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Home My WebLink About21-104125-Drainage Technical Information Report-10-05-2021-V1 Western Washington Division Eastern Washington Division 165 NE Juniper St., Ste 201, Issaquah, WA 98027 407 Swiftwater Blvd Street, Cle Elum, WA 98922 Phone: (425) 392-0250 Fax: (425) 391-3055 Phone: (509) 674-7433 Fax: (509) 674-7419 www.EncompassES.net PRELIMINARY TECHNICAL INFORMATION REPORT City of Federal Way For VSM Plat 2625 S 298th St Federal Way, WA 98003 October 4, 2021 Prepared By: Ian Dahl Encompass Engineering Job No. 20606 Prepared For: Sikander Sekhon PO Box 1226 Kent, WA 98035 VSM Plat Preliminary Technical Information Report 10/04/2021 Page i Table of Contents I. PROJECT OVERVIEW .............................................................................................................................. 1 II. CONDITIONS AND REQUIREMENTS SUMMARY .................................................................................... 6 III. OFF-SITE ANALYSIS ................................................................................................................................ 9 IV. FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN ......................................... 14 V. CONVEYANCE SYSTEM ANALYSIS AND DESIGN .................................................................................. 17 VI. SPECIAL REPORTS AND STUDIES ......................................................................................................... 17 VII. OTHER PERMITS .................................................................................................................................. 17 VIII. CSWPPP ANALYSIS AND DESIGN ......................................................................................................... 17 IX. BOND QUANTITIES AND DECLARATION OF COVENANT ..................................................................... 17 X. OPERATION AND MAINTENANCE MANUAL ........................................................................................ 17 List of Figures Figure 1- TIR Worksheet Figure 2- Vicinity Map Figure 3- Soils Map and Legend Figure 4- Existing Conditions Map Figure 5- Developed Conditions Map Figure 6- Drainage Review Flow Chart Figure 7- Downstream Map Appendix A Wetland and Stream Delineation and Rating Report by Evergreen Aquatic Resource Consultants, LCC dated March 15, 2021 Appendix B WWHM2012 Output KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 1 PROJECT OWNER AND PROJECT ENGINEER Part 2 PROJECT LOCATION AND DESCRIPTION Project Owner ___________________________ Phone _________________________________ Address _______________________________ _______________________________________ Project Engineer _________________________ Company ______________________________ Phone _________________________________ Project Name _________________________ DPER Permit # ________________________ Location Township ______________ Range ________________ Section ________________ Site Address __________________________ _____________________________________ Part 3 TYPE OF PERMIT APPLICATION Part 4 OTHER REVIEWS AND PERMITS  Landuse (e.g.,Subdivision / Short Subd. / UPD)  Building (e.g.,M/F / Commercial / SFR)  Clearing and Grading  Right-of-Way Use  Other _______________________  DFW HPA  COE 404  DOE Dam Safety  FEMA Floodplain  COE Wetlands  Other ________  Shoreline Management  Structural Rockery/Vault/_____  ESA Section 7 Part 5 PLAN AND REPORT INFORMATION Technical Information Report Site Improvement Plan (Engr. Plans) Type of Drainage Review (check one): Date (include revision dates): Date of Final:  Full  Targeted  Simplified  Large Project  Directed __________________ __________________ __________________ Plan Type (check one): Date (include revision dates): Date of Final:  Full  Modified  Simplified __________________ __________________ __________________ Part 6 SWDM ADJUSTMENT APPROVALS Type (circle one): Standard / Experimental / Blanket Description: (include conditions in TIR Section 2) ____________________________________________________________________________________ ____________________________________________________________________________________ ____________________________________________________________________________________ Approved Adjustment No. ______________________ Date of Approval: ______________________ 2016 Surface Water Design Manual 4/24/2016 1 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 7 MONITORING REQUIREMENTS Monitoring Required: Yes / No Start Date: _______________________ Completion Date: _______________________ Describe: _________________________________ _________________________________________ _________________________________________ Re: KCSWDM Adjustment No. ________________ Part 8 SITE COMMUNITY AND DRAINAGE BASIN Community Plan : ____________________________________________________________________ Special District Overlays: ______________________________________________________________ Drainage Basin: _____________________________________________________________________ Stormwater Requirements: ____________________________________________________________ Part 9 ONSITE AND ADJACENT SENSITIVE AREAS  River/Stream ________________________  Lake ______________________________  Wetlands ____________________________  Closed Depression ____________________  Floodplain ___________________________  Other _______________________________ _______________________________  Steep Slope __________________________  Erosion Hazard _______________________  Landslide Hazard ______________________  Coal Mine Hazard ______________________  Seismic Hazard _______________________  Habitat Protection ______________________  _____________________________________ Part 10 SOILS Soil Type _________________ _________________ _________________ _________________ Slopes _________________ _________________ _________________ _________________ Erosion Potential _________________ _________________ _________________ _________________  High Groundwater Table (within 5 feet)  Other ________________________________  Sole Source Aquifer  Seeps/Springs  Additional Sheets Attached 2016 Surface Water Design Manual 4/24/2016 2 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 11 DRAINAGE DESIGN LIMITATIONS REFERENCE  Core 2 – Offsite Analysis_________________  Sensitive/Critical Areas__________________  SEPA________________________________  LID Infeasibility________________________  Other________________________________  _____________________________________ LIMITATION / SITE CONSTRAINT _______________________________________ _______________________________________ _______________________________________ _______________________________________ _______________________________________ _______________________________________  Additional Sheets Attached Part 12 TIR SUMMARY SHEET (provide one TIR Summary Sheet per Threshold Discharge Area) Threshold Discharge Area: (name or description) Core Requirements (all 8 apply): Discharge at Natural Location Number of Natural Discharge Locations: Offsite Analysis Level: 1 / 2 / 3 dated:__________________ Flow Control (include facility summary sheet) Level: 1 / 2 / 3 or Exemption Number ____________ Flow Control BMPs _______________________________ Conveyance System Spill containment located at: _________________________ Erosion and Sediment Control / Construction Stormwater Pollution Prevention CSWPP/CESCL/ESC Site Supervisor: _____________________ Contact Phone: _________________________ After Hours Phone: _________________________ Maintenance and Operation Responsibility (circle one): Private / Public If Private, Maintenance Log Required: Yes / No Financial Guarantees and Liability Provided: Yes / No Water Quality (include facility summary sheet) Type (circle one): Basic / Sens. Lake / Enhanced Basic / Bog or Exemption No. ______________________ Landscape Management Plan: Yes / No Special Requirements (as applicable): Area Specific Drainage Requirements Type: CDA / SDO / MDP / BP / LMP / Shared Fac. / None Name: ________________________ Floodplain/Floodway Delineation Type (circle one): Major / Minor / Exemption / None 100-year Base Flood Elevation (or range): ______________ Datum: Flood Protection Facilities Describe: 2016 Surface Water Design Manual 4/24/2016 3 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 12 TIR SUMMARY SHEET (provide one TIR Summary Sheet per Threshold Discharge Area) Source Control (comm ercial / industrial land use) Describe land use: Describe any structural controls: Oil Control High-use Site: Yes / No Treatment BMP: ________________________________ Maintenance Agreement: Yes / No with whom? ____________________________________ Other Drainage Structures Describe: Part 13 EROSION AND SEDIMENT CONTROL REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION  Clearing Limits  Cover Measures  Perimeter Protection  Traffic Area Stabilization  Sediment Retention  Surface Water Collection  Dewatering Control  Dust Control  Flow Control  Protection of Flow Control BMP Facilities (existing and proposed)  Maintain BMPs / Manage Project MINIMUM ESC REQUIREMENTS AFTER CONSTRUCTION  Stabilize exposed surfaces  Remove and restore Temporary ESC Facilities  Clean and remove all silt and debris, ensure operation of Permanent Facilities, restore operation of Flow Control BMP Facilities as necessary  Flag limits of SAO and open space preservation areas  Other ______________________ Part 14 STORMWATER FACILITY DESCRIPTIONS (Note: Include Facility Summary and Sketch) Flow Control Type/Description Water Quality Type/Description  Detention  Infiltration  Regional Facility  Shared Facility  Flow Control BMPs  Other ________________ ________________ ________________ ________________ ________________ ________________  Vegetated Flowpath  Wetpool  Filtration  Oil Control  Spill Control  Flow Control BMPs  Other ________________ ________________ ________________ ________________ ________________ ________________ ________________ 2016 Surface Water Design Manual 4/24/2016 4 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 15 EASEMENTS/TRACTS Part 16 STRUCTURAL ANALYSIS  Drainage Easement  Covenant  Native Growth Protection Covenant  Tract  Other ___________________________  Cast in Place Vault  Retaining Wall  Rockery > 4’ High  Structural on Steep Slope  Other ______________________________ Part 17 SIGNATURE OF PROFESSIONAL ENGINEER I, or a civil engineer under my supervision, have visited the site. Actual site conditions as observed were incorporated into this worksheet and the attached Technical Information Report. To the best of my knowledge the information provided here is accurate. Signed/Date 2016 Surface Water Design Manual 4/24/2016 5 VSM Plat Preliminary Technical Information Report 10/04/2021 Page 1 I. PROJECT OVERVIEW Project: VSM Plat Tax Parcel #: 768380-0280, 768380-0290 Site Address: 2625 S 298th St Federal Way 98003 Site Area: 177,756 SF (4.08 AC) Legal Description: Parcel 768380-0280: SECOMA SUBURBAN TRS PCL B OF FEDERAL WAY LLA # 03- 100726-00 REC #20030430900001 SD LLA BEING LOCATED IN LOT 33 OF SECOMA HEIGHTS #1 TGW LOTS 27 & 28 OF SECOMA SUBURBAN TRS Parcel 768380-0290: SECOMA SUBURBAN TRS LESS N 155 FT EXC W 20 FT LESS S 135 FT Figure 2: Vicinity Map Pre-Developed Site Conditions The 177,756 SF (4.08 AC) project site is made up of two parcels (768380-0280 and 768380-0290) located in the City of Federal Way. Both parcels are currently developed with single-family residences with driveway accesses from S 298th Street. Parcel 768380-0280 is an irregular U-shaped lot with an existing residence in its northeast corner and three sheds located across the lot. The pervious portions of the lot are covered by meadow and lawn area. A Type Ns stream with a 35-foot buffer flows to the northwest through the western portion of the site. Three small wetlands with 50-foot buffers are located on-site in the proximity of the Type Ns stream. Parcel 768380-0290 is a flag-shaped lot with a residence in the center of the parcel, surrounded by driveway areas and various out-building structures. Both lots slope at approximately 5-10% toward the Type Ns stream that runs through parcel 768380-0280. The stream flows through an 18” culvert beneath S 298th Street where it is discharged north of the road into a storm drainage ditch. See Figure 4 for an Existing Site Conditions map. VSM Plat Preliminary Technical Information Report 10/04/2021 Page 2 Critical Areas Three small wetlands with 50-foot standard buffers and 15-foot building setbacks have been identified on the western portion of parcel 768380-0280 according to the Wetland and Stream Delineation and Rating Report by Evergreen Aquatic Resource Consultants, LLC dated March 15, 2021 (Appendix A). In addition, a Type Ns Stream with 35-foot standard buffer and 15-foot building setback was identified on the western portion of the site adjacent to the wetlands. This stream enters the property along the southern property line through a 12” concrete culvert and flows to the north, exiting the site via an 18” concrete culvert in the northwest corner of the site. No other critical areas were identified on the project site. Soils Per the US Department of Agriculture (USDA), Natural Resources Conservation Service (NCRS) Web Soil Survey (WSS) information, the project site is generally underlain with Alderwood gravelly sandy loam with 0-8% slopes, and Arents, Alderwood material with 6-15% slopes. Figure 3: Soils Map and Legend VSM Plat Preliminary Technical Information Report 10/04/2021 Page 3 Developed Site Conditions The proposal incorporates the clearing, grading, and platting of the 177,756 SF (4.08 AC) project site to accommodate the construction of 11 new single-family lots, a stormwater Tract, critical area tract, public access road, and all wet and dry utilities associated with the development. The existing residence on parcel 768380-0280 will be retained within the proposed Lot 1 boundary. 10 new single-family homes will be constructed on the remaining lots. The total limits of disturbance including off-site road and frontage improvements is 112,707 SF (2.59 AC). Additionally, frontage improvements in the northwest corner of the site have been shown on the planset for visual purposes only, as an exemption will be applied for this requirement. The project site is located within the Lower Green River Drainage Basin which is classified as a Conservation Flow Control Area on the City of Federal Way Flow Control Applications Map. A stormwater detention pond and an Oldcastle BioPod water quality vault will be located within a stormwater tract to provide the required Level 2 flow control and Enhanced Basic water quality treatment. See Figure 5 for a Developed Site Conditions Map. S 298TH STREETPREPARED FOR VSM Encompass Eastern Washington Division 407 Swiftwater Blvd. ▪ Cle Elum, WA 98922 ▪ Phone: (509) 674-7433 Western Washington Division 165 NE Juniper Street, Suite 201 ▪ Issaquah, WA 98027 ▪ Phone: (425) 392-0250 ENGINEERING & SURVEYINGVSM PLAT PREDEVELOPMENT CONDITIONS REVISIONS JOB NO. DATE SCALE SHEET 1 S. 298TH STREETLOT 9LOT 10LOT 11LOT 8LOT 1LOT 2LOT 7LOT 6LOT 5LOT 4LOT 3WETLAND AWETLAND BWETLAND C PREPARED FOR VSM Encompass Eastern Washington Division 407 Swiftwater Blvd. ▪ Cle Elum, WA 98922 ▪ Phone: (509) 674-7433 Western Washington Division 165 NE Juniper Street, Suite 201 ▪ Issaquah, WA 98027 ▪ Phone: (425) 392-0250 ENGINEERING & SURVEYINGVSM PLAT POSTDEVELOPMENT CONDITIONS REVISIONS JOB NO. DATE SCALE SHEET 2 VSM Plat Preliminary Technical Information Report 10/04/2021 Page 6 II. CONDITIONS AND REQUIREMENTS SUMMARY The 2016 King County Surface Water Design Manual (KCSWDM) and the City of Federal Way Addendum to the King County Surface Water Design Manual (Federal Way Addendum) were utilized for stormwater design per the City of Federal Way requirements. This project is subject to a Full Drainage Review per Section 1.1.2.4 of the 2016 KCSWDM. This project proposes to create approximately 60,055 SF of new plus replaced impervious areas both on- and off-site. Figure 6: Drainage Review Flow Chart VSM Plat Preliminary Technical Information Report 10/04/2021 Page 7 Core Requirements Core Requirement #1: Discharge at the Natural Location Currently, the existing site drains to a Type Ns Stream located on the western portion of the site, which flows to the north and exits the site though an 18” concrete culvert. All proposed impervious areas on the developed site (i.e., rooftop, sidewalk, driveway and roads) will be collected and conveyed to a stormwater detention pond located within a stormwater tract. This pond will discharge to the Type Ns stream at the natural location. Refer to the Downstream Analysis in Section III for additional description of the existing discharge location and downstream drainage patterns. Core Requirement #2: Offsite Analysis A Level 1 Downstream Analysis per section 1.2.2 of the KCSWDM was performed by Encompass Engineering and Surveying on Tuesday July 27, 2021 and is included as Section III of this TIR. Core Requirement #3: Flow Control Facilities The project site is located within the Lower Green River Drainage Basin which is classified as a Conservation (Level 2) Flow Control Area on the City of Federal Way Flow Control Applications Map. This requires the project to match the developed discharge durations to the predeveloped durations for the range of predeveloped discharge rates from 50% of the 2-year peak flow up to the full 50-year peak flow, match the developed peak discharge rates to predeveloped peak discharge rates for the 2- and 10-year return periods. Historic site conditions (forested) have been assumed for the predeveloped site conditions. The design volume for the proposed detention pond has been determined using the WWHM software approved by the Washington Department of Ecology. See the Flow Control Facilities design in Section IV of this report for a full discussion. Core Requirement #4: Conveyance System Conveyance system analysis will be provided with final engineering. Core Requirement #5: Construction Stormwater Pollution Prevention A temporary erosion and sediment control (TESC) plan to provide BMPs to be implemented during construction is included with the preliminary engineering plan set. Since the project includes over an acre of disturbance, a Construction Stormwater Pollution Prevention Plan will be required. A CSWPPP will be provided with final engineering. Core Requirement #6: Maintenance and Operations A Maintenance and Operations Plan is required for the project. See Section X of this report for details. Core Requirement #7: Financial Guarantees and Liability The owner will arrange for any financial guarantees and liabilities required by the permit. Core Requirement #8: Water Quality Facilities The proposed project will create approximately 15,683 SF of pollution-generating impervious surfaces (PGIS). The project site is located within the “Enhanced Basic Water Quality Treatment Menu Required” area of the City of Federal Way Water Quality Applications Map. Enhanced Basic Water Quality treatment will be applied to the project per Section 1.2.8.1 of the KCSWDM and Section 1.2.8 of the Federal Way Addendum. Water quality requirements are proposed to be met VSM Plat Preliminary Technical Information Report 10/04/2021 Page 8 using an Oldcastle BioPod underground vault. See Section IV of this report for a full discussion on the water quality facility design. Core Requirement #9: On-Site BMPs This project is located within the Urban Growth Area (UGA) on a site less than 5 acres in size. The construction of the plat infrastructure is subject to the Small Subdivision and Urban Subdivision Projects BMP Requirements detailed in Section 1.2.9.3.1 of the KCSWDM. The proposed lots are less than 22,000 SF; therefore, Individual Lot BMPs for the future single-family residence have been evaluated per Section 1.2.9.2.1 of the KSWDM. Plat Infrastructure BMPs Per section 1.2.9.1 of the KSWDM, Target surfaces for flow control BMP requirements include new impervious surfaces, new pervious surfaces, and replaced impervious surfaces not already mitigated with an approved flow control BMP or flow control facility. This project proposes a stormwater detention pond to mitigate all target surfaces on-site associated with the plat infrastructure. Therefore, flow control BMPs are not required. Individual Lot BMPs Per section 1.2.9.1 of the KSWDM, Target surfaces for flow control BMP requirements include new impervious surfaces, new pervious surfaces, and replaced impervious surfaces not already mitigated with an approved flow control BMP or flow control facility. This project proposes a stormwater detention pond to mitigate all future target surfaces on-site associated with the future single-family residence construction on Lots 2 through 11. Therefore, flow control BMPs are not required. Special Requirements Special Requirement #1: Other Adopted Area-Specific Requirements Critical Drainage Areas – N/A Master Drainage Plan – N/A Basin Plan – N/A Salmon Conservation Plan – N/A Stormwater Compliance Plans – N/A Lake Management Plan – N/A Flood Hazard Mitigation Plan – N/A Shared Facility Drainage Plan – N/A Special Requirement #2: Flood Hazard Area Delineation This project does not lie in the FEMA 100-year floodplain. Special Requirement #3: Flood Protection Facilities This project does not rely on or propose to modify or construct a new flood protection facility. Special Requirement #4: Source controls Source control is not required for this project. Special Requirement #5: Oil Control This project is not considered high-use or in need of oil control. VSM Plat Preliminary Technical Information Report 10/04/2021 Page 9 III. OFF-SITE ANALYSIS Task 1: Study Area Definition and Maps A Level 1 Offsite Analysis has been performed for the project site per Section 1.2.2.1 of the 2016 KCSWDM. The project site is located within the Lower Green River Drainage Basin, in the Duwamish-Green River Watershed. Existing on-site slopes range from 5-10% with runoff sheet flowing to the east and north. The study area for this analysis extends downstream for approximately ¼ mile and contains two natural discharge areas which converge in under ¼ of a mile, a single threshold discharge area (TDA) for the site. A map showing the study area is included in Figure 7 on the following page. Task 2: Resource Review Encompass has reviewed the site and the applicable resources for both listed and potential problems. The site contains three small wetlands with 50-foot standard buffers and 15-foot building setbacks as well as a Type Ns Stream with 35-foot standard buffer and 15-foot building setback on the western portion of the site. No additional critical areas or critical area buffers were located on the site per King County iMap, FEMA maps, King County Sensitive Areas Folio, or the CED Wetlands Inventory. Task 3: Field Inspection The field inspection portion of the Level 1 Downstream Analysis was performed by Encompass Engineering & Surveying on Tuesday July 27, 2021. The analysis was performed at approximately 11:00 AM under clear conditions with a temperature of approximately 75°. Soil conditions were observed to be moderately dry. Information collected during this study is included in the Task 4 system description. Task 4: Drainage System Description and Problem Descriptions Runoff leaves the site in two Natural Discharge Areas that converge under ¼ mile downstream, creating a single TDA for the site. Stormwater from NDA A is collected from the rooftop and driveway areas from the existing residence on parcel 768380-0280 and conveyed to the north, where it discharges into a roadside ditch (A1) on the south side of S 298th St via a 4” PVC pipe. The roadside ditch flows to the west, where it crosses under a paved driveway via a 12” concrete culvert (A2) and continues west through an open grass ditch (A3). The grass ditch reaches a low point in the road profile, and enters a stream/wetland area at the northwest corner of the project site and converges with runoff from NDA B. The combined runoff cross S 298th St to the north via an 18” concrete culvert (B1/A4) and deposits into a densely vegetated shallow ravine on the north side of the road. The ravine continues north through property (B2) for approximately 700 feet where it joins Bingamon Creek (B3) and flows to the east. Bingamon Creek bends to the northeast and crosses under Military Rd S via a 24” concrete culvert (B4). The creek continues to the northeast through a maintained wide grass swale (B5) adjacent to a residential development at approximately ¼ mile downstream of the project site. This is where the Level 1 downstream Analysis was concluded. For detailed descriptions of the drainage features from both NDAs, see the Off-site Analysis Drainage System Tables on the following page. VSM Plat Preliminary Technical Information Report 10/04/2021 Page 10 Figure 7: Downstream Map VSM Plat Preliminary Technical Information Report 10/04/2021 Page 11 Off-site Analysis Drainage System Table Surface Water Design Manual, Core Requirement #2 BASIN: Lower Green River SUBBASIN NAME: SUBBASIN NUMBER: 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; Size: diameter, surface area Drainage basin, vegetation, cover, depth, type of sensitive area, volume % 1/4 Mile = 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 A1 ROADSIDE DITCH GRASS 5-10% POINT OF DISCHARGE (NDA A) NONE NONE RUNOFF FROM EX. RESIDENCE DISCHARGES VIA 4” PVC PIPE A2 12” CONCRETE CULVERT UNDER DRIVEWAY 5% 75’ NONE NONE A3 ROADSIDE DITCH GRASS 3-5% 95’ NONE NONE B1/A4 18” CONCRETE CULVERT CROSSES S 298TH ST 2% POINT OF DISCHARGE (NDA B) NONE OVER- VEGETATION MAY EVENTUALLY BLOCK INLET CONVERGANCE OF NDA A&B. OVERGROWN INLET/OUTLET B2 SHALLOW RAVINE FORESTED 1-5% 70’ NONE NONE PRIVATE PROPERTY- NO VISUAL B3 BINGAMON CREEK GRASS/SHRUBS 1-5% 750’ NONE NONE B4 24” CONCRETE CULVERT CROSSES MILITARY RD S 2% 1000’ NONE NONE OVERGROWN INLET B5 BINGAMON CREEK WIDE GRASS SWALE 1-5% 1300’ NONE NONE Downstream Table VSM Plat Preliminary Technical Information Report 10/04/2021 Page 12 Element A1- Roadside Ditch at Ex. Residence frontage Element B1/A4- 18” Concrete culvert (hidden) under S 298th St 4” PVC Outlet VSM Plat Preliminary Technical Information Report 10/04/2021 Page 13 Element B3- Bingamon Creek Element B4- 24” Concrete Culvert crosses under Military Rd S 24” Concrete Outlet VSM Plat Preliminary Technical Information Report 10/04/2021 Page 14 IV. FLOW CONTROL, LOW IMPACT DEVELOPMENT (LID) AND WATER QUALITY FACILITY ANALYSIS AND DESIGN Part A: Existing Site Hydrology The 177,756 SF (4.08 AC) project site is made up of two parcels (768380-0280 and 768380-0290) located in the City of Federal Way. Both parcels are currently developed with single-family residences with driveway accesses from S 298th Street. Parcel 768380-0280 is an irregular U-shaped lot with an existing residence in its northeast corner and three sheds located across the lot. The pervious portions of the lot are covered by meadow and lawn area. A Type Ns stream with a 35-foot buffer flows to the northwest through the western portion of the site. Three small wetlands with 50-foot buffers are located on-site in the proximity of the Type Ns stream. Parcel 768380-0290 is a flag-shaped lot with a residence in the center of the parcel, surrounded by driveway areas and various out-building structures. Both lots slope at approximately 5-10% toward the Type Ns stream that runs through parcel 768380-0280. The stream flows through an 18” culvert beneath S 298th Street where it is discharged north of the road into a storm drainage ditch. The full Downstream Analysis is included in Section III of this Technical Information Report (TIR). WWHM 2012 was used to model the existing condition within the 112,707 (2.59 AC) limits of disturbance using the historic forested condition. See the summary of existing and developed areas on the following pages, as well as the existing conditions map provided as Figure 4 for more details. Part B: Developed Site Hydrology The proposal incorporates the clearing, grading, and platting of the project site to accommodate the construction of 11 new single-family lots, a stormwater tract, critical area tract, public access road, and all wet and dry utilities associated with the development. The existing residence on parcel 768380-0280 will be retained within the proposed Lot 1 boundary. 10 new single-family homes will be constructed on the remaining lots. The total limits of disturbance including off-site road and frontage improvements is 112,707 SF (2.59 AC). This project proposes to convey all target impervious surface runoff to a stormwater detention pond located in Tract B. This facility will discharge towards the Type Ns Stream on the west side of the site and flow off-site to the north. An Oldcastle BioPod will be located in Tract B upstream of the detention pond to provide Enhanced Basic water quality treatment. See Figure 5 for a Developed Site Conditions Map. Part C: Performance Standards The project site is located within the Lower Green River Drainage Basin which is classified as a Conservation (Level 2) Flow Control Area on the City of Federal Way Flow Control Applications Map. This requires the project to match the developed discharge durations to the predeveloped durations for the range of predeveloped discharge rates from 50% of the 2-year peak flow up to the full 50-year peak flow, match the developed peak discharge rates to predeveloped peak discharge rates for the 2- and 10- year return periods. See the predeveloped and mitigated flows meeting these standards below. In addition, this site is designed to comply with the Small Subdivision Project BMP Requirements detailed in Section 1.2.9.3.1 of the 2016 KCSWDM. VSM Plat Preliminary Technical Information Report 10/04/2021 Page 15 This project proposes to create approximately 15,683 SF of pollution-generating impervious surfaces (PGIS). The project site is located within the “Enhanced Basic Water Quality Treatment Menu Required” area of the City of Federal Way Water Quality Applications Map. Enhanced Basic Water Quality treatment will be applied to the project per Section 1.2.8.1 of the KCSWDM and Section 1.2.8 of the Federal Way Addendum. Part D: Flow Control System This project proposes the construction of a stormwater detention pond designed per Section 5.1.1 of the KCSWDM, sized using WWHM 2012. The proposed facility is located in the southwest portion of the site in Tract B, and will outlet via a control structure and discharge towards the Type Ns Stream before flowing off-site to the north. Surface areas for the existing and proposed conditions tributary to the stormwater detention pond are listed in the table below, and the full WWHM output is attached in Appendix C. Areas modeled include all surfaces within the 112,707 SF clearing limits. Rooftop areas were calculated by assuming a maximum impervious per lot of 50% (Less than the 60% max by zoning). As lots 2-11 sum to 78,749 SF, 78,749 x (0.50)= 39,375 SF of rooftop area was assumed. Existing conditions were modeled as Forest to represent historical conditions. On-site + Off-Site Existing Proposed Condition Measured Modeled Measured Modeled Forest, Mod 9,779 SF (0.22 AC) 112,707 SF (2.59 AC) Pasture, Mod 106,521 SF (2.45 AC) 68,190 SF (1.56 AC) Lawn, Flat 22,733 SF (0.525 AC) 22,733 SF (0.525 AC) Lawn, Mod: 45,690 SF (1.05 AC) 22,733 SF (0.525 AC) 22,733 SF (0.525 AC) Rooftop, Flat 5,898 SF (0.14 AC) 39,375 SF (0.90 AC) 39,375 SF (0.90 AC) Road/Driveway, Mod: 11,961 SF (0.27 AC) 15,683 SF (0.36 AC) 15,683 SF (0.36 AC) Sidewalk, Flat: 1,048 SF (0.02 AC) 4,997 SF (0.12 AC) 4,997 SF (0.12 AC) VSM Plat Preliminary Technical Information Report 10/04/2021 Page 16 Pond 7,186 SF (0.16 AC) 7,186 SF (0.16 AC) Total Area: 180,897 SF (4.15 AC) 112,707 SF (2.59 AC) 180,897 SF (4.15 AC) 112,707 SF (2.59 AC) Basin Area Breakdown The 7.19-foot deep detention pond has a required volume of 34,434 CF. The proposed pond will provide a total detention volume of 34,500 CF. The full WWHM output is attached as Appendix C. Part E: Water Quality System Developed stormwater runoff from Pollution-Generating Impervious Surfaces will be treated to meet the Enhanced Basic water quality standards detailed in Section 1.2.8.1.A of the KCSWDM. An Oldcastle Biopod BPU-412IB is proposed to meet these requirements. This 4’x12’ water quality vault will be located upstream of the stormwater detention pond in Tract B in the southwest portion of the site. This facility has been sized for the flowrate (off-line) of 0.141 CFS, determined by WWHM. The BPU-412IB underground vault with internal high-flow bypass is approved by the WA Ecology GULD for a capacity of 0.143 CFS. VSM Plat Preliminary Technical Information Report 10/04/2021 Page 17 V. CONVEYANCE SYSTEM ANALYSIS AND DESIGN Conveyance system analysis and design will be provided with final engineering. VI. SPECIAL REPORTS AND STUDIES Geotechnical Engineering Study, by Earth Solutions NW, LLC, dated May 22, 2018 VII. OTHER PERMITS Building Permits, NPDES, and Lakehaven Utility District permits are required and will be provided with final engineering. VIII. CSWPPP ANALYSIS AND DESIGN An Erosion and Sediment Control Plan (TESC) and is included with the preliminary engineering plan set. A Construction Stormwater Pollution Prevention Plan (CSWPPP) will be prepared and provided with final engineering. IX. BOND QUANTITIES AND DECLARATION OF COVENANT Bond Quantities and Declaration of Covenant documents will be provided with final engineering. X. OPERATION AND MAINTENANCE MANUAL An Operation and Maintenance Manual will be provided with final engineering. Appendix A Wetland and Stream Delineation and Rating Report by Evergreen Aquatic Resource Consultants, LCC dated March 15, 2021 Wetland and Stream Delineation and Rating Report 2625 S 298th Street – Federal Way, Washington King County Tax Parcel No. 768380-0280 Project No. 20030 Prepared for: VSM PO Box 1226 Kent, Washington 98035 Prepared by: Evergreen Aquatic Resource Consultants, LLC PO Box 1721 Issaquah, Washington 98027 March 15, 2021 WETLAND DELINEATION • MITIGATION DESIGN • COMPLIANCE MONITORING March 15, 2021 Project Number 20030 VSM Attention: Sikander Sekhon PO Box 1226 Kent, Washington 98035 Wetland and Stream Delineation and Rating Report 2625 S 298th Street – Federal Way, Washington King County Tax Parcel No. 768380-0280 Sikander, Evergreen Aquatic Resource Consultants, LLC is pleased to present this wetland and stream delineation and rating report for your residential property located at 2625 S 298th Street in Federal Way, Washington. I determined that three small Category IV wetlands and a Type Ns stream exist within the western portions of the site. A 50 ft standard width buffer is required from each wetland and a 15 ft setback is required from the outer limits of each wetland buffer for buildings and other structures. A 35 ft standard width buffer is required from the stream and a 15 ft setback is required from the outer limits of the stream buffer for buildings and other structures. The wetlands and stream as well as related buffers and setbacks encumber much of the western portion of the project site. The information presented in this report is based on an analysis of conditions within and adjacent to the site, an examination of the wetland and stream development standards contained within Federal Way Revised Code (FWRC) Chapter 19.145 (Environmentally Critical Areas), and the best available science regarding wetlands and streams. I trust that this report meets your present needs. If you have any questions regarding the information presented in this report or require additional assistance with this project, please do not hesitate to call or email. Sincerely, Evergreen Aquatic Resource Consultants, LLC Peter P. Super Professional Wetland Scientist PO Box 1721 Issaquah, Washington 98027 (425) 677-7166 www.evergreenarc.com Wetland and Stream Delineation and Rating Report 2625 S 298th Street Federal Way, Washington King County Tax Parcel No. 768380-0280 Project No. 20030 Prepared for: VSM PO Box 1226 Kent, Washington 98035 Prepared by: Evergreen Aquatic Resource Consultants, LLC PO Box 1721 – Issaquah, Washington 98027 (425) 677-7166 | www.evergreenarc.com March 15, 2021 Wetland and Stream Delineation and Rating Report 2625 S 298th Street – Federal Way, Washington Page i March 15, 2021 TABLE OF CONTENTS 1.0 INTRODUCTION ...................................................................................................................................... 1 2.0 PROJECT SITE & LANDSCAPE SETTING ................................................................................................ 1 3.0 WETLAND AND STREAM DELINEATION AND RATING ASSESSMENT ............................................. 1 3.1 Methodology ........................................................................................................................................................................... 2 3.2 Background Research ........................................................................................................................................................... 3 3.3 Site Assessment ...................................................................................................................................................................... 3 3.3.1 Wetland 1 .......................................................................................................................................................................... 4 3.3.2 Stream 1 ............................................................................................................................................................................. 5 3.3.3 Upland ................................................................................................................................................................................ 5 3.3.4 Off-Site Wetlands and Streams ................................................................................................................................ 6 4.0 CONCLUSIONS ......................................................................................................................................... 6 5.0 RECOMMENDATIONS ............................................................................................................................. 7 6.0 REPORT LIMITATIONS ............................................................................................................................ 8 7.0 REFERENCES ............................................................................................................................................. 8 LIST OF APPENDICES Appendix A – Critical Area Map: Wetlands and Streams Appendix B – Photographs Appendix C – Wetland Determination Forms Appendix D – Wetland Rating Form Wetland and Stream Delineation and Rating Report 2625 S 298th Street – Federal Way, Washington Page 1 March 15, 2021 1.0 INTRODUCTION This wetland and stream delineation and rating report has been prepared to describe existing wetland and stream conditions within and adjacent to an existing residential property located at 2625 S 298th Street in Federal Way, Washington. Where applicable, an opinion of buffers and setbacks has been provided per Federal Way Revised Code (FWRC) Chapter 19.145 (Environmentally Critical Areas). It is understood that this report may be used, in part, to supplement site planning and permitting efforts related to future development of the site. The exact scope and timing of development is not known, but it is understood that future development may include a residential land subdivision comprising up to approximately five lots as well as tracts for access, stormwater control, critical areas, and open space. 2.0 PROJECT SITE & LANDSCAPE SETTING The project site is an irregularly shaped developed residential parcel located at 2625 S 298th Street in Federal Way, Washington. The site is situated in the northwest quarter of the southeast quarter of Section 4, Township 21 North, Range 4 East, W.M. The King County tax parcel number for the site is 768380-0280. A legal description for the site is Parcel B, City of Federal Way boundary line adjustment No. 03-100726- 00, recorded under recording No. 20030430900001, records of King County Auditor, situate in the City of Federal Way, County of King, State of Washington. The project site has a total area of 124,582 sf (5.4 acres) and measures approximately 326 feet wide (east to west) by approximately 461 feet deep (north to south). Access to the site is from S 298th Street, which is a paved roadway within dedicated public right-of-way. Topography within the site trends to the northwest. Total elevation change across the site is approximately 34 feet, ranging from a maximum elevation of 364 feet (NGVD 29) in both the southeast and southwest corners of the site to a minimum elevation of approximately 330 feet (NGVD 29) in the northwest corner of the site. A 1,920 sf single- family residence exists in the northeast corner of the site and several older outbuildings exist elsewhere throughout the site. Vegetation within the site includes primarily mowed pasture grasses and a few scattered trees. The City of Federal Way comprehensive plan designation for the site is “Single-Family Residential - High Density”. The City of Federal Way zoning designation for the site is RS7.2 (single-family residential, one dwelling unit per 7,200 sf). There are no known critical area special district or zoning overlays that apply to the site. The project site is situated south of S 298th Street, west of Military Road S, north Steele Lake, and east of Pacific Highway S. Land use surrounding the site is primarily single-family residential, though Wildwood Elementary School is located southwest of project site and Laurelwood Park is located northwest of the project site. 3.0 WETLAND AND STREAM DELINEATION AND RATING ASSESSMENT The wetland and stream delineation and rating assessment summarized in this report included an initial site reconnaissance completed on August 19, 2020, a detailed site assessment completed on January 15, 2021, and a follow-up site review completed on January 29, 2021. The purpose of this work was to screen Wetland and Stream Delineation and Rating Report 2625 S 298th Street – Federal Way, Washington Page 2 March 15, 2021 the project site and local vicinity for wetlands and streams. The entire project site was assessed and areas located within 200 ft of the project site were also reviewed to determine buffer widths and any related buffer encroachments onto the project site. Off-site areas were assessed using information obtained from readily available literature and aerial photographs as well as by observing conditions directly from the project site and public right-of-way. The wetland and stream delineation and rating assessment was not conducted during the growing season. Climatic conditions prior to the assessment as well as natural seasonal variations related to the time of year were considered. Rainfall measured at SeaTac International Airport during the period October 1, 2020 to January 7, 2021 was higher than the historical mean for the 43 year period of historic record. Rainfall during the seven days preceding the January 15, 2021 site assessment totaled 3.77 inches, with 2.33 inches of the total 3.77 inches received two days prior to the site assessment. The higher-than- normal rainfall preceding the site assessment resulted in atypical soil saturation and high water table conditions throughout the site. At the time of the wetland and stream delineation and rating assessment, it was determined that “normal circumstances” exist within the project site as defined by the wetland delineation manual. There was no evidence of a recent change to the site that would limit or otherwise prevent an accurate wetland determination. Although vegetation within the site is highly modified from a native condition and has been historically managed as pasture, problematic or atypical wetland conditions do not exist within the site. 3.1 Methodology The wetland and stream delineation and rating assessment included background research and site assessments to determine if wetlands are present on or adjacent to the project site. Wetland determinations were made using the “routine determination” methods required for “on-site inspections” as described in the 1987 Corps of Engineers Wetlands Delineation Manual (Environmental Laboratory 1987). Vegetation, soil, and hydrology characteristics were examined at multiple locations and then compared to the specific criteria established for the three wetland indicators described in the Regional Supplement To The Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys, and Coast Region - Version 2.0 (US Army Corps of Engineers 2010). When hydrophytic vegetation, hydric soil, and wetland hydrology indicators were present, an area was determined to be a wetland. In the absence of all three indicators or when exclusionary situations apply, an area was considered non-wetland, or “upland”. Delineated wetland limits were marked on-site using sequentially numbered pink wire stake flags labeled “Wetland Delineation”. Wetland determination points were marked on-site using sequentially numbered orange wire stake flagging. Each delineated wetland was rated (classified) using the methods described in the Washington State Wetland Rating System for Western Washington – 2014 Update (Hruby, T 2014). Stream determinations utilized the definitions and related water typing criteria described within Washington Administrative Code (WAC) 222-16-030 (Water Typing System) and Article III of FWRC Chapter 19.145 (Environmental Critical Areas). An aquatic feature was considered a stream if there was clear evidence of the passage of water including, but not limited to, defined channels, swales, and hydraulically sorted gravel, sand, and silt beds. Salmonid utilization within a stream considered the Wetland and Stream Delineation and Rating Report 2625 S 298th Street – Federal Way, Washington Page 3 March 15, 2021 physical parameters of the stream such as width, gradient, and flow as well as records of any known naturally reoccurring salmonid populations and barriers to fish migration. The ordinary high water mark (OHWM) for each stream was marked on-site using sequentially numbered blue flagging wire stake flagging. Following the critical area delineation and rating assessment, Encompass Engineering & Surveying completed a boundary and topographic survey to map the delineated wetland and stream limits. 3.2 Background Research The project site exists within the lower Duwamish River drainage area of Water Resource Inventory Area (WRIA) 9 – Duwamish-Green River Basin. The upper portion of Bingaman Creek (09-0045) exists approximately 700 feet north of the project site. Bingaman Creek originates in Laurelwood Park and then drains northeast to Mullen Slough via the Bingaman Pond Natural Area with eventual discharge to the Green River at approximately river mile 21.75. The United States Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) online “Web Soil Survey” maps Alderwood gravelly sandy loam, 0 to 8 percent slopes (AgB) throughout much of the project site and Arents, Alderwood material, 6 to 15 percent slopes (AmC) in the extreme southern and eastern portions of the site. Alderwood soils are moderately well drained soils formed under conifers in glacial deposits (Snyder et al. 1975). Arents, Alderwood material consists of Alderwood soils that have been so disturbed by urbanization that the soil can longer be classified as Alderwood series soils (Snyder et al. 1975). The USDA “Soil Data Access (SDA) Hydric Soil List” website does not classify either mapped soil type as a hydric soil; however, inclusions of hydric soils are known to occur within Alderwood soils when the soil type is found in depressional landforms and along drainageways. Wetlands have not been previously mapped within or immediately adjacent to the project site. The closest mapped wetland is located approximately 950 feet northwest of the project site in and adjacent to Laurelwood Park. The National Wetlands Inventory (NWI) “Surface Waters & Wetlands” online mapper identifies this wetland as a 13.61 acre freshwater forested/shrub wetland habitat that is classified palustrine scrub-shrub seasonally flooded (PSSC). The outlet from the wetland is Bingaman Creek. The City of Federal Way’s “Critical Areas Map” identifies a stream within the project site. The stream originates at the southern property line and flows northwest across the project site. The stream continues off-site to the northwest, eventually draining to Bingaman Creek near the outlet of the Laurelwood Park wetland. Historic aerial photographs of the project site show that the site was converted to pasture use between 1936 and 1957. Except for the construction of a new single-family residence in 2003, the project site has remained largely unchanged for the last approximately 20 years. 3.3 Site Assessment Environmental conditions within the project site are uniform and include former pasture areas that support predominantly grass. Ten wetland determination points were established throughout the site Wetland and Stream Delineation and Rating Report 2625 S 298th Street – Federal Way, Washington Page 4 March 15, 2021 to document representative conditions. The location of each wetland determination point was selected to document representative conditions within wetlands and adjoining uplands. Vegetation within the site is mowed on at least an annual basis. At the time of the wetland and stream delineation and rating, grass species was difficult to identify to species due to the combination of mowing and the time of year. With few exceptions, wetland determinations were made based largely on the soil and hydrologic conditions. It was determined that three small Category IV wetlands and a Type Ns water (stream) exist within the western portion of the site. A map showing the location of wetlands, streams, buffers, and related building setbacks is included with this report in Appendix A. Photographs of the site are included with this report in Appendix B. Wetland determination forms are included with this report in Appendix C. Wetland rating forms are included with this report in Appendix D. This report section describes each delineated wetland and stream. 3.3.1 Wetland 1 TABLE 1 – SUMMARY INFORMATION FOR WETLAND 1 Flagging Scheme Cowardin Classification HGM Classification Hydrologic Regimes Rating Standard Buffer Building Setback WL 1-101 to WL 1-105 WL1-1 to WL1-12 WL1-201 to WL1-210 PEMB slope seasonally saturated Category IV 4 habitat points 50 ft 15 ft Wetland 1 is a series of three small wetlands located in shallow sloping landforms along Stream 1. The Cowardin classification for each wetland is palustrine emergent, persistent, seasonally saturated (PEM1B). Total wetland area for the three wetlands is 10,947 sf, ranging from 532 sf for Wetland 1A to 8,616 sf for Wetland 1C. The determination for each wetland was made based on the presence of wetland hydrology and hydric soil indicators as well as a dominance by hydrophytic vegetation within the local area. Vegetation within the wetlands is dominated by tall fescue (Festuca arundinacea, FAC) with occasional creeping jenny (Lysimachia nummularia, FACW), common rush (Juncus effusus, FACW), bird’s-foot trefoil (Lotus corniculatus, FAC), and creeping buttercup (Ranunculus repens, FACW). The hydric soil field indicator present within each wetland was depleted below dark surface. Soil was generally a very dark gray (10YR 3/1) sandy loam overlying a mottled dark grayish brown (10YR 4/2) gravelly to sandy clay loam. Each wetland appears to have a seasonally saturated hydrologic regime supported primarily by localized shallow groundwater conditions, though Wetland 1C also receives stormwater flows from a roadside ditch located east of the wetland. Flood or overbank flows from Stream 1 do not appear to be an appreciable source of supporting wetland hydrology. It is expected that soil within the wetlands would be saturated at or near the soil surface for extended periods during the early growing season, but unsaturated conditions would prevail by the end of the growing season in most years. Surface water would typically be absent within the wetlands but may occur for a few days after heavy rain. Wetland hydrology indicators present within each wetland at the time of the wetland delineation included a high water table and saturated soils. Surface water from the wetlands drains to Stream 1 and subsequently the Green River via Bingaman Creek. Because of very similar characteristics and proximity to each other, Wetland 1A, Wetland 1B, and Wetland 1C were rated collectively and each assigned a Category IV rating based on the total score of Wetland and Stream Delineation and Rating Report 2625 S 298th Street – Federal Way, Washington Page 5 March 15, 2021 15 that the wetlands received for functions. The wetlands rated moderate for water quality improvement functions (score = 6/9), moderately low for hydrologic functions (score = 5/9), and low for habitat functions (4/9). Each wetland requires a 50 foot standard width buffer. In addition, a 15 foot building setback is required from the outer limits of the buffer for buildings and other structures. 3.3.2 Stream 1 Stream 1 is a narrow, low gradient linear aquatic feature that begins at a 12 inch diameter concrete culvert located near the center point of the southern property line. Stream 1 drains north-northwest across the project site to an 18 inch diameter concrete culvert located in the northwest corner of the site. The horizontal limits of the OHWM are defined by the top of stream bank and were flagged 1-1E through 1-20E and 1-1W through 1-20W. Stream 1 measures an average of approximately three feet wide by approximately six inches deep. Average channel gradient was calculated to be 3.5 percent. Channel substrate includes occasional hydraulically sorted small gravels with patchy areas of sand and silt, though the stream channel is vegetated in topographically flatter areas. Flow within Stream 1 is seasonal, possibly ephemeral, and derived from the concentration of stormwater generated by impervious surfaces located in the residential subdivision south of the project site. A reconnaissance of the subdivision revealed that no stream or wetland located south of the project site drains to Stream 1. Stream 1 is not mapped by the Washington State Department of Natural Resources (DNR), the Washington State Department of Fish and Wildlife (WDFW), or King County. The City of Federal Way maps that Stream 1 flows northwest from S 298th Street to Bingaman Creek near the outlet of the Laurelwood Park wetland. A defined channel, drainage patterns, or similar features north of S 298th Street were not visible on historic aerial photographs extending back to 1937. Based on the limited contributing basin as well as the observable environmental conditions located north of S 298th Street, it is assumed that off-site stream characteristics, at most, would be similar in width, gradient, and flow regime to the on-site stream segment, though it is very possible that any defined channel would become more defuse and potentially simply a wetland based on a broadening topography and lack of stream flow. Fisheries utilization within Stream 1 is likely limited by natural blockages presented by stream flow and the potential for the absence of an above ground open-channel system and/or open water wetland north of S 298th Street. Stream 1 was classified a Type Ns water as 1) it is as a seasonal, non-fish bearing stream, 2) it is not located downstream of a known Type Np water, and 3) is presumably physically connected to a Type S, F, or Np water (Bingaman Creek). A 35 foot buffer is required from the OHWM of Stream 1. A 15 foot setback is required from the outer limits of the stream buffer for buildings and other structures. 3.3.3 Upland Upland areas within the project site include the eastern portion of the site as well as areas located south and west of Stream 1. Vegetation within upland areas includes pasture grasses with occasional herbaceous weeds. Soils are generally a very dark brown (10YR 2/2) gravelly sandy loam overlying a dark brown (10YR 3/3) to brown (10YR 4/3) gravely sandy loam to gravelly clay loam. A high water table and saturated soils were occasionally present in upland areas due to the unusually heavy rainfall immediately prior to the site assessment. Wetland and Stream Delineation and Rating Report 2625 S 298th Street – Federal Way, Washington Page 6 March 15, 2021 3.3.4 Off-Site Wetlands and Streams Stream 1 is mapped north of S 298th Street. The off-site stream segment and any associated wetlands is separated from the project site by S 298th Street. Excavated roadside ditches also exist along S 298th Street but would not be regulated critical areas because they are entirely artificial features excavated in upland soils. No other off-site wetlands or streams exist within 200 feet of the project site. 4.0 CONCLUSIONS Based on the recent critical area delineation and rating assessment, the following conclusions have been developed: 1. Wetlands: Three small wetlands exist within the western portion of the project site. Each wetland requires a 50 foot standard width buffer plus a 15 foot setback from the outer limits of the buffer for buildings and other structures. The buffer and building setback associated with the three wetlands occupy much of the western portion of the project site. Development within or otherwise affecting the wetlands, buffers, or building setbacks would likely require notification to and/or permits from the City of Federal Way. 2. Streams: A Type Ns stream crosses the project site in a southeast to northwest orientation. Flow within the stream is seasonal and likely ephemeral derived primarily from the concentration of stormwater runoff from impervious surfaces. The stream requires a 35 foot standard width buffer plus a 15 foot setback from the outer limits of the buffer for buildings and other structures. The buffer and building setback associated with the stream occupies much of the western portion of the project site. Development within or otherwise affecting the stream, buffer, or building setback would likely require notification to and/or permits from the City of Federal Way. 3. Buffer Increases: The City of Federal Way can require buffer increases beyond the standard critical area buffers discussed in this report to protect critical area functions, values, or hazards. The specific on-site conditions outlined in FWRC Chapter 19.145 for buffer increases do not exist within the project site. 4. Wetland Buffer Averaging: Wetland buffer averaging can be used to reduce standard wetland buffers by 75 percent. Subject to specific conditions, buffer averaging could be used to accommodate future development within the project site. Buffer averaging is approved by the City of Federal Way Community Development Director and approvals can be appealed via the City’s hearing examiner. 5. Wetland Buffer Reduction with Enhancement: Wetland buffer reduction with enhancement can be used to reduce standard wetland buffers by 25 percent (12.5 feet for a 50 ft buffer). Subject to specific conditions, wetland buffer reduction with enhancement could be used to accommodate future development within the project site. Wetland buffer reduction with enhancement is approved by the City of Federal Way Community Development Director and approvals can be appealed via the City’s hearing examiner. 6. Stream Buffer Intrusions: Stream buffer intrusions may be permitted with a buffer enhancement Wetland and Stream Delineation and Rating Report 2625 S 298th Street – Federal Way, Washington Page 7 March 15, 2021 plan. Subject to specific conditions, stream buffer intrusion with enhancement could be used to accommodate future development within the project site. Stream buffer intrusions are approved by the City of Federal Way Community Development Director and approvals can be appealed via the City’s hearing examiner. 7. Notice on Title: A critical area notice on title is required for any property containing critical areas or buffers on which development is proposed or on any property for which critical area mitigation is proposed. The form and content of the critical area notice is subject to City of Federal Way review and the notice must be recorded with King County recorder’s office. For land subdivisions, the critical area notice is typically incorporated into the plat documents via tract designation and related notes. 8. Critical Area Signage and Fencing: For new development, permanent critical area fencing and signage is required along the outer limits of the wetland and stream buffers described in this report. Acceptable fencing types include a standard three foot tall cedar split rail design. 9. State and Federal Permitting: Any proposed filling, grading, or other similar impacts to the wetlands discussed in this report may require notification to and/or permits from the Corps of Engineers, the Washington State Department of Ecology, and/or the Washington State Department of Fish and Wildlife. Work within wetlands could also require consultation with the U.S. Fish and Wildlife Service and/or the NOAA Fisheries to address Endangered Species Act compliance. In addition, any work within wetlands could require a cultural resource study per Section 106 of the National Historic Preservation Act. 5.0 RECOMMENDATIONS Based on the recent critical area delineation and rating assessment, the following recommendations have been developed: 1. Wetland Basic Review Service: Apply for and obtain a wetland basic review service from the City of Federal Way. This is a flat fee service the City of Federal Way offers to review and confirm the findings of this report. More information and an application form for this service can be found on this website: https://www.cityoffederalway.com/sites/default/files/Documents/Department/CD/Planning/Land%20 Use%20Apps%20and%20Info%20Handouts/063%20Wetland%20%26%20Stream%20Review%20Basic %20Service.pdf 2. Future Development: Plans for future development should accurately depict the wetlands, streams, buffers, and setbacks discussed in this report. Impacts to wetlands and streams should be completely avoided. Unavoidable impacts to wetland and stream buffers should be minimized and appropriately mitigated. 3. Critical Area Report and Mitigation Plan: Unless waived or modified by the City of Federal Way, a critical area report and mitigation plan should be prepared for impacts or alterations to the critical areas, buffers, and/or setbacks discussed in this report. The critical area report should evaluate the proposed development and probable impacts to affected buffers as well as the net improvement to critical area buffer functioning resulting from any proposed mitigation. The mitigation plan should Wetland and Stream Delineation and Rating Report 2625 S 298th Street – Federal Way, Washington Page 8 March 15, 2021 detail the specifics of the proposed work that will offset adverse impacts to critical areas and buffers. 6.0 REPORT LIMITATIONS Within the limitations of scope, schedule, and budget, the consulting services summarized in this report conform to the generally accepted standard of care in effect at the time the work was conducted. No other warranty, express or implied, is made. The collection, assessment, and determinations made, if any, related to soil characteristics and groundwater conditions are for the sole purpose of wetland delineation and have been conducted in accordance with the wetland delineation methods adopted under RCW 90.58.380 and WAC 173-22-035. The purpose of the work described in this report is to describe site conditions per City of Federal Way critical area regulations in effect at the time of report preparation. All opinions presented in this report should be considered preliminary until reviewed and confirmed by the City of Federal Way. 7.0 REFERENCES Environmental Laboratory. (1987). Corps of Engineers Wetlands Delineation Manual. Vicksburg, MS: Technical Report Y-87-1. US Army Engineer Waterway Experiment Station. Hruby, T. (2014). Washington State Wetland Rating System for Western Washington: 2014 Update. Washington State Department of Ecology Publication #14-06-029. Olympia, Washington: Washington State Department of Ecology. King County. 2021a. iMap online GIS available at the following website: https://gismaps.kingcounty.gov/iMap/. Accessed January 15, 2021. King County. 2021b. SeaTac precipitation data available from the Hydrologic Information Center at the following website: https://www.kingcounty.gov/services/environment/watersheds/hic/SeaTacPrecipitation.aspx. Accessed March 12, 2021. Federal Way Revised Code Chapter 19-145 – Environmentally Critical Areas. Current through Ordinance 20-904, passed December 1, 2020. Federal Way, City of. 2019. “City of Federal Way: Official Zoning Map”. Effective date: April 10, 2019 by ordinance #19-866. Available at the following website: https://www.cityoffederalway.com/sites/default/files/maps/zoning_0.pdf. Accessed January 15, 2021. Federal Way, City of. undated. “City of Federal Way: Critical Areas Map”. Available at the following website: https://www.cityoffederalway.com/sites/default/files/maps/sensitive_2016.pdf. Accessed January 15, 2021. United States Army Corps of Engineers. (2010). Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys, and Coast Region (Version 2.0.). Vicksburg, MS: US Army Engineer Research and Development Center: ed. J.S. Wakeley, R.W. Lichvar, and C.V. Noble. ERDC/EL TR-10-3. Wetland and Stream Delineation and Rating Report 2625 S 298th Street – Federal Way, Washington Page 9 March 15, 2021 United States Department of Agriculture, National Resources Conservation Service. “Web Soil Survey” website available at the following address: websoilsurvey.sc.egov.usda.gov/App/WebSoilSurvey.aspx. Accessed January 15, 2021. United States Department of Agriculture, National Resources Conservation Service. “Soil Data Access (SDA) Hydric Soil List” available at the following website: www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcseprd1316620.html. Accessed February 8, 2021. United States Department of Fish and Wildlife. “National Wetlands Inventory – Surface Waters and Wetlands” website available at the following address: https://www.fws.gov/wetlands/data/mapper.html. Accessed January 15, 2021. Washington State Department of Ecology. Washington State Water Quality Atlas online website available at the following address: https://fortress.wa.gov/ecy/waterqualityatlas/map.aspx. Accessed January 15, 2021. Washington State Department of Fish and Wildlife. 2021. “Priority Habitats on the Web” website available at the following address: https://geodataservices.wdfw.wa.gov/hp/phs/. Accessed January 15, 2021. Williams, R. Laramie, R., and Ames, J. 1975. A Catalog of Washington Streams and Salmon Utilization: Volume 1 – Puget Sound Region. Washington State Department of Fisheries. November 1975. Appendix A Critical Area Map 50 FT 50 FT 50 FT 50 FT 35 FT 35 FT 35 FT 50 FT S 298th Street DP1 DP7 DP3 DP2 DP8 DP9 DP10 DP4 DP5 DP6 Wetland 1A Category IV Wetland 1B Category IV Wetland 1C Category IV Stream 1 Type Ns Unregulated Roadside Ditches CulvertsCulverts Culverts 2625 S 298th Street Federal Way, Washington Evergreen Aquatic Wetland Delineation Mitigation Design Compliance Monitoring Resource Consultants, LLC03060 N Critical Area Map Wetlands and Streams Figure 1 Legend Flagged Wetland Flagged Stream Critical Area Buffer 15' Building Setback Wetland Determination PointDP1 Appendix B Photographs 2625 S 298th Street Federal Way, Washington Evergreen Aquatic Wetland Delineation Mitigation Design Compliance Monitoring Resource Consultants, LLC Photographs Photo 1 Wetland 1A January 15, 2021 Wetland 1B January 15, 2021 Stream 1 January 15, 2021 Soil & Hydrology Conditions @ DP1 January 15, 2021 Wetland 1C January 15, 2021 Vegetation Conditions @ DP 1 January 15, 2021 2625 S 298th Street Federal Way, Washington Evergreen Aquatic Wetland Delineation Mitigation Design Compliance Monitoring Resource Consultants, LLC Photographs Photo 2 Vegetation Conditions @ DP2 January 15, 2021 Soil & Hydrology Conditions @ DP2 January 15, 2021 Soil & Hydrology Conditions @ DP3 January 15, 2021 Soil & Hydrology Conditions @ DP4 January 15, 2021 Vegetation Conditions @ DP3 January 15, 2021 Vegetation Conditions @ DP4 January 15, 2021 2625 S 298th Street Federal Way, Washington Evergreen Aquatic Wetland Delineation Mitigation Design Compliance Monitoring Resource Consultants, LLC Photographs Photo 3 Vegetation Conditions @ DP5 January 15, 2021 Soil & Hydrology Conditions @ DP5 January 15, 2021 Soil & Hydrology Conditions @ DP6 January 15, 2021 Soil & Hydrology Conditions @ DP7 January 15, 2021 Vegetation Conditions @ DP6 January 15, 2021 Vegetation Conditions @ DP7 January 15, 2021 2625 S 298th Street Federal Way, Washington Evergreen Aquatic Wetland Delineation Mitigation Design Compliance Monitoring Resource Consultants, LLC Photographs Photo 4 Vegetation Conditions @ DP8 January 15, 2021 Soil & Hydrology Conditions @ DP8 January 29, 2021 Soil & Hydrology Conditions @ DP9 January 29, 2021 Vegetation Conditions @ DP10 January 29, 2021 Soil and Hydrologic Conditions @ DP10 January 29, 2021 Vegetation Conditions @ DP9 January 29, 2021 Appendix C Wetland Determination Forms WETLAND DETERMINATION DATA FORM – Western Mountains, Valleys, and Coast Region VEGETATION Tree Stratum (Plot Size: 10 meter) Absolute % Cover Dominant Species? Indicator Status Dominance Test Worksheet: 1. Number of Dominant Species That Are OBL, FACW, or FAC: (A) 2. 3. Total Number of Dominant Species Across All Strata: (B) 4. n/a = Total Cover Percent of Dominant Species That Are OBL, FACW, or FAC: (A/B) Sapling/Shrub Stratum (Plot Size: 5 meter) 1. Prevalence Index worksheet: 2. Total % Cover of: Multiply by: 3. OBL species x1 = 4. FACW species x2 = 5. FAC species x3 = n/a = Total Cover FACU species x4 = Herb Stratum (Plot Size: 1 meter) UPL species x5 = 1. Pasture grasses 100 Column Totals: (A) (B) 2. Prevalence Index = 3. Hydrophytic Vegetation Indicators: 4. Dominance Test is >50% 5. Prevalence Index is <3.01 6. Morphological Adaptations1 (Provide supporting data in Remarks or on a separate sheet) 7. 8. Wetland Non-Vascular Plants1 9. Problematic Hydrophytic Vegetation1 (Explain) 10. 1 Indicators of hydric soil and wetland hydrology must be present, unless disturbed or problematic. 11. 100 = Total Cover Woody Vine Stratum (Plot Size: 1 meter) Hydrophytic Vegetation Present? Yes No 1. 2. n/a = Total Cover % Bare Ground in Herb Stratum – n/a Remarks: Wetland determination made based on soil and hydrology only. Project Site: 2625 S 298th Street City/County: Federal Way Sampling Date: 01/15/2021 Applicant/Owner: VSM State: WA Sampling Point: DP 1 Investigator(s): Peter P. Super – Professional Wetland Scientist Section, Township, Range: NE ¼ of SE ¼ S 4, T 21 N, R 4 E Landform (hillslope, terrace, etc.): Hillslope Local relief (concave, convex, none): None Slope (%): 10% Subregion (LRR): A Lat: 47.33418 Long: -122.29936 Datum: NAD 88 Soil Map Unit Name: Alderwood gravelly sandy loam, 0 to 8 percent slopes (AgB) NWI classification: none Are climatic / hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.) Rainfall is higher than normal. 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 Hydrophytic Vegetation Present? Yes No Is the Sampling Area within a Wetland? Hydric Soil Present? Yes No Wetland Hydrology Present? Yes No Remarks: NO SOIL DP 1 Profile Description: Depth (inches) Matrix Redox Features Color (moist) % Color (Moist) % Type1 Loc2 Texture Remarks 0 to 7 10YR 2/2 100 gravelly sandy loam 7 to 18+ 10YR 3/3 80 10YR 3/6 20 C M gravelly sandy 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) Other (Explain in Remarks) Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Depleted Below Dark Surface (A11) Depleted Matrix (F3) 3 Indicators 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: Soil textures stated are apparent field textures. Soil colors are for moist soil per Munsell Soil Color Charts (GretagMacbeth 2001 with updated color charts). 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): n/a Wetland Hydrology Present? Yes No Water Table Present? Yes No Depth (inches): 6 Saturation Present? (includes capillary fringe) Yes No Depth (inches): 2 Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available: Remarks: Project Site: 2625 S 298th Street – Federal Way, Washington WETLAND DETERMINATION DATA FORM – Western Mountains, Valleys, and Coast Region VEGETATION Tree Stratum (Plot Size: 10 meter) Absolute % Cover Dominant Species? Indicator Status Dominance Test Worksheet: 1. Number of Dominant Species That Are OBL, FACW, or FAC: 1 (A) 2. 3. Total Number of Dominant Species Across All Strata: 1 (B) 4. n/a = Total Cover Percent of Dominant Species That Are OBL, FACW, or FAC: 100 (A/B) Sapling/Shrub Stratum (Plot Size: 5 meter) 1. Prevalence Index worksheet: 2. Total % Cover of: Multiply by: 3. OBL species x1 = 4. FACW species x2 = 5. FAC species x3 = n/a = Total Cover FACU species x4 = Herb Stratum (Plot Size: 1 meter) UPL species x5 = 1. Festuca arundinacea 100 YES FAC Column Totals: (A) (B) 2. Prevalence Index = 3. Hydrophytic Vegetation Indicators: 4. YES Dominance Test is >50% 5. Prevalence Index is <3.01 6. Morphological Adaptations1 (Provide supporting data in Remarks or on a separate sheet) 7. 8. Wetland Non-Vascular Plants1 9. Problematic Hydrophytic Vegetation1 (Explain) 10. 1 Indicators of hydric soil and wetland hydrology must be present, unless disturbed or problematic. 11. 100 = Total Cover Woody Vine Stratum (Plot Size: 1 meter) Hydrophytic Vegetation Present? Yes No 1. 2. n/a = Total Cover % Bare Ground in Herb Stratum – n/a Remarks: Project Site: 2625 S 298th Street City/County: Federal Way Sampling Date: 01/15/2021 Applicant/Owner: VSM State: WA Sampling Point: DP 2 Investigator(s): Peter P. Super – Professional Wetland Scientist Section, Township, Range: NE ¼ of SE ¼ S 4, T 21 N, R 4 E Landform (hillslope, terrace, etc.): Hillslope Local relief (concave, convex, none): None Slope (%): 10% Subregion (LRR): A Lat: 47.33418 Long: -122.29936 Datum: NAD 88 Soil Map Unit Name: Alderwood gravelly sandy loam, 0 to 8 percent slopes (AgB) NWI classification: none Are climatic / hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.) Rainfall is higher than normal. 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 Hydrophytic Vegetation Present? Yes No Is the Sampling Area within a Wetland? Hydric Soil Present? Yes No Wetland Hydrology Present? Yes No Remarks: YES SOIL DP 2 Profile Description: Depth (inches) Matrix Redox Features Color (moist) % Color (Moist) % Type1 Loc2 Texture Remarks 0 to 9 10YR 3/1 100 gravelly silty clay loam 9 to 18+ 10YR 4/2 85 10YR 3/6 10YR 4/6 15 C M 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) Other (Explain in Remarks) Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Depleted Below Dark Surface (A11) Depleted Matrix (F3) 3 Indicators 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: Soil textures stated are apparent field textures. Soil colors are for moist soil per Munsell Soil Color Charts (GretagMacbeth 2001 with updated color charts). 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): n/a Wetland Hydrology Present? Yes No Water Table Present? Yes No Depth (inches): 10 Saturation Present? (includes capillary fringe) Yes No Depth (inches): 0 Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available: Remarks: Project Site: 2625 S 298th Street – Federal Way, Washington WETLAND DETERMINATION DATA FORM – Western Mountains, Valleys, and Coast Region VEGETATION Tree Stratum (Plot Size: 10 meter) Absolute % Cover Dominant Species? Indicator Status Dominance Test Worksheet: 1. Number of Dominant Species That Are OBL, FACW, or FAC: (A) 2. 3. Total Number of Dominant Species Across All Strata: (B) 4. n/a = Total Cover Percent of Dominant Species That Are OBL, FACW, or FAC: (A/B) Sapling/Shrub Stratum (Plot Size: 5 meter) 1. Prevalence Index worksheet: 2. Total % Cover of: Multiply by: 3. OBL species x1 = 4. FACW species x2 = 5. FAC species x3 = n/a = Total Cover FACU species x4 = Herb Stratum (Plot Size: 1 meter) UPL species x5 = 1. pasture grasses 100 Column Totals: (A) (B) 2. Prevalence Index = 3. Hydrophytic Vegetation Indicators: 4. Dominance Test is >50% 5. Prevalence Index is <3.01 6. Morphological Adaptations1 (Provide supporting data in Remarks or on a separate sheet) 7. 8. Wetland Non-Vascular Plants1 9. Problematic Hydrophytic Vegetation1 (Explain) 10. 1 Indicators of hydric soil and wetland hydrology must be present, unless disturbed or problematic. 11. 100 = Total Cover Woody Vine Stratum (Plot Size: 1 meter) Hydrophytic Vegetation Present? Yes No 1. 2. n/a = Total Cover % Bare Ground in Herb Stratum – 0 Remarks: Wetland determination made based on soil and hydrology only. Project Site: 2625 S 298th Street City/County: Federal Way Sampling Date: 01/15/2021 Applicant/Owner: VSM State: WA Sampling Point: DP 3 Investigator(s): Peter P. Super – Professional Wetland Scientist Section, Township, Range: NE ¼ of SE ¼ S 4, T 21 N, R 4 E Landform (hillslope, terrace, etc.): Hillslope Local relief (concave, convex, none): None Slope (%): 10% Subregion (LRR): A Lat: 47.33418 Long: -122.29936 Datum: NAD 88 Soil Map Unit Name: Alderwood gravelly sandy loam, 0 to 8 percent slopes (AgB) NWI classification: none Are climatic / hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.) Rainfall is higher than normal. 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 Hydrophytic Vegetation Present? Yes No Is the Sampling Area within a Wetland? Hydric Soil Present? Yes No Wetland Hydrology Present? Yes No Remarks: NO SOIL DP 3 Profile Description: Depth (inches) Matrix Redox Features Color (moist) % Color (Moist) % Type1 Loc2 Texture Remarks 0 to 12 10YR 2/2 100 gravelly sandy loam 12 to 18+ 10YR 4/3 100 gravelly sandy 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) Other (Explain in Remarks) Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Depleted Below Dark Surface (A11) Depleted Matrix (F3) 3 Indicators 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: Soil textures stated are apparent field textures. Soil colors are for moist soil per Munsell Soil Color Charts (GretagMacbeth 2001 with updated color charts). 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): n/a Wetland Hydrology Present? Yes No Water Table Present? Yes No Depth (inches): 7 Saturation Present? (includes capillary fringe) Yes No Depth (inches): 3 Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available: Remarks: Project Site: 2625 S 298th Street – Federal Way, Washington WETLAND DETERMINATION DATA FORM – Western Mountains, Valleys, and Coast Region VEGETATION Tree Stratum (Plot Size: 10 meter) Absolute % Cover Dominant Species? Indicator Status Dominance Test Worksheet: 1. Number of Dominant Species That Are OBL, FACW, or FAC: (A) 2. 3. Total Number of Dominant Species Across All Strata: (B) 4. n/a = Total Cover Percent of Dominant Species That Are OBL, FACW, or FAC: (A/B) Sapling/Shrub Stratum (Plot Size: 5 meter) 1. Prevalence Index worksheet: 2. Total % Cover of: Multiply by: 3. OBL species x1 = 4. FACW species x2 = 5. FAC species x3 = n/a = Total Cover FACU species x4 = Herb Stratum (Plot Size: 1 meter) UPL species x5 = 1. Pasture grasses 100 Column Totals: (A) (B) 2. Prevalence Index = 3.8 3. Hydrophytic Vegetation Indicators: 4. Dominance Test is >50% 5. Prevalence Index is <3.01 6. Morphological Adaptations1 (Provide supporting data in Remarks or on a separate sheet) 7. 8. Wetland Non-Vascular Plants1 9. Problematic Hydrophytic Vegetation1 (Explain) 10. 1 Indicators of hydric soil and wetland hydrology must be present, unless disturbed or problematic. 11. 100 = Total Cover Woody Vine Stratum (Plot Size: 1 meter) Hydrophytic Vegetation Present? Yes No 1. 2. n/a = Total Cover % Bare Ground in Herb Stratum – n/a Remarks: Wetland determination made based on soil and hydrology only. Project Site: 2625 S 298th Street City/County: Federal Way Sampling Date: 01/15/2021 Applicant/Owner: VSM State: WA Sampling Point: DP 4 Investigator(s): Peter P. Super – Professional Wetland Scientist Section, Township, Range: NE ¼ of SE ¼ S 4, T 21 N, R 4 E Landform (hillslope, terrace, etc.): Hillslope Local relief (concave, convex, none): None Slope (%): 10% Subregion (LRR): A Lat: 47.33418 Long: -122.29936 Datum: NAD 88 Soil Map Unit Name: Alderwood gravelly sandy loam, 0 to 8 percent slopes (AgB) NWI classification: none Are climatic / hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.) Rainfall is higher than normal. 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 Hydrophytic Vegetation Present? Yes No Is the Sampling Area within a Wetland? Hydric Soil Present? Yes No Wetland Hydrology Present? Yes No Remarks: NO SOIL DP 4 Profile Description: Depth (inches) Matrix Redox Features Color (moist) % Color (Moist) % Type1 Loc2 Texture Remarks 0 to 11 10YR3/2 100 gravelly sandy loam 11 to 18+ 10YR 4/3 98 10YR 3/6 2 C M sandy 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) Other (Explain in Remarks) Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Depleted Below Dark Surface (A11) Depleted Matrix (F3) 3 Indicators 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: Soil textures stated are apparent field textures. Soil colors are for moist soil per Munsell Soil Color Charts (GretagMacbeth 2001 with updated color charts). 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): n/a Wetland Hydrology Present? Yes No Water Table Present? Yes No Depth (inches): 18 Saturation Present? (includes capillary fringe) Yes No Depth (inches): 14 Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available: Remarks: Project Site: 2625 S 298th Street – Federal Way, Washington WETLAND DETERMINATION DATA FORM – Western Mountains, Valleys, and Coast Region VEGETATION Tree Stratum (Plot Size: 10 meter) Absolute % Cover Dominant Species? Indicator Status Dominance Test Worksheet: 1. Number of Dominant Species That Are OBL, FACW, or FAC: (A) 2. 3. Total Number of Dominant Species Across All Strata: (B) 4. n/a = Total Cover Percent of Dominant Species That Are OBL, FACW, or FAC: (A/B) Sapling/Shrub Stratum (Plot Size: 5 meter) 1. Prevalence Index worksheet: 2. Total % Cover of: Multiply by: 3. OBL species x1 = 4. FACW species x2 = 5. FAC species x3 = n/a = Total Cover FACU species x4 = Herb Stratum (Plot Size: 1 meter) UPL species x5 = 1. Pasture grasses 100 Column Totals: (A) (B) 2. Prevalence Index = 3.8 3. Hydrophytic Vegetation Indicators: 4. Dominance Test is >50% 5. Prevalence Index is <3.01 6. Morphological Adaptations1 (Provide supporting data in Remarks or on a separate sheet) 7. 8. Wetland Non-Vascular Plants1 9. Problematic Hydrophytic Vegetation1 (Explain) 10. 1 Indicators of hydric soil and wetland hydrology must be present, unless disturbed or problematic. 11. 100 = Total Cover Woody Vine Stratum (Plot Size: 1 meter) Hydrophytic Vegetation Present? Yes No 1. 2. n/a = Total Cover % Bare Ground in Herb Stratum – n/a Remarks: Wetland determination made based on soil and hydrology only. Project Site: 2625 S 298th Street City/County: Federal Way Sampling Date: 01/15/2021 Applicant/Owner: VSM State: WA Sampling Point: DP 5 Investigator(s): Peter P. Super – Professional Wetland Scientist Section, Township, Range: NE ¼ of SE ¼ S 4, T 21 N, R 4 E Landform (hillslope, terrace, etc.): Hillslope Local relief (concave, convex, none): None Slope (%): 10% Subregion (LRR): A Lat: 47.33418 Long: -122.29936 Datum: NAD 88 Soil Map Unit Name: Alderwood gravelly sandy loam, 0 to 8 percent slopes (AgB) NWI classification: none Are climatic / hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.) Rainfall is higher than normal. 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 Hydrophytic Vegetation Present? Yes No Is the Sampling Area within a Wetland? Hydric Soil Present? Yes No Wetland Hydrology Present? Yes No Remarks: NO SOIL DP 5 Profile Description: Depth (inches) Matrix Redox Features Color (moist) % Color (Moist) % Type1 Loc2 Texture Remarks 0 to 14 10YR 3/2 100 gravelly sandy loam 14 to 18+ 10YR 4/2+ 98 10YR 3/6 2 C M gravelly sandy 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) Other (Explain in Remarks) Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Depleted Below Dark Surface (A11) Depleted Matrix (F3) 3 Indicators 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: Soil textures stated are apparent field textures. Soil colors are for moist soil per Munsell Soil Color Charts (GretagMacbeth 2001 with updated color charts). 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): n/a Wetland Hydrology Present? Yes No Water Table Present? Yes No Depth (inches): 8.5 Saturation Present? (includes capillary fringe) Yes No Depth (inches): 3 Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available: Remarks: Project Site: 2625 S 298th Street – Federal Way, Washington WETLAND DETERMINATION DATA FORM – Western Mountains, Valleys, and Coast Region VEGETATION Tree Stratum (Plot Size: 10 meter) Absolute % Cover Dominant Species? Indicator Status Dominance Test Worksheet: 1. Number of Dominant Species That Are OBL, FACW, or FAC: 1 (A) 2. 3. Total Number of Dominant Species Across All Strata: 1 (B) 4. n/a = Total Cover Percent of Dominant Species That Are OBL, FACW, or FAC: 100 (A/B) Sapling/Shrub Stratum (Plot Size: 5 meter) 1. Prevalence Index worksheet: 2. Total % Cover of: Multiply by: 3. OBL species x1 = 4. FACW species x2 = 5. FAC species x3 = n/a = Total Cover FACU species x4 = Herb Stratum (Plot Size: 1 meter) UPL species x5 = 1. Festuca arundinacea 100 YES FAC Column Totals: (A) (B) 2. Prevalence Index = 3. Hydrophytic Vegetation Indicators: 4. YES Dominance Test is >50% 5. Prevalence Index is <3.01 6. Morphological Adaptations1 (Provide supporting data in Remarks or on a separate sheet) 7. 8. Wetland Non-Vascular Plants1 9. Problematic Hydrophytic Vegetation1 (Explain) 10. 1 Indicators of hydric soil and wetland hydrology must be present, unless disturbed or problematic. 11. 100 = Total Cover Woody Vine Stratum (Plot Size: 1 meter) Hydrophytic Vegetation Present? Yes No 1. 2. n/a = Total Cover % Bare Ground in Herb Stratum – n/a Remarks: Project Site: 2625 S 298th Street City/County: Federal Way Sampling Date: 01/15/2021 Applicant/Owner: VSM State: WA Sampling Point: DP 6 Investigator(s): Peter P. Super – Professional Wetland Scientist Section, Township, Range: NE ¼ of SE ¼ S 4, T 21 N, R 4 E Landform (hillslope, terrace, etc.): Hillslope Local relief (concave, convex, none): None Slope (%): 10% Subregion (LRR): A Lat: 47.33418 Long: -122.29936 Datum: NAD 88 Soil Map Unit Name: Alderwood gravelly sandy loam, 0 to 8 percent slopes (AgB) NWI classification: none Are climatic / hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.) Rainfall is higher than normal. 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 Hydrophytic Vegetation Present? Yes No Is the Sampling Area within a Wetland? Hydric Soil Present? Yes No Wetland Hydrology Present? Yes No Remarks: YES SOIL DP 6 Profile Description: Depth (inches) Matrix Redox Features Color (moist) % Color (Moist) % Type1 Loc2 Texture Remarks 0 to 13 10YR 3/1 100 sandy loam 13 to 18+ 10YR 4/2 95 10YR 3/6 5 C M sandy 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) Other (Explain in Remarks) Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Depleted Below Dark Surface (A11) Depleted Matrix (F3) 3 Indicators 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: Soil textures stated are apparent field textures. Soil colors are for moist soil per Munsell Soil Color Charts (GretagMacbeth 2001 with updated color charts). 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): n/a Wetland Hydrology Present? Yes No Water Table Present? Yes No Depth (inches): 3 Saturation Present? (includes capillary fringe) Yes No Depth (inches): 0 Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available: Remarks: Project Site: 2625 S 298th Street – Federal Way, Washington WETLAND DETERMINATION DATA FORM – Western Mountains, Valleys, and Coast Region VEGETATION Tree Stratum (Plot Size: 10 meter) Absolute % Cover Dominant Species? Indicator Status Dominance Test Worksheet: 1. Number of Dominant Species That Are OBL, FACW, or FAC: 1 (A) 2. 3. Total Number of Dominant Species Across All Strata: 1 (B) 4. n/a = Total Cover Percent of Dominant Species That Are OBL, FACW, or FAC: 100 (A/B) Sapling/Shrub Stratum (Plot Size: 5 meter) 1. Prevalence Index worksheet: 2. Total % Cover of: Multiply by: 3. OBL species x1 = 4. FACW species x2 = 5. FAC species x3 = n/a = Total Cover FACU species x4 = Herb Stratum (Plot Size: 1 meter) UPL species x5 = 1. Festuca arundinacea 100 YES FAC Column Totals: (A) (B) 2. Prevalence Index = 3. Hydrophytic Vegetation Indicators: 4. YES Dominance Test is >50% 5. Prevalence Index is <3.01 6. Morphological Adaptations1 (Provide supporting data in Remarks or on a separate sheet) 7. 8. Wetland Non-Vascular Plants1 9. Problematic Hydrophytic Vegetation1 (Explain) 10. 1 Indicators of hydric soil and wetland hydrology must be present, unless disturbed or problematic. 11. 100 = Total Cover Woody Vine Stratum (Plot Size: 1 meter) Hydrophytic Vegetation Present? Yes No 1. 2. n/a = Total Cover % Bare Ground in Herb Stratum – n/a Remarks: Project Site: 2625 S 298th Street City/County: Federal Way Sampling Date: 01/15/2021 Applicant/Owner: VSM State: WA Sampling Point: DP 7 Investigator(s): Peter P. Super – Professional Wetland Scientist Section, Township, Range: NE ¼ of SE ¼ S 4, T 21 N, R 4 E Landform (hillslope, terrace, etc.): Hillslope Local relief (concave, convex, none): None Slope (%): 10% Subregion (LRR): A Lat: 47.33418 Long: -122.29936 Datum: NAD 88 Soil Map Unit Name: Alderwood gravelly sandy loam, 0 to 8 percent slopes (AgB) NWI classification: none Are climatic / hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.) Rainfall is higher than normal. 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 Hydrophytic Vegetation Present? Yes No Is the Sampling Area within a Wetland? Hydric Soil Present? Yes No Wetland Hydrology Present? Yes No Remarks: YES SOIL DP 7 Profile Description: Depth (inches) Matrix Redox Features Color (moist) % Color (Moist) % Type1 Loc2 Texture Remarks 0 to 10 10YR 3/1 100 silt loam 10 to 18+ 10YR 4/2 95 10R 3/6 5 C M sandy 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) Other (Explain in Remarks) Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Depleted Below Dark Surface (A11) Depleted Matrix (F3) 3 Indicators 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: Soil textures stated are apparent field textures. Soil colors are for moist soil per Munsell Soil Color Charts (GretagMacbeth 2001 with updated color charts). 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): n/a Wetland Hydrology Present? Yes No Water Table Present? Yes No Depth (inches): 9 Saturation Present? (includes capillary fringe) Yes No Depth (inches): 3 Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available: Remarks: Project Site: 2625 S 298th Street – Federal Way, Washington WETLAND DETERMINATION DATA FORM – Western Mountains, Valleys, and Coast Region VEGETATION Tree Stratum (Plot Size: 10 meter) Absolute % Cover Dominant Species? Indicator Status Dominance Test Worksheet: 1. Number of Dominant Species That Are OBL, FACW, or FAC: (A) 2. 3. Total Number of Dominant Species Across All Strata: (B) 4. n/a = Total Cover Percent of Dominant Species That Are OBL, FACW, or FAC: (A/B) Sapling/Shrub Stratum (Plot Size: 5 meter) 1. Prevalence Index worksheet: 2. Total % Cover of: Multiply by: 3. OBL species x1 = 4. FACW species x2 = 5. FAC species x3 = n/a = Total Cover FACU species x4 = Herb Stratum (Plot Size: 1 meter) UPL species x5 = 1. Pasture grasses 100 Column Totals: (A) (B) 2. Prevalence Index = 3. Hydrophytic Vegetation Indicators: 4. Dominance Test is >50% 5. Prevalence Index is <3.01 6. Morphological Adaptations1 (Provide supporting data in Remarks or on a separate sheet) 7. 8. Wetland Non-Vascular Plants1 9. Problematic Hydrophytic Vegetation1 (Explain) 10. 1 Indicators of hydric soil and wetland hydrology must be present, unless disturbed or problematic. 11. 100 = Total Cover Woody Vine Stratum (Plot Size: 1 meter) Hydrophytic Vegetation Present? Yes No 1. 2. n/a = Total Cover % Bare Ground in Herb Stratum – n/a Remarks: Wetland determination made based on soil and hydrology only. Project Site: 2625 S 298th Street City/County: Federal Way Sampling Date: 01/29/2021 Applicant/Owner: VSM State: WA Sampling Point: DP 8 Investigator(s): Peter P. Super – Professional Wetland Scientist Section, Township, Range: NE ¼ of SE ¼ S 4, T 21 N, R 4 E Landform (hillslope, terrace, etc.): Hillslope Local relief (concave, convex, none): None Slope (%): 10% Subregion (LRR): A Lat: 47.33418 Long: -122.29936 Datum: NAD 88 Soil Map Unit Name: Alderwood gravelly sandy loam, 0 to 8 percent slopes (AgB) NWI classification: none Are climatic / hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.) Rainfall is higher than normal. 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 Hydrophytic Vegetation Present? Yes No Is the Sampling Area within a Wetland? Hydric Soil Present? Yes No Wetland Hydrology Present? Yes No Remarks: NO SOIL DP 8 Profile Description: Depth (inches) Matrix Redox Features Color (moist) % Color (Moist) % Type1 Loc2 Texture Remarks 0 to 10 10YR 2/2 100 sandy loam 10 to 18+ 10YR 5/3 85 10YR 3/6 15 C M sandy 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) Other (Explain in Remarks) Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Depleted Below Dark Surface (A11) Depleted Matrix (F3) 3 Indicators 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: Soil textures stated are apparent field textures. Soil colors are for moist soil per Munsell Soil Color Charts (GretagMacbeth 2001 with updated color charts). 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): n/a Wetland Hydrology Present? Yes No Water Table Present? Yes No Depth (inches): 18 Saturation Present? (includes capillary fringe) Yes No Depth (inches): 10 Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available: Remarks: Project Site: 2625 S 298th Street – Federal Way, Washington WETLAND DETERMINATION DATA FORM – Western Mountains, Valleys, and Coast Region VEGETATION Tree Stratum (Plot Size: 10 meter) Absolute % Cover Dominant Species? Indicator Status Dominance Test Worksheet: 1. Number of Dominant Species That Are OBL, FACW, or FAC: (A) 2. 3. Total Number of Dominant Species Across All Strata: (B) 4. n/a = Total Cover Percent of Dominant Species That Are OBL, FACW, or FAC: (A/B) Sapling/Shrub Stratum (Plot Size: 5 meter) 1. Prevalence Index worksheet: 2. Total % Cover of: Multiply by: 3. OBL species x1 = 4. FACW species x2 = 5. FAC species x3 = n/a = Total Cover FACU species x4 = Herb Stratum (Plot Size: 1 meter) UPL species x5 = 1. Pasture grasses 100 Column Totals: (A) (B) 2. Prevalence Index = 3. Hydrophytic Vegetation Indicators: 4. Dominance Test is >50% 5. Prevalence Index is <3.01 6. Morphological Adaptations1 (Provide supporting data in Remarks or on a separate sheet) 7. 8. Wetland Non-Vascular Plants1 9. Problematic Hydrophytic Vegetation1 (Explain) 10. 1 Indicators of hydric soil and wetland hydrology must be present, unless disturbed or problematic. 11. 100 = Total Cover Woody Vine Stratum (Plot Size: 1 meter) Hydrophytic Vegetation Present? Yes No 1. 2. n/a = Total Cover % Bare Ground in Herb Stratum – n/a Remarks: Wetland determination made based on soil and hydrology only. Project Site: 2625 S 298th Street City/County: Federal Way Sampling Date: 01/29/2021 Applicant/Owner: VSM State: WA Sampling Point: DP 9 Investigator(s): Peter P. Super – Professional Wetland Scientist Section, Township, Range: NE ¼ of SE ¼ S 4, T 21 N, R 4 E Landform (hillslope, terrace, etc.): Hillslope Local relief (concave, convex, none): None Slope (%): 10% Subregion (LRR): A Lat: 47.33418 Long: -122.29936 Datum: NAD 88 Soil Map Unit Name: Alderwood gravelly sandy loam, 0 to 8 percent slopes (AgB) NWI classification: none Are climatic / hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.) Rainfall is higher than normal. 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 Hydrophytic Vegetation Present? Yes No Is the Sampling Area within a Wetland? Hydric Soil Present? Yes No Wetland Hydrology Present? Yes No Remarks: NO SOIL DP 9 Profile Description: Depth (inches) Matrix Redox Features Color (moist) % Color (Moist) % Type1 Loc2 Texture Remarks 0 to 13 10YR 4/2 10YR 4/3 10YR 3/3 95 5 10YR 4/6 2.5Y 5/4 C/D M mixed matrix 13 to 18+ 10YR 2/2 100 gravelly sandy 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) Other (Explain in Remarks) Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Depleted Below Dark Surface (A11) Depleted Matrix (F3) 3 Indicators 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: Soil textures stated are apparent field textures. Soil colors are for moist soil per Munsell Soil Color Charts (GretagMacbeth 2001 with updated color charts). 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): n/a Wetland Hydrology Present? Yes No Water Table Present? Yes No Depth (inches): n/a Saturation Present? (includes capillary fringe) Yes No Depth (inches): n/a Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available: Remarks: Soils were wet, but not saturated. Project Site: 2625 S 298th Street – Federal Way, Washington WETLAND DETERMINATION DATA FORM – Western Mountains, Valleys, and Coast Region VEGETATION Tree Stratum (Plot Size: 10 meter) Absolute % Cover Dominant Species? Indicator Status Dominance Test Worksheet: 1. Number of Dominant Species That Are OBL, FACW, or FAC: (A) 2. 3. Total Number of Dominant Species Across All Strata: (B) 4. n/a = Total Cover Percent of Dominant Species That Are OBL, FACW, or FAC: (A/B) Sapling/Shrub Stratum (Plot Size: 5 meter) 1. Prevalence Index worksheet: 2. Total % Cover of: Multiply by: 3. OBL species x1 = 4. FACW species x2 = 5. FAC species x3 = n/a = Total Cover FACU species x4 = Herb Stratum (Plot Size: 1 meter) UPL species x5 = 1. Pasture grasses 100 Column Totals: (A) (B) 2. Prevalence Index = 3. Hydrophytic Vegetation Indicators: 4. Dominance Test is >50% 5. Prevalence Index is <3.01 6. Morphological Adaptations1 (Provide supporting data in Remarks or on a separate sheet) 7. 8. Wetland Non-Vascular Plants1 9. Problematic Hydrophytic Vegetation1 (Explain) 10. 1 Indicators of hydric soil and wetland hydrology must be present, unless disturbed or problematic. 11. 100 = Total Cover Woody Vine Stratum (Plot Size: 1 meter) Hydrophytic Vegetation Present? Yes No 3. 4. n/a = Total Cover % Bare Ground in Herb Stratum – n/a Remarks: Wetland determination made based on soil and hydrology only. Project Site: 2625 S 298th Street City/County: Federal Way Sampling Date: 01/29/2021 Applicant/Owner: VSM State: WA Sampling Point: DP 10 Investigator(s): Peter P. Super – Professional Wetland Scientist Section, Township, Range: NE ¼ of SE ¼ S 4, T 21 N, R 4 E Landform (hillslope, terrace, etc.): Hillslope Local relief (concave, convex, none): None Slope (%): 10% Subregion (LRR): A Lat: 47.33418 Long: -122.29936 Datum: NAD 88 Soil Map Unit Name: Alderwood gravelly sandy loam, 0 to 8 percent slopes (AgB) NWI classification: none Are climatic / hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.) Rainfall is higher than normal. 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 Hydrophytic Vegetation Present? Yes No Is the Sampling Area within a Wetland? Hydric Soil Present? Yes No Wetland Hydrology Present? Yes No Remarks: NO SOIL DP 10 Profile Description: Depth (inches) Matrix Redox Features Color (moist) % Color (Moist) % Type1 Loc2 Texture Remarks 0 to 18+ 10YR 3+/2 to 10YR 4/2 90 10YR 4/6 10 C M gravelly sandy clay loam mixed matrix – large angular rock present 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) Other (Explain in Remarks) Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Depleted Below Dark Surface (A11) Depleted Matrix (F3) 3 Indicators 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: Soil textures stated are apparent field textures. Soil colors are for moist soil per Munsell Soil Color Charts (GretagMacbeth 2001 with updated color charts). 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): n/a Wetland Hydrology Present? Yes No Water Table Present? Yes No Depth (inches): n/a Saturation Present? (includes capillary fringe) Yes No Depth (inches): 15 Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available: Remarks: Soils were wet, but not saturated. Project Site: 2625 S 298th Street – Federal Way, Washington Appendix D Wetland Rating Form 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 Wetland 1 Wetland 1 01/15/2020 Peter Super X Slope X see attached IV X X 6 5 4 15 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 Figure 1 Figure 1 Figure 1 Figure 1 Figure 1 attached attached Figure 2 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. X X X 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. 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 2 0 0 2 X X 1 0 1 0 0 0 3 X Wetland is mowed on a seasonal basis. None known. Wetland drains north to Laurelwood Park. Laurelwood Park drains east via Bingaman Creek and Mullen Slough to the Green River. Mullen Slough is 303d listed for bioassessment and bacteria. The Green River is 303d listed for dissolved oxygen and the Duwamish River further downstream maintains multiple 303d listings. 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: X X 0 1 1 0 1 X Wetland is mowed on a seasonal basis. King County iMAP maps drainage complaints downstream of the project site along Bingaman Creek. Although the status and accuracy of the drainage complaints could not be confirmed, the presence of drainage complaints suggests that flooding problems may exist downstream of the wetland within the drainage subbasin. 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 ft 2. 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 X 0 1 0 0 X X 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 X 1 X 2 X 0 1 -2 -1 X 1 0 0 0 10 2.6 12.6 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. X 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 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 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 2625 S 298th Street Federal Way, Washington Evergreen Aquatic Wetland Delineation Mitigation Design Compliance Monitoring Resource Consultants, LLC050100 N Wetland 1A, 1B, & 1C 150' offset 150' offset 150' offset PEM1B PEM1B Culvert Wetland unit Area that can generate pollutants Area that can generate excess surface water runoff S 298th Street S 300th Street Area does not drain to wetland Note: Project site has not been recently used for pasture or farm use. Figure 1 2.3% 1% 1.6% 2.8%0.2%0.6% 0.5% 2.3% 0.7% 1.0% 1.8% 0.4% 2625 S 298th Street Federal Way, Washington Evergreen Aquatic Wetland Delineation Mitigation Design Compliance Monitoring Resource Consultants, LLC 0 750 1500 N Accessible Habitat, Relative Undist. Habitat, & Low Intensity Land Use within 1 km of Wetland Wetland unit Accessible Undisturbed Habitat (0%) Relatively Undisturbed Habitat (10%) Moderate/Low Intensity Land Use (5.2%) 1 KM Figure 2 303d Map 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 21, 2021 0 0.25 0.50.125Miles 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 S 298th Street 12" PVC culvert 12" concrete culvert 24" concrete culvert Stream 1 1-1E to 1-20E 1-1W to 1-20W Wetland 1C WL1-201 to WL 1-210 Wetland 1A WL1-101 to WL 1-105 5 ft building setback 35 ft buffer Wetland 1B WL1-1 to WL 1-12 50 ft buffer (assumed) 5 ft building setback 50 ft buffer (assumed) 5 ft building setback 50 ft buffer (assumed) 5 ft building setback DP7 DP3 DP1 DP2 DP4 DP5 DP6 DP8 DP9 DP10 2625 S 298th Street Federal Way, Washington 01/15/2021Evergreen Aquatic Wetland Delineation Mitigation Design Compliance Monitoring Resource Consultants, LLC03060 N Delineation Notes: 1. Wetland limits are marked using pink wire stake flags. 2. Stream limits are marked using blue wire stake flags. 3 Wetland determination points are marked using orange wire stake flags. Wetland and Stream Delineation Map to Surveyor Appendix B WWHM2012 Output WWHM2012 PROJECT REPORT 20606 VSM 9-27-21 9/27/2021 12:17:11 PM Page 2 General Model Information Project Name:20606 VSM 9-27-21 Site Name: Site Address: City: Report Date:9/27/2021 Gage:Seatac Data Start:1948/10/01 Data End:2009/09/30 Timestep:15 Minute Precip Scale:1.000 Version Date:2019/09/13 Version:4.2.17 POC Thresholds Low Flow Threshold for POC1:50 Percent of the 2 Year High Flow Threshold for POC1:50 Year 20606 VSM 9-27-21 9/27/2021 12:17:11 PM Page 3 Landuse Basin Data Predeveloped Land Use Basin 1 Bypass:No GroundWater:No Pervious Land Use acre C, Forest, Mod 2.59 Pervious Total 2.59 Impervious Land Use acre Impervious Total 0 Basin Total 2.59 Element Flows To: Surface Interflow Groundwater 20606 VSM 9-27-21 9/27/2021 12:17:11 PM Page 4 Mitigated Land Use Basin 1 Bypass:No GroundWater:No Pervious Land Use acre C, Lawn, Mod 0.525 C, Lawn, Flat 0.525 Pervious Total 1.05 Impervious Land Use acre ROADS MOD 0.36 ROOF TOPS FLAT 0.9 SIDEWALKS MOD 0.12 POND 0.16 Impervious Total 1.54 Basin Total 2.59 Element Flows To: Surface Interflow Groundwater Trapezoidal Pond 1 Trapezoidal Pond 1 20606 VSM 9-27-21 9/27/2021 12:17:11 PM Page 5 Routing Elements Predeveloped Routing 20606 VSM 9-27-21 9/27/2021 12:17:11 PM Page 6 Mitigated Routing Trapezoidal Pond 1 Bottom Length:55.02 ft. Bottom Width:55.02 ft. Depth:7.17 ft. Volume at riser head:0.7905 acre-feet. Side slope 1:3 To 1 Side slope 2:3 To 1 Side slope 3:3 To 1 Side slope 4:3 To 1 Discharge Structure Riser Height:6.17 ft. Riser Diameter:18 in. Notch Type:Rectangular Notch Width:0.012 ft. Notch Height:2.122 ft. Orifice 1 Diameter:0.85 in.Elevation:0 ft. Element Flows To: Outlet 1 Outlet 2 Pond Hydraulic Table Stage(feet)Area(ac.)Volume(ac-ft.)Discharge(cfs)Infilt(cfs) 0.0000 0.069 0.000 0.000 0.000 0.0797 0.070 0.005 0.005 0.000 0.1593 0.071 0.011 0.007 0.000 0.2390 0.073 0.017 0.009 0.000 0.3187 0.074 0.022 0.011 0.000 0.3983 0.075 0.028 0.012 0.000 0.4780 0.076 0.035 0.013 0.000 0.5577 0.078 0.041 0.014 0.000 0.6373 0.079 0.047 0.015 0.000 0.7170 0.080 0.053 0.016 0.000 0.7967 0.082 0.060 0.017 0.000 0.8763 0.083 0.066 0.018 0.000 0.9560 0.084 0.073 0.019 0.000 1.0357 0.086 0.080 0.020 0.000 1.1153 0.087 0.087 0.020 0.000 1.1950 0.088 0.094 0.021 0.000 1.2747 0.090 0.101 0.022 0.000 1.3543 0.091 0.108 0.022 0.000 1.4340 0.092 0.116 0.023 0.000 1.5137 0.094 0.123 0.024 0.000 1.5933 0.095 0.131 0.024 0.000 1.6730 0.097 0.138 0.025 0.000 1.7527 0.098 0.146 0.026 0.000 1.8323 0.100 0.154 0.026 0.000 1.9120 0.101 0.162 0.027 0.000 1.9917 0.102 0.170 0.027 0.000 2.0713 0.104 0.178 0.028 0.000 2.1510 0.105 0.187 0.028 0.000 2.2307 0.107 0.195 0.029 0.000 2.3103 0.108 0.204 0.029 0.000 2.3900 0.110 0.213 0.030 0.000 2.4697 0.112 0.222 0.030 0.000 20606 VSM 9-27-21 9/27/2021 12:17:11 PM Page 7 2.5493 0.113 0.231 0.031 0.000 2.6290 0.115 0.240 0.031 0.000 2.7087 0.116 0.249 0.032 0.000 2.7883 0.118 0.258 0.032 0.000 2.8680 0.119 0.268 0.033 0.000 2.9477 0.121 0.277 0.033 0.000 3.0273 0.122 0.287 0.034 0.000 3.1070 0.124 0.297 0.034 0.000 3.1867 0.126 0.307 0.035 0.000 3.2663 0.127 0.317 0.035 0.000 3.3460 0.129 0.327 0.035 0.000 3.4257 0.131 0.338 0.036 0.000 3.5053 0.132 0.348 0.036 0.000 3.5850 0.134 0.359 0.037 0.000 3.6647 0.136 0.370 0.037 0.000 3.7443 0.137 0.380 0.037 0.000 3.8240 0.139 0.391 0.038 0.000 3.9037 0.141 0.403 0.038 0.000 3.9833 0.143 0.414 0.039 0.000 4.0630 0.144 0.425 0.039 0.000 4.1427 0.146 0.437 0.041 0.000 4.2223 0.148 0.449 0.043 0.000 4.3020 0.150 0.461 0.045 0.000 4.3817 0.151 0.473 0.048 0.000 4.4613 0.153 0.485 0.050 0.000 4.5410 0.155 0.497 0.053 0.000 4.6207 0.157 0.510 0.057 0.000 4.7003 0.159 0.522 0.060 0.000 4.7800 0.160 0.535 0.063 0.000 4.8597 0.162 0.548 0.067 0.000 4.9393 0.164 0.561 0.070 0.000 5.0190 0.166 0.574 0.073 0.000 5.0987 0.168 0.587 0.077 0.000 5.1783 0.170 0.601 0.082 0.000 5.2580 0.172 0.614 0.086 0.000 5.3377 0.173 0.628 0.090 0.000 5.4173 0.175 0.642 0.095 0.000 5.4970 0.177 0.656 0.117 0.000 5.5767 0.179 0.670 0.123 0.000 5.6563 0.181 0.685 0.130 0.000 5.7360 0.183 0.699 0.137 0.000 5.8157 0.185 0.714 0.143 0.000 5.8953 0.187 0.729 0.150 0.000 5.9750 0.189 0.744 0.157 0.000 6.0547 0.191 0.759 0.164 0.000 6.1343 0.193 0.775 0.172 0.000 6.2140 0.195 0.790 0.322 0.000 6.2937 0.197 0.806 0.865 0.000 6.3733 0.199 0.822 1.615 0.000 6.4530 0.201 0.838 2.484 0.000 6.5327 0.203 0.854 3.393 0.000 6.6123 0.205 0.870 4.259 0.000 6.6920 0.207 0.886 5.008 0.000 6.7717 0.210 0.903 5.589 0.000 6.8513 0.212 0.920 5.996 0.000 6.9310 0.214 0.937 6.360 0.000 7.0107 0.216 0.954 6.676 0.000 7.0903 0.218 0.971 6.977 0.000 20606 VSM 9-27-21 9/27/2021 12:17:11 PM Page 8 7.1700 0.220 0.989 7.266 0.000 7.2497 0.222 1.007 7.543 0.000 20606 VSM 9-27-21 9/27/2021 12:17:11 PM Page 9 Analysis Results POC 1 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area:2.59 Total Impervious Area:0 Mitigated Landuse Totals for POC #1 Total Pervious Area:1.05 Total Impervious Area:1.54 Flow Frequency Method:Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.077118 5 year 0.126364 10 year 0.158029 25 year 0.195695 50 year 0.221785 100 year 0.246155 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.046665 5 year 0.072222 10 year 0.093834 25 year 0.127365 50 year 0.157475 100 year 0.192535 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 0.089 0.034 1950 0.105 0.044 1951 0.168 0.132 1952 0.053 0.031 1953 0.043 0.037 1954 0.066 0.038 1955 0.105 0.037 1956 0.084 0.061 1957 0.068 0.038 1958 0.076 0.039 20606 VSM 9-27-21 9/27/2021 12:17:42 PM Page 10 1959 0.065 0.034 1960 0.116 0.094 1961 0.064 0.047 1962 0.040 0.031 1963 0.055 0.038 1964 0.077 0.039 1965 0.051 0.060 1966 0.049 0.036 1967 0.118 0.040 1968 0.067 0.037 1969 0.065 0.036 1970 0.052 0.038 1971 0.059 0.039 1972 0.128 0.089 1973 0.057 0.057 1974 0.063 0.039 1975 0.087 0.036 1976 0.063 0.038 1977 0.009 0.032 1978 0.053 0.042 1979 0.032 0.030 1980 0.151 0.119 1981 0.047 0.038 1982 0.098 0.067 1983 0.084 0.039 1984 0.050 0.033 1985 0.030 0.034 1986 0.132 0.051 1987 0.117 0.077 1988 0.046 0.034 1989 0.030 0.033 1990 0.279 0.103 1991 0.148 0.084 1992 0.060 0.045 1993 0.059 0.033 1994 0.020 0.029 1995 0.085 0.046 1996 0.196 0.134 1997 0.151 0.142 1998 0.037 0.033 1999 0.165 0.088 2000 0.059 0.041 2001 0.011 0.028 2002 0.068 0.058 2003 0.102 0.036 2004 0.109 0.124 2005 0.081 0.038 2006 0.091 0.060 2007 0.211 0.189 2008 0.257 0.127 2009 0.120 0.056 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.2793 0.1891 2 0.2573 0.1416 3 0.2111 0.1340 20606 VSM 9-27-21 9/27/2021 12:17:42 PM Page 11 4 0.1956 0.1316 5 0.1685 0.1272 6 0.1655 0.1236 7 0.1509 0.1187 8 0.1506 0.1027 9 0.1481 0.0939 10 0.1321 0.0891 11 0.1279 0.0879 12 0.1200 0.0837 13 0.1184 0.0772 14 0.1166 0.0673 15 0.1163 0.0608 16 0.1087 0.0598 17 0.1054 0.0596 18 0.1048 0.0579 19 0.1018 0.0572 20 0.0977 0.0557 21 0.0908 0.0508 22 0.0888 0.0472 23 0.0875 0.0461 24 0.0846 0.0448 25 0.0844 0.0436 26 0.0835 0.0423 27 0.0807 0.0415 28 0.0775 0.0395 29 0.0757 0.0394 30 0.0682 0.0393 31 0.0681 0.0392 32 0.0667 0.0391 33 0.0656 0.0390 34 0.0649 0.0384 35 0.0649 0.0382 36 0.0639 0.0381 37 0.0628 0.0379 38 0.0625 0.0378 39 0.0605 0.0378 40 0.0590 0.0377 41 0.0588 0.0373 42 0.0588 0.0373 43 0.0567 0.0368 44 0.0546 0.0363 45 0.0529 0.0362 46 0.0528 0.0361 47 0.0521 0.0359 48 0.0515 0.0343 49 0.0503 0.0342 50 0.0495 0.0341 51 0.0473 0.0339 52 0.0461 0.0334 53 0.0427 0.0331 54 0.0398 0.0327 55 0.0369 0.0327 56 0.0320 0.0321 57 0.0305 0.0312 58 0.0299 0.0307 59 0.0198 0.0297 60 0.0106 0.0292 61 0.0092 0.0281