Exhibit F -Critical Area Report-09-27-2021
304TH STREET PROPERTY
CITY OF FEDERAL WAY, WASHINGTON
CRITICAL AREAS REPORT
Prepared By:
Curtis Wambach, M.S.
Senior Biologist and Principal
27 September 2021
360-790-1559
www.envirovector.com
304TH STREET PROPERTY
CRITICAL AREAS REPORT
Prepared For:
Soundbuilt Homes
Prepared By:
Curtis Wambach, M.S.,
Senior Biologist and Principal
EnviroVector
Olympia, WA 98502
(360) 790-1559
www.envirovector.com
27 September 2021
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Table of Contents
1.0 INTRODUCTION ............................................................................................................... 1
1.1 Purpose ............................................................................................................................. 1
1.2 Property Location ............................................................................................................. 1
1.3 Site Evaluation ................................................................................................................. 1
1.4 Subject Property ............................................................................................................... 1
2.0 METHODOLOGY .............................................................................................................. 1
2.1 Review of Existing Literature .......................................................................................... 2
2.2 Field Investigation ............................................................................................................ 2
2.3 Wetland Identification ...................................................................................................... 2
2.3.1 Vegetation ................................................................................................................. 3
2.3.2 Soils........................................................................................................................... 3
2.3.3 Hydrology ................................................................................................................. 3
2.4 Wetland Classification and Rating ................................................................................... 4
3.0 STUDY RESULTS .............................................................................................................. 4
3.1 Background Information .................................................................................................. 4
3.1.1 NRCS Soils Data ...................................................................................................... 4
3.1.2 King County Geodata Wetlands & Streams ............................................................. 5
3.1.3 WDFW Priority Habitats and Species (PHS) Database ............................................ 5
3.1.4 City of Federal Way Critical Areas map................................................................... 5
3.2 Field Results ..................................................................................................................... 5
4.0 REGULATORY CONSIDERATIONS ............................................................................... 6
5.0 CONCLUSION .................................................................................................................... 6
6.0 REFERENCES .................................................................................................................... 7
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1.0 INTRODUCTION
1.1 Purpose
The purpose of this Critical Areas Report is to identify and map Critical Areas on and within
three hundred (300) feet of the subject property. This Critical Areas Report has been prepared to
satisfy City of Federal Way reporting requirements.
1.2 Property Location
The 5.94-acre subject property is located in Federal Way, WA (Figure 1; Table 1).
Table 1. Parcels Comprising Subject Property
Parcels Property Address Parcel Number Section Township Range Property Size
(Acres)
1 --- 0521049033 Section 05 Township 21N Range 4 5.94
1
Parcels Total Size 5.94 acres
The permitting jurisdiction is City of Federal Way.
1.3 Site Evaluation
Critical Areas evaluations were performed on the subject property on 17 June 2021, 9 August
2021, 16 August 2021.
1.4 Subject Property
The entire subject property is highly impacted by homeless encampments and residual trash,
human waste, and drug paraphernalia (Appendix A, Photos 1-14). Some gentle slopes are
located on the subject property. Understory vegetation has been cut to increase visibility to
discourage further homeless encampments. The subject property is bordered by an arterial road
to the south and subdivisions on the other borders. A public school is located southeast of the
subject property.
2.0 METHODOLOGY
This report is based on a review of existing information and field investigations. The goal of
these efforts is to collect and document existing information that reflects current site conditions
for assessing potential impacts.
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2.1 Review of Existing Literature
Prior to conducting fieldwork, and throughout the duration of project design, biologists reviewed
existing information to identify wetlands, streams, vegetation patterns, topography, soils, wildlife
habitats, and other natural resources in the project area. Existing data sources that were reviewed
for this report included, but were not limited to, the following:
• Washington. U.S. Department of Agriculture, Natural Resources Conservation Service
(NRCS) Soil Survey
• U.S. Fish and Wildlife Service (USFWS) National Wetlands Inventory (NWI), online
wetlands mapper
• Washington Department of Fish and Wildlife (WDFW) Salmonscape Database
• Washington Department of Fish and Wildlife (WDFW) Priority Habitats and Species
Database
• Washington State Department of Natural Resources (DNR) Natural Heritage Database
• Federal Emergency Management Agency (FEMA) Flood Insurance Rate Maps (FIRM)
and Flood Insurance Studies
2.2 Field Investigation
A wetland evaluation was performed onsite as well as offsite of the subject property to determine
if wetlands, streams, or their buffers extend onto the subject property. The routine on-site
determination method was used to identify potential wetlands using the procedures outlined in
the Corps of Engineers Wetland Delineation Manual (Environmental Laboratory, 1987) and the
2010 USACE Regional Wetland Supplement.
2.3 Wetland Identification
Prior to 2010, biologists delineated wetlands according to the methods specified in the U.S.
Army Corps of Engineers (USACE) Wetlands Delineation Manual (Environmental Laboratory
1987). At that time, these methods complied with those in the Washington State Wetland
Identification and Delineation Manual (Washington State Department of Ecology [Ecology]
1997).
Following 2010, biologists evaluate wetlands according to the methods specified in the
USACE’s 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) (USACE 2010). These methods comply with those
adopted by Washington State pursuant to Washington Administrative Code (WAC) 173-22-035,
Revised Code of Washington (RCW) 90.58.380.
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2.3.1 Vegetation
The dominant plants and their wetland indicator status were evaluated to determine whether the
vegetation is hydrophytic. Hydrophytic vegetation is generally defined as vegetation adapted to
prolonged saturated soil conditions. To meet the hydrophytic vegetation criterion, more than
fifty (>50) percent of the dominant plants must be facultative, facultative wetland, or obligate,
according to the plant indicator status category assigned to each plant species by the USACE
National Wetland Plant List. Table 2 provides the definitions of the indicator status categories.
The scientific and common names for plants follow the currently accepted nomenclature.
Dominant plant species were observed and recorded on wetland determination data forms for
each data plot (Appendix H).
Table 2. Key to Plant Indicator Status Categories
Plant Indicator Status
Category Symbol Description
Obligate Wetland Plants OBL Plants that almost always (>99% of the time) occur in wetlands
but may rarely (<1% of the time) occur in non-wetlands
Facultative Wetland Plants FACW Plants that often (67% to 99% of the time) occur in wetlands but
sometimes (1% to 33% of the time) occur in non-wetlands
Facultative Plants FAC Plants with a similar likelihood (33% to 66% of the time) of
occurring in both wetlands and non-wetlands
Facultative Upland Plants FACU Plants that sometimes (1% to 33% of the time) occur in wetlands
but occur more often (67% to 99% of the time) in non-wetlands
Upland Plants UPL Plants that rarely (<1% of the time) occur in wetlands and
almost always (> 99% of the time) occur in non-wetlands
2.3.2 Soils
Test plots are collected if wetland conditions are found.
2.3.3 Hydrology
The project area was examined for evidence of hydrology. The U.S. Army Corps of Engineers
(2005) provides a technical standard for monitoring hydrology on such sites. This standard
requires fourteen (14) or more consecutive days of flooding or ponding, or a water table twelve
(12) in. (thirty [30] cm) or less below the soil surface, during the growing season at a minimum
frequency of five (5) years in ten (10) (fifty percent [50%] or higher probability). The USACE
2010 Regional Supplement provides a list of hydrology indicators to evaluate whether the
hydrology standard is satisfied. If wetland hydrology, including pooling, ponding, and soil
saturation, is not clearly evident, hydrological conditions may be observed through surface or
soil indicators. Indicators of hydrological conditions include oxidized root channels, drainage
patterns, drift lines, sediment deposition, watermarks, historic records, visual observation of
saturated soils, and visual observation of inundation.
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2.4 Wetland Classification and Rating
Delineated wetlands were classified according to the USFWS Classification of Wetlands and
Deepwater Habitats of the United States. Hydrogeomorphic classifications were assigned to
wetlands using USACE methods established in a Hydrogeomorphic Classification for Wetlands
were rated using the revised Washington State Wetland Rating System for Western Washington.
3.0 STUDY RESULTS
3.1 Background Information
3.1.1 NRCS Soils Data
No hydric soils are mapped on the subject property. One (1) non-hydric soil types are mapped
on the subject property by the National Resources Conservation Service (NRCS) (Appendix B;
Table 3).
Table 3. King County Geodata Soil Summary
Soil Unit Hydric Comments
AmC: Arents, Alderwood Material, 0 to 6
percent slopes, 0 to 3% slopes No Covers entire subject property
King County Area, Washington
AmB—Arents, Alderwood material, 0 to 6 percent slopes
Map Unit Setting
• National map unit symbol: 1hmsp
• Elevation: 160 to 590 feet
• Mean annual precipitation: 35 to 60 inches
• Mean annual air temperature: 50 degrees F
• Frost-free period: 150 to 200 days
• Farmland classification: Not prime farmland
Map Unit Composition
• Arents, alderwood material, and similar soils: 100 percent
• Estimates are based on observations, descriptions, and transects of the mapunit.
Description of Arents, Alderwood Material
Setting
• Landform: Till plains
• Parent material: Basal till
Typical profile
• H1 - 0 to 26 inches: gravelly sandy loam
• H2 - 26 to 60 inches: very gravelly sandy loam
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Properties and qualities
• Slope: 0 to 6 percent
• Depth to restrictive feature: 20 to 40 inches to densic material
• Drainage class: Moderately well drained
• Capacity of the most limiting layer to transmit water (Ksat): Very low to moderately
low (0.00 to 0.06 in/hr)
• Depth to water table: About 16 to 36 inches
• Frequency of flooding: None
• Frequency of ponding: None
• Available water supply, 0 to 60 inches: Very low (about 2.3 inches)
Interpretive groups
• Land capability classification (irrigated): None specified
• Land capability classification (nonirrigated): 4s
• Hydrologic Soil Group: B/D
• Hydric soil rating: No
3.1.2 King County Geodata Wetlands & Streams
No wetlands or streams are mapped on the subject property by King County iMap (Appendix
C). One (1) off-site stream is mapped eight hundred fifty (850) feet west of the subject property
across houses and roads.
3.1.3 WDFW Priority Habitats and Species (PHS) Database
No priority habitats or species are mapped on the subject property or within one thousand (1000)
feet of the subject property by the Washington Department of Fish and Wildlife (WDFW)
Priority Habitats and Species (PHS) database (Appendix D).
3.1.4 City of Federal Way Critical Areas map
No wetlands are mapped on the subject property by the City of Federal Way Critical Areas map
(Appendix E). One (1) stream is mapped across the northern portion of the subject property.
This blue line extends across lots and other streams and may be an artifact of the map that does
not represent a feature on the ground.
3.2 Field Results
No wetlands or streams have been identified on the subject property or within three hundred
(300) feet of the subject property during this study (Figure 2). High intensity impacts from
homeless encampments cover the entire subject property (Appendix A, Photo 1 & 8-10). As
such, mountains of trash fill the site impacting soils and vegetation (Appendix A, Photo 13).
Propane canisters and drug paraphernalia, including hypodermic needles, litter the site and have
been worked into the soils and brush (Appendix A, Photo 11).
Understory vegetation on the site, primarily consisting of the introduced invasive weed
Himalayan blackberry (Rubus armeniacus), has been cut to assist in managing encampments.
Soils are disturbed as a result of historical land use activities (Appendix A, Photo 14).
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The Federal Way Critical Areas map shows a blue line across the northern portion of the subject
property. This may represent a historical drainage, underground pipe, or an artifact of the map.
No drainage was identified on the northern portion of the property that extends offsite. No other
Agency databases provided in the Appendices of this report maps any Critical Areas on the
subject property.
The topography is relatively flat with slight rolling hills. Areas of lower elevations were filled
with garbage and waste from encampments at the time of the study. Occupied tents also were
observed in areas of lower elevation (Appendix A, photos 8-10).
4.0 REGULATORY CONSIDERATIONS
Because no Critical Areas were identified on the subject property, no Critical Areas regulations
would apply.
5.0 CONCLUSION
No wetlands or streams have been identified on the subject property or within three hundred
(300) feet of the subject property during this Critical Areas study.
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6.0 REFERENCES
Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of Wetlands and
Deepwater Habitats of the United States. U.S. Fish and Wildlife Service, Department of the
Interior. FWSOBS-70/31.
Environmental Laboratory. 1987. Corps of Engineers Wetlands Delineation Manual. Technical
Report Y-87-1, US Army Engineer Waterways Experiment Station, Vicksburg, Miss.
Hitchcock, C.L., and A. Cronquist. 1973. Flora of the Pacific Northwest. University of
Washington Press. 730 pp.
Iowa State University. 1995. Hydric Soils of Washington State. U.S. Department of
Agriculture, Natural Resources Conservation Service. December 5.
Munsell Color. 1988. Munsell Soil Color Charts. Kollmorgen Instruments Corp., Baltimore,
Maryland.
Reed, P.B. Jr. 1988. National List of Plant Species that Occur in Wetlands: Northwest (Region
9). USF&WS Biol. Report 88.
Reed, P.B. Jr. 1993. Supplement to: National List of Plant Species that Occur in Wetlands:
Northwest (Region 9). USF&WS Biol. Report 88.
Reed, P.B. Jr. 1998. National List of Plant Species that Occur in Wetlands: Northwest (Region
9). USF&WS Update.
U.S. Department of Agriculture, Soil Conservation Service. June, 1991. Hydric Soils of the
United States.
U.S. Department of Agriculture, Soil Conservation Service. 1973. King County Area
Soil Survey.
Washington State Department of Ecology. 1997. Washington State Wetland Identification and
Delineation Manual. March.
Washington State Department of Ecology. 2004. . Washington State Wetland Rating System for
Western Washington. Ecology Publication # 04-06-025. August.
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FIGURES
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APPENDIX A
Photographs
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Subject Property and Vicinity
Photo 1. Active Homeless encampment onsite Photo 2. Soil test in the middle of homeless campsite
Photo 3. Soils test Photo 4. Evaluating potential depressional areas
Photo 5. Piles of trash on the property Photo 6. Many broken bicycles on property
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Photo 7. Garbage littered throughout the site Photo 8. Active homeless encampment
Photo 9. Active homeless encampment Photo 10. Active homeless encampment
Photo 11. Propane canisters and drug paraphernalia Photo 12. Abandoned tents throughout the site
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Photo 13. Piles of trash on the property Photo 14. Soils evaluation
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APPENDIX B
NRCS Soils Data
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AmB: Arents,
Alderwood
material, 0 to 6%
slopes (Non-
hydric)
Subject
Property
Norma silt
loam
(hydric)
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APPENDIX C
King County Geodata
Wetlands & Streams
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Subject
Property
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APPENDIX D
Washington Department of
Fish and Wildlife (WDFW)
Priority Habitats and Species (PHS)
Database
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Subject
Property
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APPENDIX E
City of Federal Way
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Subject
Property