HomeMy WebLinkAboutEx_11_Critical_Areas_Study July 8, 2022
AOA-6644
John Kay
john@kplusarchitects.net
SUBJECT: Critical Areas Study for New Life Church Interior Remodel
15711 – 152nd Ave. SE, Renton WA (Parcel 232305-9021)
Dear John:
On November 23, 2021 I conducted a wetland and stream reconnaissance in the
vicinity of the proposed project area utilizing the methodology outlined in the May
2010 Regional Supplement to the Corps of Engineers Wetland Delineation Manual:
Western Mountains, Valleys, and Coast Region (Version 2.0). The purpose of the
reconnaissance was to assess a known wetland and stream (Madson Creek) located
to the west of the proposed work.
Wetland A and Madson Creek
Wetland A is a Depressional Hydrogeomorphic (HGM) wetland located to the west of
the project area. The eastern edge of the wetland was delineated with pink flagging
labelled A-1 through A-4. Wetland A consists of a historically excavated pond that
currently consists of a forested plant community that was dominated by willow (Salix
sp.), black cottonwood (Populus trichocarpa), and salmonberry (Rubus spectabilis).
Overflow runoff within Wetland A drains west through a concrete dam and eventually
drains into Madson Creek which flows from northeast to southwest to the northwest
of the proposed project area.
Attachment A contains data sheets prepared for a representative location in both
the wetland and upland. These data sheets document the vegetation, soils, and
hydrology information that aided in the wetland boundary delineation.
Wetlands, in general, provide many valuable ecological and social functions,
including stormwater storage, water quality protection, groundwater recharge
and discharge, and wildlife habitat. The trapping of sediments and other
pollutants within wetlands maintains water quality in downstream areas and
aids in the prevention of fish habitat degradation by limiting silt accumulation
within spawning areas. Wetlands may also provide some further benefit to
fish and other wildlife by releasing water slowly during the summer months,
thereby contributing to the base flow of downstream areas.
RECEIVED
07/06/2023
AMorganroth
PLANNING DIVISION
DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A
John Kay July 8, 2022 Page 2 of 4
Wetlands also provide habitat for a variety of wildlife species and transport nutrients
to downstream areas. Nutrients transported to downstream areas provide biological
support for fish and other aquatic wildlife.
Wetland A is a Category II wetland with 7 Habitat Points (Attachment B) and
requires a standard 150-foot buffer plus 15-foot structure setback per RMC 4-3-
050.G.2. Madson Creek is a Type F stream that requires a standard 115-foot buffer
and 15-foot structure setback. The 150-foot standard buffer from Wetland A extends
into the middle of the existing building, while the stream buffer does not come close
to the project area.
Project Impacts
It is my understanding that the current project consists of an interior remodel and
that no new impervious surfaces would be created. Since there is no vegetation
removal or new impervious surface within the buffer, there are no wetland buffer
impacts. Since the project is well outside of the Madson Creek buffer, there are no
stream buffer impacts.
The wetland buffer on the subject property in the vicinity of the proposed work does
not provide any functional benefit to the wetland. The area of the interior remodel is
already developed and completely separated from the wetland by the wide
pavement and parking area. The area of proposed interior remodel does not provide
hydrologic support to the wetland since runoff from the area drains into catch-basins
within the drive aisle and is conveyed to the stormwater facilities for the existing
development rather than directly to the wetland. Since the area of proposed remodel
is not vegetated, it also does not provide any stormwater filtration or water quality
benefit to the wetland.
As a non-vegetated area, the existing infrastructure does not provide any significant
habitat for wildlife that may currently be utilizing the wetland. In addition, the
developed area in the vicinity of the proposed addition does not provide nutrients or
any beneficial allochthonous inputs to the wetland either through vegetation blowing
into the wetland or through water draining into the wetland.
If you have any questions, please give me a call.
Sincerely,
ALTMANN OLIVER ASSOCIATES, LLC
John Altmann
Ecologist
DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A
John Kay July 8, 2022 Page 3 of 4
View looking south. Wetland beyond fence on right and existing building and
infrastructure to left.
DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A
John Kay July 8, 2022 Page 4 of 4
View looking north. Existing large, paved access road separating wetland buffer at
left from existing building at right.
DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A
King County, EagleView Technologies, Inc.
±0 75 150 225 30037.5
US Feet
Subject Property Parcel: 232305-9021
Approximate Wetland A Cat. II
Approximate Madson Creek
Approximate 150' Wetland Buffer
Approximate 115' Creek Buffer
Approximate 15' Building Setback
Critical Areas Map AOA - 6644City of Renton
Parcel 232305-9021
A-4
A-1
DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A
DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A
US Army Corps of Engineers Western Mountains, Valleys, and Coast – Version 2.0
WETLAND DETERMINATION DATA FORM – Western Mountains, Valleys, and Coast Region
VEGETATION – Use scientific names of plants
Tree Stratum (Plot size: 8) Absolute
% Cover
Dominant
Species?
Indicator
Status Dominance Test Worksheet:
1. Salix lucida 100 yes FACW Number of Dominant Species
That Are OBL, FACW, or FAC: 3 (A) 2.
3. Total Number of Dominant
Species Across All Strata: 3 (B) 4.
50% = 50, 20% = 20 100 = Total Cover Percent of Dominant Species
That Are OBL, FACW, or FAC: 100 (A/B) Sapling/Shrub Stratum (Plot size: 8)
1. Salix lucida 30 yes FACW Prevalence Index worksheet:
2. Total % Cover of: Multiply by:
3. OBL species x1 =
4. FACW species x2 =
5. FAC species x3 =
50% = 15, 20% = 6 30 = Total Cover FACU species x4 =
Herb Stratum (Plot size: 8) UPL species x5 =
1. Ranunculus repens 30 yes FAC Column Totals: (A) (B)
2. Prevalence Index = B/A =
3. Hydrophytic Vegetation Indicators:
4. 1 – Rapid Test for Hydrophytic Vegetation
5. 2 - Dominance Test is >50%
6. 3 - Prevalence Index is <3.01
7. 4 - Morphological Adaptations1 (Provide supporting
data in Remarks or on a separate sheet) 8.
9. 5 - Wetland Non-Vascular Plants1
10. Problematic Hydrophytic Vegetation1 (Explain)
11.
1Indicators of hydric soil and wetland hydrology must
be present, unless disturbed or problematic. 50% = 15, 20% = 6 30 = Total Cover
Woody Vine Stratum (Plot size: )
1.
Hydrophytic
Vegetation
Present?
Yes No 2.
50% = , 20% = = Total Cover
% Bare Ground in Herb Stratum
Remarks:
Project Site: Parcel 232305-9021 City/County: City of Renton/ Sampling Date: 11-23-21
Applicant/Owner: New Life Church State: WA Sampling Point: DP#1
Investigator(s): John Altmann, Dain Altmann Section, Township, Range: S23,T23N,R5E
Landform (hillslope, terrace, etc.): Local relief (concave, convex, none): Slope (%):
Subregion (LRR): A Lat: 47.4623 Long: -122.14005 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
Is the Sampled Area
within a Wetland? Yes No Hydric Soil Present? Yes No
Wetland Hydrology Present? Yes No
Remarks:
Located 8' into wetland at A-3, Soils heavily disturbed through historic pond excavation. Delineation based largely on hydrology and topographic break
DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A
US Army Corps of Engineers Western Mountains, Valleys, and Coast – Version 2.0
SOIL Sampling Point: DP#1
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
0-15 subsoil heavily compacted
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)
3Indicators of hydrophytic vegetation and
wetland hydrology must be present,
unless disturbed or problematic.
Thick Dark Surface (A12) Redox Dark Surface (F6)
Sandy Mucky Mineral (S1) Depleted Dark Surface (F7)
Sandy Gleyed Matrix (S4) Redox Depressions (F8)
Restrictive Layer (if present):
Hydric Soils Present? Yes No
Type:
Depth (inches):
Remarks: Soils are heavily disturbed, delineation based primarily on hydrology and topography.
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) Water-Stained Leaves (B9)
High Water Table (A2) (except MLRA 1, 2, 4A, and 4B) (MLRA 1, 2, 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 Stresses 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):
Wetland Hydrology Present?
Yes
No
Water Table Present? Yes No Depth (inches): Surface
Saturation Present?
(includes capillary fringe) Yes No Depth (inches): Surface
Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available:
Remarks:
Project Site: Parcel 232305-9021
DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A
US Army Corps of Engineers Western Mountains, Valleys, and Coast – Version 2.0
WETLAND DETERMINATION DATA FORM – Western Mountains, Valleys, and Coast Region
VEGETATION – Use scientific names of plants
Tree Stratum (Plot size: 8) Absolute
% Cover
Dominant
Species?
Indicator
Status Dominance Test Worksheet:
1. Alnus rubra 50 yes FAC Number of Dominant Species
That Are OBL, FACW, or FAC: 3 (A) 2. Salix lucida 20 yes FACW
3. Total Number of Dominant
Species Across All Strata: 4 (B) 4.
50% = 35, 20% = 14 70 = Total Cover Percent of Dominant Species
That Are OBL, FACW, or FAC: 75 (A/B) Sapling/Shrub Stratum (Plot size: 8)
1. Rubus armeniacus 80 yes FAC Prevalence Index worksheet:
2. Total % Cover of: Multiply by:
3. OBL species x1 =
4. FACW species x2 =
5. FAC species x3 =
50% = 40, 20% = 16 80 = Total Cover FACU species x4 =
Herb Stratum (Plot size: 8) UPL species x5 =
1. Polystichum munitum 20 yes FACU Column Totals: (A) (B)
2. Prevalence Index = B/A =
3. Hydrophytic Vegetation Indicators:
4. 1 – Rapid Test for Hydrophytic Vegetation
5. 2 - Dominance Test is >50%
6. 3 - Prevalence Index is <3.01
7. 4 - Morphological Adaptations1 (Provide supporting
data in Remarks or on a separate sheet) 8.
9. 5 - Wetland Non-Vascular Plants1
10. Problematic Hydrophytic Vegetation1 (Explain)
11.
1Indicators of hydric soil and wetland hydrology must
be present, unless disturbed or problematic. 50% = 10, 20% = 4 20 = Total Cover
Woody Vine Stratum (Plot size: )
1.
Hydrophytic
Vegetation
Present?
Yes No 2.
50% = , 20% = = Total Cover
% Bare Ground in Herb Stratum
Remarks:
Project Site: Parcel 232305-9021 City/County: City of Renton/ Sampling Date: 11-23-21
Applicant/Owner: New Life Church State: WA Sampling Point: DP#2
Investigator(s): John Altmann, Dain Altmann Section, Township, Range: S23,T23N,R5E
Landform (hillslope, terrace, etc.): Local relief (concave, convex, none): Slope (%):
Subregion (LRR): A Lat: 47.4623 Long: -122.14005 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
Is the Sampled Area
within a Wetland? Yes No Hydric Soil Present? Yes No
Wetland Hydrology Present? Yes No
Remarks:
Located 8' into upland at A-3
DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A
US Army Corps of Engineers Western Mountains, Valleys, and Coast – Version 2.0
SOIL Sampling Point: DP#2
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
0-15 10YR3/2 100 GCL gravelly clay loam
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)
3Indicators of hydrophytic vegetation and
wetland hydrology must be present,
unless disturbed or problematic.
Thick Dark Surface (A12) Redox Dark Surface (F6)
Sandy Mucky Mineral (S1) Depleted Dark Surface (F7)
Sandy Gleyed Matrix (S4) Redox Depressions (F8)
Restrictive Layer (if present):
Hydric Soils Present? Yes No
Type:
Depth (inches):
Remarks: no redoximorphic features
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) Water-Stained Leaves (B9)
High Water Table (A2) (except MLRA 1, 2, 4A, and 4B) (MLRA 1, 2, 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 Stresses 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):
Wetland Hydrology Present?
Yes
No
Water Table Present? Yes No Depth (inches):
Saturation Present?
(includes capillary fringe) Yes No Depth (inches):
Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available:
Remarks: dry
Project Site: Parcel 232305-9021
DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A
ATTACHMENT B
WETLAND RATING
DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A
Wetland name or number A
Name of wetland (or ID #):Date of site visit:11/23/2021
Rated by Trained by Ecology? Yes No Date of training 03/08 & 03/15
HGM Class used for rating Wetland has multiple HGM classes? Yes No
NOTE: Form is not complete with out the figures requested (figures can be combined ).
Source of base aerial photo/map
OVERALL WETLAND CATEGORY II (based on functions or special characteristics )
1. Category of wetland based on FUNCTIONS
Category I - Total score = 23 - 27 Score for each
X Category II - Total score = 20 - 22 function based
Category III - Total score = 16 - 19 on three
Category IV - Total score = 9 - 15 ratings
(order of ratings
is not
important )
M L 9 = H, H, H
M H 8 = H, H, M
H H Total 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
2. Category based on SPECIAL CHARACTERISTICS of wetland
X
Depressional & Flats
RATING SUMMARY – Western Washington
List appropriate rating (H, M, L)
HydrologicImproving
Water Quality
MSite Potential
Landscape Potential
Habitat
M
FUNCTION
Parcel 232305-9021
Altmann
King County iMAP
Coastal Lagoon
Interdunal
Value
Score Based on
Ratings 6 7 7 20
M
CHARACTERISTIC Category
Estuarine
Wetland of High Conservation Value
Bog
Mature Forest
Old Growth Forest
None of the above
Wetland Rating System for Western WA: 2014 Update
Rating Form - Effective January 1, 2015 1 WSDOT Adapted Form - March 2, 2015
DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A
Wetland name or number A
Maps and Figures required to answer questions correctly for
Western Washington
Depressional Wetlands
Map of: Figure #
Cowardin plant classes F
Hydroperiods E
Location of outlet (can be added to map of hydroperiods )B
Boundary of area within 150 ft of the wetland (can be added to another figure )B
Map of the contributing basin G
1 km Polygon: Area that extends 1 km from entire wetland edge - including
polygons for accessible habitat and undisturbed habitat
Screen capture of map of 303(d) listed waters in basin (from Ecology website)C
Screen capture of list of TMDLs for WRIA in which unit is found (from web)D
Riverine Wetlands
Map of: Figure #
Cowardin plant classes
Hydroperiods
Ponded depressions
Boundary of area within 150 ft of the wetland (can be added to another figure )
Plant cover of trees, shrubs, and herbaceous plants
Width of unit vs. width of stream (can be added to another figure )
Map of the contributing basin
1 km Polygon: Area that extends 1 km from entire wetland edge - including
polygons for accessible habitat and undisturbed habitat
Screen capture of map of 303(d) listed waters in basin (from Ecology website)
Screen capture of list of TMDLs for WRIA in which unit is found (from web)
Lake Fringe Wetlands
Map of: Figure #
Cowardin plant classes
Plant cover of trees, shrubs, and herbaceous plants
Boundary of area within 150 ft of the wetland (can be added to another figure )
1 km Polygon: Area that extends 1 km from entire wetland edge - including
polygons for accessible habitat and undisturbed habitat
Screen capture of map of 303(d) listed waters in basin (from Ecology website)
Screen capture of list of TMDLs for WRIA in which unit is found (from web)
Slope Wetlands
Map of: Figure #
Cowardin plant classes
Hydroperiods
Plant cover of dense trees, shrubs, and herbaceous plants
Plant cover of dense, rigid trees, shrubs, and herbaceous plants
(can be added to another figure )
Boundary of area within 150 ft of the wetland (can be added to another figure )
1 km Polygon: Area that extends 1 km from entire wetland edge - including
polygons for accessible habitat and undisturbed habitat
Screen capture of map of 303(d) listed waters in basin (from Ecology website)
Screen capture of list of TMDLs for WRIA in which unit is found (from web)
A
S 3.1, S 3.2
S 3.3
S 4.1
S 2.1, S 5.1
To answer questions:
H 1.1, H 1.4
H 1.2
S 1.3
H 2.1, H 2.2, H 2.3
L 3.1, L 3.2
L 3.3
H 2.1, H 2.2, H 2.3
R 3.1
R 3.2, R 3.3
To answer questions:
L 1.1, L 4.1, H 1.1, H 1.4
H 1.2
R 1.1
R 2.4
R 1.2, R 4.2
R 4.1
R 2.2, R 2.3, R 5.2
H 2.1, H 2.2, H 2.3
L 1.2
L 2.2
D 1.1, D 4.1
D 2.2, D 5.2
D 4.3, D 5.3
H 2.1, H 2.2, H 2.3
D 3.1, D 3.2
D 3.3
To answer questions:
H 1.1, H 1.4
To answer questions:
D 1.3, H 1.1, H 1.4
D 1.4, H 1.2
Wetland Rating System for Western WA: 2014 Update
Rating Form - Effective January 1, 2015 2 WSDOT Adapted Form - March 2, 2015
DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A
Wetland name or number A
For questions 1 -7, the criteria described must apply to the entire unit being rated.
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
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?
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 leaves the wetland without being impounded.
NO - go to 5 YES - The wetland class is Slope
5. Does the entire wetland unit meet all of the following criteria?
The overbank flooding occurs at least once every 2 years.
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.
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.
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;
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.
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).
The unit is in a valley, or stream channel, where it gets inundated by overbank flooding
from that stream or river,
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.
HGM Classification of Wetland in Western Washington
If 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.
At least 30% of the open water area is deeper than 6.6 ft (2 m).
Wetland Rating System for Western WA: 2014 Update
Rating Form - Effective January 1, 2015 3 WSDOT Adapted Form - March 2, 2015
DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A
Wetland name or number A
NO - go to 7 YES - The wetland class is Depressional
NO - go to 8 YES - The wetland class is Depressional
NOTES and FIELD OBSERVATIONS:
Salt Water Tidal Fringe and any other
class of freshwater wetland
HGM class to
use in rating
Riverine
Depressional
Lake Fringe
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.
Riverine
Treat as
ESTUARINE
Slope + Lake Fringe
Depressional + Riverine along stream
within boundary of depression
Depressional + Lake Fringe
Riverine + Lake Fringe
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
Slope + Riverine
Slope + Depressional
Depressional
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.
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.
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.
Wetland Rating System for Western WA: 2014 Update
Rating Form - Effective January 1, 2015 4 WSDOT Adapted Form - March 2, 2015
DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A
Wetland name or number A
D 1.1. Characteristics of surface water outflows from the wetland:
points = 3
points = 2
points = 1
points = 1
Yes = 4 No = 0
Wetland has persistent, ungrazed, plants > 95% of area points = 5
Wetland has persistent, ungrazed, plants > ½ of area points = 3
Wetland has persistent, ungrazed plants > 1/10 of area points = 1
Wetland has persistent, ungrazed plants < 1/10 of area points = 0
D 1.4. Characteristics of seasonal ponding or inundation:
This is the area that is ponded for at least 2 months. See description in manual.
Area seasonally ponded is > ½ total area of wetland points = 4
Area seasonally ponded is > ¼ total area of wetland points = 2
Area seasonally ponded is < ¼ total area of wetland points = 0
Total for D 1 Add the points in the boxes above 11
Rating of Site Potential If score is: 12 - 16 = H 6 - 11 = M 0 - 5 = L Record the rating on the first page
D 2.1. Does the wetland unit receive stormwater discharges?Yes = 1 No = 0 0
Yes = 1 No = 0
D 2.3. Are there septic systems within 250 ft of the wetland?Yes = 1 No = 0 0
Source Yes = 1 No = 0
Total for D 2 Add the points in the boxes above 1
Rating of Landscape Potential If score is: 3 or 4 = H 1 or 2 = M 0 = L Record the rating on the first page
Yes = 1 No = 0
Yes = 1 No = 0
Yes = 2 No = 0
Total for D 3 Add the points in the boxes above 1
Rating of Value If score is: 2 - 4 = H 1 = M 0 = L Record the rating on the first page
1
0
Water Quality Functions - Indicators that the site functions to improve water quality
D 1.0. Does the site have the potential to improve water quality?
2
Wetland has an unconstricted, or slightly constricted, surface outlet
that is permanently flowing
Wetland has an intermittently flowing stream or ditch, OR highly
constricted permanently flowing outlet.
Wetland is a depression or flat depression (QUESTION 7 on key)
with no surface water leaving it (no outlet).
Wetland is a flat depression (QUESTION 7 on key), whose outlet is
a permanently flowing ditch.
4
D 2.0. Does the landscape have the potential to support the water quality function of the site?
DEPRESSIONAL AND FLATS WETLANDS
D 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 the unit is found )?
D 1.2. The soil 2 in below the surface (or duff layer) is true clay or true organic
(use NRCS definitions ).
D 1.3. Characteristics and distribution of persistent plants (Emergent, Scrub-shrub, and/or
Forested Cowardin classes):
D 2.4. Are there other sources of pollutants coming into the wetland that are
not listed in questions D 2.1 - D 2.3?
D 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?
D 2.2. Is > 10% of the area within 150 ft of the wetland in land uses that
generate pollutants?
D 3.2. Is the wetland in a basin or sub-basin where an aquatic resource is on the 303(d) list?
D 3.0. Is the water quality improvement provided by the site valuable to society?
1
0
0
0
5
Wetland Rating System for Western WA: 2014 Update
Rating Form - Effective January 1, 2015 5 WSDOT Adapted Form - March 2, 2015
DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A
Wetland name or number A
D 4.1. Characteristics of surface water outflows from the wetland:
points = 4
points = 2
points = 1
points = 0
Marks of ponding are 3 ft or more above the surface or bottom of outlet points = 7
Marks of ponding between 2 ft to < 3 ft from surface or bottom of outlet points = 5
Marks are at least 0.5 ft to < 2 ft from surface or bottom of outlet points = 3
The wetland is a “headwater” wetland points = 3
Wetland is flat but has small depressions on the surface that trap water points = 1
Marks of ponding less than 0.5 ft (6 in)points = 0
The area of the basin is less than 10 times the area of the unit points = 5
The area of the basin is 10 to 100 times the area of the unit points = 3
The area of the basin is more than 100 times the area of the unit points = 0
Entire wetland is in the Flats class points = 5
Total for D 4 Add the points in the boxes above 10
Rating of Site Potential If score is: 12 - 16 = H 6 - 11 = M 0 - 5 = L Record the rating on the first page
D 5.1. Does the wetland unit receive stormwater discharges?Yes = 1 No = 0 0
D 5.2. Is > 10% of the area within 150 ft of the wetland in land uses that generate excess runoff?
Yes = 1 No = 0
Yes = 1 No = 0
Total for D 5 Add the points in the boxes above 1
Rating of Landscape Potential If score is: 3 = H 1 or 2 = M 0 = L Record the rating on the first page
points = 2
points = 1
Flooding from groundwater is an issue in the sub-basin.points = 1
points = 0
There are no problems with flooding downstream of the wetland.points = 0
Yes = 2 No = 0
Total for D 6 Add the points in the boxes above 2
Rating of Value If score is: 2 - 4 = H 1 = M 0 = L Record the rating on the first page
DEPRESSIONAL AND FLATS WETLANDS
D 6.0. Are the hydrologic functions provided by the site valuable to society?
The wetland captures surface water that would otherwise flow down-gradient into areas
where flooding has damaged human or natural resources (e.g., houses or salmon redds):
Flooding occurs in a sub-basin that is immediately down-
gradient of unit.
Surface flooding problems are in a sub-basin farther down-
gradient.
Hydrologic Functions - Indicators that the site functions to reduce flooding and stream degradation
D 4.0. Does the site have the potential to reduce flooding and erosion?
2
Wetland is a depression or flat depression with no surface water
leaving it (no outlet)
Wetland has an unconstricted, or slightly constricted, surface outlet
that is permanently flowing
Wetland has an intermittently flowing stream or ditch, OR highly
constricted permanently flowing outlet
Wetland is a flat depression (QUESTION 7 on key), whose outlet is
a permanently flowing ditch
5
D 5.0. Does the landscape have the potential to support hydrologic function of the site?
1
0
D 5.3. Is more than 25% of the contributing basin of the wetland covered with intensive human
land uses (residential at >1 residence/ac, urban, commercial, agriculture, etc.)?
The existing or potential outflow from the wetland is so constrained
by human or natural conditions that the water stored by the wetland
cannot reach areas that flood. Explain why
2
0
3
D 4.2. Depth of storage during wet periods: Estimate the height of ponding above the bottom of
the outlet. For wetlands with no outlet, measure from the surface of permanent water or if dry, the
deepest part.
D 4.3. Contribution of the wetland to storage in the watershed: Estimate the ratio of the area of
upstream basin contributing surface water to the wetland to the area of the wetland unit itself.
D 6.1. The unit is in a landscape that has flooding problems. Choose the description that best
matches conditions around the wetland unit being rated. Do not add points. Choose the highest
score if more than one condition is met.
D 6.2. Has the site been identified as important for flood storage or flood
conveyance in a regional flood control plan?
Wetland Rating System for Western WA: 2014 Update
Rating Form - Effective January 1, 2015 6 WSDOT Adapted Form - March 2, 2015
DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A
Wetland name or number A
HABITAT FUNCTIONS - Indicators that site functions to provide important habitat
H 1.0. Does the site have the potential to provide habitat?
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 :
H 1.2. 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 types 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
If you counted:> 19 species points = 2
5 - 19 species points = 1
< 5 species points = 0
H 1.4. Interspersion of habitats
These questions apply to wetlands of all HGM classes.
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
1
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.
None = 0 points Low = 1 point Moderate = 2 points
All three diagrams
in this row are
HIGH = 3 points
0
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 ).
1
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 1
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.
Wetland Rating System for Western WA: 2014 Update
Rating Form - Effective January 1, 2015 7 WSDOT Adapted Form - March 2, 2015
DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A
Wetland name or number A
H 1.5. Special habitat features:
Large, downed, woody debris within the wetland (> 4 in diameter and 6 ft long)
Standing snags (dbh > 4 in) within the wetland
Total for H 1 Add the points in the boxes above 6
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 function of the site?
H 2.1 Accessible habitat (include only habitat that directly abuts wetland unit ).
Calculate:
25.5 % undisturbed habitat + (7.3 % moderate & low intensity land uses / 2 ) = 29.15%
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:
36.1 % undisturbed habitat + (20.3 % moderate & low intensity land uses / 2 ) = 46.25%
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 1km Polygon is high intensity points = 0
Total for H 2 Add the points in the boxes above 4
Rating of Landscape Potential If Score is: 4 - 6 = H 1 - 3 = M < 1 = L Record the rating on the first page
Site meets ANY of the following criteria:points = 2
It has 3 or more priority habitats within 100 m (see next page)
It is mapped as a location for an individual WDFW priority species
Site has 1 or 2 priority habitats (listed on next page) with in 100m 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
2
2
0
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 .
It provides habitat for Threatened or Endangered species (any plant
or animal on the state or federal lists)
It is a Wetland of High Conservation Value as determined by the
Department of Natural Resources
2
Invasive plants cover less than 25% of the wetland area in every stratum of plants (see
H 1.1 for list of strata )
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 )
3
Check the habitat features that are present in the wetland. The number of checks is the number
of points.
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
Wetland Rating System for Western WA: 2014 Update
Rating Form - Effective January 1, 2015 8 WSDOT Adapted Form - March 2, 2015
DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A
Wetland name or number A
Aspen Stands: Pure or mixed stands of aspen greater than 1 ac (0.4 ha).
Herbaceous Balds: Variable size patches of grass and forbs on shallow soils over bedrock.
Cliffs: Greater than 25 ft (7.6 m) high and occurring below 5000 ft elevation.
http://wdfw.wa.gov/publications/00165/wdfw00165.pdf or access the list from here:
http://wdfw.wa.gov/conservation/phs/list/
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.
Note: All vegetated wetlands are by definition a priority habitat but are not included in this list because they are
addressed elsewhere.
WDFW Priority Habitats
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.
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 ).
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.
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.
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 ).
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.
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.
Wetland Rating System for Western WA: 2014 Update
Rating Form - Effective January 1, 2015 9 WSDOT Adapted Form - March 2, 2015
DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A
EagleView Technologies, Inc.
0 1,000 2,000 3,000 4,000500
US Feet
Subject Property Parcel: 232305-9021
Approximate Wetland A Rating Unit
1 Km Habitat Classifciation Polygon
Approximate Relatively Undisturbed Habitat 25.5%
Accessible Low_Moderate Intensity Habitat 7.3%
Relatively Undisturbed Habitat 10.6%
Low_Moderate Intensity Habitat 13.0%
High Intensity Habitat 43.6%
Figure A AOA - 6644City of Renton
Parcel 232305-9021
DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A
King County, EagleView Technologies, Inc.
±0 60 120 180 24030
US Feet
Subject Property Parcel: 232305-9021
Approximate Wetland Rating Unit
150' Pollution Assessment Polygon
Pollution Generating Surfaces 29.9%
Figure B AOA - 6644City of Renton
Parcel 232305-9021
Outlet
DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A
Figure C-D
Sources: Esri, HERE, Garmin, Intermap, increment P Corp., GEBCO, USGS,FAO, NPS, NRCAN, GeoBase, IGN, Kadaster NL, Ordnance Survey, EsriJapan, METI, Esri China (Hong Kong), (c) OpenStreetMap contributors, and
January 28, 2022
0 1 20.5Miles
K
Assessed Water/SedimentWater
Category 5 - 303d
Category 4C
Category 4B
Category 4A
Category 2
Category 1
Sediment
Category 5 - 303d
Category 4C
Category 4B
Category 4A
Category 2
Category 1
WQ Improvement ProjectsApproved
In Development
Site is not located
within an approved
WQ Improvement
Project area.
DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A
King County, EagleView Technologies, Inc.
±0 10 20 30 405
US Feet
Subject Property Parcel: 232305-9021
Approximate Wetland Rating Unit
Seasonally Ponded
Figure E AOA - 6644City of Renton
Parcel 232305-9021
Likely narrow
Saturated Only
Fringe
DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A
King County, EagleView Technologies, Inc.
±0 10 20 30 405
US Feet
Subject Property Parcel: 232305-9021
Approximate Wetland Rating Unit
PFO
Figure F AOA - 6644City of Renton
Parcel 232305-9021
DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A
King C oun ty, Eag le Vie w
Figu re G
Date: 7 /6/202 2 Notes:
Th e infor matio n in clu de d on t his map has been comp ile d b y Kin g Count y staf f from a variety of source s an d is su bject to cha ng ewithout n otice. Kin g Co unt y makes no re present ations o r wa rra nties, exp re ss o r im plied , a s to accu ra cy, complet en ess, t ime lin ess,or rig hts to the use of such informa tion . This d ocu me nt is not intended for u se as a survey pr od uct. King Cou nty shall n ot be lia blefor a ny g en er al, sp ecial, indirect, incide ntal, o r conse qu en tial damag es including , but not limited to , lost revenu es or lo st profitsresulting from th e use or m isu se of t he info rmat ion cont aine d on this map . An y sale of this map or in formation o n t his map isprohibited except by written p er mission of King County.±
Wetland A Basin:
approx. 1.00 acres
Wetland A: approx.
0.15 acres
DocuSign Envelope ID: 8DC95E5E-DFD2-4FC3-AECA-A837B4E4B02A