hydrology Present? Yes No
Is the Sampled Area
within a Wetland? Yes No
Remarks:
VEGETATION – Use scientific names of plants.
Absolute Dominant Indicator
Tree Stratum (Plot size:
) % Cover Species? Status
1.
2.
3.
4.
= Total Cover Sapling/Shrub Stratum (Plot size:
)
1.
2.
3.
4.
5.
= Total Cover
Herb Stratum (Plot size:
)
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
= Total Cover
Woody Vine Stratum (Plot size:
)
1.
2.
= Total Cover
% Bare Ground in Herb Stratum
Dominance Test worksheet:
Number of Dominant Species
That Are OBL, FACW, or FAC:
(A)
Total Number of Dominant
Species Across All Strata:
(B)
Percent of Dominant Species
That Are OBL, FACW, or FAC:
(A/B)
Prevalence Index worksheet:
Total % Cover of: Multiply by:
OBL species
x 1 =
FACW species
x 2 =
FAC species
x 3 =
FACU species
x 4 =
UPL species
x 5 =
Column Totals:
(A)
(B)
Prevalence Index = B/A =
Hydrophytic Vegetation Indicators:
Rapid Test for Hydrophytic Vegetation
Dominance Test is >50%
Prevalence Index is ≤3.01
Morphological Adaptations1 (Provide supporting
data in Remarks or on a separate sheet)
Wetland Non-Vascular Plants1
Problematic Hydrophytic Vegetation1 (Explain)
1Indicators of hydric soil and wetland hydrology must
be present, unless disturbed or problematic.
Hydrophytic
Vegetation
Present? Yes No
Remarks:
Blue Fern Development - Vino Veritas Vista City of Renton/King Co.5/23/2018
Blue Fern Development, LLC WA S5
J. Rothwell, T. Amen S32, T24N, R05E, W.M.
Upland hillslope None 9%
LRR-A 47.529 -122.180 NAD83
Alderwood gravelly sandy loam, 8 to 15 percent slopes None
4
4
4
4
4 4
Outside Wetland B
5m^2
Alnus rubra 90 Y FAC
90
3m^2
Rubus armeniacus 100 Y FAC
Crataegus monogyna 15 N FAC
115
1m^2
Polystichum munitum 15 Y FACU
Equisetum telmateia 5 Y FACW
20
3m^2
0
80
3
4
75%
0
0
0
0
0
0 0
4
4
US Army Corps of Engineers Western Mountains, Valleys, and Coast – Version 2.0
SOIL Sampling Point:
Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.)
Depth Matrix Redox Features
(inches) Color (moist) % Color (moist) % Type1 Loc2 Texture Remarks
1Type: C=Concentration, D=Depletion, RM=Reduced Matrix, CS=Covered or Coated Sand Grains. 2Location: PL=Pore Lining, M=Matrix.
Hydric Soil Indicators: (Applicable to all LRRs, unless otherwise noted.) Indicators for Problematic Hydric Soils3:
Histosol (A1) Sandy Redox (S5) 2 cm Muck (A10)
Histic Epipedon (A2) Stripped Matrix (S6) Red Parent Material (TF2)
Black Histic (A3) Loamy Mucky Mineral (F1) (except MLRA 1) Very Shallow Dark Surface (TF12)
Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Other (Explain in Remarks)
Depleted Below Dark Surface (A11) Depleted Matrix (F3)
Thick Dark Surface (A12) Redox Dark Surface (F6) 3Indicators of hydrophytic vegetation and
Sandy Mucky Mineral (S1) Depleted Dark Surface (F7) wetland hydrology must be present,
Sandy Gleyed Matrix (S4) Redox Depressions (F8) unless disturbed or problematic.
Restrictive Layer (if present):
Type:________________________________
Depth (inches):________________________
Hydric Soil Present? Yes No
Remarks:
HYDROLOGY
Wetland Hydrology Indicators:
Primary Indicators (minimum of one required; check all that apply) Secondary Indicators (2 or more required)
Surface Water (A1) Water-Stained Leaves (B9) (except MLRA Water-Stained Leaves (B9) (MLRA 1, 2,
High Water Table (A2) 1, 2, 4A, and 4B) 4A, and 4B)
Saturation (A3) Salt Crust (B11) Drainage Patterns (B10)
Water Marks (B1) Aquatic Invertebrates (B13) Dry-Season Water Table (C2)
Sediment Deposits (B2) Hydrogen Sulfide Odor (C1) Saturation Visible on Aerial Imagery (C9)
Drift Deposits (B3) Oxidized Rhizospheres along Living Roots (C3) Geomorphic Position (D2)
Algal Mat or Crust (B4) Presence of Reduced Iron (C4) Shallow Aquitard (D3)
Iron Deposits (B5) Recent Iron Reduction in Tilled Soils (C6) FAC-Neutral Test (D5)
Surface Soil Cracks (B6) Stunted or Stressed Plants (D1) (LRR A) Raised Ant Mounds (D6) (LRR A)
Inundation Visible on Aerial Imagery (B7) Other (Explain in Remarks) Frost-Heave Hummocks (D7)
Sparsely Vegetated Concave Surface (B8)
Field Observations:
Surface Water Present? Yes No Depth (inches):
Water Table Present? Yes No Depth (inches):
Saturation Present? Yes No Depth (inches):
(includes capillary fringe)
Wetland Hydrology Present? Yes No
Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available:
Remarks:
S5
0-10 10YR 3/2 100 Sandy Loam
10-17 10YR 3/3 98 10YR 4/4 2 C M Sandy Loam
4
4
4
4 4
US Army Corps of Engineers Western Mountains, Valleys, and Coast – Version 2.0
WETLAND DETERMINATION DATA FORM – Western Mountains, Valleys, and Coast Region
Project/Site:
City/County:
Sampling Date:
Applicant/Owner:
State:
Sampling Point:
Investigator(s):
Section, Township, Range:
Landform (hillslope, terrace, etc.):
Local relief (concave, convex, none):
Slope (%):
Subregion (LRR):
Lat:
Long:
Datum:
Soil Map Unit Name:
NWI classification:
Are climatic / hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.)
Are Vegetation
, Soil
, or Hydrology
significantly disturbed? Are “Normal Circumstances” present? Yes No
Are Vegetation
, Soil
, or Hydrology
naturally problematic? (If needed, explain any answers in Remarks.)
SUMMARY OF FINDINGS – Attach site map showing sampling point locations, transects, important features, etc.
Hydrophytic Vegetation Present? Yes No
Hydric Soil Present? Yes No
Wetland Hydrology Present? Yes No
Is the Sampled Area
within a Wetland? Yes No
Remarks:
VEGETATION – Use scientific names of plants.
Absolute Dominant Indicator
Tree Stratum (Plot size:
) % Cover Species? Status
1.
2.
3.
4.
= Total Cover Sapling/Shrub Stratum (Plot size:
)
1.
2.
3.
4.
5.
= Total Cover
Herb Stratum (Plot size:
)
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
= Total Cover
Woody Vine Stratum (Plot size:
)
1.
2.
= Total Cover
% Bare Ground in Herb Stratum
Dominance Test worksheet:
Number of Dominant Species
That Are OBL, FACW, or FAC:
(A)
Total Number of Dominant
Species Across All Strata:
(B)
Percent of Dominant Species
That Are OBL, FACW, or FAC:
(A/B)
Prevalence Index worksheet:
Total % Cover of: Multiply by:
OBL species
x 1 =
FACW species
x 2 =
FAC species
x 3 =
FACU species
x 4 =
UPL species
x 5 =
Column Totals:
(A)
(B)
Prevalence Index = B/A =
Hydrophytic Vegetation Indicators:
Rapid Test for Hydrophytic Vegetation
Dominance Test is >50%
Prevalence Index is ≤3.01
Morphological Adaptations1 (Provide supporting
data in Remarks or on a separate sheet)
Wetland Non-Vascular Plants1
Problematic Hydrophytic Vegetation1 (Explain)
1Indicators of hydric soil and wetland hydrology must
be present, unless disturbed or problematic.
Hydrophytic
Vegetation
Present? Yes No
Remarks:
Blue Fern Development - Vino Veritas Vista City of Renton/King Co.5/24/2018
Blue Fern Development, LLC WA S6 (Wet. A)
J. Rothwell S32, T24N, R05E, W.M.
Outwash hillslope None 15%
LRR-A 47.529 -122.180 NAD83
Alderwood gravelly sandy loam, 8 to 15 percent slopes PFO
4
4
4
4
4 4
Inside Wetland A
5m^2
Alnus rubra 100 Y FAC
100
3m^2
Rubus armeniacus 20 Y FAC
20
1m^2
Phalaris arundinacea 100 Y FACW
Ranunculus repens 20 N FAC
Convolvulus arvensis Trace N NI
120
3m^2
0
0
3
3
100%
0
0
0
0
0
0 0
4
4
US Army Corps of Engineers Western Mountains, Valleys, and Coast – Version 2.0
SOIL Sampling Point:
Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.)
Depth Matrix Redox Features
(inches) Color (moist) % Color (moist) % Type1 Loc2 Texture Remarks
1Type: C=Concentration, D=Depletion, RM=Reduced Matrix, CS=Covered or Coated Sand Grains. 2Location: PL=Pore Lining, M=Matrix.
Hydric Soil Indicators: (Applicable to all LRRs, unless otherwise noted.) Indicators for Problematic Hydric Soils3:
Histosol (A1) Sandy Redox (S5) 2 cm Muck (A10)
Histic Epipedon (A2) Stripped Matrix (S6) Red Parent Material (TF2)
Black Histic (A3) Loamy Mucky Mineral (F1) (except MLRA 1) Very Shallow Dark Surface (TF12)
Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Other (Explain in Remarks)
Depleted Below Dark Surface (A11) Depleted Matrix (F3)
Thick Dark Surface (A12) Redox Dark Surface (F6) 3Indicators of hydrophytic vegetation and
Sandy Mucky Mineral (S1) Depleted Dark Surface (F7) wetland hydrology must be present,
Sandy Gleyed Matrix (S4) Redox Depressions (F8) unless disturbed or problematic.
Restrictive Layer (if present):
Type:________________________________
Depth (inches):________________________
Hydric Soil Present? Yes No
Remarks:
HYDROLOGY
Wetland Hydrology Indicators:
Primary Indicators (minimum of one required; check all that apply) Secondary Indicators (2 or more required)
Surface Water (A1) Water-Stained Leaves (B9) (except MLRA Water-Stained Leaves (B9) (MLRA 1, 2,
High Water Table (A2) 1, 2, 4A, and 4B) 4A, and 4B)
Saturation (A3) Salt Crust (B11) Drainage Patterns (B10)
Water Marks (B1) Aquatic Invertebrates (B13) Dry-Season Water Table (C2)
Sediment Deposits (B2) Hydrogen Sulfide Odor (C1) Saturation Visible on Aerial Imagery (C9)
Drift Deposits (B3) Oxidized Rhizospheres along Living Roots (C3) Geomorphic Position (D2)
Algal Mat or Crust (B4) Presence of Reduced Iron (C4) Shallow Aquitard (D3)
Iron Deposits (B5) Recent Iron Reduction in Tilled Soils (C6) FAC-Neutral Test (D5)
Surface Soil Cracks (B6) Stunted or Stressed Plants (D1) (LRR A) Raised Ant Mounds (D6) (LRR A)
Inundation Visible on Aerial Imagery (B7) Other (Explain in Remarks) Frost-Heave Hummocks (D7)
Sparsely Vegetated Concave Surface (B8)
Field Observations:
Surface Water Present? Yes No Depth (inches):
Water Table Present? Yes No Depth (inches):
Saturation Present? Yes No Depth (inches):
(includes capillary fringe)
Wetland Hydrology Present? Yes No
Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available:
Remarks:
S6 (Wet. A)
0-16 7.5YR 2.5/1 100 Loam
4
Despite lack of visible indicators, soil is considered hydric due to presence of hydrophytic plant community and strong
presence of hydrology. Determination based on best professional judgment.
Possibly meets Thick Dark Surface (A12) indicator.
4
4
4
4
4 9"
4 Surface 4
US Army Corps of Engineers Western Mountains, Valleys, and Coast – Version 2.0
WETLAND DETERMINATION DATA FORM – Western Mountains, Valleys, and Coast Region
Project/Site:
City/County:
Sampling Date:
Applicant/Owner:
State:
Sampling Point:
Investigator(s):
Section, Township, Range:
Landform (hillslope, terrace, etc.):
Local relief (concave, convex, none):
Slope (%):
Subregion (LRR):
Lat:
Long:
Datum:
Soil Map Unit Name:
NWI classification:
Are climatic / hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.)
Are Vegetation
, Soil
, or Hydrology
significantly disturbed? Are “Normal Circumstances” present? Yes No
Are Vegetation
, Soil
, or Hydrology
naturally problematic? (If needed, explain any answers in Remarks.)
SUMMARY OF FINDINGS – Attach site map showing sampling point locations, transects, important features, etc.
Hydrophytic Vegetation Present? Yes No
Hydric Soil Present? Yes No
Wetland Hydrology Present? Yes No
Is the Sampled Area
within a Wetland? Yes No
Remarks:
VEGETATION – Use scientific names of plants.
Absolute Dominant Indicator
Tree Stratum (Plot size:
) % Cover Species? Status
1.
2.
3.
4.
= Total Cover Sapling/Shrub Stratum (Plot size:
)
1.
2.
3.
4.
5.
= Total Cover
Herb Stratum (Plot size:
)
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
= Total Cover
Woody Vine Stratum (Plot size:
)
1.
2.
= Total Cover
% Bare Ground in Herb Stratum
Dominance Test worksheet:
Number of Dominant Species
That Are OBL, FACW, or FAC:
(A)
Total Number of Dominant
Species Across All Strata:
(B)
Percent of Dominant Species
That Are OBL, FACW, or FAC:
(A/B)
Prevalence Index worksheet:
Total % Cover of: Multiply by:
OBL species
x 1 =
FACW species
x 2 =
FAC species
x 3 =
FACU species
x 4 =
UPL species
x 5 =
Column Totals:
(A)
(B)
Prevalence Index = B/A =
Hydrophytic Vegetation Indicators:
Rapid Test for Hydrophytic Vegetation
Dominance Test is >50%
Prevalence Index is ≤3.01
Morphological Adaptations1 (Provide supporting
data in Remarks or on a separate sheet)
Wetland Non-Vascular Plants1
Problematic Hydrophytic Vegetation1 (Explain)
1Indicators of hydric soil and wetland hydrology must
be present, unless disturbed or problematic.
Hydrophytic
Vegetation
Present? Yes No
Remarks:
Blue Fern Development - Vino Veritas Vista City of Renton/King Co.5/24/2018
Blue Fern Development, LLC WA S7
J. Rothwell S32, T24N, R05E, W.M.
Upland hillslope None 15%
LRR-A 47.529 -122.180 NAD83
Alderwood gravelly sandy loam, 8 to 15 percent slopes
4
4
4
4
4 4
Outside Wetland A
5m^2
Alnus rubra 50 Y FAC
50
3m^2
Rubus armeniacus 10 Y FAC
10
1m^2
Phalaris arundinacea 40 Y FACW
Equisetum sp.30 Y
Ranunculus repens 15 N FAC
Gallium aparine 10 N FACU
Polystichum munitum 5 N FACU
100
3m^2
0
0
3
4
75%
0
0
0
0
0
0 0
4
4
US Army Corps of Engineers Western Mountains, Valleys, and Coast – Version 2.0
SOIL Sampling Point:
Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.)
Depth Matrix Redox Features
(inches) Color (moist) % Color (moist) % Type1 Loc2 Texture Remarks
1Type: C=Concentration, D=Depletion, RM=Reduced Matrix, CS=Covered or Coated Sand Grains. 2Location: PL=Pore Lining, M=Matrix.
Hydric Soil Indicators: (Applicable to all LRRs, unless otherwise noted.) Indicators for Problematic Hydric Soils3:
Histosol (A1) Sandy Redox (S5) 2 cm Muck (A10)
Histic Epipedon (A2) Stripped Matrix (S6) Red Parent Material (TF2)
Black Histic (A3) Loamy Mucky Mineral (F1) (except MLRA 1) Very Shallow Dark Surface (TF12)
Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Other (Explain in Remarks)
Depleted Below Dark Surface (A11) Depleted Matrix (F3)
Thick Dark Surface (A12) Redox Dark Surface (F6) 3Indicators of hydrophytic vegetation and
Sandy Mucky Mineral (S1) Depleted Dark Surface (F7) wetland hydrology must be present,
Sandy Gleyed Matrix (S4) Redox Depressions (F8) unless disturbed or problematic.
Restrictive Layer (if present):
Type:________________________________
Depth (inches):________________________
Hydric Soil Present? Yes No
Remarks:
HYDROLOGY
Wetland Hydrology Indicators:
Primary Indicators (minimum of one required; check all that apply) Secondary Indicators (2 or more required)
Surface Water (A1) Water-Stained Leaves (B9) (except MLRA Water-Stained Leaves (B9) (MLRA 1, 2,
High Water Table (A2) 1, 2, 4A, and 4B) 4A, and 4B)
Saturation (A3) Salt Crust (B11) Drainage Patterns (B10)
Water Marks (B1) Aquatic Invertebrates (B13) Dry-Season Water Table (C2)
Sediment Deposits (B2) Hydrogen Sulfide Odor (C1) Saturation Visible on Aerial Imagery (C9)
Drift Deposits (B3) Oxidized Rhizospheres along Living Roots (C3) Geomorphic Position (D2)
Algal Mat or Crust (B4) Presence of Reduced Iron (C4) Shallow Aquitard (D3)
Iron Deposits (B5) Recent Iron Reduction in Tilled Soils (C6) FAC-Neutral Test (D5)
Surface Soil Cracks (B6) Stunted or Stressed Plants (D1) (LRR A) Raised Ant Mounds (D6) (LRR A)
Inundation Visible on Aerial Imagery (B7) Other (Explain in Remarks) Frost-Heave Hummocks (D7)
Sparsely Vegetated Concave Surface (B8)
Field Observations:
Surface Water Present? Yes No Depth (inches):
Water Table Present? Yes No Depth (inches):
Saturation Present? Yes No Depth (inches):
(includes capillary fringe)
Wetland Hydrology Present? Yes No
Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available:
Remarks:
S7
0-18 10YR 3/2 100 Sandy Loam Very gritty texture
4
4
4
4 4
US Army Corps of Engineers Western Mountains, Valleys, and Coast – Version 2.0
WETLAND DETERMINATION DATA FORM – Western Mountains, Valleys, and Coast Region
Project/Site:
City/County:
Sampling Date:
Applicant/Owner:
State:
Sampling Point:
Investigator(s):
Section, Township, Range:
Landform (hillslope, terrace, etc.):
Local relief (concave, convex, none):
Slope (%):
Subregion (LRR):
Lat:
Long:
Datum:
Soil Map Unit Name:
NWI classification:
Are climatic / hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.)
Are Vegetation
, Soil
, or Hydrology
significantly disturbed? Are “Normal Circumstances” present? Yes No
Are Vegetation
, Soil
, or Hydrology
naturally problematic? (If needed, explain any answers in Remarks.)
SUMMARY OF FINDINGS – Attach site map showing sampling point locations, transects, important features, etc.
Hydrophytic Vegetation Present? Yes No
Hydric Soil Present? Yes No
Wetland Hydrology Present? Yes No
Is the Sampled Area
within a Wetland? Yes No
Remarks:
VEGETATION – Use scientific names of plants.
Absolute Dominant Indicator
Tree Stratum (Plot size:
) % Cover Species? Status
1.
2.
3.
4.
= Total Cover Sapling/Shrub Stratum (Plot size:
)
1.
2.
3.
4.
5.
= Total Cover
Herb Stratum (Plot size:
)
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
= Total Cover
Woody Vine Stratum (Plot size:
)
1.
2.
= Total Cover
% Bare Ground in Herb Stratum
Dominance Test worksheet:
Number of Dominant Species
That Are OBL, FACW, or FAC:
(A)
Total Number of Dominant
Species Across All Strata:
(B)
Percent of Dominant Species
That Are OBL, FACW, or FAC:
(A/B)
Prevalence Index worksheet:
Total % Cover of: Multiply by:
OBL species
x 1 =
FACW species
x 2 =
FAC species
x 3 =
FACU species
x 4 =
UPL species
x 5 =
Column Totals:
(A)
(B)
Prevalence Index = B/A =
Hydrophytic Vegetation Indicators:
Rapid Test for Hydrophytic Vegetation
Dominance Test is >50%
Prevalence Index is ≤3.01
Morphological Adaptations1 (Provide supporting
data in Remarks or on a separate sheet)
Wetland Non-Vascular Plants1
Problematic Hydrophytic Vegetation1 (Explain)
1Indicators of hydric soil and wetland hydrology must
be present, unless disturbed or problematic.
Hydrophytic
Vegetation
Present? Yes No
Remarks:
Blue Fern Development - Vino Veritas Vista City of Renton/King Co.5/24/2018
Blue Fern Development, LLC WA S8 (Wet. D)
J. Rothwell S32, T24N, R05E, W.M.
Hillslope None 15%
LRR-A 47.529 -122.180 NAD83
Alderwood gravelly sandy loam, 8 to 15 percent slopes PEM/PSS
4
4
4
4
4 4
Inside Wetland D
5m^2
Alnus rubra 15 Y FAC
Prunus sp.10 Y
25
3m^2
Rubus armeniacus 25 Y FAC
Salix sitchensis 10 Y FACW
Cornus sericea 5 N FACW
40
1m^2
Glyceria striata 90 Y OBL
Carex stipata 10 N OBL
Equisetum telmateia 5 N FACW
Ranunculus repens Trace N FAC
Geranium robertianum Trace N FACU
105
3m^2
0
0
4
5
80%
0
0
0
0
0
0 0
4
4
US Army Corps of Engineers Western Mountains, Valleys, and Coast – Version 2.0
SOIL Sampling Point:
Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.)
Depth Matrix Redox Features
(inches) Color (moist) % Color (moist) % Type1 Loc2 Texture Remarks
1Type: C=Concentration, D=Depletion, RM=Reduced Matrix, CS=Covered or Coated Sand Grains. 2Location: PL=Pore Lining, M=Matrix.
Hydric Soil Indicators: (Applicable to all LRRs, unless otherwise noted.) Indicators for Problematic Hydric Soils3:
Histosol (A1) Sandy Redox (S5) 2 cm Muck (A10)
Histic Epipedon (A2) Stripped Matrix (S6) Red Parent Material (TF2)
Black Histic (A3) Loamy Mucky Mineral (F1) (except MLRA 1) Very Shallow Dark Surface (TF12)
Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Other (Explain in Remarks)
Depleted Below Dark Surface (A11) Depleted Matrix (F3)
Thick Dark Surface (A12) Redox Dark Surface (F6) 3Indicators of hydrophytic vegetation and
Sandy Mucky Mineral (S1) Depleted Dark Surface (F7) wetland hydrology must be present,
Sandy Gleyed Matrix (S4) Redox Depressions (F8) unless disturbed or problematic.
Restrictive Layer (if present):
Type:________________________________
Depth (inches):________________________
Hydric Soil Present? Yes No
Remarks:
HYDROLOGY
Wetland Hydrology Indicators:
Primary Indicators (minimum of one required; check all that apply) Secondary Indicators (2 or more required)
Surface Water (A1) Water-Stained Leaves (B9) (except MLRA Water-Stained Leaves (B9) (MLRA 1, 2,
High Water Table (A2) 1, 2, 4A, and 4B) 4A, and 4B)
Saturation (A3) Salt Crust (B11) Drainage Patterns (B10)
Water Marks (B1) Aquatic Invertebrates (B13) Dry-Season Water Table (C2)
Sediment Deposits (B2) Hydrogen Sulfide Odor (C1) Saturation Visible on Aerial Imagery (C9)
Drift Deposits (B3) Oxidized Rhizospheres along Living Roots (C3) Geomorphic Position (D2)
Algal Mat or Crust (B4) Presence of Reduced Iron (C4) Shallow Aquitard (D3)
Iron Deposits (B5) Recent Iron Reduction in Tilled Soils (C6) FAC-Neutral Test (D5)
Surface Soil Cracks (B6) Stunted or Stressed Plants (D1) (LRR A) Raised Ant Mounds (D6) (LRR A)
Inundation Visible on Aerial Imagery (B7) Other (Explain in Remarks) Frost-Heave Hummocks (D7)
Sparsely Vegetated Concave Surface (B8)
Field Observations:
Surface Water Present? Yes No Depth (inches):
Water Table Present? Yes No Depth (inches):
Saturation Present? Yes No Depth (inches):
(includes capillary fringe)
Wetland Hydrology Present? Yes No
Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available:
Remarks:
S8 (Wet. D)
0-8 10YR 2/2 100 Clay Loam
8-11 10YR 3/2 95 7.5YR 2.5/3 5 C M Clay Loam
11-17 10YR 4/2 93 7.5YR 2.5/3 7 C M Clay Loam
4
4
4
4
4
4
4 8"4
US Army Corps of Engineers Western Mountains, Valleys, and Coast – Version 2.0
WETLAND DETERMINATION DATA FORM – Western Mountains, Valleys, and Coast Region
Project/Site:
City/County:
Sampling Date:
Applicant/Owner:
State:
Sampling Point:
Investigator(s):
Section, Township, Range:
Landform (hillslope, terrace, etc.):
Local relief (concave, convex, none):
Slope (%):
Subregion (LRR):
Lat:
Long:
Datum:
Soil Map Unit Name:
NWI classification:
Are climatic / hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.)
Are Vegetation
, Soil
, or Hydrology
significantly disturbed? Are “Normal Circumstances” present? Yes No
Are Vegetation
, Soil
, or Hydrology
naturally problematic? (If needed, explain any answers in Remarks.)
SUMMARY OF FINDINGS – Attach site map showing sampling point locations, transects, important features, etc.
Hydrophytic Vegetation Present? Yes No
Hydric Soil Present? Yes No
Wetland Hydrology Present? Yes No
Is the Sampled Area
within a Wetland? Yes No
Remarks:
VEGETATION – Use scientific names of plants.
Absolute Dominant Indicator
Tree Stratum (Plot size:
) % Cover Species? Status
1.
2.
3.
4.
= Total Cover Sapling/Shrub Stratum (Plot size:
)
1.
2.
3.
4.
5.
= Total Cover
Herb Stratum (Plot size:
)
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
= Total Cover
Woody Vine Stratum (Plot size:
)
1.
2.
= Total Cover
% Bare Ground in Herb Stratum
Dominance Test worksheet:
Number of Dominant Species
That Are OBL, FACW, or FAC:
(A)
Total Number of Dominant
Species Across All Strata:
(B)
Percent of Dominant Species
That Are OBL, FACW, or FAC:
(A/B)
Prevalence Index worksheet:
Total % Cover of: Multiply by:
OBL species
x 1 =
FACW species
x 2 =
FAC species
x 3 =
FACU species
x 4 =
UPL species
x 5 =
Column Totals:
(A)
(B)
Prevalence Index = B/A =
Hydrophytic Vegetation Indicators:
Rapid Test for Hydrophytic Vegetation
Dominance Test is >50%
Prevalence Index is ≤3.01
Morphological Adaptations1 (Provide supporting
data in Remarks or on a separate sheet)
Wetland Non-Vascular Plants1
Problematic Hydrophytic Vegetation1 (Explain)
1Indicators of hydric soil and wetland hydrology must
be present, unless disturbed or problematic.
Hydrophytic
Vegetation
Present? Yes No
Remarks:
Blue Fern Development - Vino Veritas Vista City of Renton/King Co.5/24/2018
Blue Fern Development, LLC WA S9
J. Rothwell S32, T24N, R05E, W.M.
Upland hillslope None 15%
LRR-A 47.529 -122.180 NAD83
Alderwood gravelly sandy loam, 8 to 15 percent slopes None
4
4
4
4
4 4
Outside Wetland D
5m^2
0
3m^2
Rubus armeniacus 60 Y FAC
60
1m^2
Polystichum munitum 25 Y FACU
Juncus effusus 20 Y FACW
Poa sp.10 N FAC
Epilobium ciliatum 10 N FACW
Carex stipata Trace N OBL
65
3m^2
35
2
3
66%
0
0
0
0
0
0 0
4
4
US Army Corps of Engineers Western Mountains, Valleys, and Coast – Version 2.0
SOIL Sampling Point:
Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.)
Depth Matrix Redox Features
(inches) Color (moist) % Color (moist) % Type1 Loc2 Texture Remarks
1Type: C=Concentration, D=Depletion, RM=Reduced Matrix, CS=Covered or Coated Sand Grains. 2Location: PL=Pore Lining, M=Matrix.
Hydric Soil Indicators: (Applicable to all LRRs, unless otherwise noted.) Indicators for Problematic Hydric Soils3:
Histosol (A1) Sandy Redox (S5) 2 cm Muck (A10)
Histic Epipedon (A2) Stripped Matrix (S6) Red Parent Material (TF2)
Black Histic (A3) Loamy Mucky Mineral (F1) (except MLRA 1) Very Shallow Dark Surface (TF12)
Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Other (Explain in Remarks)
Depleted Below Dark Surface (A11) Depleted Matrix (F3)
Thick Dark Surface (A12) Redox Dark Surface (F6) 3Indicators of hydrophytic vegetation and
Sandy Mucky Mineral (S1) Depleted Dark Surface (F7) wetland hydrology must be present,
Sandy Gleyed Matrix (S4) Redox Depressions (F8) unless disturbed or problematic.
Restrictive Layer (if present):
Type:________________________________
Depth (inches):________________________
Hydric Soil Present? Yes No
Remarks:
HYDROLOGY
Wetland Hydrology Indicators:
Primary Indicators (minimum of one required; check all that apply) Secondary Indicators (2 or more required)
Surface Water (A1) Water-Stained Leaves (B9) (except MLRA Water-Stained Leaves (B9) (MLRA 1, 2,
High Water Table (A2) 1, 2, 4A, and 4B) 4A, and 4B)
Saturation (A3) Salt Crust (B11) Drainage Patterns (B10)
Water Marks (B1) Aquatic Invertebrates (B13) Dry-Season Water Table (C2)
Sediment Deposits (B2) Hydrogen Sulfide Odor (C1) Saturation Visible on Aerial Imagery (C9)
Drift Deposits (B3) Oxidized Rhizospheres along Living Roots (C3) Geomorphic Position (D2)
Algal Mat or Crust (B4) Presence of Reduced Iron (C4) Shallow Aquitard (D3)
Iron Deposits (B5) Recent Iron Reduction in Tilled Soils (C6) FAC-Neutral Test (D5)
Surface Soil Cracks (B6) Stunted or Stressed Plants (D1) (LRR A) Raised Ant Mounds (D6) (LRR A)
Inundation Visible on Aerial Imagery (B7) Other (Explain in Remarks) Frost-Heave Hummocks (D7)
Sparsely Vegetated Concave Surface (B8)
Field Observations:
Surface Water Present? Yes No Depth (inches):
Water Table Present? Yes No Depth (inches):
Saturation Present? Yes No Depth (inches):
(includes capillary fringe)
Wetland Hydrology Present? Yes No
Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available:
Remarks:
S9
0-18 10YR 2/2 98 7.5YR 3/4 2 C M Sandy Loam
4
4
4
4 4
APPENDIX B
DOE WETLAND RATING
FORMS
THIS PAGE IS INTENTIONALLY LEFT BLANK
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 1
Rating Form – Effective January 1, 2015
Score for each function based on three ratings (order of ratings is not important)
9 = H,H,H
8 = H,H,M
7 = H,H,L
7 = H,M,M
6 = H,M,L
6 = M,M,M
5 = H,L,L
5 = M,M,L
4 = M,L,L
3 = L,L,L
RATING SUMMARY – Western Washington
Name of wetland (or ID #): _________________________________ Date of site visit: _____
Rated by____________________________ Trained by Ecology?__ Yes ___No Date of training______
HGM Class used for rating_________________ Wetland has multiple HGM classes?___Y ____N
NOTE: Form is not complete without the figures requested (figures can be combined).
Source of base aerial photo/map ______________________________________
OVERALL WETLAND CATEGORY ____ (based on functions___ or special characteristics___)
1. Category of wetland based on FUNCTIONS
_______Category I – Total score = 23 - 27
_______Category II – Total score = 20 - 22
_______Category III – Total score = 16 - 19
_______Category IV – Total score = 9 - 15
FUNCTION
Improving
Water Quality
Hydrologic
Habitat
Circle the appropriate ratings
Site Potential H M L H M L H M L
Landscape Potential H M L H M L H M L
Value H M L H M L H M L TOTAL
Score Based on
Ratings
2. Category based on SPECIAL CHARACTERISTICS of wetland
CHARACTERISTIC CATEGORY
Estuarine I II
Wetland of High Conservation Value I
Bog I
Mature Forest I
Old Growth Forest I
Coastal Lagoon I II
Interdunal I II III IV
None of the above
A
6 5 4 15
4
Wetland A 5/23/18
T. Amen, J. Rothwell 4 6/17
SLOPE 4
King County iMap
IV 4
4
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 2
Rating Form – Effective January 1, 2015
Maps and figures required to answer questions correctly for
Western Washington
Depressional Wetlands
Map of: To answer questions: Figure #
Cowardin plant classes D 1.3, H 1.1, H 1.4
Hydroperiods D 1.4, H 1.2
Location of outlet (can be added to map of hydroperiods) D 1.1, D 4.1
Boundary of area within 150 ft of the wetland (can be added to another figure) D 2.2, D 5.2
Map of the contributing basin D 4.3, D 5.3
1 km Polygon: Area that extends 1 km from entire wetland edge - including
polygons for accessible habitat and undisturbed habitat
H 2.1, H 2.2, H 2.3
Screen capture of map of 303(d) listed waters in basin (from Ecology website) D 3.1, D 3.2
Screen capture of list of TMDLs for WRIA in which unit is found (from web) D 3.3
Riverine Wetlands
Map of: To answer questions: Figure #
Cowardin plant classes H 1.1, H 1.4
Hydroperiods H 1.2
Ponded depressions R 1.1
Boundary of area within 150 ft of the wetland (can be added to another figure) R 2.4
Plant cover of trees, shrubs, and herbaceous plants R 1.2, R 4.2
Width of unit vs. width of stream (can be added to another figure) R 4.1
Map of the contributing basin R 2.2, R 2.3, R 5.2
1 km Polygon: Area that extends 1 km from entire wetland edge - including
polygons for accessible habitat and undisturbed habitat
H 2.1, H 2.2, H 2.3
Screen capture of map of 303(d) listed waters in basin (from Ecology website) R 3.1
Screen capture of list of TMDLs for WRIA in which unit is found (from web) R 3.2, R 3.3
Lake Fringe Wetlands
Map of: To answer questions: Figure #
Cowardin plant classes L 1.1, L 4.1, H 1.1, H 1.4
Plant cover of trees, shrubs, and herbaceous plants L 1.2
Boundary of area within 150 ft of the wetland (can be added to another figure) L 2.2
1 km Polygon: Area that extends 1 km from entire wetland edge - including
polygons for accessible habitat and undisturbed habitat
H 2.1, H 2.2, H 2.3
Screen capture of map of 303(d) listed waters in basin (from Ecology website) L 3.1, L 3.2
Screen capture of list of TMDLs for WRIA in which unit is found (from web) L 3.3
Slope Wetlands
Map of: To answer questions: Figure #
Cowardin plant classes H 1.1, H 1.4
Hydroperiods H 1.2
Plant cover of dense trees, shrubs, and herbaceous plants S 1.3
Plant cover of dense, rigid trees, shrubs, and herbaceous plants
(can be added to figure above)
S 4.1
Boundary of 150 ft buffer (can be added to another figure) S 2.1, S 5.1
1 km Polygon: Area that extends 1 km from entire wetland edge - including
polygons for accessible habitat and undisturbed habitat
H 2.1, H 2.2, H 2.3
Screen capture of map of 303(d) listed waters in basin (from Ecology website) S 3.1, S 3.2
Screen capture of list of TMDLs for WRIA in which unit is found (from web) S 3.3
A
A1
A1
A1
A5
A1
A2
A3
A4
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 3
Rating Form – Effective January 1, 2015
HGM Classification of Wetlands in Western Washington
1. Are the water levels in the entire unit usually controlled by tides except during floods?
NO – go to 2 YES – the wetland class is Tidal Fringe – go to 1.1
1.1 Is the salinity of the water during periods of annual low flow below 0.5 ppt (parts per thousand)?
NO – Saltwater Tidal Fringe (Estuarine) YES – Freshwater Tidal Fringe
If your wetland can be classified as a Freshwater Tidal Fringe use the forms for Riverine wetlands. If it
is Saltwater Tidal Fringe it is an Estuarine wetland and is not scored. This method cannot be used to
score functions for estuarine wetlands.
2. The entire wetland unit is flat and precipitation is the only source (>90%) of water to it. Groundwater
and surface water runoff are NOT sources of water to the unit.
NO – go to 3 YES – The wetland class is Flats
If your wetland can be classified as a Flats wetland, use the form for Depressional wetlands.
3. Does the entire wetland unit meet all of the following criteria?
___The vegetated part of the wetland is on the shores of a body of permanent open water (without any
plants on the surface at any time of the year) at least 20 ac (8 ha) in size;
___At least 30% of the open water area is deeper than 6.6 ft (2 m).
NO – go to 4 YES – The wetland class is Lake Fringe (Lacustrine Fringe)
4. Does the entire wetland unit meet all of the following criteria?
____The wetland is on a slope (slope can be very gradual),
____The water flows through the wetland in one direction (unidirectional) and usually comes from
seeps. It may flow subsurface, as sheetflow, or in a swale without distinct banks,
____The water leaves the wetland without being impounded.
NO – go to 5 YES – The wetland class is Slope
NOTE: Surface water does not pond in these type of wetlands except occasionally in very small and
shallow depressions or behind hummocks (depressions are usually <3 ft diameter and less than 1 ft
deep).
5. Does the entire wetland unit meet all of the following criteria?
____The unit is in a valley, or stream channel, where it gets inundated by overbank flooding from that
stream or river,
____The overbank flooding occurs at least once every 2 years.
For questions 1-7, the criteria described must apply to the entire unit being rated.
If the hydrologic criteria listed in each question do not apply to the entire unit being rated, you
probably have a unit with multiple HGM classes. In this case, identify which hydrologic criteria in
questions 1-7 apply, and go to Question 8.
A
4
4
4
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 4
Rating Form – Effective January 1, 2015
NO – go to 6 YES – The wetland class is Riverine
NOTE: The Riverine unit can contain depressions that are filled with water when the river is not
flooding
6. Is the entire wetland unit in a topographic depression in which water ponds, or is saturated to the
surface, at some time during the year? This means that any outlet, if present, is higher than the interior
of the wetland.
NO – go to 7 YES – The wetland class is Depressional
7. Is the entire wetland unit located in a very flat area with no obvious depression and no overbank
flooding? The unit does not pond surface water more than a few inches. The unit seems to be
maintained by high groundwater in the area. The wetland may be ditched, but has no obvious natural
outlet.
NO – go to 8 YES – The wetland class is Depressional
8. Your wetland unit seems to be difficult to classify and probably contains several different HGM
classes. For example, seeps at the base of a slope may grade into a riverine floodplain, or a small
stream within a Depressional wetland has a zone of flooding along its sides. GO BACK AND IDENTIFY
WHICH OF THE HYDROLOGIC REGIMES DESCRIBED IN QUESTIONS 1-7 APPLY TO DIFFERENT
AREAS IN THE UNIT (make a rough sketch to help you decide). Use the following table to identify the
appropriate class to use for the rating system if you have several HGM classes present within the
wetland unit being scored.
NOTE: Use this table only if the class that is recommended in the second column represents 10% or
more of the total area of the wetland unit being rated. If the area of the HGM class listed in column 2
is less than 10% of the unit; classify the wetland using the class that represents more than 90% of the
total area.
HGM classes within the wetland unit
being rated
HGM class to
use in rating
Slope + Riverine Riverine
Slope + Depressional Depressional
Slope + Lake Fringe Lake Fringe
Depressional + Riverine along stream
within boundary of depression
Depressional
Depressional + Lake Fringe Depressional
Riverine + Lake Fringe Riverine
Salt Water Tidal Fringe and any other
class of freshwater wetland
Treat as
ESTUARINE
If you are still unable to determine which of the above criteria apply to your wetland, or if you have
more than 2 HGM classes within a wetland boundary, classify the wetland as Depressional for the
rating.
A
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 11
Rating Form – Effective January 1, 2015
SLOPE WETLANDS
Water Quality Functions - Indicators that the site functions to improve water quality
S 1.0. Does the site have the potential to improve water quality?
S 1.1. Characteristics of the average slope of the wetland: (a 1% slope has a 1 ft vertical drop in elevation for every
100 ft of horizontal distance)
Slope is 1% or less points = 3
Slope is > 1%-2% points = 2
Slope is > 2%-5% points = 1
Slope is greater than 5% points = 0
S 1.2. The soil 2 in below the surface (or duff layer) is true clay or true organic (use NRCS definitions): Yes = 3 No = 0
S 1.3. Characteristics of the plants in the wetland that trap sediments and pollutants:
Choose the points appropriate for the description that best fits the plants in the wetland. Dense means you
have trouble seeing the soil surface (>75% cover), and uncut means not grazed or mowed and plants are higher
than 6 in.
Dense, uncut, herbaceous plants > 90% of the wetland area points = 6
Dense, uncut, herbaceous plants > ½ of area points = 3
Dense, woody, plants > ½ of area points = 2
Dense, uncut, herbaceous plants > ¼ of area points = 1
Does not meet any of the criteria above for plants points = 0
Total for S 1 Add the points in the boxes above
Rating of Site Potential If score is: 12 = H 6-11 = M 0-5 = L Record the rating on the first page
S 2.0. Does the landscape have the potential to support the water quality function of the site?
S 2.1. Is > 10% of the area within 150 ft on the uphill side of the wetland in land uses that generate pollutants?
Yes = 1 No = 0
S 2.2. Are there other sources of pollutants coming into the wetland that are not listed in question S 2.1?
Other sources ________________ Yes = 1 No = 0
Total for S 2 Add the points in the boxes above
Rating of Landscape Potential If score is: 1-2 = M 0 = L Record the rating on the first page
S 3.0. Is the water quality improvement provided by the site valuable to society?
S 3.1. Does the wetland discharge directly (i.e., within 1 mi) to a stream, river, lake, or marine water that is on the
303(d) list? Yes = 1 No = 0
S 3.2. Is the wetland in a basin or sub-basin where water quality is an issue? At least one aquatic resource in the basin is
on the 303(d) list. Yes = 1 No = 0
S 3.3. Has the site been identified in a watershed or local plan as important for maintaining water quality? Answer YES
if there is a TMDL for the basin in which unit is found. Yes = 2 No = 0
Total for S 3 Add the points in the boxes above
Rating of Value If score is: 2-4 = H 1 = M 0 = L Record the rating on the first page
A
4
0
0
4
2
2
4
0
1
0
1
4
1
2
3
4
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 12
Rating Form – Effective January 1, 2015
SLOPE WETLANDS
Hydrologic Functions - Indicators that the site functions to reduce flooding and stream erosion
S 4.0. Does the site have the potential to reduce flooding and stream erosion?
S 4.1. Characteristics of plants that reduce the velocity of surface flows during storms: Choose the points appropriate
for the description that best fits conditions in the wetland. Stems of plants should be thick enough (usually > 1/8
in), or dense enough, to remain erect during surface flows.
Dense, uncut, rigid plants cover > 90% of the area of the wetland points = 1
All other conditions points = 0
Rating of Site Potential If score is: 1 = M 0 = L Record the rating on the first page
S 5.0. Does the landscape have the potential to support the hydrologic functions of the site?
S 5.1. Is more than 25% of the area within 150 ft upslope of wetland in land uses or cover that generate excess
surface runoff? Yes = 1 No = 0
Rating of Landscape Potential If score is: 1 = M 0 = L Record the rating on the first page
S 6.0. Are the hydrologic functions provided by the site valuable to society?
S 6.1. Distance to the nearest areas downstream that have flooding problems:
The sub-basin immediately down-gradient of site has flooding problems that result in damage to human or
natural resources (e.g., houses or salmon redds) points = 2
Surface flooding problems are in a sub-basin farther down-gradient points = 1
No flooding problems anywhere downstream points = 0
S 6.2. Has the site been identified as important for flood storage or flood conveyance in a regional flood control plan?
Yes = 2 No = 0
Total for S 6 Add the points in the boxes above
Rating of Value If score is: 2-4 = H 1 = M 0 = L Record the rating on the first page
NOTES and FIELD OBSERVATIONS:
A
4
1
4
4
1
4
0
0
4
0
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 13
Rating Form – Effective January 1, 2015
These questions apply to wetlands of all HGM classes.
HABITAT FUNCTIONS - Indicators that site functions to provide important habitat
H 1.0. Does the site have the potential to provide habitat?
H 1.1. Structure of plant community: Indicators are Cowardin classes and strata within the Forested class. Check the
Cowardin plant classes in the wetland. Up to 10 patches may be combined for each class to meet the threshold
of ¼ ac or more than 10% of the unit if it is smaller than 2.5 ac. Add the number of structures checked.
____Aquatic bed 4 structures or more: points = 4
____Emergent 3 structures: points = 2
____Scrub-shrub (areas where shrubs have > 30% cover) 2 structures: points = 1
____Forested (areas where trees have > 30% cover) 1 structure: points = 0
If the unit has a Forested class, check if:
____The Forested class has 3 out of 5 strata (canopy, sub-canopy, shrubs, herbaceous, moss/ground-cover)
that each cover 20% within the Forested polygon
H 1.2. Hydroperiods
Check the types of water regimes (hydroperiods) present within the wetland. The water regime has to cover
more than 10% of the wetland or ¼ ac to count (see text for descriptions of hydroperiods).
____Permanently flooded or inundated 4 or more types present: points = 3
____Seasonally flooded or inundated 3 types present: points = 2
____Occasionally flooded or inundated 2 types present: points = 1
____Saturated only 1 type present: points = 0
____Permanently flowing stream or river in, or adjacent to, the wetland
____Seasonally flowing stream in, or adjacent to, the wetland
____Lake Fringe wetland 2 points
____Freshwater tidal wetland 2 points
H 1.3. Richness of plant species
Count the number of plant species in the wetland that cover at least 10 ft2.
Different patches of the same species can be combined to meet the size threshold and you do not have to name
the species. Do not include Eurasian milfoil, reed canarygrass, purple loosestrife, Canadian thistle
If you counted: > 19 species points = 2
5 - 19 species points = 1
< 5 species points = 0
H 1.4. Interspersion of habitats
Decide from the diagrams below whether interspersion among Cowardin plants classes (described in H 1.1), or
the classes and unvegetated areas (can include open water or mudflats) is high, moderate, low, or none. If you
have four or more plant classes or three classes and open water, the rating is always high.
None = 0 points Low = 1 point Moderate = 2 points
All three diagrams
in this row
are HIGH = 3points
A
4
4
1
0
4
1
0
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 14
Rating Form – Effective January 1, 2015
H 1.5. Special habitat features:
Check the habitat features that are present in the wetland. The number of checks is the number of points.
____Large, downed, woody debris within the wetland (> 4 in diameter and 6 ft long).
____Standing snags (dbh > 4 in) within the wetland
____Undercut banks are present for at least 6.6 ft (2 m) and/or overhanging plants extends at least 3.3 ft (1 m)
over a stream (or ditch) in, or contiguous with the wetland, for at least 33 ft (10 m)
____Stable steep banks of fine material that might be used by beaver or muskrat for denning (> 30 degree
slope) OR signs of recent beaver activity are present (cut shrubs or trees that have not yet weathered
where wood is exposed)
____At least ¼ ac of thin-stemmed persistent plants or woody branches are present in areas that are
permanently or seasonally inundated (structures for egg-laying by amphibians)
____Invasive plants cover less than 25% of the wetland area in every stratum of plants (see H 1.1 for list of
strata)
Total for H 1 Add the points in the boxes above
Rating of Site Potential If score is: 15-18 = H 7-14 = M 0-6 = L Record the rating on the first page
H 2.0. Does the landscape have the potential to support the habitat functions of the site?
H 2.1. Accessible habitat (include only habitat that directly abuts wetland unit).
Calculate: % undisturbed habitat + [(% moderate and low intensity land uses)/2] = _______%
If total accessible habitat is:
> 1/3 (33.3%) of 1 km Polygon points = 3
20-33% of 1 km Polygon points = 2
10-19% of 1 km Polygon points = 1
< 10% of 1 km Polygon points = 0
H 2.2. Undisturbed habitat in 1 km Polygon around the wetland.
Calculate: % undisturbed habitat + [(% moderate and low intensity land uses)/2] = _______%
Undisturbed habitat > 50% of Polygon points = 3
Undisturbed habitat 10-50% and in 1-3 patches points = 2
Undisturbed habitat 10-50% and > 3 patches points = 1
Undisturbed habitat < 10% of 1 km Polygon points = 0
H 2.3. Land use intensity in 1 km Polygon: If
> 50% of 1 km Polygon is high intensity land use points = (- 2)
≤ 50% of 1 km Polygon is high intensity points = 0
Total for H 2 Add the points in the boxes above
Rating of Landscape Potential If score is: 4-6 = H 1-3 = M < 1 = L Record the rating on the first page
H 3.0. Is the habitat provided by the site valuable to society?
H 3.1. Does the site provide habitat for species valued in laws, regulations, or policies? Choose only the highest score
that applies to the wetland being rated.
Site meets ANY of the following criteria: points = 2
It has 3 or more priority habitats within 100 m (see next page)
It provides habitat for Threatened or Endangered species (any plant or animal on the state or federal lists)
It is mapped as a location for an individual WDFW priority species
It is a Wetland of High Conservation Value as determined by the Department of Natural Resources
It has been categorized as an important habitat site in a local or regional comprehensive plan, in a
Shoreline Master Plan, or in a watershed plan
Site has 1 or 2 priority habitats (listed on next page) within 100 m points = 1
Site does not meet any of the criteria above points = 0
Rating of Value If score is: 2 = H 1 = M 0 = L Record the rating on the first page
A
4
4
2
4
4
4 3 7
0
4
13 6 20
1
4
4 -2
-1
4
2
4
4
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 15
Rating Form – Effective January 1, 2015
WDFW Priority Habitats
Priority habitats listed by WDFW (see complete descriptions of WDFW priority habitats, and the counties in which they can
be found, in: Washington Department of Fish and Wildlife. 2008. Priority Habitat and Species List. Olympia, Washington.
177 pp. http://wdfw.wa.gov/publications/00165/wdfw00165.pdf or access the list from here:
http://wdfw.wa.gov/conservation/phs/list/)
Count how many of the following priority habitats are within 330 ft (100 m) of the wetland unit: NOTE: This question is
independent of the land use between the wetland unit and the priority habitat.
Aspen Stands: Pure or mixed stands of aspen greater than 1 ac (0.4 ha).
Biodiversity Areas and Corridors: Areas of habitat that are relatively important to various species of native fish and
wildlife (full descriptions in WDFW PHS report).
Herbaceous Balds: Variable size patches of grass and forbs on shallow soils over bedrock.
Old-growth/Mature forests: Old-growth west of Cascade crest – Stands of at least 2 tree species, forming a multi-
layered canopy with occasional small openings; with at least 8 trees/ac (20 trees/ha ) > 32 in (81 cm) dbh or > 200
years of age. Mature forests – Stands with average diameters exceeding 21 in (53 cm) dbh; crown cover may be less
than 100%; decay, decadence, numbers of snags, and quantity of large downed material is generally less than that
found in old-growth; 80-200 years old west of the Cascade crest.
Oregon White Oak: Woodland stands of pure oak or oak/conifer associations where canopy coverage of the oak
component is important (full descriptions in WDFW PHS report p. 158 – see web link above).
Riparian: The area adjacent to aquatic systems with flowing water that contains elements of both aquatic and
terrestrial ecosystems which mutually influence each other.
Westside Prairies: Herbaceous, non-forested plant communities that can either take the form of a dry prairie or a wet
prairie (full descriptions in WDFW PHS report p. 161 – see web link above).
Instream: The combination of physical, biological, and chemical processes and conditions that interact to provide
functional life history requirements for instream fish and wildlife resources.
Nearshore: Relatively undisturbed nearshore habitats. These include Coastal Nearshore, Open Coast Nearshore, and
Puget Sound Nearshore. (full descriptions of habitats and the definition of relatively undisturbed are in WDFW report –
see web link on previous page).
Caves: A naturally occurring cavity, recess, void, or system of interconnected passages under the earth in soils, rock,
ice, or other geological formations and is large enough to contain a human.
Cliffs: Greater than 25 ft (7.6 m) high and occurring below 5000 ft elevation.
Talus: Homogenous areas of rock rubble ranging in average size 0.5 - 6.5 ft (0.15 - 2.0 m), composed of basalt, andesite,
and/or sedimentary rock, including riprap slides and mine tailings. May be associated with cliffs.
Snags and Logs: Trees are considered snags if they are dead or dying and exhibit sufficient decay characteristics to
enable cavity excavation/use by wildlife. Priority snags have a diameter at breast height of > 20 in (51 cm) in western
Washington and are > 6.5 ft (2 m) in height. Priority logs are > 12 in (30 cm) in diameter at the largest end, and > 20 ft
(6 m) long.
Note: All vegetated wetlands are by definition a priority habitat but are not included in this list because they are addressed
elsewhere.
A
4
4
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 16
Rating Form – Effective January 1, 2015
CATEGORIZATION BASED ON SPECIAL CHARACTERISTICS
Wetland Type
Check off any criteria that apply to the wetland. Circle the category when the appropriate criteria are met.
Category
SC 1.0. Estuarine wetlands
Does the wetland meet the following criteria for Estuarine wetlands?
The dominant water regime is tidal,
Vegetated, and
With a salinity greater than 0.5 ppt Yes –Go to SC 1.1 No= Not an estuarine wetland
SC 1.1. Is the wetland within a National Wildlife Refuge, National Park, National Estuary Reserve, Natural Area
Preserve, State Park or Educational, Environmental, or Scientific Reserve designated under WAC 332-30-151?
Yes = Category I No - Go to SC 1.2
Cat. I
SC 1.2. Is the wetland unit at least 1 ac in size and meets at least two of the following three conditions?
The wetland is relatively undisturbed (has no diking, ditching, filling, cultivation, grazing, and has less
than 10% cover of non-native plant species. (If non-native species are Spartina, see page 25)
At least ¾ of the landward edge of the wetland has a 100 ft buffer of shrub, forest, or un-grazed or un-
mowed grassland.
The wetland has at least two of the following features: tidal channels, depressions with open water, or
contiguous freshwater wetlands. Yes = Category I No = Category II
Cat. I
Cat. II
SC 2.0. Wetlands of High Conservation Value (WHCV)
SC 2.1. Has the WA Department of Natural Resources updated their website to include the list of Wetlands of High
Conservation Value? Yes – Go to SC 2.2 No – Go to SC 2.3
SC 2.2. Is the wetland listed on the WDNR database as a Wetland of High Conservation Value?
Yes = Category I No = Not a WHCV
SC 2.3. Is the wetland in a Section/Township/Range that contains a Natural Heritage wetland?
http://www1.dnr.wa.gov/nhp/refdesk/datasearch/wnhpwetlands.pdf
Yes – Contact WNHP/WDNR and go to SC 2.4 No = Not a WHCV
SC 2.4. Has WDNR identified the wetland within the S/T/R as a Wetland of High Conservation Value and listed it on
their website? Yes = Category I No = Not a WHCV
Cat. I
SC 3.0. Bogs
Does the wetland (or any part of the unit) meet both the criteria for soils and vegetation in bogs? Use the key
below. If you answer YES you will still need to rate the wetland based on its functions.
SC 3.1. Does an area within the wetland unit have organic soil horizons, either peats or mucks, that compose 16 in or
more of the first 32 in of the soil profile? Yes – Go to SC 3.3 No – Go to SC 3.2
SC 3.2. Does an area within the wetland unit have organic soils, either peats or mucks, that are less than 16 in deep
over bedrock, or an impermeable hardpan such as clay or volcanic ash, or that are floating on top of a lake or
pond? Yes – Go to SC 3.3 No = Is not a bog
SC 3.3. Does an area with peats or mucks have more than 70% cover of mosses at ground level, AND at least a 30%
cover of plant species listed in Table 4? Yes = Is a Category I bog No – Go to SC 3.4
NOTE: If you are uncertain about the extent of mosses in the understory, you may substitute that criterion by
measuring the pH of the water that seeps into a hole dug at least 16 in deep. If the pH is less than 5.0 and the
plant species in Table 4 are present, the wetland is a bog.
SC 3.4. Is an area with peats or mucks forested (> 30% cover) with Sitka spruce, subalpine fir, western red cedar,
western hemlock, lodgepole pine, quaking aspen, Engelmann spruce, or western white pine, AND any of the
species (or combination of species) listed in Table 4 provide more than 30% of the cover under the canopy?
Yes = Is a Category I bog No = Is not a bog
Cat. I
A
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 17
Rating Form – Effective January 1, 2015
SC 4.0. Forested Wetlands
Does the wetland have at least 1 contiguous acre of forest that meets one of these criteria for the WA
Department of Fish and Wildlife’s forests as priority habitats? If you answer YES you will still need to rate
the wetland based on its functions.
Old-growth forests (west of Cascade crest): Stands of at least two tree species, forming a multi-layered
canopy with occasional small openings; with at least 8 trees/ac (20 trees/ha) that are at least 200 years of
age OR have a diameter at breast height (dbh) of 32 in (81 cm) or more.
Mature forests (west of the Cascade Crest): Stands where the largest trees are 80- 200 years old OR the
species that make up the canopy have an average diameter (dbh) exceeding 21 in (53 cm).
Yes = Category I No = Not a forested wetland for this section
Cat. I
SC 5.0. Wetlands in Coastal Lagoons
Does the wetland meet all of the following criteria of a wetland in a coastal lagoon?
The wetland lies in a depression adjacent to marine waters that is wholly or partially separated from
marine waters by sandbanks, gravel banks, shingle, or, less frequently, rocks
The lagoon in which the wetland is located contains ponded water that is saline or brackish (> 0.5 ppt)
during most of the year in at least a portion of the lagoon (needs to be measured near the bottom)
Yes – Go to SC 5.1 No = Not a wetland in a coastal lagoon
SC 5.1. Does the wetland meet all of the following three conditions?
The wetland is relatively undisturbed (has no diking, ditching, filling, cultivation, grazing), and has less
than 20% cover of aggressive, opportunistic plant species (see list of species on p. 100).
At least ¾ of the landward edge of the wetland has a 100 ft buffer of shrub, forest, or un-grazed or un-
mowed grassland.
The wetland is larger than 1/10 ac (4350 ft2)
Yes = Category I No = Category II
Cat. I
Cat. II
SC 6.0. Interdunal Wetlands
Is the wetland west of the 1889 line (also called the Western Boundary of Upland Ownership or WBUO)? If
you answer yes you will still need to rate the wetland based on its habitat functions.
In practical terms that means the following geographic areas:
Long Beach Peninsula: Lands west of SR 103
Grayland-Westport: Lands west of SR 105
Ocean Shores-Copalis: Lands west of SR 115 and SR 109
Yes – Go to SC 6.1 No = not an interdunal wetland for rating
SC 6.1. Is the wetland 1 ac or larger and scores an 8 or 9 for the habitat functions on the form (rates H,H,H or H,H,M
for the three aspects of function)? Yes = Category I No – Go to SC 6.2
SC 6.2. Is the wetland 1 ac or larger, or is it in a mosaic of wetlands that is 1 ac or larger?
Yes = Category II No – Go to SC 6.3
SC 6.3. Is the unit between 0.1 and 1 ac, or is it in a mosaic of wetlands that is between 0.1 and 1 ac?
Yes = Category III No = Category IV
Cat I
Cat. II
Cat. III
Cat. IV
Category of wetland based on Special Characteristics
If you answered No for all types, enter “Not Applicable” on Summary Form
A
N/A
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 18
Rating Form – Effective January 1, 2015
This page left blank intentionally
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 1
Rating Form – Effective January 1, 2015
Score for each function based on three ratings (order of ratings is not important)
9 = H,H,H
8 = H,H,M
7 = H,H,L
7 = H,M,M
6 = H,M,L
6 = M,M,M
5 = H,L,L
5 = M,M,L
4 = M,L,L
3 = L,L,L
RATING SUMMARY – Western Washington
Name of wetland (or ID #): _________________________________ Date of site visit: _____
Rated by____________________________ Trained by Ecology?__ Yes ___No Date of training______
HGM Class used for rating_________________ Wetland has multiple HGM classes?___Y ____N
NOTE: Form is not complete without the figures requested (figures can be combined).
Source of base aerial photo/map ______________________________________
OVERALL WETLAND CATEGORY ____ (based on functions___ or special characteristics___)
1. Category of wetland based on FUNCTIONS
_______Category I – Total score = 23 - 27
_______Category II – Total score = 20 - 22
_______Category III – Total score = 16 - 19
_______Category IV – Total score = 9 - 15
FUNCTION
Improving
Water Quality
Hydrologic
Habitat
Circle the appropriate ratings
Site Potential H M L H M L H M L
Landscape Potential H M L H M L H M L
Value H M L H M L H M L TOTAL
Score Based on
Ratings
2. Category based on SPECIAL CHARACTERISTICS of wetland
CHARACTERISTIC CATEGORY
Estuarine I II
Wetland of High Conservation Value I
Bog I
Mature Forest I
Old Growth Forest I
Coastal Lagoon I II
Interdunal I II III IV
None of the above
B
6 3 4 13
4
Blue Fern - Wetland B 5/23/18
Jim Rothwell 4 3/2015
SLOPE 4
ESRI
IV 4
4
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 2
Rating Form – Effective January 1, 2015
Maps and figures required to answer questions correctly for
Western Washington
Depressional Wetlands
Map of: To answer questions: Figure #
Cowardin plant classes D 1.3, H 1.1, H 1.4
Hydroperiods D 1.4, H 1.2
Location of outlet (can be added to map of hydroperiods) D 1.1, D 4.1
Boundary of area within 150 ft of the wetland (can be added to another figure) D 2.2, D 5.2
Map of the contributing basin D 4.3, D 5.3
1 km Polygon: Area that extends 1 km from entire wetland edge - including
polygons for accessible habitat and undisturbed habitat
H 2.1, H 2.2, H 2.3
Screen capture of map of 303(d) listed waters in basin (from Ecology website) D 3.1, D 3.2
Screen capture of list of TMDLs for WRIA in which unit is found (from web) D 3.3
Riverine Wetlands
Map of: To answer questions: Figure #
Cowardin plant classes H 1.1, H 1.4
Hydroperiods H 1.2
Ponded depressions R 1.1
Boundary of area within 150 ft of the wetland (can be added to another figure) R 2.4
Plant cover of trees, shrubs, and herbaceous plants R 1.2, R 4.2
Width of unit vs. width of stream (can be added to another figure) R 4.1
Map of the contributing basin R 2.2, R 2.3, R 5.2
1 km Polygon: Area that extends 1 km from entire wetland edge - including
polygons for accessible habitat and undisturbed habitat
H 2.1, H 2.2, H 2.3
Screen capture of map of 303(d) listed waters in basin (from Ecology website) R 3.1
Screen capture of list of TMDLs for WRIA in which unit is found (from web) R 3.2, R 3.3
Lake Fringe Wetlands
Map of: To answer questions: Figure #
Cowardin plant classes L 1.1, L 4.1, H 1.1, H 1.4
Plant cover of trees, shrubs, and herbaceous plants L 1.2
Boundary of area within 150 ft of the wetland (can be added to another figure) L 2.2
1 km Polygon: Area that extends 1 km from entire wetland edge - including
polygons for accessible habitat and undisturbed habitat
H 2.1, H 2.2, H 2.3
Screen capture of map of 303(d) listed waters in basin (from Ecology website) L 3.1, L 3.2
Screen capture of list of TMDLs for WRIA in which unit is found (from web) L 3.3
Slope Wetlands
Map of: To answer questions: Figure #
Cowardin plant classes H 1.1, H 1.4
Hydroperiods H 1.2
Plant cover of dense trees, shrubs, and herbaceous plants S 1.3
Plant cover of dense, rigid trees, shrubs, and herbaceous plants
(can be added to figure above)
S 4.1
Boundary of 150 ft buffer (can be added to another figure) S 2.1, S 5.1
1 km Polygon: Area that extends 1 km from entire wetland edge - including
polygons for accessible habitat and undisturbed habitat
H 2.1, H 2.2, H 2.3
Screen capture of map of 303(d) listed waters in basin (from Ecology website) S 3.1, S 3.2
Screen capture of list of TMDLs for WRIA in which unit is found (from web) S 3.3
B
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 3
Rating Form – Effective January 1, 2015
HGM Classification of Wetlands in Western Washington
1. Are the water levels in the entire unit usually controlled by tides except during floods?
NO – go to 2 YES – the wetland class is Tidal Fringe – go to 1.1
1.1 Is the salinity of the water during periods of annual low flow below 0.5 ppt (parts per thousand)?
NO – Saltwater Tidal Fringe (Estuarine) YES – Freshwater Tidal Fringe
If your wetland can be classified as a Freshwater Tidal Fringe use the forms for Riverine wetlands. If it
is Saltwater Tidal Fringe it is an Estuarine wetland and is not scored. This method cannot be used to
score functions for estuarine wetlands.
2. The entire wetland unit is flat and precipitation is the only source (>90%) of water to it. Groundwater
and surface water runoff are NOT sources of water to the unit.
NO – go to 3 YES – The wetland class is Flats
If your wetland can be classified as a Flats wetland, use the form for Depressional wetlands.
3. Does the entire wetland unit meet all of the following criteria?
___The vegetated part of the wetland is on the shores of a body of permanent open water (without any
plants on the surface at any time of the year) at least 20 ac (8 ha) in size;
___At least 30% of the open water area is deeper than 6.6 ft (2 m).
NO – go to 4 YES – The wetland class is Lake Fringe (Lacustrine Fringe)
4. Does the entire wetland unit meet all of the following criteria?
____The wetland is on a slope (slope can be very gradual),
____The water flows through the wetland in one direction (unidirectional) and usually comes from
seeps. It may flow subsurface, as sheetflow, or in a swale without distinct banks,
____The water leaves the wetland without being impounded.
NO – go to 5 YES – The wetland class is Slope
NOTE: Surface water does not pond in these type of wetlands except occasionally in very small and
shallow depressions or behind hummocks (depressions are usually <3 ft diameter and less than 1 ft
deep).
5. Does the entire wetland unit meet all of the following criteria?
____The unit is in a valley, or stream channel, where it gets inundated by overbank flooding from that
stream or river,
____The overbank flooding occurs at least once every 2 years.
For questions 1-7, the criteria described must apply to the entire unit being rated.
If the hydrologic criteria listed in each question do not apply to the entire unit being rated, you
probably have a unit with multiple HGM classes. In this case, identify which hydrologic criteria in
questions 1-7 apply, and go to Question 8.
B
4
4
4
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 4
Rating Form – Effective January 1, 2015
NO – go to 6 YES – The wetland class is Riverine
NOTE: The Riverine unit can contain depressions that are filled with water when the river is not
flooding
6. Is the entire wetland unit in a topographic depression in which water ponds, or is saturated to the
surface, at some time during the year? This means that any outlet, if present, is higher than the interior
of the wetland.
NO – go to 7 YES – The wetland class is Depressional
7. Is the entire wetland unit located in a very flat area with no obvious depression and no overbank
flooding? The unit does not pond surface water more than a few inches. The unit seems to be
maintained by high groundwater in the area. The wetland may be ditched, but has no obvious natural
outlet.
NO – go to 8 YES – The wetland class is Depressional
8. Your wetland unit seems to be difficult to classify and probably contains several different HGM
classes. For example, seeps at the base of a slope may grade into a riverine floodplain, or a small
stream within a Depressional wetland has a zone of flooding along its sides. GO BACK AND IDENTIFY
WHICH OF THE HYDROLOGIC REGIMES DESCRIBED IN QUESTIONS 1-7 APPLY TO DIFFERENT
AREAS IN THE UNIT (make a rough sketch to help you decide). Use the following table to identify the
appropriate class to use for the rating system if you have several HGM classes present within the
wetland unit being scored.
NOTE: Use this table only if the class that is recommended in the second column represents 10% or
more of the total area of the wetland unit being rated. If the area of the HGM class listed in column 2
is less than 10% of the unit; classify the wetland using the class that represents more than 90% of the
total area.
HGM classes within the wetland unit
being rated
HGM class to
use in rating
Slope + Riverine Riverine
Slope + Depressional Depressional
Slope + Lake Fringe Lake Fringe
Depressional + Riverine along stream
within boundary of depression
Depressional
Depressional + Lake Fringe Depressional
Riverine + Lake Fringe Riverine
Salt Water Tidal Fringe and any other
class of freshwater wetland
Treat as
ESTUARINE
If you are still unable to determine which of the above criteria apply to your wetland, or if you have
more than 2 HGM classes within a wetland boundary, classify the wetland as Depressional for the
rating.
B
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 11
Rating Form – Effective January 1, 2015
SLOPE WETLANDS
Water Quality Functions - Indicators that the site functions to improve water quality
S 1.0. Does the site have the potential to improve water quality?
S 1.1. Characteristics of the average slope of the wetland: (a 1% slope has a 1 ft vertical drop in elevation for every
100 ft of horizontal distance)
Slope is 1% or less points = 3
Slope is > 1%-2% points = 2
Slope is > 2%-5% points = 1
Slope is greater than 5% points = 0
S 1.2. The soil 2 in below the surface (or duff layer) is true clay or true organic (use NRCS definitions): Yes = 3 No = 0
S 1.3. Characteristics of the plants in the wetland that trap sediments and pollutants:
Choose the points appropriate for the description that best fits the plants in the wetland. Dense means you
have trouble seeing the soil surface (>75% cover), and uncut means not grazed or mowed and plants are higher
than 6 in.
Dense, uncut, herbaceous plants > 90% of the wetland area points = 6
Dense, uncut, herbaceous plants > ½ of area points = 3
Dense, woody, plants > ½ of area points = 2
Dense, uncut, herbaceous plants > ¼ of area points = 1
Does not meet any of the criteria above for plants points = 0
Total for S 1 Add the points in the boxes above
Rating of Site Potential If score is: 12 = H 6-11 = M 0-5 = L Record the rating on the first page
S 2.0. Does the landscape have the potential to support the water quality function of the site?
S 2.1. Is > 10% of the area within 150 ft on the uphill side of the wetland in land uses that generate pollutants?
Yes = 1 No = 0
S 2.2. Are there other sources of pollutants coming into the wetland that are not listed in question S 2.1?
Other sources ________________ Yes = 1 No = 0
Total for S 2 Add the points in the boxes above
Rating of Landscape Potential If score is: 1-2 = M 0 = L Record the rating on the first page
S 3.0. Is the water quality improvement provided by the site valuable to society?
S 3.1. Does the wetland discharge directly (i.e., within 1 mi) to a stream, river, lake, or marine water that is on the
303(d) list? Yes = 1 No = 0
S 3.2. Is the wetland in a basin or sub-basin where water quality is an issue? At least one aquatic resource in the basin is
on the 303(d) list. Yes = 1 No = 0
S 3.3. Has the site been identified in a watershed or local plan as important for maintaining water quality? Answer YES
if there is a TMDL for the basin in which unit is found. Yes = 2 No = 0
Total for S 3 Add the points in the boxes above
Rating of Value If score is: 2-4 = H 1 = M 0 = L Record the rating on the first page
B
4
1
0
4
2
3
4
0
1
0
1
4
1
2
3
4
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 12
Rating Form – Effective January 1, 2015
SLOPE WETLANDS
Hydrologic Functions - Indicators that the site functions to reduce flooding and stream erosion
S 4.0. Does the site have the potential to reduce flooding and stream erosion?
S 4.1. Characteristics of plants that reduce the velocity of surface flows during storms: Choose the points appropriate
for the description that best fits conditions in the wetland. Stems of plants should be thick enough (usually > 1/8
in), or dense enough, to remain erect during surface flows.
Dense, uncut, rigid plants cover > 90% of the area of the wetland points = 1
All other conditions points = 0
Rating of Site Potential If score is: 1 = M 0 = L Record the rating on the first page
S 5.0. Does the landscape have the potential to support the hydrologic functions of the site?
S 5.1. Is more than 25% of the area within 150 ft upslope of wetland in land uses or cover that generate excess
surface runoff? Yes = 1 No = 0
Rating of Landscape Potential If score is: 1 = M 0 = L Record the rating on the first page
S 6.0. Are the hydrologic functions provided by the site valuable to society?
S 6.1. Distance to the nearest areas downstream that have flooding problems:
The sub-basin immediately down-gradient of site has flooding problems that result in damage to human or
natural resources (e.g., houses or salmon redds) points = 2
Surface flooding problems are in a sub-basin farther down-gradient points = 1
No flooding problems anywhere downstream points = 0
S 6.2. Has the site been identified as important for flood storage or flood conveyance in a regional flood control plan?
Yes = 2 No = 0
Total for S 6 Add the points in the boxes above
Rating of Value If score is: 2-4 = H 1 = M 0 = L Record the rating on the first page
NOTES and FIELD OBSERVATIONS:
B
4
0
4
4
0
4
0
0
4
0
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 13
Rating Form – Effective January 1, 2015
These questions apply to wetlands of all HGM classes.
HABITAT FUNCTIONS - Indicators that site functions to provide important habitat
H 1.0. Does the site have the potential to provide habitat?
H 1.1. Structure of plant community: Indicators are Cowardin classes and strata within the Forested class. Check the
Cowardin plant classes in the wetland. Up to 10 patches may be combined for each class to meet the threshold
of ¼ ac or more than 10% of the unit if it is smaller than 2.5 ac. Add the number of structures checked.
____Aquatic bed 4 structures or more: points = 4
____Emergent 3 structures: points = 2
____Scrub-shrub (areas where shrubs have > 30% cover) 2 structures: points = 1
____Forested (areas where trees have > 30% cover) 1 structure: points = 0
If the unit has a Forested class, check if:
____The Forested class has 3 out of 5 strata (canopy, sub-canopy, shrubs, herbaceous, moss/ground-cover)
that each cover 20% within the Forested polygon
H 1.2. Hydroperiods
Check the types of water regimes (hydroperiods) present within the wetland. The water regime has to cover
more than 10% of the wetland or ¼ ac to count (see text for descriptions of hydroperiods).
____Permanently flooded or inundated 4 or more types present: points = 3
____Seasonally flooded or inundated 3 types present: points = 2
____Occasionally flooded or inundated 2 types present: points = 1
____Saturated only 1 type present: points = 0
____Permanently flowing stream or river in, or adjacent to, the wetland
____Seasonally flowing stream in, or adjacent to, the wetland
____Lake Fringe wetland 2 points
____Freshwater tidal wetland 2 points
H 1.3. Richness of plant species
Count the number of plant species in the wetland that cover at least 10 ft2.
Different patches of the same species can be combined to meet the size threshold and you do not have to name
the species. Do not include Eurasian milfoil, reed canarygrass, purple loosestrife, Canadian thistle
If you counted: > 19 species points = 2
5 - 19 species points = 1
< 5 species points = 0
H 1.4. Interspersion of habitats
Decide from the diagrams below whether interspersion among Cowardin plants classes (described in H 1.1), or
the classes and unvegetated areas (can include open water or mudflats) is high, moderate, low, or none. If you
have four or more plant classes or three classes and open water, the rating is always high.
None = 0 points Low = 1 point Moderate = 2 points
All three diagrams
in this row
are HIGH = 3points
B
4
4
1
0
4
1
0
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 14
Rating Form – Effective January 1, 2015
H 1.5. Special habitat features:
Check the habitat features that are present in the wetland. The number of checks is the number of points.
____Large, downed, woody debris within the wetland (> 4 in diameter and 6 ft long).
____Standing snags (dbh > 4 in) within the wetland
____Undercut banks are present for at least 6.6 ft (2 m) and/or overhanging plants extends at least 3.3 ft (1 m)
over a stream (or ditch) in, or contiguous with the wetland, for at least 33 ft (10 m)
____Stable steep banks of fine material that might be used by beaver or muskrat for denning (> 30 degree
slope) OR signs of recent beaver activity are present (cut shrubs or trees that have not yet weathered
where wood is exposed)
____At least ¼ ac of thin-stemmed persistent plants or woody branches are present in areas that are
permanently or seasonally inundated (structures for egg-laying by amphibians)
____Invasive plants cover less than 25% of the wetland area in every stratum of plants (see H 1.1 for list of
strata)
Total for H 1 Add the points in the boxes above
Rating of Site Potential If score is: 15-18 = H 7-14 = M 0-6 = L Record the rating on the first page
H 2.0. Does the landscape have the potential to support the habitat functions of the site?
H 2.1. Accessible habitat (include only habitat that directly abuts wetland unit).
Calculate: % undisturbed habitat + [(% moderate and low intensity land uses)/2] = _______%
If total accessible habitat is:
> 1/3 (33.3%) of 1 km Polygon points = 3
20-33% of 1 km Polygon points = 2
10-19% of 1 km Polygon points = 1
< 10% of 1 km Polygon points = 0
H 2.2. Undisturbed habitat in 1 km Polygon around the wetland.
Calculate: % undisturbed habitat + [(% moderate and low intensity land uses)/2] = _______%
Undisturbed habitat > 50% of Polygon points = 3
Undisturbed habitat 10-50% and in 1-3 patches points = 2
Undisturbed habitat 10-50% and > 3 patches points = 1
Undisturbed habitat < 10% of 1 km Polygon points = 0
H 2.3. Land use intensity in 1 km Polygon: If
> 50% of 1 km Polygon is high intensity land use points = (- 2)
≤ 50% of 1 km Polygon is high intensity points = 0
Total for H 2 Add the points in the boxes above
Rating of Landscape Potential If score is: 4-6 = H 1-3 = M < 1 = L Record the rating on the first page
H 3.0. Is the habitat provided by the site valuable to society?
H 3.1. Does the site provide habitat for species valued in laws, regulations, or policies? Choose only the highest score
that applies to the wetland being rated.
Site meets ANY of the following criteria: points = 2
It has 3 or more priority habitats within 100 m (see next page)
It provides habitat for Threatened or Endangered species (any plant or animal on the state or federal lists)
It is mapped as a location for an individual WDFW priority species
It is a Wetland of High Conservation Value as determined by the Department of Natural Resources
It has been categorized as an important habitat site in a local or regional comprehensive plan, in a
Shoreline Master Plan, or in a watershed plan
Site has 1 or 2 priority habitats (listed on next page) within 100 m points = 1
Site does not meet any of the criteria above points = 0
Rating of Value If score is: 2 = H 1 = M 0 = L Record the rating on the first page
B
3
1
4
4
4 3 7
0
4
14 6 20
1
4
4 -2
-1
4
1
4
4
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 15
Rating Form – Effective January 1, 2015
WDFW Priority Habitats
Priority habitats listed by WDFW (see complete descriptions of WDFW priority habitats, and the counties in which they can
be found, in: Washington Department of Fish and Wildlife. 2008. Priority Habitat and Species List. Olympia, Washington.
177 pp. http://wdfw.wa.gov/publications/00165/wdfw00165.pdf or access the list from here:
http://wdfw.wa.gov/conservation/phs/list/)
Count how many of the following priority habitats are within 330 ft (100 m) of the wetland unit: NOTE: This question is
independent of the land use between the wetland unit and the priority habitat.
Aspen Stands: Pure or mixed stands of aspen greater than 1 ac (0.4 ha).
Biodiversity Areas and Corridors: Areas of habitat that are relatively important to various species of native fish and
wildlife (full descriptions in WDFW PHS report).
Herbaceous Balds: Variable size patches of grass and forbs on shallow soils over bedrock.
Old-growth/Mature forests: Old-growth west of Cascade crest – Stands of at least 2 tree species, forming a multi-
layered canopy with occasional small openings; with at least 8 trees/ac (20 trees/ha ) > 32 in (81 cm) dbh or > 200
years of age. Mature forests – Stands with average diameters exceeding 21 in (53 cm) dbh; crown cover may be less
than 100%; decay, decadence, numbers of snags, and quantity of large downed material is generally less than that
found in old-growth; 80-200 years old west of the Cascade crest.
Oregon White Oak: Woodland stands of pure oak or oak/conifer associations where canopy coverage of the oak
component is important (full descriptions in WDFW PHS report p. 158 – see web link above).
Riparian: The area adjacent to aquatic systems with flowing water that contains elements of both aquatic and
terrestrial ecosystems which mutually influence each other.
Westside Prairies: Herbaceous, non-forested plant communities that can either take the form of a dry prairie or a wet
prairie (full descriptions in WDFW PHS report p. 161 – see web link above).
Instream: The combination of physical, biological, and chemical processes and conditions that interact to provide
functional life history requirements for instream fish and wildlife resources.
Nearshore: Relatively undisturbed nearshore habitats. These include Coastal Nearshore, Open Coast Nearshore, and
Puget Sound Nearshore. (full descriptions of habitats and the definition of relatively undisturbed are in WDFW report –
see web link on previous page).
Caves: A naturally occurring cavity, recess, void, or system of interconnected passages under the earth in soils, rock,
ice, or other geological formations and is large enough to contain a human.
Cliffs: Greater than 25 ft (7.6 m) high and occurring below 5000 ft elevation.
Talus: Homogenous areas of rock rubble ranging in average size 0.5 - 6.5 ft (0.15 - 2.0 m), composed of basalt, andesite,
and/or sedimentary rock, including riprap slides and mine tailings. May be associated with cliffs.
Snags and Logs: Trees are considered snags if they are dead or dying and exhibit sufficient decay characteristics to
enable cavity excavation/use by wildlife. Priority snags have a diameter at breast height of > 20 in (51 cm) in western
Washington and are > 6.5 ft (2 m) in height. Priority logs are > 12 in (30 cm) in diameter at the largest end, and > 20 ft
(6 m) long.
Note: All vegetated wetlands are by definition a priority habitat but are not included in this list because they are addressed
elsewhere.
B
4
4
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 16
Rating Form – Effective January 1, 2015
CATEGORIZATION BASED ON SPECIAL CHARACTERISTICS
Wetland Type
Check off any criteria that apply to the wetland. Circle the category when the appropriate criteria are met.
Category
SC 1.0. Estuarine wetlands
Does the wetland meet the following criteria for Estuarine wetlands?
The dominant water regime is tidal,
Vegetated, and
With a salinity greater than 0.5 ppt Yes –Go to SC 1.1 No= Not an estuarine wetland
SC 1.1. Is the wetland within a National Wildlife Refuge, National Park, National Estuary Reserve, Natural Area
Preserve, State Park or Educational, Environmental, or Scientific Reserve designated under WAC 332-30-151?
Yes = Category I No - Go to SC 1.2
Cat. I
SC 1.2. Is the wetland unit at least 1 ac in size and meets at least two of the following three conditions?
The wetland is relatively undisturbed (has no diking, ditching, filling, cultivation, grazing, and has less
than 10% cover of non-native plant species. (If non-native species are Spartina, see page 25)
At least ¾ of the landward edge of the wetland has a 100 ft buffer of shrub, forest, or un-grazed or un-
mowed grassland.
The wetland has at least two of the following features: tidal channels, depressions with open water, or
contiguous freshwater wetlands. Yes = Category I No = Category II
Cat. I
Cat. II
SC 2.0. Wetlands of High Conservation Value (WHCV)
SC 2.1. Has the WA Department of Natural Resources updated their website to include the list of Wetlands of High
Conservation Value? Yes – Go to SC 2.2 No – Go to SC 2.3
SC 2.2. Is the wetland listed on the WDNR database as a Wetland of High Conservation Value?
Yes = Category I No = Not a WHCV
SC 2.3. Is the wetland in a Section/Township/Range that contains a Natural Heritage wetland?
http://www1.dnr.wa.gov/nhp/refdesk/datasearch/wnhpwetlands.pdf
Yes – Contact WNHP/WDNR and go to SC 2.4 No = Not a WHCV
SC 2.4. Has WDNR identified the wetland within the S/T/R as a Wetland of High Conservation Value and listed it on
their website? Yes = Category I No = Not a WHCV
Cat. I
SC 3.0. Bogs
Does the wetland (or any part of the unit) meet both the criteria for soils and vegetation in bogs? Use the key
below. If you answer YES you will still need to rate the wetland based on its functions.
SC 3.1. Does an area within the wetland unit have organic soil horizons, either peats or mucks, that compose 16 in or
more of the first 32 in of the soil profile? Yes – Go to SC 3.3 No – Go to SC 3.2
SC 3.2. Does an area within the wetland unit have organic soils, either peats or mucks, that are less than 16 in deep
over bedrock, or an impermeable hardpan such as clay or volcanic ash, or that are floating on top of a lake or
pond? Yes – Go to SC 3.3 No = Is not a bog
SC 3.3. Does an area with peats or mucks have more than 70% cover of mosses at ground level, AND at least a 30%
cover of plant species listed in Table 4? Yes = Is a Category I bog No – Go to SC 3.4
NOTE: If you are uncertain about the extent of mosses in the understory, you may substitute that criterion by
measuring the pH of the water that seeps into a hole dug at least 16 in deep. If the pH is less than 5.0 and the
plant species in Table 4 are present, the wetland is a bog.
SC 3.4. Is an area with peats or mucks forested (> 30% cover) with Sitka spruce, subalpine fir, western red cedar,
western hemlock, lodgepole pine, quaking aspen, Engelmann spruce, or western white pine, AND any of the
species (or combination of species) listed in Table 4 provide more than 30% of the cover under the canopy?
Yes = Is a Category I bog No = Is not a bog
Cat. I
B
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 17
Rating Form – Effective January 1, 2015
SC 4.0. Forested Wetlands
Does the wetland have at least 1 contiguous acre of forest that meets one of these criteria for the WA
Department of Fish and Wildlife’s forests as priority habitats? If you answer YES you will still need to rate
the wetland based on its functions.
Old-growth forests (west of Cascade crest): Stands of at least two tree species, forming a multi-layered
canopy with occasional small openings; with at least 8 trees/ac (20 trees/ha) that are at least 200 years of
age OR have a diameter at breast height (dbh) of 32 in (81 cm) or more.
Mature forests (west of the Cascade Crest): Stands where the largest trees are 80- 200 years old OR the
species that make up the canopy have an average diameter (dbh) exceeding 21 in (53 cm).
Yes = Category I No = Not a forested wetland for this section
Cat. I
SC 5.0. Wetlands in Coastal Lagoons
Does the wetland meet all of the following criteria of a wetland in a coastal lagoon?
The wetland lies in a depression adjacent to marine waters that is wholly or partially separated from
marine waters by sandbanks, gravel banks, shingle, or, less frequently, rocks
The lagoon in which the wetland is located contains ponded water that is saline or brackish (> 0.5 ppt)
during most of the year in at least a portion of the lagoon (needs to be measured near the bottom)
Yes – Go to SC 5.1 No = Not a wetland in a coastal lagoon
SC 5.1. Does the wetland meet all of the following three conditions?
The wetland is relatively undisturbed (has no diking, ditching, filling, cultivation, grazing), and has less
than 20% cover of aggressive, opportunistic plant species (see list of species on p. 100).
At least ¾ of the landward edge of the wetland has a 100 ft buffer of shrub, forest, or un-grazed or un-
mowed grassland.
The wetland is larger than 1/10 ac (4350 ft2)
Yes = Category I No = Category II
Cat. I
Cat. II
SC 6.0. Interdunal Wetlands
Is the wetland west of the 1889 line (also called the Western Boundary of Upland Ownership or WBUO)? If
you answer yes you will still need to rate the wetland based on its habitat functions.
In practical terms that means the following geographic areas:
Long Beach Peninsula: Lands west of SR 103
Grayland-Westport: Lands west of SR 105
Ocean Shores-Copalis: Lands west of SR 115 and SR 109
Yes – Go to SC 6.1 No = not an interdunal wetland for rating
SC 6.1. Is the wetland 1 ac or larger and scores an 8 or 9 for the habitat functions on the form (rates H,H,H or H,H,M
for the three aspects of function)? Yes = Category I No – Go to SC 6.2
SC 6.2. Is the wetland 1 ac or larger, or is it in a mosaic of wetlands that is 1 ac or larger?
Yes = Category II No – Go to SC 6.3
SC 6.3. Is the unit between 0.1 and 1 ac, or is it in a mosaic of wetlands that is between 0.1 and 1 ac?
Yes = Category III No = Category IV
Cat I
Cat. II
Cat. III
Cat. IV
Category of wetland based on Special Characteristics
If you answered No for all types, enter “Not Applicable” on Summary Form
B
N/A
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 18
Rating Form – Effective January 1, 2015
This page left blank intentionally
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 1
Rating Form – Effective January 1, 2015
Score for each function based on three ratings (order of ratings is not important)
9 = H,H,H
8 = H,H,M
7 = H,H,L
7 = H,M,M
6 = H,M,L
6 = M,M,M
5 = H,L,L
5 = M,M,L
4 = M,L,L
3 = L,L,L
RATING SUMMARY – Western Washington
Name of wetland (or ID #): _________________________________ Date of site visit: _____
Rated by____________________________ Trained by Ecology?__ Yes ___No Date of training______
HGM Class used for rating_________________ Wetland has multiple HGM classes?___Y ____N
NOTE: Form is not complete without the figures requested (figures can be combined).
Source of base aerial photo/map ______________________________________
OVERALL WETLAND CATEGORY ____ (based on functions___ or special characteristics___)
1. Category of wetland based on FUNCTIONS
_______Category I – Total score = 23 - 27
_______Category II – Total score = 20 - 22
_______Category III – Total score = 16 - 19
_______Category IV – Total score = 9 - 15
FUNCTION
Improving
Water Quality
Hydrologic
Habitat
Circle the appropriate ratings
Site Potential H M L H M L H M L
Landscape Potential H M L H M L H M L
Value H M L H M L H M L TOTAL
Score Based on
Ratings
2. Category based on SPECIAL CHARACTERISTICS of wetland
CHARACTERISTIC CATEGORY
Estuarine I II
Wetland of High Conservation Value I
Bog I
Mature Forest I
Old Growth Forest I
Coastal Lagoon I II
Interdunal I II III IV
None of the above
C
6 3 6 15
4
Wetland C 5/23/18
T. Amen, J. Rothwell 4 6/17
SLOPE
King County iMap
IV 4
4
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 2
Rating Form – Effective January 1, 2015
Maps and figures required to answer questions correctly for
Western Washington
Depressional Wetlands
Map of: To answer questions: Figure #
Cowardin plant classes D 1.3, H 1.1, H 1.4
Hydroperiods D 1.4, H 1.2
Location of outlet (can be added to map of hydroperiods) D 1.1, D 4.1
Boundary of area within 150 ft of the wetland (can be added to another figure) D 2.2, D 5.2
Map of the contributing basin D 4.3, D 5.3
1 km Polygon: Area that extends 1 km from entire wetland edge - including
polygons for accessible habitat and undisturbed habitat
H 2.1, H 2.2, H 2.3
Screen capture of map of 303(d) listed waters in basin (from Ecology website) D 3.1, D 3.2
Screen capture of list of TMDLs for WRIA in which unit is found (from web) D 3.3
Riverine Wetlands
Map of: To answer questions: Figure #
Cowardin plant classes H 1.1, H 1.4
Hydroperiods H 1.2
Ponded depressions R 1.1
Boundary of area within 150 ft of the wetland (can be added to another figure) R 2.4
Plant cover of trees, shrubs, and herbaceous plants R 1.2, R 4.2
Width of unit vs. width of stream (can be added to another figure) R 4.1
Map of the contributing basin R 2.2, R 2.3, R 5.2
1 km Polygon: Area that extends 1 km from entire wetland edge - including
polygons for accessible habitat and undisturbed habitat
H 2.1, H 2.2, H 2.3
Screen capture of map of 303(d) listed waters in basin (from Ecology website) R 3.1
Screen capture of list of TMDLs for WRIA in which unit is found (from web) R 3.2, R 3.3
Lake Fringe Wetlands
Map of: To answer questions: Figure #
Cowardin plant classes L 1.1, L 4.1, H 1.1, H 1.4
Plant cover of trees, shrubs, and herbaceous plants L 1.2
Boundary of area within 150 ft of the wetland (can be added to another figure) L 2.2
1 km Polygon: Area that extends 1 km from entire wetland edge - including
polygons for accessible habitat and undisturbed habitat
H 2.1, H 2.2, H 2.3
Screen capture of map of 303(d) listed waters in basin (from Ecology website) L 3.1, L 3.2
Screen capture of list of TMDLs for WRIA in which unit is found (from web) L 3.3
Slope Wetlands
Map of: To answer questions: Figure #
Cowardin plant classes H 1.1, H 1.4
Hydroperiods H 1.2
Plant cover of dense trees, shrubs, and herbaceous plants S 1.3
Plant cover of dense, rigid trees, shrubs, and herbaceous plants
(can be added to figure above)
S 4.1
Boundary of 150 ft buffer (can be added to another figure) S 2.1, S 5.1
1 km Polygon: Area that extends 1 km from entire wetland edge - including
polygons for accessible habitat and undisturbed habitat
H 2.1, H 2.2, H 2.3
Screen capture of map of 303(d) listed waters in basin (from Ecology website) S 3.1, S 3.2
Screen capture of list of TMDLs for WRIA in which unit is found (from web) S 3.3
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Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 3
Rating Form – Effective January 1, 2015
HGM Classification of Wetlands in Western Washington
1. Are the water levels in the entire unit usually controlled by tides except during floods?
NO – go to 2 YES – the wetland class is Tidal Fringe – go to 1.1
1.1 Is the salinity of the water during periods of annual low flow below 0.5 ppt (parts per thousand)?
NO – Saltwater Tidal Fringe (Estuarine) YES – Freshwater Tidal Fringe
If your wetland can be classified as a Freshwater Tidal Fringe use the forms for Riverine wetlands. If it
is Saltwater Tidal Fringe it is an Estuarine wetland and is not scored. This method cannot be used to
score functions for estuarine wetlands.
2. The entire wetland unit is flat and precipitation is the only source (>90%) of water to it. Groundwater
and surface water runoff are NOT sources of water to the unit.
NO – go to 3 YES – The wetland class is Flats
If your wetland can be classified as a Flats wetland, use the form for Depressional wetlands.
3. Does the entire wetland unit meet all of the following criteria?
___The vegetated part of the wetland is on the shores of a body of permanent open water (without any
plants on the surface at any time of the year) at least 20 ac (8 ha) in size;
___At least 30% of the open water area is deeper than 6.6 ft (2 m).
NO – go to 4 YES – The wetland class is Lake Fringe (Lacustrine Fringe)
4. Does the entire wetland unit meet all of the following criteria?
____The wetland is on a slope (slope can be very gradual),
____The water flows through the wetland in one direction (unidirectional) and usually comes from
seeps. It may flow subsurface, as sheetflow, or in a swale without distinct banks,
____The water leaves the wetland without being impounded.
NO – go to 5 YES – The wetland class is Slope
NOTE: Surface water does not pond in these type of wetlands except occasionally in very small and
shallow depressions or behind hummocks (depressions are usually <3 ft diameter and less than 1 ft
deep).
5. Does the entire wetland unit meet all of the following criteria?
____The unit is in a valley, or stream channel, where it gets inundated by overbank flooding from that
stream or river,
____The overbank flooding occurs at least once every 2 years.
For questions 1-7, the criteria described must apply to the entire unit being rated.
If the hydrologic criteria listed in each question do not apply to the entire unit being rated, you
probably have a unit with multiple HGM classes. In this case, identify which hydrologic criteria in
questions 1-7 apply, and go to Question 8.
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Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 4
Rating Form – Effective January 1, 2015
NO – go to 6 YES – The wetland class is Riverine
NOTE: The Riverine unit can contain depressions that are filled with water when the river is not
flooding
6. Is the entire wetland unit in a topographic depression in which water ponds, or is saturated to the
surface, at some time during the year? This means that any outlet, if present, is higher than the interior
of the wetland.
NO – go to 7 YES – The wetland class is Depressional
7. Is the entire wetland unit located in a very flat area with no obvious depression and no overbank
flooding? The unit does not pond surface water more than a few inches. The unit seems to be
maintained by high groundwater in the area. The wetland may be ditched, but has no obvious natural
outlet.
NO – go to 8 YES – The wetland class is Depressional
8. Your wetland unit seems to be difficult to classify and probably contains several different HGM
classes. For example, seeps at the base of a slope may grade into a riverine floodplain, or a small
stream within a Depressional wetland has a zone of flooding along its sides. GO BACK AND IDENTIFY
WHICH OF THE HYDROLOGIC REGIMES DESCRIBED IN QUESTIONS 1-7 APPLY TO DIFFERENT
AREAS IN THE UNIT (make a rough sketch to help you decide). Use the following table to identify the
appropriate class to use for the rating system if you have several HGM classes present within the
wetland unit being scored.
NOTE: Use this table only if the class that is recommended in the second column represents 10% or
more of the total area of the wetland unit being rated. If the area of the HGM class listed in column 2
is less than 10% of the unit; classify the wetland using the class that represents more than 90% of the
total area.
HGM classes within the wetland unit
being rated
HGM class to
use in rating
Slope + Riverine Riverine
Slope + Depressional Depressional
Slope + Lake Fringe Lake Fringe
Depressional + Riverine along stream
within boundary of depression
Depressional
Depressional + Lake Fringe Depressional
Riverine + Lake Fringe Riverine
Salt Water Tidal Fringe and any other
class of freshwater wetland
Treat as
ESTUARINE
If you are still unable to determine which of the above criteria apply to your wetland, or if you have
more than 2 HGM classes within a wetland boundary, classify the wetland as Depressional for the
rating.
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Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 11
Rating Form – Effective January 1, 2015
SLOPE WETLANDS
Water Quality Functions - Indicators that the site functions to improve water quality
S 1.0. Does the site have the potential to improve water quality?
S 1.1. Characteristics of the average slope of the wetland: (a 1% slope has a 1 ft vertical drop in elevation for every
100 ft of horizontal distance)
Slope is 1% or less points = 3
Slope is > 1%-2% points = 2
Slope is > 2%-5% points = 1
Slope is greater than 5% points = 0
S 1.2. The soil 2 in below the surface (or duff layer) is true clay or true organic (use NRCS definitions): Yes = 3 No = 0
S 1.3. Characteristics of the plants in the wetland that trap sediments and pollutants:
Choose the points appropriate for the description that best fits the plants in the wetland. Dense means you
have trouble seeing the soil surface (>75% cover), and uncut means not grazed or mowed and plants are higher
than 6 in.
Dense, uncut, herbaceous plants > 90% of the wetland area points = 6
Dense, uncut, herbaceous plants > ½ of area points = 3
Dense, woody, plants > ½ of area points = 2
Dense, uncut, herbaceous plants > ¼ of area points = 1
Does not meet any of the criteria above for plants points = 0
Total for S 1 Add the points in the boxes above
Rating of Site Potential If score is: 12 = H 6-11 = M 0-5 = L Record the rating on the first page
S 2.0. Does the landscape have the potential to support the water quality function of the site?
S 2.1. Is > 10% of the area within 150 ft on the uphill side of the wetland in land uses that generate pollutants?
Yes = 1 No = 0
S 2.2. Are there other sources of pollutants coming into the wetland that are not listed in question S 2.1?
Other sources ________________ Yes = 1 No = 0
Total for S 2 Add the points in the boxes above
Rating of Landscape Potential If score is: 1-2 = M 0 = L Record the rating on the first page
S 3.0. Is the water quality improvement provided by the site valuable to society?
S 3.1. Does the wetland discharge directly (i.e., within 1 mi) to a stream, river, lake, or marine water that is on the
303(d) list? Yes = 1 No = 0
S 3.2. Is the wetland in a basin or sub-basin where water quality is an issue? At least one aquatic resource in the basin is
on the 303(d) list. Yes = 1 No = 0
S 3.3. Has the site been identified in a watershed or local plan as important for maintaining water quality? Answer YES
if there is a TMDL for the basin in which unit is found. Yes = 2 No = 0
Total for S 3 Add the points in the boxes above
Rating of Value If score is: 2-4 = H 1 = M 0 = L Record the rating on the first page
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Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 12
Rating Form – Effective January 1, 2015
SLOPE WETLANDS
Hydrologic Functions - Indicators that the site functions to reduce flooding and stream erosion
S 4.0. Does the site have the potential to reduce flooding and stream erosion?
S 4.1. Characteristics of plants that reduce the velocity of surface flows during storms: Choose the points appropriate
for the description that best fits conditions in the wetland. Stems of plants should be thick enough (usually > 1/8
in), or dense enough, to remain erect during surface flows.
Dense, uncut, rigid plants cover > 90% of the area of the wetland points = 1
All other conditions points = 0
Rating of Site Potential If score is: 1 = M 0 = L Record the rating on the first page
S 5.0. Does the landscape have the potential to support the hydrologic functions of the site?
S 5.1. Is more than 25% of the area within 150 ft upslope of wetland in land uses or cover that generate excess
surface runoff? Yes = 1 No = 0
Rating of Landscape Potential If score is: 1 = M 0 = L Record the rating on the first page
S 6.0. Are the hydrologic functions provided by the site valuable to society?
S 6.1. Distance to the nearest areas downstream that have flooding problems:
The sub-basin immediately down-gradient of site has flooding problems that result in damage to human or
natural resources (e.g., houses or salmon redds) points = 2
Surface flooding problems are in a sub-basin farther down-gradient points = 1
No flooding problems anywhere downstream points = 0
S 6.2. Has the site been identified as important for flood storage or flood conveyance in a regional flood control plan?
Yes = 2 No = 0
Total for S 6 Add the points in the boxes above
Rating of Value If score is: 2-4 = H 1 = M 0 = L Record the rating on the first page
NOTES and FIELD OBSERVATIONS:
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Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 13
Rating Form – Effective January 1, 2015
These questions apply to wetlands of all HGM classes.
HABITAT FUNCTIONS - Indicators that site functions to provide important habitat
H 1.0. Does the site have the potential to provide habitat?
H 1.1. Structure of plant community: Indicators are Cowardin classes and strata within the Forested class. Check the
Cowardin plant classes in the wetland. Up to 10 patches may be combined for each class to meet the threshold
of ¼ ac or more than 10% of the unit if it is smaller than 2.5 ac. Add the number of structures checked.
____Aquatic bed 4 structures or more: points = 4
____Emergent 3 structures: points = 2
____Scrub-shrub (areas where shrubs have > 30% cover) 2 structures: points = 1
____Forested (areas where trees have > 30% cover) 1 structure: points = 0
If the unit has a Forested class, check if:
____The Forested class has 3 out of 5 strata (canopy, sub-canopy, shrubs, herbaceous, moss/ground-cover)
that each cover 20% within the Forested polygon
H 1.2. Hydroperiods
Check the types of water regimes (hydroperiods) present within the wetland. The water regime has to cover
more than 10% of the wetland or ¼ ac to count (see text for descriptions of hydroperiods).
____Permanently flooded or inundated 4 or more types present: points = 3
____Seasonally flooded or inundated 3 types present: points = 2
____Occasionally flooded or inundated 2 types present: points = 1
____Saturated only 1 type present: points = 0
____Permanently flowing stream or river in, or adjacent to, the wetland
____Seasonally flowing stream in, or adjacent to, the wetland
____Lake Fringe wetland 2 points
____Freshwater tidal wetland 2 points
H 1.3. Richness of plant species
Count the number of plant species in the wetland that cover at least 10 ft2.
Different patches of the same species can be combined to meet the size threshold and you do not have to name
the species. Do not include Eurasian milfoil, reed canarygrass, purple loosestrife, Canadian thistle
If you counted: > 19 species points = 2
5 - 19 species points = 1
< 5 species points = 0
H 1.4. Interspersion of habitats
Decide from the diagrams below whether interspersion among Cowardin plants classes (described in H 1.1), or
the classes and unvegetated areas (can include open water or mudflats) is high, moderate, low, or none. If you
have four or more plant classes or three classes and open water, the rating is always high.
None = 0 points Low = 1 point Moderate = 2 points
All three diagrams
in this row
are HIGH = 3points
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Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 14
Rating Form – Effective January 1, 2015
H 1.5. Special habitat features:
Check the habitat features that are present in the wetland. The number of checks is the number of points.
____Large, downed, woody debris within the wetland (> 4 in diameter and 6 ft long).
____Standing snags (dbh > 4 in) within the wetland
____Undercut banks are present for at least 6.6 ft (2 m) and/or overhanging plants extends at least 3.3 ft (1 m)
over a stream (or ditch) in, or contiguous with the wetland, for at least 33 ft (10 m)
____Stable steep banks of fine material that might be used by beaver or muskrat for denning (> 30 degree
slope) OR signs of recent beaver activity are present (cut shrubs or trees that have not yet weathered
where wood is exposed)
____At least ¼ ac of thin-stemmed persistent plants or woody branches are present in areas that are
permanently or seasonally inundated (structures for egg-laying by amphibians)
____Invasive plants cover less than 25% of the wetland area in every stratum of plants (see H 1.1 for list of
strata)
Total for H 1 Add the points in the boxes above
Rating of Site Potential If score is: 15-18 = H 7-14 = M 0-6 = L Record the rating on the first page
H 2.0. Does the landscape have the potential to support the habitat functions of the site?
H 2.1. Accessible habitat (include only habitat that directly abuts wetland unit).
Calculate: % undisturbed habitat + [(% moderate and low intensity land uses)/2] = _______%
If total accessible habitat is:
> 1/3 (33.3%) of 1 km Polygon points = 3
20-33% of 1 km Polygon points = 2
10-19% of 1 km Polygon points = 1
< 10% of 1 km Polygon points = 0
H 2.2. Undisturbed habitat in 1 km Polygon around the wetland.
Calculate: % undisturbed habitat + [(% moderate and low intensity land uses)/2] = _______%
Undisturbed habitat > 50% of Polygon points = 3
Undisturbed habitat 10-50% and in 1-3 patches points = 2
Undisturbed habitat 10-50% and > 3 patches points = 1
Undisturbed habitat < 10% of 1 km Polygon points = 0
H 2.3. Land use intensity in 1 km Polygon: If
> 50% of 1 km Polygon is high intensity land use points = (- 2)
≤ 50% of 1 km Polygon is high intensity points = 0
Total for H 2 Add the points in the boxes above
Rating of Landscape Potential If score is: 4-6 = H 1-3 = M < 1 = L Record the rating on the first page
H 3.0. Is the habitat provided by the site valuable to society?
H 3.1. Does the site provide habitat for species valued in laws, regulations, or policies? Choose only the highest score
that applies to the wetland being rated.
Site meets ANY of the following criteria: points = 2
It has 3 or more priority habitats within 100 m (see next page)
It provides habitat for Threatened or Endangered species (any plant or animal on the state or federal lists)
It is mapped as a location for an individual WDFW priority species
It is a Wetland of High Conservation Value as determined by the Department of Natural Resources
It has been categorized as an important habitat site in a local or regional comprehensive plan, in a
Shoreline Master Plan, or in a watershed plan
Site has 1 or 2 priority habitats (listed on next page) within 100 m points = 1
Site does not meet any of the criteria above points = 0
Rating of Value If score is: 2 = H 1 = M 0 = L Record the rating on the first page
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Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 15
Rating Form – Effective January 1, 2015
WDFW Priority Habitats
Priority habitats listed by WDFW (see complete descriptions of WDFW priority habitats, and the counties in which they can
be found, in: Washington Department of Fish and Wildlife. 2008. Priority Habitat and Species List. Olympia, Washington.
177 pp. http://wdfw.wa.gov/publications/00165/wdfw00165.pdf or access the list from here:
http://wdfw.wa.gov/conservation/phs/list/)
Count how many of the following priority habitats are within 330 ft (100 m) of the wetland unit: NOTE: This question is
independent of the land use between the wetland unit and the priority habitat.
Aspen Stands: Pure or mixed stands of aspen greater than 1 ac (0.4 ha).
Biodiversity Areas and Corridors: Areas of habitat that are relatively important to various species of native fish and
wildlife (full descriptions in WDFW PHS report).
Herbaceous Balds: Variable size patches of grass and forbs on shallow soils over bedrock.
Old-growth/Mature forests: Old-growth west of Cascade crest – Stands of at least 2 tree species, forming a multi-
layered canopy with occasional small openings; with at least 8 trees/ac (20 trees/ha ) > 32 in (81 cm) dbh or > 200
years of age. Mature forests – Stands with average diameters exceeding 21 in (53 cm) dbh; crown cover may be less
than 100%; decay, decadence, numbers of snags, and quantity of large downed material is generally less than that
found in old-growth; 80-200 years old west of the Cascade crest.
Oregon White Oak: Woodland stands of pure oak or oak/conifer associations where canopy coverage of the oak
component is important (full descriptions in WDFW PHS report p. 158 – see web link above).
Riparian: The area adjacent to aquatic systems with flowing water that contains elements of both aquatic and
terrestrial ecosystems which mutually influence each other.
Westside Prairies: Herbaceous, non-forested plant communities that can either take the form of a dry prairie or a wet
prairie (full descriptions in WDFW PHS report p. 161 – see web link above).
Instream: The combination of physical, biological, and chemical processes and conditions that interact to provide
functional life history requirements for instream fish and wildlife resources.
Nearshore: Relatively undisturbed nearshore habitats. These include Coastal Nearshore, Open Coast Nearshore, and
Puget Sound Nearshore. (full descriptions of habitats and the definition of relatively undisturbed are in WDFW report –
see web link on previous page).
Caves: A naturally occurring cavity, recess, void, or system of interconnected passages under the earth in soils, rock,
ice, or other geological formations and is large enough to contain a human.
Cliffs: Greater than 25 ft (7.6 m) high and occurring below 5000 ft elevation.
Talus: Homogenous areas of rock rubble ranging in average size 0.5 - 6.5 ft (0.15 - 2.0 m), composed of basalt, andesite,
and/or sedimentary rock, including riprap slides and mine tailings. May be associated with cliffs.
Snags and Logs: Trees are considered snags if they are dead or dying and exhibit sufficient decay characteristics to
enable cavity excavation/use by wildlife. Priority snags have a diameter at breast height of > 20 in (51 cm) in western
Washington and are > 6.5 ft (2 m) in height. Priority logs are > 12 in (30 cm) in diameter at the largest end, and > 20 ft
(6 m) long.
Note: All vegetated wetlands are by definition a priority habitat but are not included in this list because they are addressed
elsewhere.
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Wetland Rating System for Western WA: 2014 Update 16
Rating Form – Effective January 1, 2015
CATEGORIZATION BASED ON SPECIAL CHARACTERISTICS
Wetland Type
Check off any criteria that apply to the wetland. Circle the category when the appropriate criteria are met.
Category
SC 1.0. Estuarine wetlands
Does the wetland meet the following criteria for Estuarine wetlands?
The dominant water regime is tidal,
Vegetated, and
With a salinity greater than 0.5 ppt Yes –Go to SC 1.1 No= Not an estuarine wetland
SC 1.1. Is the wetland within a National Wildlife Refuge, National Park, National Estuary Reserve, Natural Area
Preserve, State Park or Educational, Environmental, or Scientific Reserve designated under WAC 332-30-151?
Yes = Category I No - Go to SC 1.2
Cat. I
SC 1.2. Is the wetland unit at least 1 ac in size and meets at least two of the following three conditions?
The wetland is relatively undisturbed (has no diking, ditching, filling, cultivation, grazing, and has less
than 10% cover of non-native plant species. (If non-native species are Spartina, see page 25)
At least ¾ of the landward edge of the wetland has a 100 ft buffer of shrub, forest, or un-grazed or un-
mowed grassland.
The wetland has at least two of the following features: tidal channels, depressions with open water, or
contiguous freshwater wetlands. Yes = Category I No = Category II
Cat. I
Cat. II
SC 2.0. Wetlands of High Conservation Value (WHCV)
SC 2.1. Has the WA Department of Natural Resources updated their website to include the list of Wetlands of High
Conservation Value? Yes – Go to SC 2.2 No – Go to SC 2.3
SC 2.2. Is the wetland listed on the WDNR database as a Wetland of High Conservation Value?
Yes = Category I No = Not a WHCV
SC 2.3. Is the wetland in a Section/Township/Range that contains a Natural Heritage wetland?
http://www1.dnr.wa.gov/nhp/refdesk/datasearch/wnhpwetlands.pdf
Yes – Contact WNHP/WDNR and go to SC 2.4 No = Not a WHCV
SC 2.4. Has WDNR identified the wetland within the S/T/R as a Wetland of High Conservation Value and listed it on
their website? Yes = Category I No = Not a WHCV
Cat. I
SC 3.0. Bogs
Does the wetland (or any part of the unit) meet both the criteria for soils and vegetation in bogs? Use the key
below. If you answer YES you will still need to rate the wetland based on its functions.
SC 3.1. Does an area within the wetland unit have organic soil horizons, either peats or mucks, that compose 16 in or
more of the first 32 in of the soil profile? Yes – Go to SC 3.3 No – Go to SC 3.2
SC 3.2. Does an area within the wetland unit have organic soils, either peats or mucks, that are less than 16 in deep
over bedrock, or an impermeable hardpan such as clay or volcanic ash, or that are floating on top of a lake or
pond? Yes – Go to SC 3.3 No = Is not a bog
SC 3.3. Does an area with peats or mucks have more than 70% cover of mosses at ground level, AND at least a 30%
cover of plant species listed in Table 4? Yes = Is a Category I bog No – Go to SC 3.4
NOTE: If you are uncertain about the extent of mosses in the understory, you may substitute that criterion by
measuring the pH of the water that seeps into a hole dug at least 16 in deep. If the pH is less than 5.0 and the
plant species in Table 4 are present, the wetland is a bog.
SC 3.4. Is an area with peats or mucks forested (> 30% cover) with Sitka spruce, subalpine fir, western red cedar,
western hemlock, lodgepole pine, quaking aspen, Engelmann spruce, or western white pine, AND any of the
species (or combination of species) listed in Table 4 provide more than 30% of the cover under the canopy?
Yes = Is a Category I bog No = Is not a bog
Cat. I
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Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 17
Rating Form – Effective January 1, 2015
SC 4.0. Forested Wetlands
Does the wetland have at least 1 contiguous acre of forest that meets one of these criteria for the WA
Department of Fish and Wildlife’s forests as priority habitats? If you answer YES you will still need to rate
the wetland based on its functions.
Old-growth forests (west of Cascade crest): Stands of at least two tree species, forming a multi-layered
canopy with occasional small openings; with at least 8 trees/ac (20 trees/ha) that are at least 200 years of
age OR have a diameter at breast height (dbh) of 32 in (81 cm) or more.
Mature forests (west of the Cascade Crest): Stands where the largest trees are 80- 200 years old OR the
species that make up the canopy have an average diameter (dbh) exceeding 21 in (53 cm).
Yes = Category I No = Not a forested wetland for this section
Cat. I
SC 5.0. Wetlands in Coastal Lagoons
Does the wetland meet all of the following criteria of a wetland in a coastal lagoon?
The wetland lies in a depression adjacent to marine waters that is wholly or partially separated from
marine waters by sandbanks, gravel banks, shingle, or, less frequently, rocks
The lagoon in which the wetland is located contains ponded water that is saline or brackish (> 0.5 ppt)
during most of the year in at least a portion of the lagoon (needs to be measured near the bottom)
Yes – Go to SC 5.1 No = Not a wetland in a coastal lagoon
SC 5.1. Does the wetland meet all of the following three conditions?
The wetland is relatively undisturbed (has no diking, ditching, filling, cultivation, grazing), and has less
than 20% cover of aggressive, opportunistic plant species (see list of species on p. 100).
At least ¾ of the landward edge of the wetland has a 100 ft buffer of shrub, forest, or un-grazed or un-
mowed grassland.
The wetland is larger than 1/10 ac (4350 ft2)
Yes = Category I No = Category II
Cat. I
Cat. II
SC 6.0. Interdunal Wetlands
Is the wetland west of the 1889 line (also called the Western Boundary of Upland Ownership or WBUO)? If
you answer yes you will still need to rate the wetland based on its habitat functions.
In practical terms that means the following geographic areas:
Long Beach Peninsula: Lands west of SR 103
Grayland-Westport: Lands west of SR 105
Ocean Shores-Copalis: Lands west of SR 115 and SR 109
Yes – Go to SC 6.1 No = not an interdunal wetland for rating
SC 6.1. Is the wetland 1 ac or larger and scores an 8 or 9 for the habitat functions on the form (rates H,H,H or H,H,M
for the three aspects of function)? Yes = Category I No – Go to SC 6.2
SC 6.2. Is the wetland 1 ac or larger, or is it in a mosaic of wetlands that is 1 ac or larger?
Yes = Category II No – Go to SC 6.3
SC 6.3. Is the unit between 0.1 and 1 ac, or is it in a mosaic of wetlands that is between 0.1 and 1 ac?
Yes = Category III No = Category IV
Cat I
Cat. II
Cat. III
Cat. IV
Category of wetland based on Special Characteristics
If you answered No for all types, enter “Not Applicable” on Summary Form
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Wetland Rating System for Western WA: 2014 Update 18
Rating Form – Effective January 1, 2015
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Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 1
Rating Form – Effective January 1, 2015
Score for each function based on three ratings (order of ratings is not important)
9 = H,H,H
8 = H,H,M
7 = H,H,L
7 = H,M,M
6 = H,M,L
6 = M,M,M
5 = H,L,L
5 = M,M,L
4 = M,L,L
3 = L,L,L
RATING SUMMARY – Western Washington
Name of wetland (or ID #): _________________________________ Date of site visit: _____
Rated by____________________________ Trained by Ecology?__ Yes ___No Date of training______
HGM Class used for rating_________________ Wetland has multiple HGM classes?___Y ____N
NOTE: Form is not complete without the figures requested (figures can be combined).
Source of base aerial photo/map ______________________________________
OVERALL WETLAND CATEGORY ____ (based on functions___ or special characteristics___)
1. Category of wetland based on FUNCTIONS
_______Category I – Total score = 23 - 27
_______Category II – Total score = 20 - 22
_______Category III – Total score = 16 - 19
_______Category IV – Total score = 9 - 15
FUNCTION
Improving
Water Quality
Hydrologic
Habitat
Circle the appropriate ratings
Site Potential H M L H M L H M L
Landscape Potential H M L H M L H M L
Value H M L H M L H M L TOTAL
Score Based on
Ratings
2. Category based on SPECIAL CHARACTERISTICS of wetland
CHARACTERISTIC CATEGORY
Estuarine I II
Wetland of High Conservation Value I
Bog I
Mature Forest I
Old Growth Forest I
Coastal Lagoon I II
Interdunal I II III IV
None of the above
D
5 3 4 12
4
Wetland D 5/23/18
T. Amen, J. Rothwell 4 6/17
SLOPE
King County iMap
IV 4
4
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 2
Rating Form – Effective January 1, 2015
Maps and figures required to answer questions correctly for
Western Washington
Depressional Wetlands
Map of: To answer questions: Figure #
Cowardin plant classes D 1.3, H 1.1, H 1.4
Hydroperiods D 1.4, H 1.2
Location of outlet (can be added to map of hydroperiods) D 1.1, D 4.1
Boundary of area within 150 ft of the wetland (can be added to another figure) D 2.2, D 5.2
Map of the contributing basin D 4.3, D 5.3
1 km Polygon: Area that extends 1 km from entire wetland edge - including
polygons for accessible habitat and undisturbed habitat
H 2.1, H 2.2, H 2.3
Screen capture of map of 303(d) listed waters in basin (from Ecology website) D 3.1, D 3.2
Screen capture of list of TMDLs for WRIA in which unit is found (from web) D 3.3
Riverine Wetlands
Map of: To answer questions: Figure #
Cowardin plant classes H 1.1, H 1.4
Hydroperiods H 1.2
Ponded depressions R 1.1
Boundary of area within 150 ft of the wetland (can be added to another figure) R 2.4
Plant cover of trees, shrubs, and herbaceous plants R 1.2, R 4.2
Width of unit vs. width of stream (can be added to another figure) R 4.1
Map of the contributing basin R 2.2, R 2.3, R 5.2
1 km Polygon: Area that extends 1 km from entire wetland edge - including
polygons for accessible habitat and undisturbed habitat
H 2.1, H 2.2, H 2.3
Screen capture of map of 303(d) listed waters in basin (from Ecology website) R 3.1
Screen capture of list of TMDLs for WRIA in which unit is found (from web) R 3.2, R 3.3
Lake Fringe Wetlands
Map of: To answer questions: Figure #
Cowardin plant classes L 1.1, L 4.1, H 1.1, H 1.4
Plant cover of trees, shrubs, and herbaceous plants L 1.2
Boundary of area within 150 ft of the wetland (can be added to another figure) L 2.2
1 km Polygon: Area that extends 1 km from entire wetland edge - including
polygons for accessible habitat and undisturbed habitat
H 2.1, H 2.2, H 2.3
Screen capture of map of 303(d) listed waters in basin (from Ecology website) L 3.1, L 3.2
Screen capture of list of TMDLs for WRIA in which unit is found (from web) L 3.3
Slope Wetlands
Map of: To answer questions: Figure #
Cowardin plant classes H 1.1, H 1.4
Hydroperiods H 1.2
Plant cover of dense trees, shrubs, and herbaceous plants S 1.3
Plant cover of dense, rigid trees, shrubs, and herbaceous plants
(can be added to figure above)
S 4.1
Boundary of 150 ft buffer (can be added to another figure) S 2.1, S 5.1
1 km Polygon: Area that extends 1 km from entire wetland edge - including
polygons for accessible habitat and undisturbed habitat
H 2.1, H 2.2, H 2.3
Screen capture of map of 303(d) listed waters in basin (from Ecology website) S 3.1, S 3.2
Screen capture of list of TMDLs for WRIA in which unit is found (from web) S 3.3
D
D1
D1
D1
D5
D1
D2
D3
D4
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 3
Rating Form – Effective January 1, 2015
HGM Classification of Wetlands in Western Washington
1.Are the water levels in the entire unit usually controlled by tides except during floods?
NO – go to 2 YES – the wetland class is Tidal Fringe – go to 1.1
1.1 Is the salinity of the water during periods of annual low flow below 0.5 ppt (parts per thousand)?
NO – Saltwater Tidal Fringe (Estuarine) YES – Freshwater Tidal Fringe
If your wetland can be classified as a Freshwater Tidal Fringe use the forms for Riverine wetlands. If it
is Saltwater Tidal Fringe it is an Estuarine wetland and is not scored. This method cannot be used to
score functions for estuarine wetlands.
2.The entire wetland unit is flat and precipitation is the only source (>90%) of water to it. Groundwater
and surface water runoff are NOT sources of water to the unit.
NO – go to 3 YES – The wetland class is Flats
If your wetland can be classified as a Flats wetland, use the form for Depressional wetlands.
3.Does the entire wetland unit meet all of the following criteria?
___The vegetated part of the wetland is on the shores of a body of permanent open water (without any
plants on the surface at any time of the year) at least 20 ac (8 ha) in size;
___At least 30% of the open water area is deeper than 6.6 ft (2 m).
NO – go to 4 YES – The wetland class is Lake Fringe (Lacustrine Fringe)
4.Does the entire wetland unit meet all of the following criteria?
____The wetland is on a slope (slope can be very gradual),
____The water flows through the wetland in one direction (unidirectional) and usually comes from
seeps. It may flow subsurface, as sheetflow, or in a swale without distinct banks,
____The water leaves the wetland without being impounded.
NO – go to 5 YES – The wetland class is Slope
NOTE: Surface water does not pond in these type of wetlands except occasionally in very small and
shallow depressions or behind hummocks (depressions are usually <3 ft diameter and less than 1 ft
deep).
5.Does the entire wetland unit meet all of the following criteria?
____The unit is in a valley, or stream channel, where it gets inundated by overbank flooding from that
stream or river,
____The overbank flooding occurs at least once every 2 years.
For questions 1-7, the criteria described must apply to the entire unit being rated.
If the hydrologic criteria listed in each question do not apply to the entire unit being rated, you
probably have a unit with multiple HGM classes. In this case, identify which hydrologic criteria in
questions 1-7 apply, and go to Question 8.
D
4
4
4
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 4
Rating Form – Effective January 1, 2015
NO – go to 6 YES – The wetland class is Riverine
NOTE: The Riverine unit can contain depressions that are filled with water when the river is not
flooding
6. Is the entire wetland unit in a topographic depression in which water ponds, or is saturated to the
surface, at some time during the year? This means that any outlet, if present, is higher than the interior
of the wetland.
NO – go to 7 YES – The wetland class is Depressional
7. Is the entire wetland unit located in a very flat area with no obvious depression and no overbank
flooding? The unit does not pond surface water more than a few inches. The unit seems to be
maintained by high groundwater in the area. The wetland may be ditched, but has no obvious natural
outlet.
NO – go to 8 YES – The wetland class is Depressional
8. Your wetland unit seems to be difficult to classify and probably contains several different HGM
classes. For example, seeps at the base of a slope may grade into a riverine floodplain, or a small
stream within a Depressional wetland has a zone of flooding along its sides. GO BACK AND IDENTIFY
WHICH OF THE HYDROLOGIC REGIMES DESCRIBED IN QUESTIONS 1-7 APPLY TO DIFFERENT
AREAS IN THE UNIT (make a rough sketch to help you decide). Use the following table to identify the
appropriate class to use for the rating system if you have several HGM classes present within the
wetland unit being scored.
NOTE: Use this table only if the class that is recommended in the second column represents 10% or
more of the total area of the wetland unit being rated. If the area of the HGM class listed in column 2
is less than 10% of the unit; classify the wetland using the class that represents more than 90% of the
total area.
HGM classes within the wetland unit
being rated
HGM class to
use in rating
Slope + Riverine Riverine
Slope + Depressional Depressional
Slope + Lake Fringe Lake Fringe
Depressional + Riverine along stream
within boundary of depression
Depressional
Depressional + Lake Fringe Depressional
Riverine + Lake Fringe Riverine
Salt Water Tidal Fringe and any other
class of freshwater wetland
Treat as
ESTUARINE
If you are still unable to determine which of the above criteria apply to your wetland, or if you have
more than 2 HGM classes within a wetland boundary, classify the wetland as Depressional for the
rating.
D
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 11
Rating Form – Effective January 1, 2015
SLOPE WETLANDS
Water Quality Functions - Indicators that the site functions to improve water quality
S 1.0. Does the site have the potential to improve water quality?
S 1.1. Characteristics of the average slope of the wetland: (a 1% slope has a 1 ft vertical drop in elevation for every
100 ft of horizontal distance)
Slope is 1% or less points = 3
Slope is > 1%-2% points = 2
Slope is > 2%-5% points = 1
Slope is greater than 5% points = 0
S 1.2. The soil 2 in below the surface (or duff layer) is true clay or true organic (use NRCS definitions): Yes = 3 No = 0
S 1.3. Characteristics of the plants in the wetland that trap sediments and pollutants:
Choose the points appropriate for the description that best fits the plants in the wetland. Dense means you
have trouble seeing the soil surface (>75% cover), and uncut means not grazed or mowed and plants are higher
than 6 in.
Dense, uncut, herbaceous plants > 90% of the wetland area points = 6
Dense, uncut, herbaceous plants > ½ of area points = 3
Dense, woody, plants > ½ of area points = 2
Dense, uncut, herbaceous plants > ¼ of area points = 1
Does not meet any of the criteria above for plants points = 0
Total for S 1 Add the points in the boxes above
Rating of Site Potential If score is: 12 = H 6-11 = M 0-5 = L Record the rating on the first page
S 2.0. Does the landscape have the potential to support the water quality function of the site?
S 2.1. Is > 10% of the area within 150 ft on the uphill side of the wetland in land uses that generate pollutants?
Yes = 1 No = 0
S 2.2. Are there other sources of pollutants coming into the wetland that are not listed in question S 2.1?
Other sources ________________ Yes = 1 No = 0
Total for S 2 Add the points in the boxes above
Rating of Landscape Potential If score is: 1-2 = M 0 = L Record the rating on the first page
S 3.0. Is the water quality improvement provided by the site valuable to society?
S 3.1. Does the wetland discharge directly (i.e., within 1 mi) to a stream, river, lake, or marine water that is on the
303(d) list? Yes = 1 No = 0
S 3.2. Is the wetland in a basin or sub-basin where water quality is an issue? At least one aquatic resource in the basin is
on the 303(d) list. Yes = 1 No = 0
S 3.3. Has the site been identified in a watershed or local plan as important for maintaining water quality? Answer YES
if there is a TMDL for the basin in which unit is found. Yes = 2 No = 0
Total for S 3 Add the points in the boxes above
Rating of Value If score is: 2-4 = H 1 = M 0 = L Record the rating on the first page
D
4
0
0
4
3
3
4
0
0
0
0
4
1
2
3
4
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 12
Rating Form – Effective January 1, 2015
SLOPE WETLANDS
Hydrologic Functions - Indicators that the site functions to reduce flooding and stream erosion
S 4.0. Does the site have the potential to reduce flooding and stream erosion?
S 4.1. Characteristics of plants that reduce the velocity of surface flows during storms: Choose the points appropriate
for the description that best fits conditions in the wetland. Stems of plants should be thick enough (usually > 1/8
in), or dense enough, to remain erect during surface flows.
Dense, uncut, rigid plants cover > 90% of the area of the wetland points = 1
All other conditions points = 0
Rating of Site Potential If score is: 1 = M 0 = L Record the rating on the first page
S 5.0. Does the landscape have the potential to support the hydrologic functions of the site?
S 5.1. Is more than 25% of the area within 150 ft upslope of wetland in land uses or cover that generate excess
surface runoff? Yes = 1 No = 0
Rating of Landscape Potential If score is: 1 = M 0 = L Record the rating on the first page
S 6.0. Are the hydrologic functions provided by the site valuable to society?
S 6.1. Distance to the nearest areas downstream that have flooding problems:
The sub-basin immediately down-gradient of site has flooding problems that result in damage to human or
natural resources (e.g., houses or salmon redds) points = 2
Surface flooding problems are in a sub-basin farther down-gradient points = 1
No flooding problems anywhere downstream points = 0
S 6.2. Has the site been identified as important for flood storage or flood conveyance in a regional flood control plan?
Yes = 2 No = 0
Total for S 6 Add the points in the boxes above
Rating of Value If score is: 2-4 = H 1 = M 0 = L Record the rating on the first page
NOTES and FIELD OBSERVATIONS:
D
4
0
4
4
0
4
0
0
4
0
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 13
Rating Form – Effective January 1, 2015
These questions apply to wetlands of all HGM classes.
HABITAT FUNCTIONS - Indicators that site functions to provide important habitat
H 1.0. Does the site have the potential to provide habitat?
H 1.1. Structure of plant community: Indicators are Cowardin classes and strata within the Forested class. Check the
Cowardin plant classes in the wetland. Up to 10 patches may be combined for each class to meet the threshold
of ¼ ac or more than 10% of the unit if it is smaller than 2.5 ac. Add the number of structures checked.
____Aquatic bed 4 structures or more: points = 4
____Emergent 3 structures: points = 2
____Scrub-shrub (areas where shrubs have > 30% cover) 2 structures: points = 1
____Forested (areas where trees have > 30% cover) 1 structure: points = 0
If the unit has a Forested class, check if:
____The Forested class has 3 out of 5 strata (canopy, sub-canopy, shrubs, herbaceous, moss/ground-cover)
that each cover 20% within the Forested polygon
H 1.2. Hydroperiods
Check the types of water regimes (hydroperiods) present within the wetland. The water regime has to cover
more than 10% of the wetland or ¼ ac to count (see text for descriptions of hydroperiods).
____Permanently flooded or inundated 4 or more types present: points = 3
____Seasonally flooded or inundated 3 types present: points = 2
____Occasionally flooded or inundated 2 types present: points = 1
____Saturated only 1 type present: points = 0
____Permanently flowing stream or river in, or adjacent to, the wetland
____Seasonally flowing stream in, or adjacent to, the wetland
____Lake Fringe wetland 2 points
____Freshwater tidal wetland 2 points
H 1.3. Richness of plant species
Count the number of plant species in the wetland that cover at least 10 ft2.
Different patches of the same species can be combined to meet the size threshold and you do not have to name
the species. Do not include Eurasian milfoil, reed canarygrass, purple loosestrife, Canadian thistle
If you counted: > 19 species points = 2
5 - 19 species points = 1
< 5 species points = 0
H 1.4. Interspersion of habitats
Decide from the diagrams below whether interspersion among Cowardin plants classes (described in H 1.1), or
the classes and unvegetated areas (can include open water or mudflats) is high, moderate, low, or none. If you
have four or more plant classes or three classes and open water, the rating is always high.
None = 0 points Low = 1 point Moderate = 2 points
All three diagrams
in this row
are HIGH = 3points
D
4
4
1
0
4
1
1
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 14
Rating Form – Effective January 1, 2015
H 1.5. Special habitat features:
Check the habitat features that are present in the wetland. The number of checks is the number of points.
____Large, downed, woody debris within the wetland (> 4 in diameter and 6 ft long).
____Standing snags (dbh > 4 in) within the wetland
____Undercut banks are present for at least 6.6 ft (2 m) and/or overhanging plants extends at least 3.3 ft (1 m)
over a stream (or ditch) in, or contiguous with the wetland, for at least 33 ft (10 m)
____Stable steep banks of fine material that might be used by beaver or muskrat for denning (> 30 degree
slope) OR signs of recent beaver activity are present (cut shrubs or trees that have not yet weathered
where wood is exposed)
____At least ¼ ac of thin-stemmed persistent plants or woody branches are present in areas that are
permanently or seasonally inundated (structures for egg-laying by amphibians)
____Invasive plants cover less than 25% of the wetland area in every stratum of plants (see H 1.1 for list of
strata)
Total for H 1 Add the points in the boxes above
Rating of Site Potential If score is: 15-18 = H 7-14 = M 0-6 = L Record the rating on the first page
H 2.0. Does the landscape have the potential to support the habitat functions of the site?
H 2.1. Accessible habitat (include only habitat that directly abuts wetland unit).
Calculate: % undisturbed habitat + [(% moderate and low intensity land uses)/2] = _______%
If total accessible habitat is:
> 1/3 (33.3%) of 1 km Polygon points = 3
20-33% of 1 km Polygon points = 2
10-19% of 1 km Polygon points = 1
< 10% of 1 km Polygon points = 0
H 2.2. Undisturbed habitat in 1 km Polygon around the wetland.
Calculate: % undisturbed habitat + [(% moderate and low intensity land uses)/2] = _______%
Undisturbed habitat > 50% of Polygon points = 3
Undisturbed habitat 10-50% and in 1-3 patches points = 2
Undisturbed habitat 10-50% and > 3 patches points = 1
Undisturbed habitat < 10% of 1 km Polygon points = 0
H 2.3. Land use intensity in 1 km Polygon: If
> 50% of 1 km Polygon is high intensity land use points = (- 2)
≤ 50% of 1 km Polygon is high intensity points = 0
Total for H 2 Add the points in the boxes above
Rating of Landscape Potential If score is: 4-6 = H 1-3 = M < 1 = L Record the rating on the first page
H 3.0. Is the habitat provided by the site valuable to society?
H 3.1. Does the site provide habitat for species valued in laws, regulations, or policies? Choose only the highest score
that applies to the wetland being rated.
Site meets ANY of the following criteria: points = 2
It has 3 or more priority habitats within 100 m (see next page)
It provides habitat for Threatened or Endangered species (any plant or animal on the state or federal lists)
It is mapped as a location for an individual WDFW priority species
It is a Wetland of High Conservation Value as determined by the Department of Natural Resources
It has been categorized as an important habitat site in a local or regional comprehensive plan, in a
Shoreline Master Plan, or in a watershed plan
Site has 1 or 2 priority habitats (listed on next page) within 100 m points = 1
Site does not meet any of the criteria above points = 0
Rating of Value If score is: 2 = H 1 = M 0 = L Record the rating on the first page
D
3
0
4
4 3 7
0
4
16 7 23
1
4
4 -2
-1
4
2
4
4
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 15
Rating Form – Effective January 1, 2015
WDFW Priority Habitats
Priority habitats listed by WDFW (see complete descriptions of WDFW priority habitats, and the counties in which they can
be found, in: Washington Department of Fish and Wildlife. 2008. Priority Habitat and Species List. Olympia, Washington.
177 pp. http://wdfw.wa.gov/publications/00165/wdfw00165.pdf or access the list from here:
http://wdfw.wa.gov/conservation/phs/list/)
Count how many of the following priority habitats are within 330 ft (100 m) of the wetland unit: NOTE: This question is
independent of the land use between the wetland unit and the priority habitat.
Aspen Stands: Pure or mixed stands of aspen greater than 1 ac (0.4 ha).
Biodiversity Areas and Corridors: Areas of habitat that are relatively important to various species of native fish and
wildlife (full descriptions in WDFW PHS report).
Herbaceous Balds: Variable size patches of grass and forbs on shallow soils over bedrock.
Old-growth/Mature forests: Old-growth west of Cascade crest – Stands of at least 2 tree species, forming a multi-
layered canopy with occasional small openings; with at least 8 trees/ac (20 trees/ha ) > 32 in (81 cm) dbh or > 200
years of age. Mature forests – Stands with average diameters exceeding 21 in (53 cm) dbh; crown cover may be less
than 100%; decay, decadence, numbers of snags, and quantity of large downed material is generally less than that
found in old-growth; 80-200 years old west of the Cascade crest.
Oregon White Oak: Woodland stands of pure oak or oak/conifer associations where canopy coverage of the oak
component is important (full descriptions in WDFW PHS report p. 158 – see web link above).
Riparian: The area adjacent to aquatic systems with flowing water that contains elements of both aquatic and
terrestrial ecosystems which mutually influence each other.
Westside Prairies: Herbaceous, non-forested plant communities that can either take the form of a dry prairie or a wet
prairie (full descriptions in WDFW PHS report p. 161 – see web link above).
Instream: The combination of physical, biological, and chemical processes and conditions that interact to provide
functional life history requirements for instream fish and wildlife resources.
Nearshore: Relatively undisturbed nearshore habitats. These include Coastal Nearshore, Open Coast Nearshore, and
Puget Sound Nearshore. (full descriptions of habitats and the definition of relatively undisturbed are in WDFW report –
see web link on previous page).
Caves: A naturally occurring cavity, recess, void, or system of interconnected passages under the earth in soils, rock,
ice, or other geological formations and is large enough to contain a human.
Cliffs: Greater than 25 ft (7.6 m) high and occurring below 5000 ft elevation.
Talus: Homogenous areas of rock rubble ranging in average size 0.5 - 6.5 ft (0.15 - 2.0 m), composed of basalt, andesite,
and/or sedimentary rock, including riprap slides and mine tailings. May be associated with cliffs.
Snags and Logs: Trees are considered snags if they are dead or dying and exhibit sufficient decay characteristics to
enable cavity excavation/use by wildlife. Priority snags have a diameter at breast height of > 20 in (51 cm) in western
Washington and are > 6.5 ft (2 m) in height. Priority logs are > 12 in (30 cm) in diameter at the largest end, and > 20 ft
(6 m) long.
Note: All vegetated wetlands are by definition a priority habitat but are not included in this list because they are addressed
elsewhere.
D
4
4
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 16
Rating Form – Effective January 1, 2015
CATEGORIZATION BASED ON SPECIAL CHARACTERISTICS
Wetland Type
Check off any criteria that apply to the wetland. Circle the category when the appropriate criteria are met.
Category
SC 1.0. Estuarine wetlands
Does the wetland meet the following criteria for Estuarine wetlands?
The dominant water regime is tidal,
Vegetated, and
With a salinity greater than 0.5 ppt Yes –Go to SC 1.1 No= Not an estuarine wetland
SC 1.1. Is the wetland within a National Wildlife Refuge, National Park, National Estuary Reserve, Natural Area
Preserve, State Park or Educational, Environmental, or Scientific Reserve designated under WAC 332-30-151?
Yes = Category I No - Go to SC 1.2
Cat. I
SC 1.2. Is the wetland unit at least 1 ac in size and meets at least two of the following three conditions?
The wetland is relatively undisturbed (has no diking, ditching, filling, cultivation, grazing, and has less
than 10% cover of non-native plant species. (If non-native species are Spartina, see page 25)
At least ¾ of the landward edge of the wetland has a 100 ft buffer of shrub, forest, or un-grazed or un-
mowed grassland.
The wetland has at least two of the following features: tidal channels, depressions with open water, or
contiguous freshwater wetlands. Yes = Category I No = Category II
Cat. I
Cat. II
SC 2.0. Wetlands of High Conservation Value (WHCV)
SC 2.1. Has the WA Department of Natural Resources updated their website to include the list of Wetlands of High
Conservation Value? Yes – Go to SC 2.2 No – Go to SC 2.3
SC 2.2. Is the wetland listed on the WDNR database as a Wetland of High Conservation Value?
Yes = Category I No = Not a WHCV
SC 2.3. Is the wetland in a Section/Township/Range that contains a Natural Heritage wetland?
http://www1.dnr.wa.gov/nhp/refdesk/datasearch/wnhpwetlands.pdf
Yes – Contact WNHP/WDNR and go to SC 2.4 No = Not a WHCV
SC 2.4. Has WDNR identified the wetland within the S/T/R as a Wetland of High Conservation Value and listed it on
their website? Yes = Category I No = Not a WHCV
Cat. I
SC 3.0. Bogs
Does the wetland (or any part of the unit) meet both the criteria for soils and vegetation in bogs? Use the key
below. If you answer YES you will still need to rate the wetland based on its functions.
SC 3.1. Does an area within the wetland unit have organic soil horizons, either peats or mucks, that compose 16 in or
more of the first 32 in of the soil profile? Yes – Go to SC 3.3 No – Go to SC 3.2
SC 3.2. Does an area within the wetland unit have organic soils, either peats or mucks, that are less than 16 in deep
over bedrock, or an impermeable hardpan such as clay or volcanic ash, or that are floating on top of a lake or
pond? Yes – Go to SC 3.3 No = Is not a bog
SC 3.3. Does an area with peats or mucks have more than 70% cover of mosses at ground level, AND at least a 30%
cover of plant species listed in Table 4? Yes = Is a Category I bog No – Go to SC 3.4
NOTE: If you are uncertain about the extent of mosses in the understory, you may substitute that criterion by
measuring the pH of the water that seeps into a hole dug at least 16 in deep. If the pH is less than 5.0 and the
plant species in Table 4 are present, the wetland is a bog.
SC 3.4. Is an area with peats or mucks forested (> 30% cover) with Sitka spruce, subalpine fir, western red cedar,
western hemlock, lodgepole pine, quaking aspen, Engelmann spruce, or western white pine, AND any of the
species (or combination of species) listed in Table 4 provide more than 30% of the cover under the canopy?
Yes = Is a Category I bog No = Is not a bog
Cat. I
D
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 17
Rating Form – Effective January 1, 2015
SC 4.0. Forested Wetlands
Does the wetland have at least 1 contiguous acre of forest that meets one of these criteria for the WA
Department of Fish and Wildlife’s forests as priority habitats? If you answer YES you will still need to rate
the wetland based on its functions.
Old-growth forests (west of Cascade crest): Stands of at least two tree species, forming a multi-layered
canopy with occasional small openings; with at least 8 trees/ac (20 trees/ha) that are at least 200 years of
age OR have a diameter at breast height (dbh) of 32 in (81 cm) or more.
Mature forests (west of the Cascade Crest): Stands where the largest trees are 80- 200 years old OR the
species that make up the canopy have an average diameter (dbh) exceeding 21 in (53 cm).
Yes = Category I No = Not a forested wetland for this section
Cat. I
SC 5.0. Wetlands in Coastal Lagoons
Does the wetland meet all of the following criteria of a wetland in a coastal lagoon?
The wetland lies in a depression adjacent to marine waters that is wholly or partially separated from
marine waters by sandbanks, gravel banks, shingle, or, less frequently, rocks
The lagoon in which the wetland is located contains ponded water that is saline or brackish (> 0.5 ppt)
during most of the year in at least a portion of the lagoon (needs to be measured near the bottom)
Yes – Go to SC 5.1 No = Not a wetland in a coastal lagoon
SC 5.1. Does the wetland meet all of the following three conditions?
The wetland is relatively undisturbed (has no diking, ditching, filling, cultivation, grazing), and has less
than 20% cover of aggressive, opportunistic plant species (see list of species on p. 100).
At least ¾ of the landward edge of the wetland has a 100 ft buffer of shrub, forest, or un-grazed or un-
mowed grassland.
The wetland is larger than 1/10 ac (4350 ft2)
Yes = Category I No = Category II
Cat. I
Cat. II
SC 6.0. Interdunal Wetlands
Is the wetland west of the 1889 line (also called the Western Boundary of Upland Ownership or WBUO)? If
you answer yes you will still need to rate the wetland based on its habitat functions.
In practical terms that means the following geographic areas:
Long Beach Peninsula: Lands west of SR 103
Grayland-Westport: Lands west of SR 105
Ocean Shores-Copalis: Lands west of SR 115 and SR 109
Yes – Go to SC 6.1 No = not an interdunal wetland for rating
SC 6.1. Is the wetland 1 ac or larger and scores an 8 or 9 for the habitat functions on the form (rates H,H,H or H,H,M
for the three aspects of function)? Yes = Category I No – Go to SC 6.2
SC 6.2. Is the wetland 1 ac or larger, or is it in a mosaic of wetlands that is 1 ac or larger?
Yes = Category II No – Go to SC 6.3
SC 6.3. Is the unit between 0.1 and 1 ac, or is it in a mosaic of wetlands that is between 0.1 and 1 ac?
Yes = Category III No = Category IV
Cat I
Cat. II
Cat. III
Cat. IV
Category of wetland based on Special Characteristics
If you answered No for all types, enter “Not Applicable” on Summary Form
D
N/A
Wetland name or number ______
Wetland Rating System for Western WA: 2014 Update 18
Rating Form – Effective January 1, 2015
This page left blank intentionally
APPENDIX C
CRITICAL AREAS STUDY MAPS
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Delineation / Mitigation / Restoration / Habitat Creation / Permit Assistance
9505 19th Avenue S.E. Suite 106 Everett,Washington 98208 Phone: (425) 337-3174
Fax: (425) 337-3045
Email: mailbox@wetlandresources .com
Canopy - Lincoln Pl NE
Blue Fern Development, LLCAttn: Evan Mann
11232 120th Ave NE, #204
Kirkland, WA 98033
City of Renton
Critical Areas Study - Existing Conditions
Drawn by: ARProject Number: 18158
Sheet 1/3
Revision 3: 7/14/2021
WETLAND B
CATEGORY IV
50' BUFFER
WETLAND A
CATEGORY IV
50' BUFFER
WETLAND C
CATEGORY IV
50' BUFFER
WETLAND D
CATEGORY IV
50' BUFFER
STREAM S
TYPE NP
75' BUFFER
50'75'50'
50'
EXISTING DITCH
S5
S3
S2
S1
S4
S6 S7
S9
S8
CRITICAL AREAS - EXISTING CONDITIONS
CANOPY - LINCOLN PL NE
PORTION OF SECTION 19, TOWNSHIP 31N, RANGE 6E, W.M.
STEEP SLOPE
AREA 436 SF
STEEP SLOPE
AREA 3,571 SF
STEEP SLOPE
AREA 9,997 SF
Scale 1" = 100'
10050 150 2000
LEGEND
APPROX. STREAM
BOUNDARY
PROPERTY BOUNDARY STEEP SLOPE AREA
STREAM S9S1 DATA SAMPLING POINTS
WETLAND STANDARD BUFFER
Delineation / Mitigation / Restoration / Habitat Creation / Permit Assistance
9505 19th Avenue S.E. Suite 106 Everett,Washington 98208 Phone: (425) 337-3174
Fax: (425) 337-3045
Email: mailbox@wetlandresources .com
Revision 3: 7/14/2021
Canopy - Lincoln Pl NE
Blue Fern Development, LLCAttn: Evan Mann
11232 120th Ave NE, #204
Kirkland, WA 98033
City of Renton
Critical Areas Study - Conceptual Mitigation
Plan
Drawn by: ARProject Number: 18158
Sheet 2/3
CRITICAL AREAS STUDY - CONCEPTUAL MITIGATION PLAN
CANOPY - LINCOLN PL NE
PORTION OF SECTION 19, TOWNSHIP 31N, RANGE 6E, W.M.
SD
SDSD
SD
SDSD
SDSDSD 1098111345637545355504956(OPEN SPACE)TRACT B35363240333837393452474851(OPEN SPACE)TRACT Q2324251826192720(OPEN SPACE)TR. E2128222930(OPEN SPACE)TRACT F(OPEN SPACE)TR. D214117151614423112464544(STORM/ OPEN SPACE)TRACT H(OPEN SPACE)TRACT G(OPEN SPACE)TRACT I(STORM/OPEN SPACE)TRACT A43X
X
X
X
X
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X X X
X
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STEEP SLOPE
AREA 436 SF
STEEP SLOPE AREA
9,997 SF
WETLAND A
TO BE FILLED
1,585 SF
APPROXIMATE
BOUNDARY OF
STREAM S
EX. DITCH
INSET 2 SHT 2:
INSET 1 (SHT 2):
Scale 1" = 100'
10050 150 2000
UTILITY EASEMENT
WETLAND B
CATEGORY IV
50' BUFFER
WETLAND C
CATEGORY IV
50' BUFFER
WETLAND D
CATEGORY IV
50' BUFFER
STREAM S
TYPE NP
75' BUFFER
LEGEND
WETLAND ENHANCEMENT
BUFFER IMPACT
BUFFER ENHANCEMENT
BUFFER AVERAGING
(REDUCTION)
BUFFER AVERAGING
(ADDITION)
WETLAND PROPERTY BOUNDARY
STREAM
STANDARD BUFFER
75% OF STANDARD BUFFER
15' BUFFER STRUCTURE
SETBACK
APPROX. STREAM
BOUNDARY
FINAL BUFFER/PERMANENT
FENCE/SIGNSXX
APPROXIMATE
LOCATION OF
TRAIL IMPACT
APPROXIMATE LOCATION
OF TRAIL TO CONNECT TO
CITY OF NEWCASTLES TRAIL
ALONG NE 43RD ST RIGHT-OF-WAY
APPROXIMATE
LOCATION OF
STREAM CROSSING
UNOPENED
RIGHT-OF-WAY
OF 112TH AVE SE
WETLAND IMPACT
RIGHT-OF-WAY
PROPOSED TRAIL
Delineation / Mitigation / Restoration / Habitat Creation / Permit Assistance
9505 19th Avenue S.E. Suite 106 Everett,Washington 98208 Phone: (425) 337-3174
Fax: (425) 337-3045
Email: mailbox@wetlandresources .com
Canopy - Lincoln Pl NE
Blue Fern Development, LLC
Attn: Evan Mann
11232 120th Ave NE, #204Kirkland, WA 98033
City of Renton
Critical Areas Study - Conceptual Mitigation
Plan Insets
Drawn by: ARProject Number: 18158
Sheet 3/3
Revision 3: 7/14/2021
CRITICAL AREAS STUDY - CONCEPTUAL MITIGATION PLAN INSETS
CANOPY - LINCOLN PL NE
PORTION OF SECTION 19, TOWNSHIP 31N, RANGE 6E, W.M.SDSDSD
SD 67(OPEN SPACE)TRACT QX
X
X
X
X
X X
X X X
X
X
X
X 101113545355504956(OPEN SPACE)TRACT B5247485117151614421246454443X
X
X
X
X X X
X X X X
X X X
X
X
X
X
X
X
X
X
X
X
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X
X
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X
X X
X
X
WETLAND C
WETLAND D
TO BE ENHANCED
3,100 SF
STREAM S
BUFFER REDUCTION
2,095 SF
BUFFER ADDITION
645 SF
STREAM S
BUFFER REDUCTION
2,635 SF
37.5' BUFFER
ENHANCEMENT
AREA A
6,788 SF
BUFFER ADDITION
1,660 SF
STREAM S
BUFFER ADDITION
2,695 SF
WETLAND B
TO BE ENHANCED
1,765 SF
BUFFER REDUCTION
1,032 SF
BUFFER ADDITION
1,092 SF
BUFFER IMPACT
240 SF
BUFFER
ENHANCEMENT
700 SF 52'50'INSET 2:
INSET 1:
Inset 2 Scale 1" = 60'
6030 90 1200
Inset 1 Scale 1" = 50'
5025 75 1000
15'15'15'
37 .5'97'BUFFER
ENHANCEMENT
1,356 SF
LEGEND
WETLAND ENHANCEMENT
BUFFER IMPACT
BUFFER ENHANCEMENT
BUFFER AVERAGING
(REDUCTION)
BUFFER AVERAGING
(ADDITION)
WETLAND PROPERTY BOUNDARY
STREAM
STANDARD BUFFER
75% OF STANDARD BUFFER
15' BUFFER STRUCTURE
SETBACK
APPROX. STREAM
BOUNDARY
FINAL BUFFER/PERMANENT
FENCE/SIGNSXXWETLAND IMPACT
RIGHT-OF-WAY
WETLAND IMPACT
134 SF
BUFFER IMPACT
274 SF
BUFFER IMPACT
680 SF
BUFFER IMPACT
380 SF
BUFFER IMPACT
401 SF
BUFFER
ENHANCEMENT
AREA B
781 SF
APPENDIX D
SLOPE ANALYSIS FIGURES
Delineation / Mitigation / Restoration / Habitat Creation / Permit Assistance
9505 19th Avenue S.E. Suite 106 Everett,Washington 98208 Phone: (425) 337-3174
Fax: (425) 337-3045
Email: mailbox@wetlandresources .com
Revision 3: 7/14/2021
Canopy - Lincoln Pl NE
Blue Fern Development, LLC
Attn: Evan Mann
11232 120th Ave NE, #204
Kirkland, WA 98033
City of Renton
Slope Analysis Figures
Drawn by: TAProject Number: 18158Sheet 1/1
CRITICAL AREAS STUDY - SLOPE ANALYSIS FIGURES
CANOPY - LINCOLN PL NE
PORTION OF SECTION 19, TOWNSHIP 31N, RANGE 6E, W.M.
LEGEND
<16% SLOPE
16-20% SLOPE
>20% SLOPE
Scale 1" = 60'
6030 90 12001101201301401501601701801902001234567
8
9
WETLAND C
STREAM A
WETLAND C
STREAM A