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coterra 321 3rd Avenue South, Suite 406 Seattle, Washington 98104 206.596.7115 TECHNICAL INFORMATION REPORT Project: Habitat For Humanity Seattle/King County La Fortuna Phase III Renton, WA 98058 Prepared For: Tonkin Architecture 2701 1st Ave #520 Seattle, WA 98121 Prepared By: Max Berde, PE Reviewed By: Peter Apostol, PE Date: May 22, 2020 ENGINEERING PLLC APPROVED 06/03/2020 msippo DEVELOPMENT ENGINEERING DIVISION SURFACE WATER UTILITY jfarah 06/03/2020 TABLE OF CONTENTS Section No. Subject Page No. SECTION I PROJECT OVERVIEW .....................................................................1 SECTION II CONDITIONS AND REQUIREMENTS SUMMARY .....................7 SECTION III OFFSITE ANALYSIS ......................................................................11 SECTION IV FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN ..........................................15 SECTION V CONVEYANCE SYSTEM ANALYSIS AND DESIGN ................17 SECTION VI SPECIAL REPORTS AND STUDIES .............................................19 SECTION VII OTHER PERMITS ...........................................................................19 SECTION VIII EROSION AND SEDIMENT CONTROL ......................................19 SECTION IX BOND QUANTITIES AND DECLARATION OF COVENANTS ...............................................21 SECTION X OPERATIONS AND MAINTENANCE MANUAL .......................22 LIST OF FIGURES FIGURE 1 VICINITY MAP .................................................................................3 FIGURE 2 TIR WORKSHEET ............................................................................4 FIGURE 3 EXISTING SITE SOILS...................................................................11 FIGURE 4 EXISTING SITE AREAS.................................................................15 FIGURE 5 PROPOSED SITE AREAS...............................................................16 LIST OF APPENDICIES APPENDIX A CIVIL PLANS APPENDIX B FLOW CONTROL/DETENTION CALCULATIONS APPENDIX C WATER QUALITY CALCULATIONS APPENDIX D CONVEYANCE CALCULATIONS APPENDIX E DRAINAGE REVIEW FLOWCHART APPENDIX F BOND QUANTITY WORKSHEET APPENDIX G DECLARATION OF COVENTANTS APPENDIX H OPERATIONS AND MAINTENANCE MANUAL APPENDIX I EROSION CONTROL CALCULATIONS APPENDIX J SPECIAL REPORTS AND STUDIES La Fortuna Phase III Page 1 Project No. 19006 Renton, WA Coterra Engineering PLLC SECTION I – PROJECT OVERVIEW General Description: The current phase of the proposed La Fortuna Townhomes project includes the construction of three multi-story townhome buildings, totally twelve additional units, on a partially developed 4.51 acre site. The proposed project includes associated parking areas and development of several open space areas. Included in the project are landscape and street lighting improvements, as well as associated storm drainage and utility improvements for the proposed residential buildings. Existing improvements including the private access drive and water and sewer mains were installed previously with the first phase of the La Fortuna Townhomes project. The project site is located on 173th Ave SE – a private road, south of SE 172nd St and north of SE Petrovisky Rd in the City of Renton, WA. See Figure 1 for Vicinity Map. The proposed project has been designed to meet the requirements of the 2017 City of Renton Surface Water Design Manual (SWDM). A summary of the project data is provided in the TIR worksheet (see Figure 2). Site Soils: Per the project geotechnical report, prepared by South Sound Geotechnical Consulting, and dated July 31, 2019, fill was discovered at all geotechnical borings to an approximate depth of 3 ft. Below the fill layer, native soils consist of silty sand with gravel and occasional cobbles. Per the geotechnical report, it is “medium dense condition below the surface soils and graded dense at shallow depth. This soil is interpreted to be glacial till and continued to the termination depth of the test pits.” For more information, see the geotechnical report included in Appendix J. Predeveloped Conditions: The overall project site is partially developed from a previous phase of the La Fortuna Townhomes project. The existing site conditions of the current phase – totaling 1.14 acres – consists of mostly stripped, cleared, and graded land. For the purposes of storm drainage modelling, the existing site condition is forested. The project site consists of one Threshold Discharge Area which is defined by the City of Renton Surface Water Design Manual as: “an onsite area draining to a single natural discharge location, or multiple natural discharge locations that combine within one- quarter –mile downstream.” The existing land coverage of the project site is presented in the table below. The downstream path of stormwater runoff is described in the offsite analysis in Section III. Table 1 – Existing Site Land Coverage for Storm Drainage Modeling (Acres) Impervious (Acres) Pervious Till Forest (Acres) Total (Acres) La Fortuna Ph III 0.00 1.14 1.14 La Fortuna Phase III Page 2 Project No. 19006 Renton, WA Coterra Engineering PLLC Developed Conditions: The proposed developed condition includes three townhome buildings; paved parking areas; pedestrian walkways; and associated storm drainage, utility, and landscape improvements. The following table quantifies the areas of the proposed land coverage for the Habitat La Fortuna Phase III project. Proposed site areas are shown visually in Figure 5. Table 2 – Developed Site Land Coverage (Acres) Rooftop (Acres) Parking PGIS (Acres) Hardscape (Acres) Landscape (Acres) Total (Acres) La Fortuna Ph III 0.19 0.25 0.08 0.62 1.14 The existing site topography will not be dramatically altered in the proposed condition. In general, the site will continue to drain from north to the southwest to the existing wetland. The proposed improvements within the project site described above and delineated in Table 2 trigger both flow control and water quality mitigation per the City of Renton Surface Water Design Manual. Stormwater runoff will be collected by roof drains, catch basins, and area drains. Per Core Requirement #4 of the 2017 City of Renton Surface Water Design Manual, the proposed conveyance system will be designed to convey runoff resulting from the peak rates resulting from the 25-year storm event. The proposed storm drainage design for La Fortuna Phase III consists of three separate mitigation methods for portions of the proposed site. A detention tank is proposed under the east parking lot and which will discharge to the existing wetland west of the project site. The central parking lot will use full dispersion into the existing native vegetation onsite as well as wetland areas to mitigate for both flow control and water quality requirements. Bioretention cells will treat stormwater and help attenuate flows from stormwater runoff in the northwest and eastern parking lots. See Section IV for a detailed description of the design of the flow control and water quality facilities. La Fortuna Phase III Page 3 Project No. 19006 Renton, WA Coterra Engineering PLLC FIGURE 1 – VICINITY MAP PROJECT SITE La Fortuna Phase III Page 4 Project No. 19006 Renton, WA Coterra Engineering PLLC FIGURE 2 CITY OF RENTON TECHNICAL INFORMATION REPORT (TIR) WORKSHEET CITY OF RENTON SURFACE WATER DESIGN MANUAL 2017 City of Renton Surface Water Design Manual 12/12/2016 8-A-1 REFERENCE 8-A 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 __________________________ CED Permit # ________________________ Location Township ________________ Range __________________ Section _________________ Site Address __________________________ _____________________________________ Part 3 TYPE OF PERMIT APPLICATION Part 4 OTHER REVIEWS AND PERMITS Land Use (e.g., Subdivision / Short Subd.) Building (e.g., M/F / Commercial / SFR) 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 ____________________________________ __________________ Habitat for Humanity (425)453-2950 560 Naches Ave SW Suite 110 Seattle,WA 98057 PETER APOSTOL,PE COTERRA ENGINEERING,PLLC (206)596-7115 Habitat La Fortuna Phase III 23N 5E 28 12710-12748 SE 173rd Street, 17210-17324 127th Street SE RENTON,WA 980058 X X X X X 10/15/2019 (LAND USE) 01/22/2020 (CCR) 04/08/2020 (CCR REV) 10/15/2019 (LAND USE) 01/22/2020 (CCR) 04/08/2020 (CCR REV) C20-000611 REFERENCE 8: PLAN REVIEW FORMS AND WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 12/12/2016 2017 City of Renton Surface Water Design Manual 8-A-2 Part 6 SWDM ADJUSTMENT APPROVALS Type (circle one): Standard / Blanket Description: (include conditions in TIR Section 2) ____________________________________________________________________________________ ____________________________________________________________________________________ ____________________________________________________________________________________ Approved Adjustment No. ______________________ Date of Approval: _______________________ Part 7 MONITORING REQUIREMENTS Monitoring Required: Yes / No Start Date: _______________________ Completion Date: _______________________ Describe: _________________________________ _________________________________________ _________________________________________ Re: SWDM 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 ______________________ _____________________________________ SOOS CREEK SUB BASIN:SOOS CREEK MAIN MIN REQUIREMENTS #1 -#9;ENHANCED BASIN WQ TREATMENT RENTON X SEE BELOW WETLANDS: "WETLAND A"-CATEGORY II "WETLAND B"-CATEGORY III "WETLAND C"-CATEGORY III REFERENCE 8-A: TECHNICAL INFORMATION REPORT (TIR) WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 2017 City of Renton Surface Water Design Manual 12/12/2016 Ref 8-A-3 Part 10 SOILS Soil Type ______________________ ______________________ ______________________ ______________________ Slopes ________________________ ________________________ ________________________ ________________________ Erosion Potential _________________________ _________________________ _________________________ _________________________ High Groundwater Table (within 5 feet) Other ________________________________ Sole Source Aquifer Seeps/Springs Additional Sheets Attached 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) Standard: _______________________________ or Exemption Number: ____________ On-site 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: _________________________ AmC -ARDENTS,ALDERWOOD MATERIALS 6 -15%LOW SITE CORE REQUIREMENTS #1 -#9 1 FLOW CONTROL DURATION STANDARD -FORESTED REQUIRED MEF PER CORE REQUIREMENT #9 TBD Sk -Seattle muck 0 -5%LOW AgC -Alderwood gravelly sandy loam 8 -1 5%LOW EX ONSITE SOILS HAVE LOW INFILTRATION CAPACITY EX ONSITE WETLANDS (3) JAN 28,2020 12710-12748 SE 173rd Street,RENTON,WA 980058 REFERENCE 8: PLAN REVIEW FORMS AND WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 12/12/2016 2017 City of Renton Surface Water Design Manual 8-A-4 Part 12 TIR SUMMARY SHEET (provide one TIR Summary Sheet per Threshold Discharge Area) 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. _______________________ Special Requirements (as applicable): Area Specific Drainage Requirements Type: SDO / MDP / BP / 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: Source Control (commercial / 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: MULTI-FAMILY DETENTION FACILITY -DETENTION TANK -East parking area mitigated by detention tank discharging to existing wetland. DETENTION FACILITY -DETENTION VAULT -Runoff from proposed townhome buildings route to existing detention vault which has additional capacity based on original planned condition. TRASH ENCLOSURE DRAIN INCLUDES DOWNTURN ELBOW AND ROUTES TO SANITARY SEWER REFERENCE 8-A: TECHNICAL INFORMATION REPORT (TIR) WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 2017 City of Renton Surface Water Design Manual 12/12/2016 Ref 8-A-5 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 Control Pollutants Protect Existing and Proposed BMPs/Facilities Maintain Protective 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 BMPs/Facilities, restore operation of BMPs/Facilities as necessary Flag limits of sensitive areas 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 On-site BMPs Other ________________ ________________ ________________ ________________ ________________ ________________ Vegetated Flowpath Wetpool Filtration Oil Control Spill Control On-site BMPs Other ________________ ________________ ________________ ________________ ________________ ________________ ________________ 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 _______________________________ X X X X XX X X X X X X X DETENTION TANK / EX DETENTION VAULT X X BIORETENTION CELLS X BIORETENTION CELLS X X X X X X X FULL DISPERSION X 100'FLOW PATH THROUGH NATIVE VEGETATION FROM DISPERSION DEVICE REFERENCE 8: PLAN REVIEW FORMS AND WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 12/12/2016 2017 City of Renton Surface Water Design Manual 8-A-6 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 5/13/2020 La Fortuna Phase III Page 6 Project No. 19006 Renton, WA Coterra Engineering PLLC FIGURE 3 – EXISTING SITE SOIL CONDITIONS La Fortuna Phase III Page 7 Project No. 19006 Renton, WA Coterra Engineering PLLC SECTION II – CONDITIONS AND REQUIREMENTS SUMMARY The proposed project is subject to a Full Drainage Review per the 2017 City of Renton Surface Water Design Manual and is therefore subject to all nine core requirements and all six special requirements. These requirements are listed below along with a discussion of their applicability to this project. See Appendix E for drainage review type flow chart. Core Requirements: Req. #1 Discharge at Natural Location: Existing discharge locations will be maintained; existing site runoff flows to existing onsite wetlands on the southwest portion of the site which eventually drain from the property to the south, entering the Soos Creek Basin. Req. #2 Offsite Analysis: See Section III below. Req. #3 Flow Control: The project is required to meet the Flow Control Duration Standard (Forested Condition). The proposed improvements exceed the threshold of 5,000 sf of new and replaced impervious surface, therefore triggering the requirement of a flow control facility and on-site flow control BMPs. Onsite BMPs are also required as part of the project and are discussed below in Core Requirement #9. For further details see Section IV. Req. #4 Conveyance System: The new conveyance system has been designed to convey the 25-year peak flow from the developed site conditions. Conveyance calculations are included with this submittal for each of the separate onsite basins. La Fortuna Phase III Page 8 Project No. 19006 Renton, WA Coterra Engineering PLLC Req. #5 Erosion and Sediment Control: Construction erosion and sediment control systems are included with this submittal and are shown on the TESC Plan. Req. #6 Maintenance and Operations: A Declaration of Covenant is required for this project for the maintenance and operation of the proposed onsite storm drainage facilities and on-site stormwater BMPs. A draft of the Declaration of Covenant is provided in Appendix G. The proposed facilities will be owned and maintained by Habitat For Humanity. An Operations and Maintenance Manual is included in Appendix H. Req. #7 Financial Guarantees: A financial guarantee will be necessary for this project. Bonding will be required for the construction of improvements and will be obtained prior to construction. Req. #8 Water Quality: The proposed improvements located on the project site exceed 5,000 sf of new and replaced Pollution-Generating Impervious Surface (PGIS), therefore triggering the requirement of a water quality facility. Based on the proposed site usage, multi-family housing, Enhanced Basic Water Quality treatment is required per Core Requirement #8 of the 2017 City of Renton Surface Water Design Manual for targeted PGIS. Bioretention cells are proposed to provide water quality treatment of targeted pollution-generating impervious surfaces in the proposed parking lots (Basins A & C) Additionally, the central parking lot (Basin B) is mitigated via full dispersion of stormwater into native vegetative area. The use of full dispersion allows the new pollution-generating impervious surfaces to no longer be considered a targeted surface for Core Requirement #8. For further details see Section IV. La Fortuna Phase III Page 9 Project No. 19006 Renton, WA Coterra Engineering PLLC Req. #9 On-Site BMPs: The proposed improvements exceed the threshold of 5,000 sf of new and replaced impervious surface, therefore triggering the requirements of Core Requirement #9 to implement on-site flow control facilities to the maximum extent feasible. Following the City of Renton SWDM required list method for Large Lots implementing on-site BMPs (C1.3.2) to comply with Core Requirement #9, all onsite BMPs were considered per the list approach in the SWDM. Full dispersion is being utilized for a portion of the site to mitigate for new targeted surfaces. Additionally, although not on-site BMPs, two bioretention cells are proposed to mitigate additional areas of new targeted surfaces. For further details see Section IV. Special Requirements: Req. #1 Area Specific Requirements: No known area specific requirements. Req. #2: Floodplain/Floodway Delineation This project is not adjacent to any floodplains or floodways. Therefore no delineation is necessary. Req. #3 Flood Protection Facilities: This project is not adjacent to any applicable areas and will not affect any applicable facility. Req. #4 Source Controls: This project is a multi-family project and will provide appropriate source controls per King County recommendations for multi-family projects including containment and proper storage of chemicals and structural measures to prevent the release of pollutants to waterways. The proposed trash enclosure drains to a separate catch basin with a downturn elbow to capture oils and the outlet drains to the sanitary sewer. La Fortuna Phase III Page 10 Project No. 19006 Renton, WA Coterra Engineering PLLC Req. #5 Oil Control: No oil control requirements are applicable to this project. Req. #6 Aquifer Protection Area The proposed project site is not located within an Aquifer Protection Area. La Fortuna Phase III Page 11 Project No. 19006 Renton, WA Coterra Engineering PLLC SECTION III – OFFSITE ANALYSIS Task 1 – Study Area Definition and Maps Maps of the project site and surrounding area were obtained from the King County GIS website. Topographical site information is from the topographical survey for the project. Storm drainage system maps were compiled from City of Renton GIS maps and as-built plans. Aerial images were obtained from Google Earth. The downstream analysis is further illustrated and detailed in the Downstream Map and Downstream Table. The downstream area was evaluated by reviewing available resources, and by conducting field reconnaissance. The downstream analysis began at Point “A” on the map located approximately 90 feet to the east of the southwesterly most corner of the Site. The runoff leaves the Site as southerly flow and is collected in a detention tank located in the southwestern corner of the Site. The outlet of this tank drains to the wetland located to the east of the Site and at Point “B” on the map. This wetland is approximately 270 ft. by 700 ft. and drains south for 480 ft. into two 42” culverts located at Point “C.” These culverts are equipped with debris racks and run beneath Petrovitsky Rd. with a length of 106 ft until reaching a channel located at Point “D.” This channel is approximately 88 ft. wide and flows 328 ft. until it reaches a much larger wetland located south of the Site. The offsite analysis was ended at Point “C” due to the inaccessibility of the channel south of Petrovitsky Rd. due to private property on both sides of the channel. Task 2 – Resource Review The City of Renton Public Works Department was contacted regarding the resources listed in section 2.3.1.1 of the 2017 City of Renton Surface Water Design Manual. The following is a summary of the resource review: Adopted Basin Plans o City of Renton Basin Name: Soos Creek Basin Reconnaissance Summary Reports o None completed to our knowledge. Floodplain/Floodway (FEMA) Maps o The site is not within a floodplain or floodway per FEMA mapping. Other Offsite Analysis Reports o The previous Technical Information Report for the project site -- which was partially developed in 2004 -- was reviewed and referenced in the current project design. La Fortuna Phase III Page 12 Project No. 19006 Renton, WA Coterra Engineering PLLC Environmentally Sensitive Areas Map o There are three mapped wetlands located on the project site. USDA Soils Survey o A geotechnical investigation report has been completed and site soils are primarily medium dense sand with silt that was underlain by impermeable glacial till soil. Wetlands Inventory Maps o There are three mapped wetlands on the project site to the west of the construction limits which the proposed project stormwater discharges to. The wetland boundaries were recently inspected and re-delineated by a wetland biologist. The Wetland Delineation Report is provided in Appendix J. o There are two wetlands located within one mile downstream of the project site. Soos Creek Wetland No. 13-B: located approximately 1/8th mile downstream from project site. Soos Creek Wetland No. 2: located approximately ¾ mile downstream from project site. Task 3 – Field Inspection A site visit was conducted on January 28, 2020 by Coterra Engineering from 10:00 a.m. to 12:00 p.m. for the purpose of analyzing the project site and its upstream and downstream corridors. The weather conditions were overcast with a temperature of 52 degrees Fahrenheit and light sprinkling throughout the visit. The following is a summary of a full Level 1 downstream analysis performed for civil construction permit submittal. 1. The project site lies to the east and southeast of the existing residential structures. The current site discharges to the detention facility located in the southwestern corner of the site which then discharges to the wetland located the west of the site. 2. During wet weather, it was observed that runoff from land located east of the site was flowing onto the project site. Drains behind the proposed retaining wall along the eastern property line of the project site are proposed to intercept and mitigate any offsite run-on. 3. There were no signs of significant destruction of habitat or organisms. It was noted that there have been 4 drainage complaints associated with the downstream system, but in consultation with Mike Sippo, City of Renton Development Review Engineer, the drainage complaints were not applicable due to the age of the complaints being older than 10 years ago. La Fortuna Phase III Page 13 Project No. 19006 Renton, WA Coterra Engineering PLLC Task 4 – Drainage System Description and Problem Description There are no known problems with the downstream system. Task 5 – Mitigation of Existing or Potential Problems Based on the requirements for the design of the proposed drainage systems, no negative impacts to the systems downstream of the project site are anticipated. Existing Upslope Drainage Areas Although some visible amount of surface runoff was observed from the adjacent upslope property during the field visit, it is not considered to be a significant source of upslope run-on. The proposed retaining wall design at the eastern property line includes drains to intercept upslope flow. La Fortuna Phase III Page 14 Project No. 19006 Renton, WA Coterra Engineering PLLC FIGURE 1 – DOWNSTREAM SYSTEM OFF-SITE ANALYSIS DRAINAGE SYSTEM TABLE KING COUNTY SURFACE WATER DESIGN MANUAL, CORE REQUIREMENT #2 Basin: Subbasin Name: Subbasin Number: Date Symbol Drainage Component Type, Name, and Size Drainage Component Description Slope Distance from site discharge Existing Problems Potential Problems Observations of field inspector, resource reviewer, or resident see map Type: sheet flow, swale, stream, channel, pipe, pond, flow control/wq BMP; Size: diameter, surface area drainage basin, vegetation, cover, depth, type of sensitive area, volume % ¼ ml = 1,320 ft. constrictions, under capacity, ponding, overtopping, flooding, habitat or organism destruction, scouring, bank sloughing, sedimentation, incision, other erosion tributary area, likelihood of problem, overflow pathways, potential impacts 2016 Draft Surface Water Design Manual 4/24/2016 Soos Creek 05-14-2020SoosCreekMain A Detention vault discharging to existing wetland. Site runoff will be collected by roof drains,catch basins, and area drains.The proposed detention vault will discharge to the existing wetland west of the project site.The wetland is approximately 270 ft by 700 ft and drains south. +-2%0 -480 ft. B Wetland flows into stormwater Culvert;42-in diameter and length of 106 ft. +-2%480 -592 ft.The existing wetland drains to a 42"culvert that runs beneath Petrovitsky Rd. C Culvert discharging into a southerly flowing channel. 0.6%592 ft.+The discharge from the culvert enters a channel approx.88 ft.wide and flows 328 ft.until it reaches another large wetland located to the south of the site. PROJECT:HABITAT LA FORTUNA PH III OFF-SITE ANALYSIS DRAINAGE SYSTEM TABLE KING COUNTY SURFACE WATER DESIGN MANUAL, CORE REQUIREMENT #2 Basin: Subbasin Name: Subbasin Number: Date Symbol Drainage Component Type, Name, and Size Drainage Component Description Slope Distance from site discharge Existing Problems Potential Problems Observations of field inspector, resource reviewer, or resident see map Type: sheet flow, swale, stream, channel, pipe, pond, flow control/wq BMP; Size: diameter, surface area drainage basin, vegetation, cover, depth, type of sensitive area, volume % ¼ ml = 1,320 ft. constrictions, under capacity, ponding, overtopping, flooding, habitat or organism destruction, scouring, bank sloughing, sedimentation, incision, other erosion tributary area, likelihood of problem, overflow pathways, potential impacts 2016 Draft Surface Water Design Manual 4/24/2016 05-14-2020 D Southerly flowing channel discharges to large wetland south of the site. The wetland has an approx. area of 2,280 ft^2 and connects to another wetland that streches both north and south on the east side of the site. +-2%920 ft.-1320 ft. Soos Creek Soos Creek Main PROJECT:HABITAT LA FORTUNA PH III La Fortuna Phase III Page 15 Project No. 19006 Renton, WA Coterra Engineering PLLC SECTION IV – FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN Flow Control The project site is located in the Flow Control Duration Standard (Forested Conditions) area per the 2017 City of Renton Surface Water Design Manual. The proposed improvements will create more than 2,000 SF of new plus replaced imperious surfaces, therefore the project is required to meet the flow control durations standard and implement on-site flow control BMPs. The existing onsite detention vault has been analyzed to determine excess storage capacity and utilized with this excess capacity for the detention of runoff from the three proposed townhome buildings basin (Townhome Basin). The existing vault was sized to accommodate the full build out of the project site including the impervious surfaces (buildings) that were not constructed during Phase I of the development. See further discussion and analysis of the existing on-site detention vault below. MGS Flood stormwater modeling program – utilizing a continuous hydrologic model – was implemented to size and analyze proposed detention facilities which are required to match the existing site condition (forested) flow duration from ½ the 2 year flow through the 50 year duration flow standard. Flow control mitigation to meet the Flow Control Duration Standard (Forested) for targeted surfaces on the project site are summarized below (see Figure 5 – Developed Site Map): Basin B – Central Parking Area This is a targeted surface for both flow control and water quality, totaling approximately 4618 SF of asphalt parking lot in the center portion of the site (see Figure 5). Located directly adjacent to the wetland buffer and a vegetative area, this targeted impervious surface is proposed to be mitigated for flow control and water quality requirements by full dispersion from a gravel-filled trench located just southwest of the sub-basin. Runoff in the basin is collected in a catch basin and tight-lined to the 50 LF gravel-filled trench per City of Renton SWDM standards for dispersion devices. Runoff is dispersed by the trench over a 50’ area and then disperses flowing down existing native vegetation and through the mapped wetland buffer as allowed by City of Renton SWDM. Per SWDM C2.1.5, a 50 LF gravel-filled trench with 100’ flowpath length can mitigate up to 5,000 SF of targeted impervious surface area. Based on the tributary area of impervious surface draining to the proposed dispersion trench, this BMP successfully provides full dispersion of the new impervious area in Basin B. By implementing full dispersion, the new impervious surfaces in Basin are no longer considered targeted surface for flow control and water quality requirements. coterra 321 3rd Avenue South, Suite 406Seattle, Washington 98104206.596.7115 coterraengineering.com ENGINEERING PLLC NATIVE VEGETATIONAREA MIN. AREAREQUIRED 33,000 SFcoterra 321 3rd Avenue South, Suite 406Seattle, Washington 98104206.596.7115 coterraengineering.com ENGINEERING PLLC La Fortuna Phase III Page 16 Project No. 19006 Renton, WA Coterra Engineering PLLC As required by the SWDM for full dispersion implementation and targeted surface area credit, an onsite area of native vegetation – calculated at a minimum of 6.66x the impervious surface area mitigated by the full dispersion – must be delineated and recorded by easement or covenant to remain as native vegetation area. Project surveyor will provide native vegetation easement for review and recording to City of Renton as required. Basin C – East Parking Area and Playground Runoff targeted for flow control from Basin C is mitigated by a detention tank located under the asphalt parking lot. The detained and mitigated stormwater from the detention tank in Basin C is conveyed west under the central site parking area and outfalls at the edge of the delineated buffer of Wetland B with appropriate rock outfall protection.d Based on the MGS Flood analysis, 2,553 cubic feet of storage is required to detain the runoff from the east parking lot and future playground area in Basin C. The project proposes a detention tank consisting of 135 LF of 5’ diameter pipe. The proposed detention tank was designed per the City of Renton SWDM requirements including 0.5’ sediment storage (dead storage). The proposed tank details are shown on the Storm Drainage Plan and Civil Details sheets. The MGS Flood calculations are included in Appendix B of this report. Townhouse Basin and Basin A – Northwest Parking Area Runoff from the proposed townhome buildings and associated yard areas along with treated runoff from Basin A, located at the northwest corner of the project, will be collected by catch basins, area drains, and downspouts and routed via tightline pipe to the existing detention vault at the far southwest of the La Fortuna site. The existing detention vault was designed and constructed during the first phase of the Habitat for Humanity La Fortuna development. It was designed to mitigate for flow control and water quality requirements for the full build-out of the 4.51 acre site. Only a portion of the site was built out in the initial phase of construction. Based on review and analysis of the original stormwater design and Technical Information Report, prepared by D.R. Strong Consulting Engineers, Inc. in 2004 – it was determined that the existing detention vault has additional live storage capacity for a portion of the flow control mitigation of this project. Routing the stormwater runoff from the Townhouse Basin and Basin A to the existing vault and flow control structure will provide sufficient storage capacity to meet the flow control duration standard that is required per the City of Renton SWDM for the new targeted areas on the La Fortuna Phase III project. Basin A was originally bypass area in the 2004 storm drainage design and discharged to Wetland B instead of the onsite detention vault. Because Basin A was originally considered bypass area, the proposed developed surfaces in Basin A for the current project phase is considered to be previously mitigated and are not included in the Phase III mitigation calculations. La Fortuna Phase III Page 17 Project No. 19006 Renton, WA Coterra Engineering PLLC See Table 3 below for a summary of the existing detention vault capacity, required detention volume for Phase I, and the additional required detention volume for the current project phase, La Fortuna Phase III. Table 3 – Existing Detention Vault Volume Analysis Volume (Cubic Feet) Flow Control Performance Standard Targeted Impervious Area ( Acres) Targeted Pervious Area ( Acres) Existing Detention Vault As-Built Capacity Per 2008 TIR Addendum By D.R. Strong Consulting Engineers Inc. 19,400 CF Required Detention Volume For Phase I Build Out 9,149 CF 1998 King County Level I Flow Control (Match Existing Peaks) 1.015 AC 0.212 AC Required Detention Volume For Phase III Targeted Surfaces Tributary To Detention Vault 8,713 CF 2017 City of Renton SWDM Flow Control Duration (Forested) Standard 0.29 AC 0.28 AC Total Volume Required 17,862 CF La Fortuna Phase I was originally designed and permitted in 2004 and 2005 under King County jurisdiction and following the stormwater code from the 1998 King County Surface Water Design Manual. Required flow control mitigation at the time required matching of the 2-year and 10-year developed condition peak flow rates to the pre- developed flows of the same intervals. Existing land cover surfaces, which was primarily till pasture on the site, were considered the pre-developed condition for stormwater modeling purposes, per the 1998 manual. Based on the amount of the Phase I site which was developed originally in the first phase, as shown in Table 3 above and on Figure 4, the required detention volume to meet the flow control requirement was calculated using MGS Flood. That volume, 9,149 cubic feet of detention storage, is shown above. See Appendix B for additional calculations. For the current phase of the project, the additional proposed targeted areas of impervious and pervious surfaces were calculated and are shown above in Table 3 and on Figure 5. As the rest of the proposed project areas were already mitigated with other stormwater BMPs, only the Townhouse Basin needed to be routed and detained in the existing detention vault. Following the current stormwater code in the City of Renton, the required detention volume to meet the flow control duration standard was calculated for the additional area flowing to the existing detention vault. Per the 2017 SWDM, the existing site condition for detention calculations was assumed to be forested. La Fortuna Phase III Page 18 Project No. 19006 Renton, WA Coterra Engineering PLLC The required volume to mitigate the flow control requirement for the Townhouse Basin was calculated in MGS Flood using a duration analysis and was determined to be 8,713 cubic feet of storage capacity. As shown above in Table 3, the required detention storage volume for flow control mitigation of both Phase I and Phase III is 17,862 cubic feet – which is less than the existing detention vault capacity of 19,400 cubic feet per D.R. Strong’s 2008 TIR addendum. The existing on-site detention vault has sufficient capacity to detain the required developed site flows and meet the performance standards for the developed site areas as designed and constructed in Phase I and Phase III. Detention vault sizing calculations are provided in Appendix B. The original project TIR including details of the existing detention vault design are provided in Appendix J. On-Site Flow Control BMPs The proposed site is classified as a Large Lot BMP Site as the proposed site is over 22,000 SF. Implementation of On-Site Flow Control BMPs is therefore required per Core Requirement #9. On-site BMPs are evaluated for targeted surfaces, per the list from section 1.2.9.2.2 for Large Lot BMP Projects in the 2017 City of Renton Surface Water Design Manual. Analysis of feasibility of the on-site BMPs from the SWDM list follow in order per SWDM feasibility determination instructions. Full Dispersion: Feasible. The targeted new impervious surface from the central parking lot – shown as Basin B in Figure 5, Propose Site Areas — is mitigated by full dispersion to the adjacent native vegetative area and wetland to the west of the proposed development area of the project site. Utilizing full dispersion decreases the overall area of targeted surfaces for required stormwater mitigation. Sizing calculations for the dispersion trench are included in Appendix B. Full Infiltration: Infeasible. Per Minimum Design Requirements for Full Infiltration in section C.2.2.2, existing soils must be “coarse sands or cobbles or medium sands.” Soils collected in on-site borings per geotechnical report prepared South Sound Geotechnical Consulting dated 7/31/2019, are classified as “silty sand with gravel and occasional cobbles.” This soil was interpreted by the geotechnical engineer as glacial till. These soils were found at a depth of typical on-site infiltration facilities or infiltration BMPs. Limited Infiltration: Infeasible. As described above, the geotechnical investigation has determined that the project site is underlain by glacial till and “Infiltration to assist in stormwater control is not considered feasible at this site. The dense glacial till at shallow depth will create a barrier to vertical groundwater flow.” La Fortuna Phase III Page 19 Project No. 19006 Renton, WA Coterra Engineering PLLC Bioretention: Infeasible as an Onsite BMP. Bioretention is proposed to mitigate runoff from PGIS parking areas in the propose project. Permeable Pavement: Infeasible. Permeable concrete pavement is not proposed on the project site due to poorly-infiltrating site soils. Basic Dispersion: o Splash blocks: Infeasible. Required 50’ vegetated flow path from proposed structures is infeasible based on proposed site design. Required flow path length for basic dispersion could be routed within wetland buffer but splash blocks only used for roof downspouts. Project is not proposing structures adjacent to wetland buffer area. o Rock pads: Infeasible. Required 50’ vegetated flow path is infeasible based on proposed site design. Required flow path length for basic dispersion could be routed within wetland buffer but rock pads generally used to mitigate roof downspout runoff. No applicable for proposed site design. o Gravel-filled trenches: Feasible. Basic dispersion by gravel-filled trench is proposed for runoff from central parking lot and associated hardscape (Basin B). Runoff disperse via gravel-filled trench per COR requires to the native vegetation in the wetland buffer and wetland to the west. o Sheet flow: Infeasible. Required 10’ vegetated flow path located on the project property is infeasible based on proposed site design. Soil Amendment: Feasible. New and replaced pervious surfaces within the project limits will implement soil amendment per the soil quality and depth requirements of section C2.13. Following the list to for applying onsite BMPs for a Large Lot Site per the City of Renton SWDM, the proposed project is applying stormwater BMPs to the maximum extent feasible for this site containing non-infiltrating glacial till and a significant amount of wetlands. Water Quality The proposed new and replaced pollution-generating impervious surfaces (PGIS) on the project site trigger the requirement for water quality treatment of targeted surfaces. Per the City of Renton SWDM, the project site is within the Basic Water Quality Area; but the proposed site land use of multi-family housing triggers the Enhanced Basic Water Quality Menu. The proposed project will provide mitigation of targeted PGIS using bioretention cells to provide water quality treatment meeting the Enhanced Basic requirement and meeting the 91% volume standard per Minimum Requirement #9 of the SWDM. All proposed PGIS in the current phase of development that is not fully dispersed is treated via bioretention. La Fortuna Phase III Page 20 Project No. 19006 Renton, WA Coterra Engineering PLLC As described previously, the targeted impervious surfaces in the central parking lot (Basin B) – which are considered pollution-generating – are being mitigated for both flow control and water quality requirements through the use of full dispersion of runoff to the protected native vegetation directly to the west and continuing into the existing wetland buffer. By meeting all the requirements for full dispersion, the new PGIS surfaces in Basin B are no longer considered targeted surfaces for flow control or water quality treatment requirements. Area summary of the project’s proposed PGIS surfaces and proposed bioretention areas is below. Full water quality calculations for bioretention cells are provided in Appendix C. All proposed bioretention cells are 3:1 side slopes and 6” of ponding depth. Basin A – Northwest Parking Area Targeted PGIS Area: 2120 SF (0.05ac) Bioretention Cell Min. Required Bottom Area: 24 SF Bioretention Cell Per Plans Provided Bottom Area: 138 SF Basin C – East Parking Area Targeted PGIS Area: 2678 SF (0.061ac) Bioretention Cell Min. Required Bottom Area: 32 SF Bioretention Cell Per Plans Provided Bottom Area: 43 SF La Fortuna Phase III Page 21 Project No. 19006 Renton, WA Coterra Engineering PLLC SECTION V – CONVEYANCE SYSTEM DESIGN AND ANALYSIS The new conveyance system has been designed to convey at least the 25-year peak flow rate from the developed site. Conveyance capacity calculations are provided for each onsite conveyance basin. SECTION VI – SPECIAL REPORTS AND STUDIES A geotechnical analysis of the project site was performed and is included in Appendix J. Additionally, the geotechnical engineer has provided a supplemental Retaining Wall Design memo for use on the project site. That is also included in Appendix J. An updated Wetland Delineation Report was prepared for the onsite wetlands and is located in Appendix J. SECTION VII – OTHER PERMITS In addition to the Site Plan Review, a Civil Construction Permit from the City of Renton is required. The proposed project will disturb more than 1 acre, therefore an NPDES permit from the Washington State DOE for the discharge of construction stormwater from the project site is required. As development on the project site has been phased over several years, an active NPDES permit has already been obtained by Habitat for Humanity. Owner will apply to renew NPDES permit coverage as necessary to complete proposed La Fortuna Phase III construction. SECTION VIII – EROSION AND SEDIMENT CONTROL ESC Measures are being addressed as follows: Clearing Limits: Clearing limits are being delineated by perimeter silt fencing and chain link fencing. Cover Measures: Temporary cover shall be installed if an area is to remain unworked for more than seven days during the dry season (May 1 to September 30) or for more than two consecutive working days during the wet season (October 1 to April 30). Any area to remain unworked for more than 30 days shall be seeded or sodded, unless the City of Renton determines that winter weather makes vegetation establishment infeasible. Perimeter Protection: Perimeter protection will be implemented by silt fencing around the site perimeter where drainage paths require. Traffic Area Stabilization: A stabilized construction entrance will be built for construction traffic. Sediment Retention: Catch basin protection will be provided on all drainage inlets on, adjacent to, and downstream of the project site. Additionally, three sediment La Fortuna Phase III Page 22 Project No. 19006 Renton, WA Coterra Engineering PLLC traps are shown on the TESC plan to collect runoff during grading via interceptor swales and route to sediment traps to prevent the discharge of sediment-laden water to adjacent properties or the wetlands onsite. Sediment trap sizing calculations per SWDM standards are provided in Appendix I. Surface Water Control: Surface water will be collected and conveyed via swales with check dams as necessary. Dust Control: Dust control, if required, will be provided through the limited use of water trucks. Stormwater Pollution Prevention and Spill Control (SWPPS) Because the development of the Habitat La Fortuna site has occurred in phases over several years, the current project site area is mostly developed with utility infrastructure and paved access roads and sidewalks previously constructed. Proposed grading on the project just includes minor grading for building pads and regrading for proposed parking areas. Contractor shall install and maintain BMPs during construction to prevent the tracking of sediments offsite and spread of sediment-laden water. BMPs will include stabilized construction entrance(s) and tire wash stations as needed to control tracking of sediments off the project site. Proposed grading work will be performed in the summer months and building pads establish and foundations poured prior to the end of the Dry Season in Fall 2020. Final restoration of cleared and disturbed areas will be per landscape plan. As required by the NPDES permit obtained for the project site from Washington State DOE, the contractor will prepare and implement a final CSWPP for the project. La Fortuna Phase III Page 23 Project No. 19006 Renton, WA Coterra Engineering PLLC SECTION IX – BOND QUANTITIES AND DECLARATION OF COVENANTS A bond quantity worksheet for the proposed improvements is included with this civil construction permit submittal. There are two Declaration of Covenants which are required for the proposed project; one for inspection and maintenance of proposed stormwater facilities; and one for the inspection and maintenance of the proposed on-site BMPs. A draft version of these Declaration of Covenants will be provided for review and approval by City of Renton prior to recording. They will be signed and notarized prior to recording. SECTION X – OPERATIONS AND MAINTENANCE MANUAL An operation and maintenance manual which outlines required regular maintenance necessary for the proposed stormwater facilities is provided. The Operations & Maintenance Manual is provided in Appendix H. Appendix A Civil Plans CIVIL COVER AND NOTES IN COMPLIANCE WITH CITY OF RENTON STANDARDS Ä6*564''64'06109# .#(14670#2*+++coterra 321 3rd Ave South, Suite 406Seattle, Washington 98104ph 206.596.7115coterraengineering.com ENGINEERING PLLC **.#(14670#2*+++%+8+.%105647%6+102'4/+657$/+66#.6'&ÄÄ CIVIL NOTES IN COMPLIANCE WITH CITY OF RENTON STANDARDS Ä6*564''64'06109# .#(14670#2*+++coterra 321 3rd Ave South, Suite 406Seattle, Washington 98104ph 206.596.7115coterraengineering.com ENGINEERING PLLC **.#(14670#2*+++%+8+.%105647%6+102'4/+657$/+66#.6'&ÄÄ TESC PLANIN COMPLIANCE WITH CITY OF RENTON STANDARDSÄ6*564''64'06109#.#(14670#2*+++coterra321 3rd Ave South, Suite 406Seattle, Washington 98104ph 206.596.7115coterraengineering.comENGINEERING PLLC**.#(14670#2*+++ %+8+.%105647%6+102'4/+657$/+66#. 6'&ÄÄ IN COMPLIANCE WITH CITY OF RENTON STANDARDS Ä6*564''64'06109# .#(14670#2*+++coterra 321 3rd Ave South, Suite 406Seattle, Washington 98104ph 206.596.7115coterraengineering.com ENGINEERING PLLC **.#(14670#2*+++%+8+.%105647%6+102'4/+657$/+66#.6'&ÄÄTESC DETAILS NATIVE VEGETATIONAREA MIN. AREAREQUIRED 33,000 SFPAVING AND GRADING PLANIN COMPLIANCE WITH CITY OF RENTON STANDARDSÄ6*564''64'06109#.#(14670#2*+++coterra321 3rd Ave South, Suite 406Seattle, Washington 98104ph 206.596.7115coterraengineering.comENGINEERING PLLC**.#(14670#2*+++ %+8+.%105647%6+102'4/+657$/+66#. 6'&ÄÄ NATIVE VEGETATIONAREA MIN. AREAREQUIRED 33,000 SFSTORM DRAINAGE PLANIN COMPLIANCE WITH CITY OF RENTON STANDARDSÄ6*564''64'06109#.#(14670#2*+++coterra321 3rd Ave South, Suite 406Seattle, Washington 98104ph 206.596.7115coterraengineering.comENGINEERING PLLC**.#(14670#2*+++ %+8+.%105647%6+102'4/+657$/+66#. 6'&ÄÄ UTILITY PLANIN COMPLIANCE WITH CITY OF RENTON STANDARDSÄ6*564''64'06109#.#(14670#2*+++coterra321 3rd Ave South, Suite 406Seattle, Washington 98104ph 206.596.7115coterraengineering.comENGINEERING PLLC**.#(14670#2*+++ %+8+.%105647%6+102'4/+657$/+66#. 6'&ÄÄ IN COMPLIANCE WITH CITY OF RENTON STANDARDS Ä6*564''64'06109# .#(14670#2*+++coterra 321 3rd Ave South, Suite 406Seattle, Washington 98104ph 206.596.7115coterraengineering.com ENGINEERING PLLC **.#(14670#2*+++%+8+.%105647%6+102'4/+657$/+66#.6'&ÄÄCIVIL DETAILS IN COMPLIANCE WITH CITY OF RENTON STANDARDS Ä6*564''64'06109# .#(14670#2*+++coterra 321 3rd Ave South, Suite 406Seattle, Washington 98104ph 206.596.7115coterraengineering.com ENGINEERING PLLC **.#(14670#2*+++%+8+.%105647%6+102'4/+657$/+66#.6'&ÄÄCIVIL DETAILS IN COMPLIANCE WITH CITY OF RENTON STANDARDS Ä6*564''64'06109# .#(14670#2*+++coterra 321 3rd Ave South, Suite 406Seattle, Washington 98104ph 206.596.7115coterraengineering.com ENGINEERING PLLC **.#(14670#2*+++%+8+.%105647%6+102'4/+657$/+66#.6'&ÄÄCIVIL DETAILS IN COMPLIANCE WITH CITY OF RENTON STANDARDS Ä6*564''64'06109# .#(14670#2*+++coterra 321 3rd Ave South, Suite 406Seattle, Washington 98104ph 206.596.7115coterraengineering.com ENGINEERING PLLC **.#(14670#2*+++%+8+.%105647%6+102'4/+657$/+66#.6'&ÄÄCIVIL DETAILS IN COMPLIANCE WITH CITY OF RENTON STANDARDS Ä6*564''64'06109# .#(14670#2*+++coterra 321 3rd Ave South, Suite 406Seattle, Washington 98104ph 206.596.7115coterraengineering.com ENGINEERING PLLC **.#(14670#2*+++%+8+.%105647%6+102'4/+657$/+66#.6'&ÄÄSOOS CREEK SEWER DETAILS (FOR REFERENCE ONLY) IN COMPLIANCE WITH CITY OF RENTON STANDARDS Ä6*564''64'06109# .#(14670#2*+++coterra 321 3rd Ave South, Suite 406Seattle, Washington 98104ph 206.596.7115coterraengineering.com ENGINEERING PLLC **.#(14670#2*+++%+8+.%105647%6+102'4/+657$/+66#.6'&ÄÄSOOS CREEK WATER DETAILS (FOR REFERENCE ONLY) IN COMPLIANCE WITH CITY OF RENTON STANDARDS Ä6*564''64'06109# .#(14670#2*+++coterra 321 3rd Ave South, Suite 406Seattle, Washington 98104ph 206.596.7115coterraengineering.com ENGINEERING PLLC **.#(14670#2*+++%+8+.%105647%6+102'4/+657$/+66#.6'&ÄÄCIVIL DETAILS IN COMPLIANCE WITH CITY OF RENTON STANDARDS Ä6*564''64'06109# .#(14670#2*+++coterra 321 3rd Ave South, Suite 406Seattle, Washington 98104ph 206.596.7115coterraengineering.com ENGINEERING PLLC **.#(14670#2*+++%+8+.%105647%6+102'4/+657$/+66#.6'&ÄÄCIVIL DETAILS Appendix B Flow Control/Detention Calculations ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.38 Program License Number: 201510001 Project Simulation Performed on: 05/21/2020 6:57 PM Report Generation Date: 05/21/2020 6:58 PM ————————————————————————————————— Input File Name: PHI SITE PEAKS2.fld Project Name: Habitat La Fortuna - Phase I Model Analysis Title: Phase I - Partial Build Out - Detention Vault Analysis Comments: ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Climatic Region Number: 14 Full Period of Record Available used for Routing Precipitation Station : 96004405 Puget East 44 in_5min 10/01/1939-10/01/2097 Evaporation Station : 961044 Puget East 44 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 1.227 1.227 Area of Links that Include Precip/Evap (acres) 0.000 0.000 Total (acres) 1.227 1.227 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : PH 1 - Pre-Developed Condition ---------- -------Area(Acres) -------- Till Forest 0.000 Till Pasture 1.227 Till Grass 0.000 Outwash Forest 0.000 Outwash Pasture 0.000 Outwash Grass 0.000 Wetland 0.000 Green Roof 0.000 User 2 0.000 Impervious 0.000 ---------------------------------------------- Subbasin Total 1.227 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 ---------- Subbasin : PH I - Developed Build Out ---------- -------Area(Acres) -------- Till Forest 0.000 Till Pasture 0.000 Till Grass 0.212 Outwash Forest 0.000 Outwash Pasture 0.000 Outwash Grass 0.000 Wetland 0.000 Green Roof 0.000 User 2 0.000 Impervious 1.015 ---------------------------------------------- Subbasin Total 1.227 ************************* LINK DATA ******************************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ************************* LINK DATA ******************************* ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ------------------------------------------ Link Name: EX PH I VAULT Link Type: Structure Downstream Link: None Prismatic Pond Option Used Pond Floor Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 104.40 Max Pond Elevation (ft) : 105.40 Storage Depth (ft) : 4.40 Pond Bottom Length (ft) : 45.6 Pond Bottom Width (ft) : 45.6 Pond Side Slopes (ft/ft) : L1= 0.00 L2= 0.00 W1= 0.00 W2= 0.00 Bottom Area (sq-ft) : 2079. Area at Riser Crest El (sq-ft) : 2,079. (acres) : 0.048 Volume at Riser Crest (cu-ft) : 9,149. (ac-ft) : 0.210 Area at Max Elevation (sq-ft) : 2079. (acres) : 0.048 Vol at Max Elevation (cu-ft) : 11,436. (ac-ft) : 0.263 Massmann Infiltration Option Used Hydraulic Conductivity (in/hr) : 0.00 Depth to Water Table (ft) : 100.00 Bio-Fouling Potential : Low Maintenance : Average or Better Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 12.00 Common Length (ft) : 0.000 Riser Crest Elevation : 104.40 ft Hydraulic Structure Geometry Number of Devices: 2 ---Device Number 1 --- Device Type : Circular Orifice Control Elevation (ft) : 100.00 Diameter (in) : 1.15 Orientation : Horizontal Elbow : Yes ---Device Number 2 --- Device Type : Circular Orifice Control Elevation (ft) : 103.20 Diameter (in) : 1.38 Orientation : Horizontal Elbow : Yes **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 Number of Links: 1 ********** Link: EX PH I VAULT ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 101.342 1.11-Year 101.606 1.25-Year 101.887 2.00-Year 102.308 3.33-Year 102.914 5-Year 103.261 10-Year 103.740 25-Year 104.442 50-Year 104.465 100-Year 104.498 ***********Groundwater Recharge Summary ************* Recharge is computed as input to Perlnd Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: PH 1 - Pre-Developed 230.781 _____________________________________ Total: 230.781 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: PH I - Developed Bui 27.305 Link: EX PH I VAULT 0.000 _____________________________________ Total: 27.305 Total Predevelopment Recharge is Greater than Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 1.461 ac-ft/year, Post Developed: 0.173 ac-ft/year ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ********** Link: EX PH I VAULT ********** Basic Wet Pond Volume (91% Exceedance): 5096. cu-ft Computed Large Wet Pond Volume, 1.5*Basic Volume: 7644. cu-ft Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 561.57 Inflow Volume Including PPT-Evap (ac-ft): 561.57 Total Runoff Infiltrated (ac-ft): 0.00, 0.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 561.82 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 0.00% ***********Compliance Point Results ************* Scenario Predeveloped Compliance Subbasin: PH 1 - Pre-Developed Condition Scenario Postdeveloped Compliance Link: EX PH I VAULT *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 5.102E-02 2-Year 5.098E-02 5-Year 9.861E-02 5-Year 7.254E-02 10-Year 0.142 10-Year 0.100 25-Year 0.253 25-Year 0.207 50-Year 0.368 50-Year 0.303 100-Year 0.460 100-Year 0.451 200-Year 0.480 200-Year 0.472 ** Record too Short to Compute Peak Discharge for These Recurrence Intervals ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.38 Program License Number: 201510001 Project Simulation Performed on: 05/21/2020 7:01 PM Report Generation Date: 05/21/2020 7:03 PM ————————————————————————————————— Input File Name: PHIII TOWNHOUSE BASIN2-MAXIMIZE.fld Project Name: Habitat La Fortuna - Phase III Model Analysis Title: Phase III - Townhouse Basin to Vault Sizing Comments: ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Climatic Region Number: 14 Full Period of Record Available used for Routing Precipitation Station : 96004405 Puget East 44 in_5min 10/01/1939-10/01/2097 Evaporation Station : 961044 Puget East 44 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 0.570 0.570 Area of Links that Include Precip/Evap (acres) 0.000 0.000 Total (acres) 0.570 0.570 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : PH III - Pre Dev ---------- -------Area(Acres) -------- Till Forest 0.570 Till Pasture 0.000 Till Grass 0.000 Outwash Forest 0.000 Outwash Pasture 0.000 Outwash Grass 0.000 Wetland 0.000 Green Roof 0.000 User 2 0.000 Impervious 0.000 ---------------------------------------------- Subbasin Total 0.570 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 ---------- Subbasin : PH III - Developed ---------- -------Area(Acres) -------- Till Forest 0.000 Till Pasture 0.000 Till Grass 0.280 Outwash Forest 0.000 Outwash Pasture 0.000 Outwash Grass 0.000 Wetland 0.000 Green Roof 0.000 User 2 0.000 Impervious 0.290 ---------------------------------------------- Subbasin Total 0.570 ************************* LINK DATA ******************************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ************************* LINK DATA ******************************* ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ------------------------------------------ Link Name: EX SITE DETENTION VAULT Link Type: Structure Downstream Link: None Prismatic Pond Option Used Pond Floor Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 104.40 Max Pond Elevation (ft) : 105.40 Storage Depth (ft) : 4.40 Pond Bottom Length (ft) : 44.5 Pond Bottom Width (ft) : 44.5 Pond Side Slopes (ft/ft) : L1= 0.00 L2= 0.00 W1= 0.00 W2= 0.00 Bottom Area (sq-ft) : 1980. Area at Riser Crest El (sq-ft) : 1,980. (acres) : 0.045 Volume at Riser Crest (cu-ft) : 8,713. (ac-ft) : 0.200 Area at Max Elevation (sq-ft) : 1980. (acres) : 0.045 Vol at Max Elevation (cu-ft) : 10,891. (ac-ft) : 0.250 Massmann Infiltration Option Used Hydraulic Conductivity (in/hr) : 0.00 Depth to Water Table (ft) : 100.00 Bio-Fouling Potential : Low Maintenance : Average or Better Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 12.00 Common Length (ft) : 0.000 Riser Crest Elevation : 104.40 ft Hydraulic Structure Geometry Number of Devices: 2 ---Device Number 1 --- Device Type : Circular Orifice Control Elevation (ft) : 100.00 Diameter (in) : 0.42 Orientation : Horizontal Elbow : Yes ---Device Number 2 --- Device Type : Circular Orifice Control Elevation (ft) : 103.20 Diameter (in) : 1.00 Orientation : Horizontal Elbow : Yes **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 Number of Links: 1 ********** Link: EX SITE DETENTION VAULT ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 101.320 1.11-Year 101.432 1.25-Year 101.617 2.00-Year 102.289 3.33-Year 102.756 5-Year 103.227 10-Year 103.567 25-Year 103.818 50-Year 103.975 100-Year 104.074 ***********Groundwater Recharge Summary ************* Recharge is computed as input to Perlnd Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: PH III - Pre Dev 108.437 _____________________________________ Total: 108.437 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: PH III - Developed 36.063 Link: EX SITE DETENTION VA 0.000 _____________________________________ Total: 36.063 Total Predevelopment Recharge is Greater than Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 0.686 ac-ft/year, Post Developed: 0.228 ac-ft/year ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ********** Link: EX SITE DETENTION VAULT ********** Basic Wet Pond Volume (91% Exceedance): 1762. cu-ft Computed Large Wet Pond Volume, 1.5*Basic Volume: 2643. cu-ft Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 214.33 Inflow Volume Including PPT-Evap (ac-ft): 214.33 Total Runoff Infiltrated (ac-ft): 0.00, 0.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 214.30 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 0.00% ***********Compliance Point Results ************* Scenario Predeveloped Compliance Subbasin: PH III - Pre Dev Scenario Postdeveloped Compliance Link: EX SITE DETENTION VAULT *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 1.466E-02 2-Year 6.765E-03 5-Year 2.350E-02 5-Year 1.223E-02 10-Year 3.064E-02 10-Year 2.375E-02 25-Year 4.212E-02 25-Year 2.867E-02 50-Year 5.295E-02 50-Year 3.123E-02 100-Year 5.619E-02 100-Year 3.272E-02 200-Year 8.975E-02 200-Year 3.478E-02 ** Record too Short to Compute Peak Discharge for These Recurrence Intervals **** Flow Duration Performance **** Excursion at Predeveloped 50%Q2 (Must be Less Than 0%): -42.2% PASS Maximum Excursion from 50%Q2 to Q2 (Must be Less Than 0%): -32.1% PASS Maximum Excursion from Q2 to Q50 (Must be less than 10%): 2.3% PASS Percent Excursion from Q2 to Q50 (Must be less than 50%): 9.6% PASS ------------------------------------------------------------------------------------------------- MEETS ALL FLOW DURATION DESIGN CRITERIA: PASS ------------------------------------------------------------------------------------------------- Detention Pipe Volume Calculator Blue Indicates Data Entry Cells, the rest are calculated. Storage Volume Provided by Horizontal Pipe of Diameter d LA FORTUNA PH III Pipe Diameter (d)5.0 ft Pipe Length 130 ft BASIN C - EAST PARKING AREA Overflow Elevation:105.00 ft Pond Volume at Overflow (cu ft):2518 Target Volume from MGSFlood: 2500 Note: Volume is increased by 1 for Elevations Greater than Pipe Diameter Pond Volume Table Because Routing Routine Requires Increasing Pond Volume Circular Section Geometry Read from CircularSections Tab *** Copy Table below to MGSFlood Program Elevation Volume Input Screen elev. Wetted Area storage storage DON'T INCLUDE THE COLUMN HEADINGS! ft y/d s.f. cu.ft. (ac.ft) ELEV (FT) Top Area (Dummy) VOLUME (CU FT) 100.00 0.000 0.000 0 0 100.00 10.0 0.0. 100.20 0.040 0.263 34 0.001 100.20 10.1 34.1. 100.40 0.080 0.735 96 0.002 100.40 10.2 95.6. 100.60 0.120 1.335 174 0.004 100.60 10.3 173.6. 100.80 0.160 2.028 264 0.006 100.80 10.4 263.6. 101.00 0.200 2.795 363 0.008 101.00 10.5 363.4. 101.20 0.240 3.623 471 0.011 101.20 10.6 470.9. 101.40 0.280 4.500 585 0.013 101.40 10.7 585.0. 101.60 0.320 5.418 704 0.016 101.60 10.8 704.3. 101.80 0.360 6.365 827 0.019 101.80 10.9 827.5. 102.00 0.400 7.335 954 0.022 102.00 11.0 953.6. 102.20 0.440 8.320 1082 0.025 102.20 11.1 1081.6. 102.40 0.480 9.318 1211 0.028 102.40 11.2 1211.3. 102.60 0.520 10.318 1341 0.031 102.60 11.3 1341.3. 102.80 0.560 11.315 1471 0.034 102.80 11.4 1471.0. 103.00 0.600 12.300 1599 0.037 103.00 11.5 1599.0. 103.20 0.640 13.270 1725 0.040 103.20 11.6 1725.1. 103.40 0.680 14.218 1848 0.042 103.40 11.7 1848.3. 103.60 0.720 15.135 1968 0.045 103.60 11.8 1967.6. 103.80 0.760 16.010 2081 0.048 103.80 11.9 2081.3. 104.00 0.800 16.840 2189 0.050 104.00 12.0 2189.2. 104.20 0.840 17.608 2289 0.053 104.20 12.1 2289.0. 104.40 0.880 18.300 2379 0.055 104.40 12.2 2379.0. 104.60 0.920 18.900 2457 0.056 104.60 12.3 2457.0. 104.80 0.960 19.373 2518 0.058 104.80 12.4 2518.4. 105.00 1.000 19.635 2553 0.059 105.00 12.5 2552.6. 105.20 1.040 19.635 2553 0.059 105.20 12.6 2553.6. 105.40 1.080 19.635 2553 0.059 105.40 12.7 2554.6. 105.60 1.120 19.635 2553 0.059 105.60 12.8 2555.6. 105.80 1.160 19.635 2553 0.059 105.80 12.9 2556.6. 106.00 1.200 19.635 2553 0.059 106.00 13.0 2557.6. 5/14/2020 PondPipe - BASIN C DETENTION TANK.xls ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.38 Program License Number: 201510001 Project Simulation Performed on: 05/14/2020 4:21 PM Report Generation Date: 05/14/2020 4:22 PM ————————————————————————————————— Input File Name: LA FORTUNA - CCP SIZING - DETENTION TANK PARKING C.fld Project Name: Renton Habitat - La Fortuna Analysis Title: WQ - Bioretention Comments: ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Climatic Region Number: 14 Full Period of Record Available used for Routing Precipitation Station : 96004405 Puget East 44 in_5min 10/01/1939-10/01/2097 Evaporation Station : 961044 Puget East 44 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 0.147 0.146 Area of Links that Include Precip/Evap (acres) 0.000 0.001 Total (acres) 0.147 0.147 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Basin C - Existing ---------- -------Area(Acres) -------- Till Forest 0.147 Till Pasture 0.000 Till Grass 0.000 Outwash Forest 0.000 Outwash Pasture 0.000 Outwash Grass 0.000 Wetland 0.000 Green Roof 0.000 User 2 0.000 Impervious 0.000 ---------------------------------------------- Subbasin Total 0.147 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 2 ---------- Subbasin : Sidewalk, Playground ---------- -------Area(Acres) -------- Till Forest 0.000 Till Pasture 0.000 Till Grass 0.051 Outwash Forest 0.000Outwash Pasture 0.000 Outwash Grass 0.000 Wetland 0.000 Green Roof 0.000 User 2 0.000 Impervious 0.034 ---------------------------------------------- Subbasin Total 0.085 ---------- Subbasin : Basin C - Parking Area PGIS ---------- -------Area(Acres) -------- Till Forest 0.000 Till Pasture 0.000 Till Grass 0.000 Outwash Forest 0.000 Outwash Pasture 0.000 Outwash Grass 0.000 Wetland 0.000 Green Roof 0.000 User 2 0.000 Impervious 0.061 ---------------------------------------------- Subbasin Total 0.061 ************************* LINK DATA ******************************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ************************* LINK DATA ******************************* ----------------------SCENARIO: POSTDEVELOPED Number of Links: 2 ------------------------------------------ Link Name: New Bio Lnk1 Link Type: Bioretention Facility Downstream Link Name: Basin C - Detention Tank Base Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 100.50 Storage Depth (ft) : 0.50 Bottom Length (ft) : 12.0 Bottom Width (ft) : 3.6 Side Slopes (ft/ft) : L1= 3.00 L2= 3.00 W1= 3.00 W2= 3.00 Bottom Area (sq-ft) : 43. Area at Riser Crest El (sq-ft) : 99. (acres) : 0.002 Volume at Riser Crest (cu-ft): 48. (ac-ft) : 0.001 Infiltration on Bottom only Selected Soil Properties Biosoil Thickness (ft) : 1.50 Biosoil Saturated Hydraulic Conductivity (in/hr) : 6.00 Biosoil Porosity (Percent) : 20.00 Maximum Elevation of Bioretention Soil : 101.00 Native Soil Hydraulic Conductivity (in/hr) : 0.00 Underdrain Present Orifice NOT Present in Under Drain Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 6.00Common Length (ft) : 0.000 Riser Crest Elevation : 100.50 ft Hydraulic Structure Geometry Number of Devices: 0 ------------------------------------------ Link Name: Basin C - Detention Tank Link Type: Structure Downstream Link: None User Specified Elevation Volume Table Used Elevation (ft) Pond Volume (cu-ft) 100.00 0. 100.20 34. 100.40 96. 100.60 174. 100.80 264. 101.00 363. 101.20 471. 101.40 585. 101.60 704. 101.80 828. 102.00 954. 102.20 1082. 102.40 1211. 102.60 1341. 102.80 1471. 103.00 1599. 103.20 1725. 103.40 1848. 103.60 1968. 103.80 2081. 104.00 2189. 104.20 2289. 104.40 2379. 104.60 2457. 104.80 2518. 105.00 2553. Massmann Infiltration Option Used Hydraulic Conductivity (in/hr) : 0.00 Depth to Water Table (ft) : 100.00 Bio-Fouling Potential : Low Maintenance : Average or Better Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 24.00 Common Length (ft) : 0.000 Riser Crest Elevation : 105.00 ft Hydraulic Structure Geometry Number of Devices: 3 ---Device Number 1 --- Device Type : Circular Orifice Control Elevation (ft) : 100.50 Diameter (in) : 0.23 Orientation : Horizontal Elbow : Yes ---Device Number 2 --- Device Type : Circular Orifice Control Elevation (ft) : 104.15 Diameter (in) : 0.41 Orientation : Horizontal Elbow : Yes ---Device Number 3 --- Device Type : Circular Orifice Control Elevation (ft) : 103.00 Diameter (in) : 0.30 Orientation : Horizontal Elbow : Yes **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 2 Number of Links: 2 ********** Subbasin: Sidewalk, Playground ********** Flood Frequency Data(cfs) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) Flood Peak (cfs) ====================================== 2-Year 1.896E-02 5-Year 2.584E-02 10-Year 3.177E-02 25-Year 4.063E-02 50-Year 5.418E-02 100-Year 6.789E-02 200-Year 6.828E-02 ********** Subbasin: Basin C - Parking Area PGIS ********** Flood Frequency Data(cfs) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) Flood Peak (cfs) ====================================== 2-Year 2.368E-02 5-Year 3.097E-02 10-Year 3.604E-02 25-Year 4.341E-02 50-Year 5.263E-02 100-Year 6.447E-02 200-Year 6.743E-02 ********** Link: New Bio Lnk1 ********** Link Inflow Frequency Stats Flood Frequency Data(cfs) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) Flood Peak (cfs) ====================================== 2-Year 2.368E-02 5-Year 3.097E-02 10-Year 3.604E-02 25-Year 4.341E-02 50-Year 5.263E-02 100-Year 6.447E-02 200-Year 6.743E-02 ********** Link: New Bio Lnk1 ********** Link Outflow 1 Frequency Stats Flood Frequency Data(cfs) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) Flood Peak (cfs) ====================================== 2-Year 2.124E-02 5-Year 2.852E-02 10-Year 3.357E-02 25-Year 3.817E-02 50-Year 4.665E-02 100-Year 5.967E-02 200-Year 6.617E-02 ********** Link: New Bio Lnk1 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 100.505 1.11-Year 100.510 1.25-Year 100.513 2.00-Year 100.520 3.33-Year 100.524 5-Year 100.526 10-Year 100.530 25-Year 100.533 50-Year 100.539 100-Year 100.547 ********** Link: Basin C - Detention Tank ********** Link Inflow Frequency Stats Flood Frequency Data(cfs) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) Flood Peak (cfs) ====================================== 2-Year 3.633E-02 5-Year 5.265E-02 10-Year 6.355E-02 25-Year 7.401E-02 50-Year 9.953E-02 100-Year 0.119 200-Year 0.129 ********** Link: Basin C - Detention Tank ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 101.821 1.11-Year 101.886 1.25-Year 102.116 2.00-Year 102.628 3.33-Year 103.014 5-Year 103.334 10-Year 103.815 25-Year 104.280 50-Year 104.344 100-Year 104.626 ***********Groundwater Recharge Summary ************* Recharge is computed as input to Perlnd Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Basin C - Existing 27.965 _____________________________________ Total: 27.965 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Sidewalk, Playground6.569 Subbasin: Basin C - Parking Ar 0.000 Link: New Bio Lnk1 0.000 Link: Basin C - Detention 0.000 _____________________________________ Total: 6.569 Total Predevelopment Recharge is Greater than Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 0.177 ac-ft/year, Post Developed: 0.042 ac-ft/year ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Links: 2 ********** Link: New Bio Lnk1 ********** Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 30.62 Inflow Volume Including PPT-Evap (ac-ft): 31.17 Total Runoff Infiltrated (ac-ft): 0.00, 0.00% Total Runoff Filtered (ac-ft): 30.34, 97.33% Primary Outflow To Downstream System (ac-ft): 31.16 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 97.33% ********** Link: Basin C - Detention Tank ********** Basic Wet Pond Volume (91% Exceedance): 525. cu-ft Computed Large Wet Pond Volume, 1.5*Basic Volume: 787. cu-ft Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 60.76 Inflow Volume Including PPT-Evap (ac-ft): 60.76 Total Runoff Infiltrated (ac-ft): 0.00, 0.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 60.74 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 0.00% ***********Compliance Point Results ************* Scenario Predeveloped Compliance Subbasin: Basin C - Existing Scenario Postdeveloped Compliance Link: Basin C - Detention Tank *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 3.781E-03 2-Year 1.872E-03 5-Year 6.059E-03 5-Year 3.479E-03 10-Year 7.902E-03 10-Year 4.402E-03 25-Year 1.086E-02 25-Year 6.552E-03 50-Year 1.366E-02 50-Year 7.030E-03 100-Year 1.449E-02 100-Year 8.449E-03 200-Year 2.315E-02 200-Year 1.286E-02 ** Record too Short to Compute Peak Discharge for These Recurrence Intervals **** Flow Duration Performance **** Excursion at Predeveloped 50%Q2 (Must be Less Than 0%): -16.2% PASS Maximum Excursion from 50%Q2 to Q2 (Must be Less Than 0%): -16.2% PASS Maximum Excursion from Q2 to Q50 (Must be less than 10%): 6.3% PASS Percent Excursion from Q2 to Q50 (Must be less than 50%): 2.7% PASS ------------------------------------------------------------------------------------------------- MEETS ALL FLOW DURATION DESIGN CRITERIA: PASS ------------------------------------------------------------------------------------------------- Appendix C Water Quality Calculation ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.38 Program License Number: 201510001 Project Simulation Performed on: 05/14/2020 2:36 PM Report Generation Date: 05/14/2020 2:37 PM ————————————————————————————————— Input File Name: LA FORTUNA - PRELIM SIZING - WQ BIO BASIN A.fld Project Name: Habitat La Fortuna PH III Analysis Title: WQ - Bioretention - Basin A Comments: ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Climatic Region Number: 14 Full Period of Record Available used for Routing Precipitation Station : 96004405 Puget East 44 in_5min 10/01/1939-10/01/2097 Evaporation Station : 961044 Puget East 44 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 0.049 0.049 Area of Links that Include Precip/Evap (acres) 0.000 0.001 Total (acres) 0.049 0.050 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Basin A - Existing ---------- -------Area(Acres) -------- Till Forest 0.000 Till Pasture 0.000 Till Grass 0.000 Outwash Forest 0.000 Outwash Pasture 0.000 Outwash Grass 0.000 Wetland 0.000 Green Roof 0.000 User 2 0.000 Impervious 0.049 ---------------------------------------------- Subbasin Total 0.049 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Basin A - Developed PGIS ---------- -------Area(Acres) -------- Till Forest 0.000 Till Pasture 0.000 Till Grass 0.000 Outwash Forest 0.000Outwash Pasture 0.000 Outwash Grass 0.000 Wetland 0.000 Green Roof 0.000 User 2 0.000 Impervious 0.049 ---------------------------------------------- Subbasin Total 0.049 ************************* LINK DATA ******************************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ************************* LINK DATA ******************************* ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ------------------------------------------ Link Name: New Bio Lnk1 Link Type: Bioretention Facility Downstream Link: None Base Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 100.50 Storage Depth (ft) : 0.50 Bottom Length (ft) : 8.0 Bottom Width (ft) : 3.0 Side Slopes (ft/ft) : L1= 3.00 L2= 3.00 W1= 3.00 W2= 3.00 Bottom Area (sq-ft) : 24. Area at Riser Crest El (sq-ft) : 66. (acres) : 0.002 Volume at Riser Crest (cu-ft): 29. (ac-ft) : 0.001 Infiltration on Bottom only Selected Soil Properties Biosoil Thickness (ft) : 1.50 Biosoil Saturated Hydraulic Conductivity (in/hr) : 6.00 Biosoil Porosity (Percent) : 20.00 Maximum Elevation of Bioretention Soil : 101.00 Native Soil Hydraulic Conductivity (in/hr) : 0.00 Underdrain Present Orifice NOT Present in Under Drain Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 6.00 Common Length (ft) : 0.000 Riser Crest Elevation : 100.50 ft Hydraulic Structure Geometry Number of Devices: 0 **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 Number of Links: 1 ********** Link: New Bio Lnk1 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 100.511 1.11-Year 100.512 1.25-Year 100.516 2.00-Year 100.520 3.33-Year 100.523 5-Year 100.525 10-Year 100.527 25-Year 100.533 50-Year 100.538 100-Year 100.544 ***********Groundwater Recharge Summary ************* Recharge is computed as input to Perlnd Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Basin A - Existing 0.000 _____________________________________ Total: 0.000 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Basin A - Developed 0.000 Link: New Bio Lnk1 0.000 _____________________________________ Total: 0.000 Total Predevelopment Recharge Equals Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 0.000 ac-ft/year, Post Developed: 0.000 ac-ft/year ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ********** Link: New Bio Lnk1 ********** Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 24.60 Inflow Volume Including PPT-Evap (ac-ft): 24.96 Total Runoff Infiltrated (ac-ft): 0.00, 0.00% Total Runoff Filtered (ac-ft): 23.12, 92.63% Primary Outflow To Downstream System (ac-ft): 24.94 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 92.63% ***********Compliance Point Results ************* Scenario Predeveloped Compliance Subbasin: Basin A - Existing Scenario Postdeveloped Compliance Link: New Bio Lnk1 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 1.902E-02 2-Year 1.850E-02 5-Year 2.488E-02 5-Year 2.543E-02 10-Year 2.895E-02 10-Year 2.765E-02 25-Year 3.487E-02 25-Year 3.529E-02 50-Year 4.228E-02 50-Year 4.250E-02 100-Year 5.179E-02 100-Year 5.198E-02 200-Year 5.417E-02 200-Year 5.439E-02 ** Record too Short to Compute Peak Discharge for These Recurrence Intervals ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.38 Program License Number: 201510001 Project Simulation Performed on: 05/14/2020 2:41 PM Report Generation Date: 05/14/2020 2:41 PM ————————————————————————————————— Input File Name: LA FORTUNA - PRELIM SIZING - WQ BIO BASIN C.fld Project Name: Habitat La Fortuna PH III Analysis Title: WQ - Bioretention - Basin C Comments: ———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Climatic Region Number: 14 Full Period of Record Available used for Routing Precipitation Station : 96004405 Puget East 44 in_5min 10/01/1939-10/01/2097 Evaporation Station : 961044 Puget East 44 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 0.061 0.061 Area of Links that Include Precip/Evap (acres) 0.000 0.001 Total (acres) 0.061 0.062 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Basin C - Existing ---------- -------Area(Acres) -------- Till Forest 0.000 Till Pasture 0.000 Till Grass 0.000 Outwash Forest 0.000 Outwash Pasture 0.000 Outwash Grass 0.000 Wetland 0.000 Green Roof 0.000 User 2 0.000 Impervious 0.061 ---------------------------------------------- Subbasin Total 0.061 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Basin C - Developed PGIS ---------- -------Area(Acres) -------- Till Forest 0.000 Till Pasture 0.000 Till Grass 0.000 Outwash Forest 0.000Outwash Pasture 0.000 Outwash Grass 0.000 Wetland 0.000 Green Roof 0.000 User 2 0.000 Impervious 0.061 ---------------------------------------------- Subbasin Total 0.061 ************************* LINK DATA ******************************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ************************* LINK DATA ******************************* ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ------------------------------------------ Link Name: New Bio Lnk1 Link Type: Bioretention Facility Downstream Link: None Base Elevation (ft) : 100.00 Riser Crest Elevation (ft) : 100.50 Storage Depth (ft) : 0.50 Bottom Length (ft) : 8.0 Bottom Width (ft) : 4.0 Side Slopes (ft/ft) : L1= 3.00 L2= 3.00 W1= 3.00 W2= 3.00 Bottom Area (sq-ft) : 32. Area at Riser Crest El (sq-ft) : 77. (acres) : 0.002 Volume at Riser Crest (cu-ft): 36. (ac-ft) : 0.001 Infiltration on Bottom only Selected Soil Properties Biosoil Thickness (ft) : 1.50 Biosoil Saturated Hydraulic Conductivity (in/hr) : 6.00 Biosoil Porosity (Percent) : 20.00 Maximum Elevation of Bioretention Soil : 101.00 Native Soil Hydraulic Conductivity (in/hr) : 0.00 Underdrain Present Orifice NOT Present in Under Drain Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 6.00 Common Length (ft) : 0.000 Riser Crest Elevation : 100.50 ft Hydraulic Structure Geometry Number of Devices: 0 **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 Number of Links: 1 ********** Link: New Bio Lnk1 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) ====================================== 1.05-Year 100.514 1.11-Year 100.515 1.25-Year 100.518 2.00-Year 100.522 3.33-Year 100.526 5-Year 100.529 10-Year 100.531 25-Year 100.538 50-Year 100.543 100-Year 100.550 ***********Groundwater Recharge Summary ************* Recharge is computed as input to Perlnd Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Basin C - Existing 0.000 _____________________________________ Total: 0.000 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: Basin C - Developed 0.000 Link: New Bio Lnk1 0.000 _____________________________________ Total: 0.000 Total Predevelopment Recharge Equals Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 0.000 ac-ft/year, Post Developed: 0.000 ac-ft/year ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ********** Link: New Bio Lnk1 ********** Infiltration/Filtration Statistics-------------------- Inflow Volume (ac-ft): 30.62 Inflow Volume Including PPT-Evap (ac-ft): 31.07 Total Runoff Infiltrated (ac-ft): 0.00, 0.00% Total Runoff Filtered (ac-ft): 29.07, 93.55% Primary Outflow To Downstream System (ac-ft): 31.06 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 93.55% ***********Compliance Point Results ************* Scenario Predeveloped Compliance Subbasin: Basin C - Existing Scenario Postdeveloped Compliance Link: New Bio Lnk1 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 2.368E-02 2-Year 2.279E-02 5-Year 3.097E-02 5-Year 3.150E-02 10-Year 3.604E-02 10-Year 3.435E-02 25-Year 4.341E-02 25-Year 4.389E-02 50-Year 5.263E-02 50-Year 5.273E-02 100-Year 6.447E-02 100-Year 6.424E-02 200-Year 6.743E-02 200-Year 6.750E-02 ** Record too Short to Compute Peak Discharge for These Recurrence Intervals Appendix D Conveyance Calculations Conveyance Capacity Check BASIN B from Central Parking Area to Dispersion Trench Input pipe size, n value and slope to calculate capacity of pipe flowing full Pipe Typ. Slope Qf Vf pipe full pipe full (in.)n (ft./ft.)(cfs)(ft/s) 8 0.012 0.0083 1.196 3.43 Q100 yr (developed condition) from Basin B parking area 0.317 CFS (From MGSFlood) to dispersion trench USING MANNINGS EQUATION, 8" DIAMETER STORM PIPE WITH A MINIMUM SLOPE OF 0.83% WILL MEET CAPACITY REQUIREMENTS coterra collaborative civil engineering + site development + infrastructure design ————————————————————————————————— MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.38 Program License Number: 201510001 Project Simulation Performed on: 05/14/2020 5:56 PM Report Generation Date: 05/14/2020 6:04 PM ————————————————————————————————— Input File Name: LA FORTUNA - CONVEYANCE CALCULATIONS - Basin B.fld Project Name: Renton Habitat - La Fortuna Ph IIIAnalysis Title: Pipe Conveyance - BASIN B Comments:———————————————— PRECIPITATION INPUT ———————————————— Computational Time Step (Minutes): 15 Extended Precipitation Time Series Selected Climatic Region Number: 14 Full Period of Record Available used for Routing Precipitation Station : 96004405 Puget East 44 in_5min 10/01/1939-10/01/2097Evaporation Station : 961044 Puget East 44 in MAP Evaporation Scale Factor : 0.750 HSPF Parameter Region Number: 1HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 0.300 0.300Area of Links that Include Precip/Evap (acres) 0.000 0.000 Total (acres) 0.300 0.300 ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : BASIN B - PRE-DEVELOPED ---------- -------Area(Acres) -------- Till Forest 0.300Till Pasture 0.000 Till Grass 0.000Outwash Forest 0.000 Outwash Pasture 0.000Outwash Grass 0.000 Wetland 0.000Green Roof 0.000 User 2 0.000Impervious 0.000 ----------------------------------------------Subbasin Total 0.300 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 ---------- Subbasin : BASIN B - DEVELOPED -----------------Area(Acres) -------- Till Forest 0.000Till Pasture 0.000 Till Grass 0.000Outwash Forest 0.000 Outwash Pasture 0.000Outwash Grass 0.000 Wetland 0.000Green Roof 0.000 User 2 0.000 Impervious 0.300 ---------------------------------------------- Subbasin Total 0.300 ************************* LINK DATA ******************************* ----------------------SCENARIO: PREDEVELOPEDNumber of Links: 0 ************************* LINK DATA ******************************* ----------------------SCENARIO: POSTDEVELOPED Number of Links: 0 **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* ----------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1Number of Links: 0 ***********Groundwater Recharge Summary ************* Recharge is computed as input to Perlnd Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During SimulationModel Element Recharge Amount (ac-ft) -----------------------------------------------------------------------------------------------Subbasin: BASIN B - PRE-DEVELO 57.072 _____________________________________Total: 57.072 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) ----------------------------------------------------------------------------------------------- Subbasin: BASIN B - DEVELOPED 0.000 _____________________________________ Total: 0.000 Total Predevelopment Recharge is Greater than Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 0.361 ac-ft/year, Post Developed: 0.000 ac-ft/year ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Links: 0 ***********Compliance Point Results ************* Scenario Predeveloped Compliance Subbasin: BASIN B - PRE-DEVELOPED Scenario Postdeveloped Compliance Subbasin: BASIN B - DEVELOPED *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) ---------------------------------------------------------------------------------------------------------------------- 2-Year 7.716E-03 2-Year 0.116 5-Year 1.237E-02 5-Year 0.152 10-Year 1.613E-02 10-Year 0.177 25-Year 2.217E-02 25-Year 0.214 50-Year 2.787E-02 50-Year 0.259100-Year 2.957E-02 100-Year 0.317 200-Year 4.724E-02 200-Year 0.332** Record too Short to Compute Peak Discharge for These Recurrence Intervals Q100 Conveyance Capacity Check BASIN C from Detention Tank - Outfalls to Wetland B Input pipe size, n value and slope to calculate capacity of pipe flowing full Pipe Typ. Slope Qf Vf pipe full pipe full (in.)n (ft./ft.)(cfs)(ft/s) 8 0.012 0.017 1.711 4.90 Q100 yr (developed condition) from tank to outfall 0.007 CFS (From MGSFlood) USING MANNINGS EQUATION, 8" DIAMETER STORM PIPE WITH A MINIMUM SLOPE OF 1.7% WILL MEET CAPACITY REQUIREMENTS coterra collaborative civil engineering + site development + infrastructure design Appendix E Drainage Review Flow Chart SECTION 1.1 DRAINAGE REVIEW 12/12/2016 2017 City of Renton Surface Water Design Manual 1-14 FIGURE 1.1.2.A FLOW CHART FOR DETERMINING TYPE OF DRAINAGE REVIEW REQUIRED Appendix F Bond Quantity Worksheet Planning Division |1055 South Grady Way – 6 th Floor | Renton, WA 98057 (425) 430-7200 Date Prepared: Name: PE Registration No: Firm Name: Firm Address: Phone No. Email Address: Project Name: Project Owner: CED Plan # (LUA):Phone: CED Permit # (U):Address: Site Address: Street Intersection:Addt'l Project Owner: Parcel #(s):Phone: Address: Clearing and grading greater than or equal to 5,000 board feet of timber? Yes/No:NO Water Service Provided by: If Yes, Provide Forest Practice Permit #:Sewer Service Provided by: Abbreviated Legal Description: LA FORTUNA MASTER CONDOMINIUM, ACCORDING TO THE SURVEY MAP AND PLANS RECORDED IN VOLUME 271 OF CONDOMINIUMS, PAGES 99 THROUGH 101, INCLUSIVE, AND ANY AMENDMENTS THERETO, AND THE DECLARATION THEREOF RECORDED UNDER RECORDING NO. 20110323000821, AND ANY AMENDMENTS SE 173rd Pl. Renton, WA 98058 560 Naches Ave SW #110 NA C20-000611 SE 172ND STREET AND 127TH AVE SE (206) 453-2950 5/13/2020 Prepared by: FOR APPROVALProject Phase 1 peter@coterraengineering.com Peter Apostol, PE 35163 Coterra Engineering 321 3rd Ave South, #406, Seattle, WA 98104 (206) 596-7115 SITE IMPROVEMENT BOND QUANTITY WORKSHEET PROJECT INFORMATION SOOS CREEK WATER & SEWER SOOS CREEK WATER & SEWER 1 Select the current project status/phase from the following options: For Approval - Preliminary Data Enclosed, pending approval from the City; For Construction - Estimated Data Enclosed, Plans have been approved for contruction by the City; Project Closeout - Final Costs and Quantities Enclosed for Project Close-out Submittal Engineer Stamp Required (all cost estimates must have original wet stamp and signature) Clearing and Grading Utility Providers N/A Project Location and Description Project Owner Information La Fortuna Phase III Renton, WA 98057 3956200000 Habitat for Humanity ##-###### Page 2 of 14 Ref 8-H Bond Quantity Worksheet SECTION I PROJECT INFORMATION Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 5/13/2020 CED Permit #:C20-000611 Unit Reference #Price Unit Quantity Cost Backfill & compaction-embankment ESC-1 6.50$ CY Check dams, 4" minus rock ESC-2 SWDM 5.4.6.3 80.00$ Each Catch Basin Protection ESC-3 35.50$ Each 28 994.00 Crushed surfacing 1 1/4" minus ESC-4 WSDOT 9-03.9(3)95.00$ CY Ditching ESC-5 9.00$ CY Excavation-bulk ESC-6 2.00$ CY Fence, silt ESC-7 SWDM 5.4.3.1 1.50$ LF 563 844.50 Fence, Temporary (NGPE)ESC-8 1.50$ LF Geotextile Fabric ESC-9 2.50$ SY Hay Bale Silt Trap ESC-10 0.50$ Each Hydroseeding ESC-11 SWDM 5.4.2.4 0.80$ SY Interceptor Swale / Dike ESC-12 1.00$ LF Jute Mesh ESC-13 SWDM 5.4.2.2 3.50$ SY Level Spreader ESC-14 1.75$ LF Mulch, by hand, straw, 3" deep ESC-15 SWDM 5.4.2.1 2.50$ SY Mulch, by machine, straw, 2" deep ESC-16 SWDM 5.4.2.1 2.00$ SY Piping, temporary, CPP, 6"ESC-17 12.00$ LF Piping, temporary, CPP, 8"ESC-18 14.00$ LF Piping, temporary, CPP, 12"ESC-19 18.00$ LF Plastic covering, 6mm thick, sandbagged ESC-20 SWDM 5.4.2.3 4.00$ SY Rip Rap, machine placed; slopes ESC-21 WSDOT 9-13.1(2)45.00$ CY Rock Construction Entrance, 50'x15'x1'ESC-22 SWDM 5.4.4.1 1,800.00$ Each 1 1,800.00 Rock Construction Entrance, 100'x15'x1'ESC-23 SWDM 5.4.4.1 3,200.00$ Each Sediment pond riser assembly ESC-24 SWDM 5.4.5.2 2,200.00$ Each Sediment trap, 5' high berm ESC-25 SWDM 5.4.5.1 19.00$ LF 275 5,225.00 Sed. trap, 5' high, riprapped spillway berm section ESC-26 SWDM 5.4.5.1 70.00$ LF Seeding, by hand ESC-27 SWDM 5.4.2.4 1.00$ SY Sodding, 1" deep, level ground ESC-28 SWDM 5.4.2.5 8.00$ SY Sodding, 1" deep, sloped ground ESC-29 SWDM 5.4.2.5 10.00$ SY TESC Supervisor ESC-30 110.00$ HR Water truck, dust control ESC-31 SWDM 5.4.7 140.00$ HR Unit Reference #Price Unit Quantity Cost EROSION/SEDIMENT SUBTOTAL:8,863.50 SALES TAX @ 10%886.35 EROSION/SEDIMENT TOTAL:9,749.85 (A) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR EROSION & SEDIMENT CONTROL Description No. (A) WRITE-IN-ITEMS Page 3 of 14 Ref 8-H Bond Quantity Worksheet SECTION II.a EROSION_CONTROL Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 5/13/2020 CED Permit #:C20-000611 Existing Future Public Private Right-of-Way Improvements Improvements (D) (E) Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost GENERAL ITEMS Backfill & Compaction- embankment GI-1 6.00$ CY Backfill & Compaction- trench GI-2 9.00$ CY 265 2,385.00 Clear/Remove Brush, by hand (SY)GI-3 1.00$ SY Bollards - fixed GI-4 240.74$ Each Bollards - removable GI-5 452.34$ Each Clearing/Grubbing/Tree Removal GI-6 10,000.00$ Acre 0.57 5,700.00 Excavation - bulk GI-7 2.00$ CY 1200 2,400.00 Excavation - Trench GI-8 5.00$ CY 265 1,325.00 Fencing, cedar, 6' high GI-9 20.00$ LF 120 2,400.00 Fencing, chain link, 4'GI-10 38.31$ LF Fencing, chain link, vinyl coated, 6' high GI-11 20.00$ LF Fencing, chain link, gate, vinyl coated, 20' GI-12 1,400.00$ Each Fill & compact - common barrow GI-13 25.00$ CY 300 7,500.00 Fill & compact - gravel base GI-14 27.00$ CY Fill & compact - screened topsoil GI-15 39.00$ CY Gabion, 12" deep, stone filled mesh GI-16 65.00$ SY Gabion, 18" deep, stone filled mesh GI-17 90.00$ SY Gabion, 36" deep, stone filled mesh GI-18 150.00$ SY Grading, fine, by hand GI-19 2.50$ SY Grading, fine, with grader GI-20 2.00$ SY Monuments, 3' Long GI-21 250.00$ Each Sensitive Areas Sign GI-22 7.00$ Each Sodding, 1" deep, sloped ground GI-23 8.00$ SY Surveying, line & grade GI-24 850.00$ Day 1 850.00 Surveying, lot location/lines GI-25 1,800.00$ Acre Topsoil Type A (imported)GI-26 28.50$ CY Traffic control crew ( 2 flaggers )GI-27 120.00$ HR Trail, 4" chipped wood GI-28 8.00$ SY Trail, 4" crushed cinder GI-29 9.00$ SY Trail, 4" top course GI-30 12.00$ SY Conduit, 2"GI-31 5.00$ LF Wall, retaining, concrete GI-32 55.00$ SF 340 18,700.00 Wall, rockery GI-33 15.00$ SF SUBTOTAL THIS PAGE:41,260.00 (B)(C)(D)(E) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR STREET AND SITE IMPROVEMENTS Quantity Remaining (Bond Reduction) (B)(C) Page 4 of 14 Ref 8-H Bond Quantity Worksheet SECTION II.b TRANSPORTATION Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 5/13/2020 CED Permit #:C20-000611 Existing Future Public Private Right-of-Way Improvements Improvements (D) (E) Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR STREET AND SITE IMPROVEMENTS Quantity Remaining (Bond Reduction) (B)(C) ROAD IMPROVEMENT/PAVEMENT/SURFACING AC Grinding, 4' wide machine < 1000sy RI-1 30.00$ SY AC Grinding, 4' wide machine 1000-2000sy RI-2 16.00$ SY AC Grinding, 4' wide machine > 2000sy RI-3 10.00$ SY AC Removal/Disposal RI-4 35.00$ SY Barricade, Type III ( Permanent )RI-5 56.00$ LF Guard Rail RI-6 30.00$ LF Curb & Gutter, rolled RI-7 17.00$ LF Curb & Gutter, vertical RI-8 12.50$ LF 635 7,937.50 Curb and Gutter, demolition and disposal RI-9 18.00$ LF 140 2,520.00 Curb, extruded asphalt RI-10 5.50$ LF Curb, extruded concrete RI-11 7.00$ LF Sawcut, asphalt, 3" depth RI-12 1.85$ LF 180 333.00 Sawcut, concrete, per 1" depth RI-13 3.00$ LF Sealant, asphalt RI-14 2.00$ LF Shoulder, gravel, 4" thick RI-15 15.00$ SY Sidewalk, 4" thick RI-16 38.00$ SY 240 9,120.00 Sidewalk, 4" thick, demolition and disposal RI-17 32.00$ SY 60 1,920.00 Sidewalk, 5" thick RI-18 41.00$ SY Sidewalk, 5" thick, demolition and disposal RI-19 40.00$ SY Sign, Handicap RI-20 85.00$ Each 2 170.00 Striping, per stall RI-21 7.00$ Each 23 161.00 Striping, thermoplastic, ( for crosswalk )RI-22 3.00$ SF Striping, 4" reflectorized line RI-23 0.50$ LF Additional 2.5" Crushed Surfacing RI-24 3.60$ SY HMA 1/2" Overlay 1.5" RI-25 14.00$ SY HMA 1/2" Overlay 2"RI-26 18.00$ SY HMA Road, 2", 4" rock, First 2500 SY RI-27 28.00$ SY HMA Road, 2", 4" rock, Qty. over 2500SY RI-28 21.00$ SY HMA Road, 4", 6" rock, First 2500 SY RI-29 45.00$ SY HMA Road, 4", 6" rock, Qty. over 2500 SY RI-30 37.00$ SY HMA Road, 4", 4.5" ATB RI-31 38.00$ SY Gravel Road, 4" rock, First 2500 SY RI-32 15.00$ SY Gravel Road, 4" rock, Qty. over 2500 SY RI-33 10.00$ SY Thickened Edge RI-34 8.60$ LF SUBTOTAL THIS PAGE:22,161.50 (B)(C)(D)(E) Page 5 of 14 Ref 8-H Bond Quantity Worksheet SECTION II.b TRANSPORTATION Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 5/13/2020 CED Permit #:C20-000611 Existing Future Public Private Right-of-Way Improvements Improvements (D) (E) Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR STREET AND SITE IMPROVEMENTS Quantity Remaining (Bond Reduction) (B)(C) PARKING LOT SURFACING No. 2" AC, 2" top course rock & 4" borrow PL-1 21.00$ SY 950 19,950.00 2" AC, 1.5" top course & 2.5" base course PL-2 28.00$ SY 4" select borrow PL-3 5.00$ SY 1.5" top course rock & 2.5" base course PL-4 14.00$ SY SUBTOTAL PARKING LOT SURFACING:19,950.00 (B)(C)(D)(E) LANDSCAPING & VEGETATION No. Street Trees LA-1 Median Landscaping LA-2 Right-of-Way Landscaping LA-3 Wetland Landscaping LA-4 SUBTOTAL LANDSCAPING & VEGETATION: (B)(C)(D)(E) TRAFFIC & LIGHTING No. Signs TR-1 Street Light System ( # of Poles)TR-2 1,000.00$ EACH 24 24,000.00 Traffic Signal TR-3 Traffic Signal Modification TR-4 SUBTOTAL TRAFFIC & LIGHTING:24,000.00 (B)(C)(D)(E) WRITE-IN-ITEMS Wall, Ultrablock 30.00$ SF 1100 33,000.00 SUBTOTAL WRITE-IN ITEMS:33,000.00 STREET AND SITE IMPROVEMENTS SUBTOTAL:140,371.50 SALES TAX @ 10%14,037.15 STREET AND SITE IMPROVEMENTS TOTAL:154,408.65 (B)(C)(D)(E) Page 6 of 14 Ref 8-H Bond Quantity Worksheet SECTION II.b TRANSPORTATION Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 5/13/2020 CED Permit #:C20-000611 Existing Future Public Private Right-of-Way Improvements Improvements (D) (E) Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost DRAINAGE (CPE = Corrugated Polyethylene Pipe, N12 or Equivalent) For Culvert prices, Average of 4' cover was assumed. Assume perforated PVC is same price as solid pipe.) Access Road, R/D D-1 26.00$ SY * (CBs include frame and lid) Beehive D-2 90.00$ Each Through-curb Inlet Framework D-3 400.00$ Each CB Type I D-4 1,500.00$ Each 14 21,000.00 CB Type IL D-5 1,750.00$ Each CB Type II, 48" diameter D-6 2,300.00$ Each 2 4,600.00 for additional depth over 4' D-7 480.00$ FT CB Type II, 54" diameter D-8 2,500.00$ Each 1 2,500.00 for additional depth over 4'D-9 495.00$ FT CB Type II, 60" diameter D-10 2,800.00$ Each for additional depth over 4'D-11 600.00$ FT CB Type II, 72" diameter D-12 6,000.00$ Each for additional depth over 4'D-13 850.00$ FT CB Type II, 96" diameter D-14 14,000.00$ Each for additional depth over 4'D-15 925.00$ FT Trash Rack, 12"D-16 350.00$ Each Trash Rack, 15"D-17 410.00$ Each Trash Rack, 18"D-18 480.00$ Each Trash Rack, 21"D-19 550.00$ Each Cleanout, PVC, 4"D-20 150.00$ Each Cleanout, PVC, 6"D-21 170.00$ Each Cleanout, PVC, 8"D-22 200.00$ Each 13 2,600.00 Culvert, PVC, 4" D-23 10.00$ LF 255 2,550.00 Culvert, PVC, 6" D-24 13.00$ LF Culvert, PVC, 8" D-25 15.00$ LF Culvert, PVC, 12" D-26 23.00$ LF Culvert, PVC, 15" D-27 35.00$ LF Culvert, PVC, 18" D-28 41.00$ LF Culvert, PVC, 24"D-29 56.00$ LF Culvert, PVC, 30" D-30 78.00$ LF Culvert, PVC, 36" D-31 130.00$ LF Culvert, CMP, 8"D-32 19.00$ LF Culvert, CMP, 12"D-33 29.00$ LF SUBTOTAL THIS PAGE:33,250.00 (B)(C)(D)(E) Quantity Remaining (Bond Reduction) (B)(C) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR DRAINAGE AND STORMWATER FACILITIES Page 7 of 14 Ref 8-H Bond Quantity Worksheet SECTION II.c DRAINAGE Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 5/13/2020 CED Permit #:C20-000611 Existing Future Public Private Right-of-Way Improvements Improvements (D) (E) Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost Quantity Remaining (Bond Reduction) (B)(C) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR DRAINAGE AND STORMWATER FACILITIES DRAINAGE (Continued) Culvert, CMP, 15"D-34 35.00$ LF Culvert, CMP, 18"D-35 41.00$ LF Culvert, CMP, 24"D-36 56.00$ LF Culvert, CMP, 30"D-37 78.00$ LF Culvert, CMP, 36"D-38 130.00$ LF Culvert, CMP, 48"D-39 190.00$ LF Culvert, CMP, 60"D-40 270.00$ LF Culvert, CMP, 72"D-41 350.00$ LF Culvert, Concrete, 8"D-42 42.00$ LF Culvert, Concrete, 12"D-43 48.00$ LF Culvert, Concrete, 15"D-44 78.00$ LF Culvert, Concrete, 18"D-45 48.00$ LF Culvert, Concrete, 24"D-46 78.00$ LF Culvert, Concrete, 30"D-47 125.00$ LF Culvert, Concrete, 36"D-48 150.00$ LF Culvert, Concrete, 42"D-49 175.00$ LF Culvert, Concrete, 48"D-50 205.00$ LF Culvert, CPE Triple Wall, 6" D-51 14.00$ LF Culvert, CPE Triple Wall, 8" D-52 16.00$ LF Culvert, CPE Triple Wall, 12" D-53 24.00$ LF Culvert, CPE Triple Wall, 15" D-54 35.00$ LF Culvert, CPE Triple Wall, 18" D-55 41.00$ LF Culvert, CPE Triple Wall, 24" D-56 56.00$ LF Culvert, CPE Triple Wall, 30" D-57 78.00$ LF Culvert, CPE Triple Wall, 36" D-58 130.00$ LF Culvert, LCPE, 6"D-59 60.00$ LF 144 8,640.00 Culvert, LCPE, 8"D-60 72.00$ LF 1150 82,800.00 Culvert, LCPE, 12"D-61 84.00$ LF Culvert, LCPE, 15"D-62 96.00$ LF Culvert, LCPE, 18"D-63 108.00$ LF Culvert, LCPE, 24"D-64 120.00$ LF Culvert, LCPE, 30"D-65 132.00$ LF Culvert, LCPE, 36"D-66 144.00$ LF Culvert, LCPE, 48"D-67 156.00$ LF Culvert, LCPE, 54"D-68 168.00$ LF SUBTOTAL THIS PAGE:91,440.00 (B)(C)(D)(E) Page 8 of 14 Ref 8-H Bond Quantity Worksheet SECTION II.c DRAINAGE Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 5/13/2020 CED Permit #:C20-000611 Existing Future Public Private Right-of-Way Improvements Improvements (D) (E) Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost Quantity Remaining (Bond Reduction) (B)(C) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR DRAINAGE AND STORMWATER FACILITIES DRAINAGE (Continued) Culvert, LCPE, 60"D-69 180.00$ LF Culvert, LCPE, 72"D-70 192.00$ LF Culvert, HDPE, 6"D-71 42.00$ LF Culvert, HDPE, 8"D-72 42.00$ LF Culvert, HDPE, 12"D-73 74.00$ LF Culvert, HDPE, 15"D-74 106.00$ LF Culvert, HDPE, 18"D-75 138.00$ LF Culvert, HDPE, 24"D-76 221.00$ LF Culvert, HDPE, 30"D-77 276.00$ LF Culvert, HDPE, 36"D-78 331.00$ LF Culvert, HDPE, 48"D-79 386.00$ LF Culvert, HDPE, 54"D-80 441.00$ LF Culvert, HDPE, 60"D-81 496.00$ LF Culvert, HDPE, 72"D-82 551.00$ LF Pipe, Polypropylene, 6"D-83 84.00$ LF Pipe, Polypropylene, 8"D-84 89.00$ LF Pipe, Polypropylene, 12"D-85 95.00$ LF Pipe, Polypropylene, 15"D-86 100.00$ LF Pipe, Polypropylene, 18"D-87 106.00$ LF Pipe, Polypropylene, 24"D-88 111.00$ LF Pipe, Polypropylene, 30"D-89 119.00$ LF Pipe, Polypropylene, 36"D-90 154.00$ LF Pipe, Polypropylene, 48"D-91 226.00$ LF Pipe, Polypropylene, 54"D-92 332.00$ LF Pipe, Polypropylene, 60"D-93 439.00$ LF Pipe, Polypropylene, 72"D-94 545.00$ LF Culvert, DI, 6"D-95 61.00$ LF Culvert, DI, 8"D-96 84.00$ LF Culvert, DI, 12"D-97 106.00$ LF Culvert, DI, 15"D-98 129.00$ LF Culvert, DI, 18"D-99 152.00$ LF Culvert, DI, 24"D-100 175.00$ LF Culvert, DI, 30"D-101 198.00$ LF Culvert, DI, 36"D-102 220.00$ LF Culvert, DI, 48"D-103 243.00$ LF Culvert, DI, 54"D-104 266.00$ LF Culvert, DI, 60"D-105 289.00$ LF Culvert, DI, 72"D-106 311.00$ LF SUBTOTAL THIS PAGE: (B)(C)(D)(E) Page 9 of 14 Ref 8-H Bond Quantity Worksheet SECTION II.c DRAINAGE Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 5/13/2020 CED Permit #:C20-000611 Existing Future Public Private Right-of-Way Improvements Improvements (D) (E) Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost Quantity Remaining (Bond Reduction) (B)(C) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR DRAINAGE AND STORMWATER FACILITIES Specialty Drainage Items Ditching SD-1 9.50$ CY Flow Dispersal Trench (1,436 base+)SD-3 28.00$ LF 53 2,920.00 French Drain (3' depth)SD-4 26.00$ LF Geotextile, laid in trench, polypropylene SD-5 3.00$ SY Mid-tank Access Riser, 48" dia, 6' deep SD-6 2,000.00$ Each Pond Overflow Spillway SD-7 16.00$ SY Restrictor/Oil Separator, 12"SD-8 1,150.00$ Each Restrictor/Oil Separator, 15"SD-9 1,350.00$ Each Restrictor/Oil Separator, 18"SD-10 1,700.00$ Each Riprap, placed SD-11 42.00$ CY 5 210.00 Tank End Reducer (36" diameter)SD-12 1,200.00$ Each Infiltration pond testing SD-13 125.00$ HR Permeable Pavement SD-14 Permeable Concrete Sidewalk SD-15 Culvert, Box __ ft x __ ft SD-16 SUBTOTAL SPECIALTY DRAINAGE ITEMS:3,130.00 (B)(C)(D)(E) STORMWATER FACILITIES (Include Flow Control and Water Quality Facility Summary Sheet and Sketch) Detention Pond SF-1 Each Detention Tank SF-2 25,000.00$ Each 1 25,000.00 Detention Vault SF-3 Each Infiltration Pond SF-4 Each Infiltration Tank SF-5 Each Infiltration Vault SF-6 Each Infiltration Trenches SF-7 Each Basic Biofiltration Swale SF-8 Each Wet Biofiltration Swale SF-9 Each Wetpond SF-10 Each Wetvault SF-11 Each Sand Filter SF-12 Each Sand Filter Vault SF-13 Each Linear Sand Filter SF-14 Each Proprietary Facility SF-15 Each Bioretention Facility SF-16 5,000.00$ Each 2 10,000.00 SUBTOTAL STORMWATER FACILITIES:35,000.00 (B)(C)(D)(E) Page 10 of 14 Ref 8-H Bond Quantity Worksheet SECTION II.c DRAINAGE Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 5/13/2020 CED Permit #:C20-000611 Existing Future Public Private Right-of-Way Improvements Improvements (D) (E) Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost Quantity Remaining (Bond Reduction) (B)(C) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR DRAINAGE AND STORMWATER FACILITIES WRITE-IN-ITEMS (INCLUDE ON-SITE BMPs) Area Drain, PVC, 10"WI-1 300.00$ EACH 10 3,000.00 Trench Drain WI-2 50.00$ LF 24 1,200.00 WI-3 WI-4 WI-5 WI-6 WI-7 WI-8 WI-9 WI-10 WI-11 WI-12 WI-13 WI-14 WI-15 SUBTOTAL WRITE-IN ITEMS:4,200.00 DRAINAGE AND STORMWATER FACILITIES SUBTOTAL:167,020.00 SALES TAX @ 10%16,702.00 DRAINAGE AND STORMWATER FACILITIES TOTAL:183,722.00 (B)(C)(D)(E) Page 11 of 14 Ref 8-H Bond Quantity Worksheet SECTION II.c DRAINAGE Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 5/13/2020 CED Permit #:C20-000611 Existing Future Public Private Right-of-Way Improvements Improvements (D) (E) Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost Connection to Existing Watermain W-1 2,000.00$ Each Ductile Iron Watermain, CL 52, 4 Inch Diameter W-2 50.00$ LF Ductile Iron Watermain, CL 52, 6 Inch Diameter W-3 56.00$ LF Ductile Iron Watermain, CL 52, 8 Inch Diameter W-4 60.00$ LF Ductile Iron Watermain, CL 52, 10 Inch Diameter W-5 70.00$ LF Ductile Iron Watermain, CL 52, 12 Inch Diameter W-6 80.00$ LF Gate Valve, 4 inch Diameter W-7 500.00$ Each Gate Valve, 6 inch Diameter W-8 700.00$ Each Gate Valve, 8 Inch Diameter W-9 800.00$ Each Gate Valve, 10 Inch Diameter W-10 1,000.00$ Each Gate Valve, 12 Inch Diameter W-11 1,200.00$ Each Fire Hydrant Assembly W-12 4,000.00$ Each Permanent Blow-Off Assembly W-13 1,800.00$ Each Air-Vac Assembly, 2-Inch Diameter W-14 2,000.00$ Each Air-Vac Assembly, 1-Inch Diameter W-15 1,500.00$ Each Compound Meter Assembly 3-inch Diameter W-16 8,000.00$ Each Compound Meter Assembly 4-inch Diameter W-17 9,000.00$ Each Compound Meter Assembly 6-inch Diameter W-18 10,000.00$ Each Pressure Reducing Valve Station 8-inch to 10-inch W-19 20,000.00$ Each WATER SUBTOTAL: SALES TAX @ 10% WATER TOTAL: (B)(C)(D)(E) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR WATER Quantity Remaining (Bond Reduction) (B)(C) Page 12 of 14 Ref 8-H Bond Quantity Worksheet SECTION II.d WATER Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 5/13/2020 CED Permit #:C20-000611 Existing Future Public Private Right-of-Way Improvements Improvements (D) (E) Description No. Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost Clean Outs SS-1 1,000.00$ Each Grease Interceptor, 500 gallon SS-2 8,000.00$ Each Grease Interceptor, 1000 gallon SS-3 10,000.00$ Each Grease Interceptor, 1500 gallon SS-4 15,000.00$ Each Side Sewer Pipe, PVC. 4 Inch Diameter SS-5 80.00$ LF Side Sewer Pipe, PVC. 6 Inch Diameter SS-6 95.00$ LF Sewer Pipe, PVC, 8 inch Diameter SS-7 105.00$ LF Sewer Pipe, PVC, 12 Inch Diameter SS-8 120.00$ LF Sewer Pipe, DI, 8 inch Diameter SS-9 115.00$ LF Sewer Pipe, DI, 12 Inch Diameter SS-10 130.00$ LF Manhole, 48 Inch Diameter SS-11 6,000.00$ Each Manhole, 54 Inch Diameter SS-13 6,500.00$ Each Manhole, 60 Inch Diameter SS-15 7,500.00$ Each Manhole, 72 Inch Diameter SS-17 8,500.00$ Each Manhole, 96 Inch Diameter SS-19 14,000.00$ Each Pipe, C-900, 12 Inch Diameter SS-21 180.00$ LF Outside Drop SS-24 1,500.00$ LS Inside Drop SS-25 1,000.00$ LS Sewer Pipe, PVC, ____ Inch Diameter SS-26 Lift Station (Entire System)SS-27 LS SANITARY SEWER SUBTOTAL: SALES TAX @ 10% SANITARY SEWER TOTAL: (B)(C)(D)(E) SITE IMPROVEMENT BOND QUANTITY WORKSHEET FOR SANITARY SEWER Quantity Remaining (Bond Reduction) (B)(C) Page 13 of 14 Ref 8-H Bond Quantity Worksheet SECTION II.e SANITARY SEWER Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 5/13/2020 Planning Division |1055 South Grady Way – 6 th Floor | Renton, WA 98057 (425) 430-7200 Date: Name:Project Name: PE Registration No:CED Plan # (LUA): Firm Name:CED Permit # (U): Firm Address:Site Address: Phone No.Parcel #(s): Email Address:Project Phase: Site Restoration/Erosion Sediment Control Subtotal (a) Existing Right-of-Way Improvements Subtotal (b)(b)-$ Future Public Improvements Subtotal (c)-$ Stormwater & Drainage Facilities (Public & Private) Subtotal (d)(d)183,722.00$ (e) (f) Site Restoration Civil Construction Permit Maintenance Bond 36,744.40$ Bond Reduction 2 Construction Permit Bond Amount 3 Minimum Bond Amount is $10,000.00 1 Estimate Only - May involve multiple and variable components, which will be established on an individual basis by Development Engineering. 2 The City of Renton allows one request only for bond reduction prior to the maintenance period. Reduction of not more than 70% of the original bond amount, provided that the remaining 30% will cover all remaining items to be constructed. 3 Required Bond Amounts are subject to review and modification by Development Engineering. * Note: The word BOND as used in this document means any financial guarantee acceptable to the City of Renton. ** Note: All prices include labor, equipment, materials, overhead and profit. EST1 ((b) + (c) + (d)) x 20% -$ MAINTENANCE BOND */** (after final acceptance of construction) 9,749.85$ -$ 183,722.00$ 9,749.85$ -$ 183,722.00$ -$ 193,471.85$ P (a) x 100% SITE IMPROVEMENT BOND QUANTITY WORKSHEET BOND CALCULATIONS 5/13/2020 Peter Apostol, PE 35163 Coterra Engineering R ((b x 150%) + (d x 100%)) S (e) x 150% + (f) x 100% Bond Reduction: Existing Right-of-Way Improvements (Quantity Remaining)2 Bond Reduction: Stormwater & Drainage Facilities (Quantity Remaining)2 T (P +R - S) Prepared by:Project Information CONSTRUCTION BOND AMOUNT */** (prior to permit issuance) (206) 596-7115 peter@coterraengineering.com La Fortuna Phase III ##-###### SE 173rd Pl. Renton, WA 98058 3956200000 FOR APPROVAL C20-000611 321 3rd Ave South, #406, Seattle, WA 98104 Page 14 of 14 Ref 8-H Bond Quantity Worksheet SECTION III. BOND WORKSHEET Unit Prices Updated: 06/14/2016 Version: 04/26/2017 Printed 5/13/2020 Appendix G Declaration of Covenants Page 1 of ___ Return Address: City Clerk’s Office City of Renton 1055 S Grady Way Renton, WA 98057 DECLARATION OF COVENANT FOR INSPECTION AND MAINTENANCE OF DRAINAGE FACILITIES AND ON-SITE BMPS Grantor: Grantee: City of Renton, a Washington municipal corporation Legal Description: Assessor's Tax Parcel ID#: IN CONSIDERATION of the approved City of Renton (check one of the following) Residential Building Permit Commercial Building Permit Clearing and Grading Permit Civil Construction or Utility Permit for Permit(s)_____________________ (Construction/Building/Utility Permit #) relating to the real property ("Property") described above, the Grantor(s), the owner(s) in fee of that Property, hereby covenants (covenant) with the City of Renton (“City of Renton” or “City”), a municipal corporation of the state of Washington, that he/she (they) will observe, consent to, and abide by the conditions and obligations set forth and described in Paragraphs 1 through 9 below with regard to the Property, and hereby grants (grant) an easement as described in Paragraphs 2 and 3. Grantor(s) hereby grants (grant), covenants (covenant), and agrees (agree) as follows: 1.The Grantor(s) or his/her (their) successors in interest and assigns ("Owners ") shall at their own cost, operate, maintain, and keep in good repair, the Property's drainage facilities constructed as required in the approved construction plans and specifications __________________ (Project Plan #) on file with the City of Renton and submitted to the City of Renton for the review and approval of permit(s) _____________________________ (Construction/Building/Utility Permit #). The Property's drainage facilities are shown and/or listed on Exhibit A – Site Plan. The Property’s drainage facilities shall be maintained in compliance with the operation and maintenance schedule included and attached herein as Exhibit B – Operations and Maintenance. Drainage facilities include pipes, channels, flow control facilities, water quality facilities, on-site best management practices (BMPs) and other engineered structures designed to manage and/or Page 2 of ___ treat stormwater on the Property. On-site BMPs include dispersion and infiltration devices, bioretention, permeable pavements, rainwater harvesting systems, tree retention credit, reduced impervious surface footprint, vegetated roofs and other measures designed to mimic pre-developed hydrology and minimize stormwater runoff on the Property. 2.City of Renton shall have the right to ingress and egress over those portions of the Property necessary to perform inspections of the stormwater facilities and BMPs and conduct maintenance activities specified in this Declaration of Covenant and in accordance with the Renton Municipal Code. City of Renton shall provide at least thirty (30) days’ written notice to the Owners that entry on the Property is planned for the inspection of drainage facilities. After the thirty (30) days, the Owners shall allow the City of Renton to enter for the sole purpose of inspecting drainage facilities. In lieu of inspection by the City, the Owners may elect to engage a licensed civil engineer registered in the state of Washington who has expertise in drainage to inspect the drainage facilities and provide a written report describing their condition. If the engineer option is chosen, the Owners shall provide written notice to the City of Renton within fifteen (15) days of receiving the City’s notice of inspection. Within thirty (30) days of giving this notice, the Owners, or engineer on behalf of the Owners, shall provide the engineer’s report to the City of Renton. If the report is not provided in a timely manner as specified above, the City of Renton may inspect the drainage facilities without further notice. 3.If City of Renton determines from its inspection, or from an engineer’s report provided in accordance with Paragraph 2, that maintenance, repair, restoration, and/or mitigation work is required to be done to any of the drainage facilities, City of Renton shall notify the Owners of the specific maintenance, repair, restoration, and/or mitigation work (“Work”) required pursuant to the Renton Municipal Code. The City shall also set a reasonable deadline for the Owners to complete the Work, or to provide an engineer’s report that verifies completion of the Work. After the deadline has passed, the Owners shall allow the City access to re-inspect the drainage facilities unless an engineer’s report has been provided verifying completion of the Work. If the Work is not completed within the time frame set by the City, the City may initiate an enforcement action and/or perform the Work and hereby is given access to the Property for such purposes. Written notice will be sent to the Owners stating the City’s intention to perform such Work. This Work will not commence until at least seven (7) days after such notice is mailed. If, within the sole discretion of the City, there exists an imminent or present danger, the seven (7) day notice period will be waived and Work will begin immediately. 4.The Owners shall assume all responsibility for the cost of any Work, or any measures taken by the City to address conditions as described in Paragraph 3. Such responsibility shall include reimbursement to the City within thirty (30) days of the receipt of the invoice for any such Work performed. Overdue payments will require payment of interest at the maximum legal rate allowed by RCW 19.52.020 (currently twelve percent (12%)). If the City initiates legal action to enforce this agreement, the prevailing party in such action is entitled to recover reasonable litigation costs and attorney’s fees. 5.The Owners are required to obtain written approval from City of Renton prior to filling, piping, cutting, or removing vegetation (except in routine landscape maintenance) in open vegetated stormwater facilities (such as swales, channels, ditches, ponds, etc.), or performing any alterations or modifications to the drainage facilities referenced in this Declaration of Covenant. Page 3 of ___ 6.Any notice or consent required to be given or otherwise provided for by the provisions of this Agreement shall be effective upon personal delivery, or three (3) days after mailing by Certified Mail, return receipt requested. 7.With regard to the matters addressed herein, this agreement constitutes the entire agreement between the parties, and supersedes all prior discussions, negotiations, and all agreements whatsoever whether oral or written. 8.This Declaration of Covenant is intended to protect the value and desirability and promote efficient and effective management of surface water drainage of the real property described above, and shall inure to the benefit of all the citizens of the City of Renton and its successors and assigns. This Declaration of Covenant shall run with the land and be binding upon Grantor(s), and Grantor's(s') successors in interest, and assigns. 9.This Declaration of Covenant may be terminated by execution of a written agreement by the Owners and the City that is recorded by King County in its real property records. IN WITNESS WHEREOF, this Declaration of Covenant for the Inspection and Maintenance of Drainage Facilities is executed this _____ day of ____________________, 20_____. GRANTOR, owner of the Property GRANTOR, owner of the Property STATE OF WASHINGTON ) COUNTY OF KING )ss. On this day personally appeared before me: , to me known to be the individual(s) described in and who executed the within and foregoing instrument and acknowledged that they signed the same as their free and voluntary act and deed, for the uses and purposes therein stated. Given under my hand and official seal this _____ day of ___________________, 20_____. Printed name Notary Public in and for the State of Washington, residing at My appointment expires NATIVE VEGETATION AREA MIN. AREA REQUIRED 33,000 SF coterra ENGINEERING PLLC MAINTENANCE INSTRUCTIONS FOR A BIORETENTION CELL Your property contains an on-site BMP (best management practice) called “bioretention,” which was installed to mitigate the stormwater quantity and quality impacts on both the impervious (paved or roof) and pervious surfaces (lawn or landscape) on your property. Bioretention cells, like rain gardens, are vegetated closed depressions or ponds that retain and filter stormwater from an area of impervious surface or nonnative pervious surface. Bioretention cells rely on effective infiltration performance more so than rain gardens. The soil in the bioretention cell has been enhanced to encourage and support vigorous plant growth that serves to filter the water and sustain a minimum infiltration capacity. Depending on soil conditions, bioretention cells may have water in them throughout the wet season and may overflow during major storm events. However, standing water can also be an indicator that periodic maintenance is required to sustain infiltrative performance. This on-site BMP shall be maintained per Appendix A of the City of Renton’s Surface Water Design Manual. MAINTENANCE RESTRICTIONS The size, placement, and design of the rain garden as depicted by the site plan and design details must be maintained and may not be changed without written approval from the City of Renton or through a future development permit from the City of Renton. Chemical fertilizers and pesticides must not be used. INSPECTION FREQUENCY AND MAINTENANCE GUIDELINES • Bioretention cells must be inspected annually for physical defects and sediment accumulation. • Bioretention cells have inflow and overflow inlets and outlets. These need to be maintained to ensure that water is moving into and out of the bioretention area. Check inlets/outlets for debris/sediment blockage, bare spots (exposed soil), or other signs of erosion damage (soil movement). Remove debris and obstructions as necessary. • After major storm events, the bioretention cell should be checked to see that the overflow system is working properly and sedimentation is not occurring at the inlet. If erosion damage or bare spots are evident, they should be stabilized with soil, plant material, mulch, or landscape rock. Sediment deposits should be carefully removed and the sediment source eliminated. • Plants must be adapted to wet winter conditions and dry summer conditions. Vegetation is to be watered and pruned as needed. • Frequent watering is required to keep the plants healthy: o Year 1: weekly, o Year 2: bimonthly, o Year 3: bimonthly, o Year 4 and beyond: as needed for established plantings and dry periods. • Chemical fertilizers and pesticides must not be used. • Bioretention soil must be replaced in areas where sediment accumulation is preventing adequate infiltration of water through the soil. • Compacted soil should be decompacted. • Trash and debris must be removed often from the bioretention depression. • Mulch must be applied to bare soil at a minimum of 2 inches to maintain healthy growth. • Compost may be added if soil nutrients are no longer adequate to support plant growth. • Plant materials may be changed to suit tastes. • Vegetation should be maintained as follows: 1) Replace all dead vegetation as soon as possible; 2) Remove fallen leaves and debris as needed; 3) Remove all noxious vegetation when discovered; 4) Manually weed without herbicides or pesticides; 5) To protect infiltration performance, do not compact soils in the bioretention cell with heavy maintenance equipment and/or excessive foot traffic; 6) During drought conditions, use mulch to prevent excess solar damage and water loss. RECORDING REQUIREMENT These bioretention on-site BMP maintenance and operation instructions must be recorded as an attachment to the required declaration of covenant and grant of easement per Requirement 3 of Section C.1.3.4 of the City of Renton Surface Water Design Manual. The intent of these instructions is to explain to future property owners, the purpose of the BMP and how it must be maintained and operated. These instructions are intended to be a minimum; the City of Renton may require additional instructions based on site-specific conditions. See the City of Renton’s Surface Water Design Manual website for additional information and updates. TYPICAL BIORETENTION CELL (SPILLWAY OR CATCH BASIN OUTLET) TREES, SHRUBS GROUND COVER BIORETENTION AREA PLAN VIEW NTS VEGETATEDCOMPACTEDEARTH BERM ROCKED SPILLWAY, 2'Wx4'L (OR BEYOND BERM IF LONGER), OVERFLOW TOSUITABLE DISCHARGE AREA TREES, SHRUBS GROUND COVER BIORETENTION AREA PLAN VIEW NTS VEGETATED COMPACTED EARTH BERM, TOP WIDTH2' MIN 4" RIGID PIPE OUTLET TO STORM SYSTEM CATCH BASINw/GRATE SECTION A-ANTS BIORETENTION AREA GROUNDCOVER TREES TREES SHRUBS 6" MIN TO 12" MAX WATER DEPTH OVERFLOW TO SUITABLE SURFACEDISCHARGE AREA 2' MIN TOP WIDTH COMPACTED EARTHBERM (AS NEEDED) 6" MIN FREEBOARD ABOVE OVERFLOW WS TO TOP OF BERM OR ADJACENT ROADWAY BIORETENTIONSOIL MIX PERREFERENCE 11-C, MIN.18" DEPTH MAX SLOPE 3H:1V BELOW OVERFLOW WATERSURFACE ELEVATION (TYP.) MAINTENANCE INSTRUCTIONS FOR FULL DISPERSION Your property contains an on-site BMP (best management practice) called “full dispersion.” Full dispersion is a strategy for minimizing the area disturbed by development (i.e., impervious or nonnative pervious surfaces, such as concrete areas, roofs, and lawns) relative to native vegetated areas (e.g., forested surface) together with the application of dispersion techniques that utilize the natural capacity of the native vegetated areas to mitigate the stormwater runoff quantity and quality impacts of the developed surfaces. This on-site BMP has two primary components that must be maintained per Appendix A of the City of Renton’s Surface Water Design Manual: (1) the devices that disperse runoff from the developed surfaces, and (2) the native vegetated area and flowpath receiving the dispersed runoff. Dispersion Devices The dispersion devices used on your property include the following as indicated on the site plan (CHECK THE BOX(ES) THAT APPLY): splash blocks, rock pads, gravel filled trenches, sheet flow. MAINTENANCE RESTRICTIONS The size, placement, composition, and downstream flowpaths of these devices as depicted by the site plan and design details must be maintained and may not be changed without written approval from the City of Renton or through a future development permit from the City of Renton. INSPECTION FREQUENCY AND MAINTENANCE GUIDELINES Dispersion Devices • Dispersion devices must be inspected annually and after major storm events to identify and repair any physical defects. • When native soil is exposed or erosion channels are present, the sources of the erosion or concentrated flow need to be identified and mitigated. • Bare spots should be re-vegetated with native vegetation. • Concentrated flow can be mitigated by leveling the edge of the pervious area and/or regrading or replenishing the rock in the dispersion device, such as in rock pads and gravel-filled trenches. Native Growth Retention Area • The native vegetated surface required for full dispersion is delineated as a “native growth retention area” on the on-site BMP site plan. The trees, vegetation, ground cover, and soil conditions in this area may not be disturbed, except as allowed by the following provisions for that portion of the native growth retention area outside of critical areas and critical area buffers: 1. Individual trees that have a structural defect due to disease or other defects, and which threaten to damage a structure, road, parking area, utility, or place of employment or public assembly, or block emergency access, may be topped, pruned, or removed as needed to eliminate the threat. 2. Dead or fallen trees, tree limbs within ten feet of the ground, and branches overhanging a residence may be removed to reduce the danger of wildfire. 3. Noxious weeds (i.e., plant species listed on the State noxious weed list in Chapter 16-750 WAC) and invasive vegetation (i.e., plant species listed as obnoxious weeds on the noxious weed list adopted by King County) may be removed. 4. Passive recreation uses and related facilities, including pedestrian, equestrian community and bicycle trails, nature viewing areas, fishing and camping areas, and other similar uses that do not require permanent structures, are allowed if clearing and soil compaction associated with these uses and facilities does not exceed eight percent of the native growth retention area. RECORDING REQUIREMENT These full dispersion on-site BMP maintenance and operation instructions must be recorded as an attachment to the required declaration of covenant and grant of easement per Requirement 3 of Section C.1.3.4 of the City of Renton Surface Water Design Manual. The intent of these instructions is to explain to future property owners, the purpose of the BMP and how it must be maintained and operated. These instructions are intended to be a minimum; the City of Renton may require additional instructions based on site-specific conditions. See the City of Renton’s Surface Water Design Manual website for additional information and updates. TYPICAL FULL DISPERSION APPLICATIONS MAINTENANCE INSTRUCTIONS FOR SOIL AMENDMENT Your property contains an on-site BMP (best management practice) called “soil amendment,” which was installed to mitigate the stormwater quantity and quality impacts of some or all of the pervious surfaces on your property. Soil amendment is a method of regaining greater stormwater functions in the post development landscape by increasing treatment of pollutants and sediments, and minimizing the need for some landscaping chemicals. To be successful, the soil condition must be able to soak water into the ground for a reasonable number of years. This on-site BMP shall be maintained per Appendix A of the City of Renton’s Surface Water Design Manual. MAINTENANCE RESTRICTIONS The size, placement, and composition of these devices as depicted by the site plan and design details must be maintained and may not be changed without written approval from the City of Renton or through a future development permit from the City of Renton. INSPECTION FREQUENCY AND MAINTENANCE GUIDELINES To be successful, the soil must be able to soak water into the ground for a reasonable number of years. • Return leaf fall and shredded woody materials from the landscape to the site when possible in order to replenish soil nutrients and structure. • On turf areas, “grasscycle” (mulch-mow or leave the clippings) to build turf health. • Maintain 2 to 3 inches of mulch over bare areas in landscape beds. • Re-seed bare turf areas until the vegetation fully covers the ground surface. • Avoid using pesticides (bug and weed killers) which damage the soil. • Where fertilization is needed (mainly turf and annual flower beds), a moderate fertilization program should be used which relies on compost, natural fertilizers, or slow-release synthetic balanced fertilizers. RECORDING REQUIREMENT These on-site BMP maintenance and operation instructions must be recorded as an attachment to the required declaration of covenant and grant of easement per Requirement 3 of Section C.1.3.4 of the City of Renton Surface Water Design Manual. The intent of these instructions is to explain to future property owners, the purpose of the BMP and how it must be maintained and operated. These instructions are intended to be a minimum; the City of Renton may require additional instructions based on site-specific conditions. See the City of Renton’s Surface Water Design Manual website for additional information and updates. EXHIBIT C LEGAL DESCRIPTION OF LA FORTUNA PROPERTY LA FORTUNA MASTER CONDOMINIUM, ACCORDING TO THE SURVEY MAP AND PLANS RECORDED IN VOLUME 271 OF CONDOMINIUMS, PAGES 99 THROUGH 101, INCLUSIVE, AND ANY AMENDMENTS THERETO, AND THE DECLARATION THEREOF RECORDED UNDER RECORDING NO. 20110323000821, AND ANY AMENDMENTS THERETO, RECORDS OF KING COUNTY, WASHINGTON. Appendix H Operations and Maintenance Manual APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 12/12/2016 2017 City of Renton Surface Water Design Manual A-6 NO. 3 – DETENTION TANKS AND VAULTS MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Any trash and debris which exceed 1 cubic foot per 1,000 square feet (this is about equal to the amount of trash it would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Trash and debris cleared from site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where City personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive growth of grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Tank or Vault Storage Area Trash and debris Any trash and debris accumulated in vault or tank (includes floatables and non-floatables). No trash or debris in vault. Sediment accumulation Accumulated sediment depth exceeds 10% of the diameter of the storage area for ½ length of storage vault or any point depth exceeds 15% of diameter. Example: 72-inch storage tank would require cleaning when sediment reaches depth of 7 inches for more than ½ length of tank. All sediment removed from storage area. Tank Structure Plugged air vent Any blockage of the vent. Tank or vault freely vents. Tank bent out of shape Any part of tank/pipe is bent out of shape more than 10% of its design shape. Tank repaired or replaced to design. Gaps between sections, damaged joints or cracks or tears in wall A gap wider than ½-inch at the joint of any tank sections or any evidence of soil particles entering the tank at a joint or through a wall. No water or soil entering tank through joints or walls. Vault Structure Damage to wall, frame, bottom, and/or top slab Cracks wider than ½-inch, any evidence of soil entering the structure through cracks or qualified inspection personnel determines that the vault is not structurally sound. Vault is sealed and structurally sound. Inlet/Outlet Pipes Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipes Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Access Manhole Cover/lid not in place Cover/lid is missing or only partially in place. Any open manhole requires immediate maintenance. Manhole access covered. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2017 City of Renton Surface Water Design Manual 12/12/2016 A-7 NO. 3 – DETENTION TANKS AND VAULTS MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Access Manhole (cont.) Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs of lift. Cover/lid can be removed and reinstalled by one maintenance person. Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. Large access doors/plate Damaged or difficult to open Large access doors or plates cannot be opened/removed using normal equipment. Replace or repair access door so it can opened as designed. Gaps, doesn't cover completely Large access doors not flat and/or access opening not completely covered. Doors close flat; covers access opening completely. Lifting rings missing, rusted Lifting rings not capable of lifting weight of door or plate. Lifting rings sufficient to lift or remove door or plate. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 12/12/2016 2017 City of Renton Surface Water Design Manual A-8 NO. 4 – CONTROL STRUCTURE/FLOW RESTRICTOR MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Structure Trash and debris Trash or debris of more than ½ cubic foot which is located immediately in front of the structure opening or is blocking capacity of the structure by more than 10%. No Trash or debris blocking or potentially blocking entrance to structure. Trash or debris in the structure that exceeds 1/3 the depth from the bottom of basin to invert the lowest pipe into or out of the basin. No trash or debris in the structure. Deposits of garbage exceeding 1 cubic foot in volume. No condition present which would attract or support the breeding of insects or rodents. Sediment accumulation Sediment exceeds 60% of the depth from the bottom of the structure to the invert of the lowest pipe into or out of the structure or the bottom of the FROP-T section or is within 6 inches of the invert of the lowest pipe into or out of the structure or the bottom of the FROP-T section. Sump of structure contains no sediment. Damage to frame and/or top slab Corner of frame extends more than ¾ inch past curb face into the street (If applicable). Frame is even with curb. Top slab has holes larger than 2 square inches or cracks wider than ¼ inch. Top slab is free of holes and cracks. Frame not sitting flush on top slab, i.e., separation of more than ¾ inch of the frame from the top slab. Frame is sitting flush on top slab. Cracks in walls or bottom Cracks wider than ½ inch and longer than 3 feet, any evidence of soil particles entering structure through cracks, or maintenance person judges that structure is unsound. Structure is sealed and structurally sound. Cracks wider than ½ inch and longer than 1 foot at the joint of any inlet/outlet pipe or any evidence of soil particles entering structure through cracks. No cracks more than 1/4 inch wide at the joint of inlet/outlet pipe. Settlement/ misalignment Structure has settled more than 1 inch or has rotated more than 2 inches out of alignment. Basin replaced or repaired to design standards. Damaged pipe joints Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering the structure at the joint of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of inlet/outlet pipes. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Ladder rungs missing or unsafe Ladder is unsafe due to missing rungs, misalignment, rust, cracks, or sharp edges. Ladder meets design standards and allows maintenance person safe access. FROP-T Section Damaged FROP-T T section is not securely attached to structure wall and outlet pipe structure should support at least 1,000 lbs of up or down pressure. T section securely attached to wall and outlet pipe. Structure is not in upright position (allow up to 10% from plumb). Structure in correct position. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2017 City of Renton Surface Water Design Manual 12/12/2016 A-9 NO. 4 – CONTROL STRUCTURE/FLOW RESTRICTOR MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED FROP-T Section (cont.) Damaged FROP-T (cont.) Connections to outlet pipe are not watertight or show signs of deteriorated grout. Connections to outlet pipe are water tight; structure repaired or replaced and works as designed. Any holes—other than designed holes—in the structure. Structure has no holes other than designed holes. Cleanout Gate Damaged or missing cleanout gate Cleanout gate is missing. Replace cleanout gate. Cleanout gate is not watertight. Gate is watertight and works as designed. Gate cannot be moved up and down by one maintenance person. Gate moves up and down easily and is watertight. Chain/rod leading to gate is missing or damaged. Chain is in place and works as designed. Orifice Plate Damaged or missing orifice plate Control device is not working properly due to missing, out of place, or bent orifice plate. Plate is in place and works as designed. Obstructions to orifice plate Any trash, debris, sediment, or vegetation blocking the plate. Plate is free of all obstructions and works as designed. Overflow Pipe Obstructions to overflow pipe Any trash or debris blocking (or having the potential of blocking) the overflow pipe. Pipe is free of all obstructions and works as designed. Deformed or damaged lip of overflow pipe Lip of overflow pipe is bent or deformed. Overflow pipe does not allow overflow at an elevation lower than design Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Metal Grates (If applicable) Unsafe grate opening Grate with opening wider than 7/8 inch. Grate opening meets design standards. Trash and debris Trash and debris that is blocking more than 20% of grate surface. Grate free of trash and debris. footnote to guidelines for disposal Damaged or missing grate Grate missing or broken member(s) of the grate. Grate is in place and meets design standards. Manhole Cover/Lid Cover/lid not in place Cover/lid is missing or only partially in place. Any open structure requires urgent maintenance. Cover/lid protects opening to structure. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs. of lift. Cover/lid can be removed and reinstalled by one maintenance person. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 12/12/2016 2017 City of Renton Surface Water Design Manual A-10 NO. 5 – CATCH BASINS AND MANHOLES MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Structure Sediment accumulation Sediment exceeds 60% of the depth from the bottom of the catch basin to the invert of the lowest pipe into or out of the catch basin or is within 6 inches of the invert of the lowest pipe into or out of the catch basin. Sump of catch basin contains no sediment. Trash and debris Trash or debris of more than ½ cubic foot which is located immediately in front of the catch basin opening or is blocking capacity of the catch basin by more than 10%. No Trash or debris blocking or potentially blocking entrance to catch basin. Trash or debris in the catch basin that exceeds 1/3 the depth from the bottom of basin to invert the lowest pipe into or out of the basin. No trash or debris in the catch basin. Dead animals or vegetation that could generate odors that could cause complaints or dangerous gases (e.g., methane). No dead animals or vegetation present within catch basin. Deposits of garbage exceeding 1 cubic foot in volume. No condition present which would attract or support the breeding of insects or rodents. Damage to frame and/or top slab Corner of frame extends more than ¾ inch past curb face into the street (If applicable). Frame is even with curb. Top slab has holes larger than 2 square inches or cracks wider than ¼ inch. Top slab is free of holes and cracks. Frame not sitting flush on top slab, i.e., separation of more than ¾ inch of the frame from the top slab. Frame is sitting flush on top slab. Cracks in walls or bottom Cracks wider than ½ inch and longer than 3 feet, any evidence of soil particles entering catch basin through cracks, or maintenance person judges that catch basin is unsound. Catch basin is sealed and is structurally sound. Cracks wider than ½ inch and longer than 1 foot at the joint of any inlet/outlet pipe or any evidence of soil particles entering catch basin through cracks. No cracks more than 1/4 inch wide at the joint of inlet/outlet pipe. Settlement/ misalignment Catch basin has settled more than 1 inch or has rotated more than 2 inches out of alignment. Basin replaced or repaired to design standards. Damaged pipe joints Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering the catch basin at the joint of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of inlet/outlet pipes. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2017 City of Renton Surface Water Design Manual 12/12/2016 A-11 NO. 5 – CATCH BASINS AND MANHOLES MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Inlet/Outlet Pipe (cont.) Damaged inlet/outlet pipe Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Metal Grates (Catch Basins) Unsafe grate opening Grate with opening wider than 7/8 inch. Grate opening meets design standards. Trash and debris Trash and debris that is blocking more than 20% of grate surface. Grate free of trash and debris. footnote to guidelines for disposal Damaged or missing grate Grate missing or broken member(s) of the grate. Any open structure requires urgent maintenance. Grate is in place and meets design standards. Manhole Cover/Lid Cover/lid not in place Cover/lid is missing or only partially in place. Any open structure requires urgent maintenance. Cover/lid protects opening to structure. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs. of lift. Cover/lid can be removed and reinstalled by one maintenance person. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 12/12/2016 2017 City of Renton Surface Water Design Manual A-12 NO. 6 – CONVEYANCE PIPES AND DITCHES MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Pipes Sediment & debris accumulation Accumulated sediment or debris that exceeds 20% of the diameter of the pipe. Water flows freely through pipes. Vegetation/root growth in pipe Vegetation/roots that reduce free movement of water through pipes. Water flows freely through pipes. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Damage to protective coating or corrosion Protective coating is damaged; rust or corrosion is weakening the structural integrity of any part of pipe. Pipe repaired or replaced. Damaged pipes Any dent that decreases the cross section area of pipe by more than 20% or is determined to have weakened structural integrity of the pipe. Pipe repaired or replaced. Ditches Trash and debris Trash and debris exceeds 1 cubic foot per 1,000 square feet of ditch and slopes. Trash and debris cleared from ditches. Sediment accumulation Accumulated sediment that exceeds 20% of the design depth. Ditch cleaned/flushed of all sediment and debris so that it matches design. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where City personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive vegetation growth Vegetation that reduces free movement of water through ditches. Water flows freely through ditches. Erosion damage to slopes Any erosion observed on a ditch slope. Slopes are not eroding. Rock lining out of place or missing (If applicable) One layer or less of rock exists above native soil area 5 square feet or more, any exposed native soil. Replace rocks to design standards. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 12/12/2016 2017 City of Renton Surface Water Design Manual A-40 NO. 28 – NATIVE VEGETATED SURFACE/NATIVE VEGETATED LANDSCAPE BMP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Trash and debris accumulated on the native vegetated surface/native vegetated landscape site. Native vegetated surface site free of any trash or debris. Vegetation Insufficient vegetation Less than two species each of native trees, shrubs, and groundcover occur in the design area. A minimum of two species each of native trees, shrubs, and groundcover is established and healthy. Poor vegetation coverage Less than 90% if the required vegetated area has healthy growth. A minimum of 90% of the required vegetated area has healthy growth. Undesirable vegetation present Weeds, blackberry, and other undesirable plants are invading more than 10% of vegetated area. Less than 10% undesirable vegetation occurs in the required native vegetated surface area. Vegetated Area Soil compaction Soil in the native vegetation area compacted. Less than 8% of native vegetation area is compacted. Insufficient vegetation Less than 3.5 square feet of native vegetation area for every 1 square foot of impervious surface. A minimum of 3.5 square feet of native vegetation area for every 1 square foot of impervious surface. Excess slope Slope of native vegetation area greater than 15%. Slope of native growth area does not exceed 15%. NO. 29 – PERFORATED PIPE CONNECTIONS BMP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Preventive Blocking, obstructions Debris or trash limiting flow into perforated pipe system or outfall of BMP is plugged or otherwise nonfunctioning. Outfall of BMP is receiving designed flows from perforated pipe connection. Inflow Inflow impeded Inflow into the perforated pipe is partially or fully blocked or altered to prevent flow from getting into the pipe. Inflow to the perforated pipe is unimpeded. Pipe Trench Area Surface compacted Ground surface over the perforated pipe trench is compacted or covered with impermeable material. Ground surface over the perforated pipe is not compacted and free of any impervious cover. Outflow Outflow impeded Outflow from the perforated pipe into the public drainage system is blocked. Outflow to the public drainage system is unimpeded. Outfall Area Erosion or landslides Existence of the perforated pipe is causing or exasperating erosion or landslides. Perforated pipe system is sealed off and an alternative BMP is implemented. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 12/12/2016 2017 City of Renton Surface Water Design Manual A-42 NO. 31 – BIORETENTION BMP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Preventive Vegetation Vegetation to be watered and pruned as needed and mulch applied to a minimum of 2 inches to maintain healthy growth. Healthy vegetation growth with full coverage as designed. Bioretention Area Trash and debris Trash and debris in the bioretention area; leaf drop in the fall season. No trash or debris In the bioretention area. Sediment accumulation Sediment accumulation in the bioretention area interfering with infiltration. Water in the bioretention infiltrates as designed. Excessive ponding Standing water in the bioretention area for more than two days. Standing water infiltrates at the desired rate. Inflow restricted Inflow not getting into bioretention; debris/sediment blockage at inlet features; native soil is exposed or other signs of erosion damage is present. Unobstructed and properly routed inflow into bioretention area; inlet is stabilized and appropriately armored. Overflow not controlling excess water Overflow water not controlled by outlet features; native soil is exposed or other signs of erosion damage is present. Outlet features control overflow; overflow is stabilized and appropriately armored. Underdrain not freely flowing Underdrain is not flowing when bioretention area has been infiltrating water. Underdrain flows freely when water is present. Vegetation Poor vegetation coverage Plants not thriving across at least 80% of the entire design vegetated area within the BMP; overly dense vegetation requiring pruning. Healthy water tolerant plants in bioretention area, plants thriving across at least 80% of the entire design vegetated area within the facility. Insufficient vegetation Plants not water tolerant species. Plants are water tolerant. Weeds present Weeds growing in bioretention area. No weeds in bioretention area. Watering not occurring Planting schedule requires frequent watering (approx. weekly Year 1, bimonthly Years 2 and 3) for new facilities, and as needed for established plantings or dry periods Plants are established and thriving Pest control Signs of pests, such as wilting or chewed leaves or bark, spotting or other indicators; extended ponding period encouraging mosquitoes Plant community is pest-free when following an approved Integrated Pest Management plan; bioretention functioning normally and ponding controlled as needed for pest control Containment Berm and Earthen Slopes Erosion Erosion occurring at earthen slopes or containment berm side slope. Erosion on the containment berm and side slopes has been repaired and the cause of the erosion corrected. Voids created by nuisance animals (e.g., rodents) or tree roots Voids affecting berm integrity or creating leaky pond condition Voids have been repaired; facility is free of nuisance animals following an approved Integrated Pest Management plan. Settlement Any part of the containment berm top has less than 6 inches of freeboard from the maximum pond level to the top of the berm. A minimum of 6 inches freeboard from the maximum pond level to the top of the berm. Amended Soil Poor soil nutrients Soil not providing plant nutrients. Soil providing plant nutrients. Bare spots Bare spots on soil in bioretention area. No bare spots, bioretention area covered with vegetation or mulch mixed into the underlying soil. Compaction Poor infiltration due to soil compaction in the bioretention area. No soil compaction in the bioretention area. Appendix I Erosion Control Calculations WEST SEDIMENT TRAP SIZING Habitat - La Fortuna PH III Q10 utilized; calculated via MGS Flood Job No: 19006 8-Apr-20 West Construction Basin - Sediment Trap Sizing 2. If permanent runoff control facilities are part of the project, they should be used for sediment retention. 3. To determine the trap geometry, first calculate the design surface area (SA) of the trap, measured at the invert of the weir. Use the following equation: SA = FS(Q2/Vs) where:Q2 =Design inflow based on the peak discharge from the developed 2-year runoff event from the contributing drainage area as computed in the hydrologic analysis. The 10- year peak flow shall be used if the project size, expected timing and duration of construction, or downstream conditions warrant a higher level of protection. If no hydrologic analysis is required, the Rational Method may be used Vs =The settling velocityof the soil particle of interest. The 0.02 mm (medium silt) particle with an assumed density of 2.65 g/cm3 has been selected as the part of interest and has a settline velocity (Vs) of 0.00096 ft/sec. FS = A safety factor of 2 to account for non-ideal settling. SA = 2 x Q2/0.00096 or 2080 square feet per cfs of inflow Input, Q2 =0.295 cfs Output, SA =614.5833 square feet 4. To aid in determining sediment depth, all traps shall have a staff gage with a prominent mark one foot above the bottom of the trap. settling depth, SD= 2 (ft) 2' min. length, L= 50 Z1= 3 width, W= 25 Z2= 3 Computed Surface Area, SF 614.58 SF equals above L/SD = 25 should be < 200 Bottom of Settling Surface L1 38 W1 13 Add sediment storage depth 1.5 ft Bottom of pond L2 29 W2 4 Total Excavation 2004.625 CF 74.24537 CY HLF -SedimentTrap&Pond - WEST.xlsB1-Trap CENTER SEDIMENT TRAP SIZING Habitat - La Fortuna PH III Q10 utilized; calculated via MGS Flood Job No: 19006 8-Apr-20 Basin 1- Sediment Trap Sizing 2. If permanent runoff control facilities are part of the project, they should be used for sediment retention. 3. To determine the trap geometry, first calculate the design surface area (SA) of the trap, measured at the invert of the weir. Use the following equation: SA = FS(Q2/Vs) where:Q2 =Design inflow based on the peak discharge from the developed 2-year runoff event from the contributing drainage area as computed in the hydrologic analysis. The 10- year peak flow shall be used if the project size, expected timing and duration of construction, or downstream conditions warrant a higher level of protection. If no hydrologic analysis is required, the Rational Method may be used Vs =The settling velocityof the soil particle of interest. The 0.02 mm (medium silt) particle with an assumed density of 2.65 g/cm3 has been selected as the part of interest and has a settline velocity (Vs) of 0.00096 ft/sec. FS = A safety factor of 2 to account for non-ideal settling. SA = 2 x Q2/0.00096 or 2080 square feet per cfs of inflow Input, Q2 =0.11 cfs Output, SA =229.1667 square feet 4. To aid in determining sediment depth, all traps shall have a staff gage with a prominent mark one foot above the bottom of the trap. settling depth, SD= 2 (ft) 2' min. length, L= 15 Z1= 3 width, W= 25 Z2= 3 Computed Surface Area, SF 229.17 SF equals above L/SD = 7.5 should be < 200 Bottom of Settling Surface L1 3 W1 13 Add sediment storage depth 1.5 ft Bottom of pond L2 -6 W2 4 Total Excavation 228.375 CF 8.458333 CY HLF -SedimentTrap&Pond - CENTER.xlsB1-Trap SOUTH SEDIMENT TRAP SIZING Habitat - La Fortuna PH III Q10 utilized; calculated via MGS Flood Job No: 19006 8-Apr-20 Basin 1- Sediment Trap Sizing 2. If permanent runoff control facilities are part of the project, they should be used for sediment retention. 3. To determine the trap geometry, first calculate the design surface area (SA) of the trap, measured at the invert of the weir. Use the following equation: SA = FS(Q2/Vs) where:Q2 =Design inflow based on the peak discharge from the developed 2-year runoff event from the contributing drainage area as computed in the hydrologic analysis. The 10- year peak flow shall be used if the project size, expected timing and duration of construction, or downstream conditions warrant a higher level of protection. If no hydrologic analysis is required, the Rational Method may be used Vs =The settling velocityof the soil particle of interest. The 0.02 mm (medium silt) particle with an assumed density of 2.65 g/cm3 has been selected as the part of interest and has a settline velocity (Vs) of 0.00096 ft/sec. FS = A safety factor of 2 to account for non-ideal settling. SA = 2 x Q2/0.00096 or 2080 square feet per cfs of inflow Input, Q2 =0.159 cfs Output, SA =331.25 square feet 4. To aid in determining sediment depth, all traps shall have a staff gage with a prominent mark one foot above the bottom of the trap. settling depth, SD= 2 (ft) 2' min. length, L= 50 Z1= 3 width, W= 25 Z2= 3 Computed Surface Area, SF 331.25 SF equals above L/SD = 25 should be < 200 Bottom of Settling Surface L1 38 W1 13 Add sediment storage depth 1.5 ft Bottom of pond L2 29 W2 4 Total Excavation 2004.625 CF 74.24537 CY HLF -SedimentTrap&Pond - SOUTH.xlsB1-Trap Water Quality Permitting and Reporting Information System (PARIS) La Fortuna Close Window Links Affiliations | Communications | DMR Data | Documents |Enforcements | Industrial Class | Inspections | Limits/Benchmarks | Outfalls | Permits | Submittals | Public Notices | Violations | Permits Water QualityName Permit Type PermitNumber PermitVersion PermitStatus Permit SubStatus FacilityStatus Author Issue Date EffectiveDate ExpirationDate EcologyContact La Fortuna Construction SW GP WAR124560 1 Inactive Expired Inactive Jeff Killelea 11/16/2005 8/4/2010 12/16/2010 Megan Darrow La Fortuna Construction SW GP WAR124560 2 Inactive Inactive Active Sharleen Bakeman 12/1/2010 1/1/2011 12/31/2015 Tracie Walters La Fortuna Construction SW GP WAR124560 3 Active Coverage Issued Active Amy Moon 11/18/2015 1/1/2016 12/31/2020 Mathew Kwartin Download this table Public Notices No public notice data found for this facility. Related Permits No related permits data found for this facility. Milestones Permit Number Permit Action Milestone Milestone Date Comment Notes WAR124560 New Notice Of Intent Application Received 7/1/2015 WAR124560 New Notice Of Intent IPA forward to PA 7/1/2015 WAR124560 New Notice Of Intent Administratively Complete 7/1/2015 WAR124560 New Notice Of Intent Electronically Received 6/26/2015 WAR124560 New Notice Of Intent Electronically Received 6/26/2015 WAR124560 New Notice Of Intent Application Received 8/4/2010 WAR124560 New Notice Of Intent Administratively Complete 8/4/2010 WAR124560 New Notice Of Intent Administratively Complete 7/2/2010 WAR124560 New Notice Of Intent Application Received 6/24/2010 Download this table Industrial Class Permit Type Permit Number Version Industrial Class Class Code Class Name Construction SW GP WAR124560 1 SIC 1794 EXCAVATION WORK Construction SW GP WAR124560 2 SIC 1794 EXCAVATION WORK Construction SW GP WAR124560 3 SIC 1794 EXCAVATION WORK Download this table Documents Facility Details Facility Site Name: Address: City: Zip: County: WRIA: Latitude Decimal: Longitude Decimal: Facility Details La Fortuna 17xxx 127th Avenue SE Renton 98058 King 0 47.4433056045851 -122.173678472319 -Feature Active -Feature Inactive -Facility Click here to view this facility in google maps Ecology home |PARIS home |Disclaimer |Privacy notice |Accessibility |Contact admin/Feedback |Maintenance | Paris Version : 1.0.2.0 Copyright © Washington State Department of Ecology 2020. All rights reserved. Questions? Contact:Central Regional Office Eastern Regional Office Northwest Regional Office Southwest Regional Office Industrial Regional Office Stormwater Regional Office Facility Details https://apps.ecology.wa.gov/paris/FacilityDetails.aspx?FacilityId=15017 1 of 4 3/25/2020, 10:07 AM Appendix J Special Reports and Studies South Sound Geotechnical Consulting July 31, 2019 Habitat for Humanity – Seattle/King County 560 Naches Avenue SW, Suite 110 Renton, WA 98057 Attention: Mr. Brett VanSlyke Subject: Geotechnical Engineering Report LaFortuna Development 127th Avenue E. Renton, Washington SSGC Project No. 19061 Mr. VanSlyke, South Sound Geotechnical Consulting (SSGC) has completed a geotechnical assessment for the above referenced project. Our services have been completed in general conformance with our proposal P19056 (dated June 13, 2019) and authorized per signature of our services agreement. Our evaluation included completion of four test pits on the property, engineering analyses, and preparation of this report. PROJECT INFORMATION Three town-house buildings are planned on the property, located near the looped portion of 127th Street SE, south of SE 172nd Street. Conventional spread footing foundations will be used for support of the structures, with concrete slab-on-grade floors. SITE CONDITIONS The property is characterized with west-facing sloping ground in the eastern portion, with relatively level ground in the western portion. Overall elevation change across the site is on the order of 24 (+/-) feet. The upper eastern site is covered with grass. The western portions are used for equipment storage and construction offices. It appears that cuts on the east side of 127th Street SE were completed for the road and have resulted in steeper cut slopes in this area. SUBSURFACE CONDITIONS Subsurface conditions were characterized by completing four test pits on the site on July 9, 2019. Test pits were advanced to final depths between about 3.5 and 5 feet below existing ground surface. Approximate locations of the test pits are shown on Figure 1, Exploration Plan. Logs of the test pits are provided in Appendix A. A summary description of observed subgrade conditions is provided below. Geotechnical Engineering Report SSGC LaFortuna Development 127th Avenue SE Renton, Washington SSGC Project No. 19061 July 31, 2019 2 Soil Conditions Fill was observed below the surface in two of the test pits (TP-1 and TP-2). Fill at the TP-1 location was crushed gravel for a working surface and on the order of 6 inches thick. Fill at the TP-2 location consisted of mixed silt, sand, and gravel in a loose condition. This fill extended to about 3 feet. An approximate 6 inch topsoil layer was at the surface of the remaining test pits. Native soil below the fill (or topsoil) was silty sand with gravel and occasional cobbles. It was generally in a medium dense condition below the surface soils and graded dense at shallow depth. This soil is interpreted to be glacial till and continued to the termination depth of the test pits. Groundwater Conditions Groundwater was not observed in the test pits at the time of excavation. Dense glacial till is considered impermeable to vertical groundwater flow and can cause perched groundwater conditions, particularly during the wetter seasons of the year. Wetlands are west of the site on lower elevated ground. Groundwater levels should be anticipated to fluctuate due to seasonal precipitation variations and on- and off-site drainage patterns. Geologic Setting Soils within the project area have been classified by the NRCS Soil Survey. Site soils are mapped as Alderwood gravelly sandy loam. Alderwood soils reportedly formed in glacial till. Native soils in the excavations appear to conform to the mapped soil type. GEOTECHNICAL DESIGN CONSIDERATIONS Planned development of this site is considered feasible based on observed soil conditions in the test pits. Properly prepared native soils can be used for support of conventional spread footing foundations and pavements. Daylight basement structures are anticipated for buildings on the east side of 127th Avenue SE where grades rise to the east from street elevation. Infiltration to assist in stormwater control is not considered feasible at this site. The dense glacial till at shallow depth will create a barrier to vertical groundwater flow. Recommendations presented in the following sections should be considered general and may require modifications when earthwork and grading occur. They are based upon the subsurface conditions observed in the test pits and the assumption that finish site grades will be similar to existing grades. It should be noted subsurface conditions across the site may vary from those depicted on the exploration logs and can change with time, especially on sites with previous development. Therefore, proper site preparation will depend upon the weather and soil conditions encountered at the time of construction. We recommend SSGC review final plans and further assess subgrade conditions at the time of construction, as warranted. Geotechnical Engineering Report SSGC LaFortuna Development 127th Avenue SE Renton, Washington SSGC Project No. 19061 July 31, 2019 3 General Site Preparation Site grading and earthwork should include procedures to control surface water runoff. Grading the site without adequate drainage control measures may negatively impact site soils, resulting in increased export of impacted soil and import of fill materials, potentially increasing the cost of the earthwork and subgrade preparation phases of the project. Site grading should include removal (stripping) of topsoil and fill or very loose or soft soils encountered in building and pavement areas. Subgrades should consist of firm, undisturbed native till following stripping. Stripping depths in the area of test pit TP-2 may approach 4 feet (or more), but can only be determined at the time of construction. Shallower stripping depths are expected over most of the remaining site. General Subgrade Preparation Subgrades in building footprints and pavement areas should consist of firm, undisturbed native soil. We recommend exposed subgrades in building and conventional pavement areas are proofrolled using a large roller, loaded dump truck, or other mechanical equipment to assess subgrade conditions following stripping. Proofrolling efforts should result in the upper 1 foot of subgrade soils in building and conventional pavement areas achieving a compaction level of at least 95 percent of the maximum dry density (MDD) per the ASTM D1557 test method. Wet, loose, or soft subgrades that cannot achieve this compaction level should be removed (over-excavated) and replaced with structural fill. The depth of over-excavation should be based on soil conditions at the time of construction. A representative of SSGC should be present to assess subgrade conditions during proofrolling. Grading and Drainage Positive drainage should be provided during construction and maintained throughout the life of the development. Allowing surface water into cut or fill areas, utility trenches and building footprints should be prevented. Temporary and permanent drainage systems should prevent stormwater from flowing onto the steeper south-facing slope. Structural Fill Materials The suitability of soil for use as structural fill will depend on the gradation and moisture content of the soil when it is placed. Soils with higher fines content (soil fraction passing the U.S. No. 200 sieve) will become sensitive with higher moisture content. It is often difficult to achieve adequate compaction if soil moisture is outside of optimum ranges for soils that contain more than about 5 percent fines. Geotechnical Engineering Report SSGC LaFortuna Development 127th Avenue SE Renton, Washington SSGC Project No. 19061 July 31, 2019 4 Site Soils: Topsoil and observed fill are not considered suitable as structural fill. They could be used in non-structural areas, such as lawns. Native glacial till could be suitable for use as structural fill provided it can be moisture conditioned to within optimal ranges. Till can have considerable fine (silt) content and therefore will be moisture sensitive and difficult to use as structural fill if wet. Optimum moisture is considered within about +/- 2 percent of the moisture content required to achieve the maximum dry density (MDD) per the ASTM D-1557 test method. If moisture content is higher or lower than optimum, soils would need to be dried or wetted prior to placement as structural fill. Import Fill Materials: We recommend import structural fill placed during dry weather consist of material which meets the specifications for Gravel Borrow as described in Section 9-03.14(1) of the 2018 Washington State Department of Transportation (WSDOT) Specifications for Road, Bridge, and Municipal Construction (Publication M 41-10). Gravel Borrow should be protected from disturbance if exposed to wet conditions after placement. During wet weather, or for backfill on wet subgrades, import soil suitable for compaction in wetter conditions should be provided. Imported fill for use in wet conditions should conform to specifications for Select Borrow as described in Section 9-03.14(2), or Crushed Surfacing per Section 9-03.9(3) of the 2018 WSDOT M-41 manual, with the modification that a maximum of 5 percent by weight shall pass the U.S. No. 200 sieve for these soil types. Structural fill placement and compaction is weather-dependent. Delays due to inclement weather are common, even when using select granular fill. We recommend site grading and earthwork be scheduled for the drier months of the year. Structural fill should not consist of frozen material. Structural Fill Placement We recommend structural fill is placed in lifts not exceeding about 10 inches in loose measure. It may be necessary to adjust lift thickness based on site and fill conditions during placement and compaction. Finer grained soil used as structural fill and/or lighter weight compaction equipment may require significantly thinner lifts to attain required compaction levels. Granular soil with lower fines contents could potentially be placed in thicker lifts if they can be adequately compacted. Structural fill should be compacted to attain the recommended levels presented in Table 1, Compaction Criteria. Geotechnical Engineering Report SSGC LaFortuna Development 127th Avenue SE Renton, Washington SSGC Project No. 19061 July 31, 2019 5 Table 1. Compaction Criteria Fill Application Compaction Criteria* Footing areas 95 % Upper 2 feet in pavement areas, slabs and sidewalks, and utility trenches 95 % Below 2 feet in pavement areas, slabs and sidewalks, and utility trenches 92 % Utility trenches or general fill outside of paved or building areas 90 % *Per the ASTM D 1557 test method. Trench backfill within about 2 feet of utility lines should not be over-compacted to reduce the risk of damage to the line. In some instances the top of the utility line may be within 2 feet of the surface. Backfill in these circumstances should be compacted to a firm and unyielding condition. We recommend fill procedures include maintaining grades that promote drainage and do not allow ponding of water within the fill area. The contractor should protect compacted fill subgrades from disturbance during wet weather. In the event of rain during structural fill placement, the exposed fill surface should be allowed to dry prior to placement of additional fill. Alternatively, the wet soil can be removed. We recommend consideration is given to protecting haul routes and other high traffic areas with free-draining granular fill material (i.e. sand and gravel containing less than 5 percent fines) or quarry spalls to reduce the potential for disturbance to the subgrade during inclement weather. Structural or embankment fill placed on slopes should be benched into firm (dense) native glacial till. Benches should be excavated level (or with a slight incline into the hillside). Benches should be a maximum of 2 feet high and wide enough to accommodate a conventional vibratory smooth-drum roller capable of compacting fill to at least 95 percent of the MDD per the ASTM D 1557 test method. Earthwork Procedures Conventional earthmoving equipment should be suitable for earthwork at this site. Earthwork may be difficult during periods of wet weather or if elevated soil moisture is present. Excavated site soils may not be suitable as structural fill depending on the soil moisture content and weather conditions at the time of earthwork. If soils are stockpiled and wet weather is anticipated, the stockpile should be protected with securely anchored plastic sheeting. If stockpiled soils become wet and unusable, it will become necessary to import clean, granular soils to complete wet weather site work. Wet or disturbed subgrade soils should be over-excavated to expose firm, non-yielding, non-organic soils and backfilled with compacted structural fill. We recommend the earthwork portion of this project be completed during extended periods of dry weather. If earthwork is completed during the wet season (typically October through May) it may be necessary to take extra measures to protect subgrade soils. Geotechnical Engineering Report SSGC LaFortuna Development 127th Avenue SE Renton, Washington SSGC Project No. 19061 July 31, 2019 6 If earthwork takes place during freezing conditions, we recommend the exposed subgrade is allowed to thaw and re-compacted prior to placing subsequent lifts of structural fill. Alternatively, the frozen soil can be removed to unfrozen soil and replaced with structural fill. The contractor is responsible for designing and constructing stable, temporary excavations (including utility trenches) as required to maintain stability of excavation sides and bottoms. Excavations should be sloped or shored in the interest of safety following local and federal regulations, including current OSHA excavation and trench safety standards. Temporary excavation cuts should be sloped at inclinations of 1H:1V (Horizontal:Vertical) or flatter, unless the contractor can demonstrate the safety of steeper cut slopes. Permanent cut and fill slopes should be inclined at 2H:1V, or flatter. Erosion control measures should be implemented on all temporary and permanent cut or fill slopes immediately after grading. A qualified geotechnical engineer and materials testing firm should be retained during the construction phase of the project to observe earthwork operations and to perform necessary tests and observations during subgrade preparation, placement and compaction of structural fill, and backfilling of excavations. Foundations Foundations can be placed on native glacial till or on a zone of structural fill above prepared native subgrades as described in this report. The following recommendations are for conventional spread footing foundations: Bearing Capacity (net allowable): 3,000 pounds per square foot (psf) for footings supported on firm native till subgrades or structural fill prepared as described in this report. Footing Width (Minimum): 16 inches (Strip) 24 inches (Column) Embedment Depth (Minimum): 18 inches (Exterior) 12 inches (Interior) Settlement: Total: < 1 inch Differential: < 1/2 inch (over 30 feet) Allowable Lateral Passive Resistance: 325 psf/ft* (below 12 inches) Allowable Coefficient of Friction: 0.40* *These values include a factor of safety of approximately 1.5. Geotechnical Engineering Report SSGC LaFortuna Development 127th Avenue SE Renton, Washington SSGC Project No. 19061 July 31, 2019 7 The net allowable bearing pressures presented above may be increased by one-third to resist transient, dynamic loads such as wind or seismic forces. Lateral resistance to footings should be ignored in the upper 12-inches from exterior finish grade. Foundation Construction Considerations All foundation subgrades should be free of water and loose soil prior to placing concrete, and should be prepared as recommended in this report. Concrete should be placed soon after excavating and compaction to reduce disturbance to bearing soils. Should soils at foundation level become excessively dry, disturbed, saturated, or frozen, the affected soil should be removed prior to placing concrete. We recommend SSGC observe all foundation subgrades prior to placement of concrete. Foundation Drainage Ground surface adjacent foundations should be sloped away to facilitate drainage. We recommend footing drains are installed around perimeter footings. Footing drains should include a minimum 4- inch diameter perforated rigid plastic or metal drain line installed along the exterior base of the footing. The perforated drain lines should be connected to a tight line pipe that discharges to an approved storm drain receptor. The drain line should be surrounded by a zone of clean, free-draining granular material having less than 5 percent passing the No. 200 sieve or meeting the requirements of section 9-03.12(2) “Gravel Backfill for Walls” in the 2018 WSDOT (M41-10) manual. The free- draining aggregate zone should be at least 12 inches wide and wrapped in filter fabric. The granular fill should extend to within 6 inches of final grade where it should be capped with compacted fill containing sufficient fines to reduce infiltration of surface water into the footing drains. Alternately, the ground surface can be paved with asphalt or concrete. Cleanouts are recommended for maintenance of the drain system. On-Grade Floor Slabs On-grade floor slabs should be placed on native soils or structural fill prepared as described in this report. We recommend a modulus subgrade reaction of 200 pounds per square inch per inch (psi/in) for upper native soil or compacted granular structural fill over properly prepared native soil. An increased subgrade reaction of 250 (psi/in) can be used for slabs placed on dense glacial till. We recommend a capillary break is provided between the prepared subgrade and bottom of slab. Capillary break material should be a minimum of 4 inches thick and consist of compacted clean, free- draining, well graded course sand and gravel. The capillary break material should contain less than 5 percent fines, based on that soil fraction passing the U.S. No. 4 sieve. Alternatively, a clean angular gravel such as No. 7 aggregate per Section 9-03.1(4) C of the 2018 WSDOT (M41-10) manual could be used for this purpose. Geotechnical Engineering Report SSGC LaFortuna Development 127th Avenue SE Renton, Washington SSGC Project No. 19061 July 31, 2019 8 We recommend positive separations and/or isolation joints are provided between slabs and foundations, and columns or utility lines to allow independent movement where needed. Backfill in interior trenches beneath slabs should be compacted in accordance with recommendations presented in this report. A vapor retarder should be considered beneath concrete slabs that will be covered with moisture sensitive or impervious coverings (such as tile, wood, etc.), or when the slab will support equipment or stored materials sensitive to moisture. We recommend the slab designer refer to ACI 302 and/or ACI 360 for procedures and limitations regarding the use and placement of vapor retarders. Lateral Earth Pressures Below grade and retaining walls will be subject to lateral earth pressures. Subgrade walls are typically designed for “active” or “at-rest” earth pressure conditions. Active earth pressure is commonly used for design of free-standing cantilever retaining walls and assumes lateral movement at the top of the wall of around 0.002H to 0.004H, where H is the height of the wall. The at-rest condition assumes no wall movement. The following recommended earth pressures (Table 2) should be applied as a triangular distribution starting at the top of the wall (for active and at-rest) and bottom of wall (for passive) and assume: Backfill behind walls is level and no surcharge loads will be applied; Drainage is provided behind the wall to prevent the development of hydrostatic pressures. Table 2. Lateral Earth Pressures Soil Type Earth Pressure Coefficient* Equivalent Fluid Pressure (pcf)* Native Glacial Till Active: 0.28 At-rest: 0.44 Passive: 3.50 Active: 30 At-rest: 45 Passive: 350 * A factor of safety of about 1.5 should be applied to these values. Additional lateral pressure should be added to these values to model surcharges such as sloped backfill, traffic, construction, or seismic loads. We recommend an active seismic pressure of 4H psf (where H is the height of the subgrade wall) and an at-rest seismic pressure of 7H. The effects of other surcharge loads should be accounted for as appropriate. Geotechnical Engineering Report SSGC LaFortuna Development 127th Avenue SE Renton, Washington SSGC Project No. 19061 July 31, 2019 9 Wall Backfill Backfill behind the drainage zone should consist of granular material that satisfies the criteria of Section 9-03.12(2) “Gravel Backfill for Walls” per the 2018 WSDOT (M 41-10) manual, or as approved by the engineer. Backfill should be placed in lifts not exceeding 8 inches and compacted with hand-operated compaction equipment. Compaction of wall backfill should be between 90 to 92 percent of the maximum dry density (MDD) per the ASTM D1557 test method within 3 feet of the back of the wall to limit additional lateral pressures. At a distance greater than 3 feet behind the back of the wall, backfill can be compacted using conventional rollers, with backfill compacted to at least 92 percent of the MDD. Seismic Considerations Seismic parameters and values in Table 3 are based on the 2015 International Building Code (IBC). Table 3. Seismic Parameters PARAMETER VALUE 2015 International Building Code (IBC) Site Classification1 C Ss Spectral Acceleration for a Short Period 1.381 S1 Spectral Acceleration for a 1-Second Period 0.515g Fa Site Coefficient for a Short Period 1.00 Fv Site Coefficient for a 1-Second Period 1.3 1 Note: In general accordance with 2015 International Building Code, Section 1613.3.1 for risk categories I,II,III. IBC Site Class is based on estimated characteristics of the upper 100 feet of the subsurface profile. Ss, S1, Fa, and Fv values based on the OSHPD Seismic Design Maps website. Liquefaction Soil liquefaction is a condition where loose, typically granular soils located below the groundwater surface lose strength during ground shaking, and is often associated with earthquakes. The King County “Liquefaction Susceptibility” map (Map 11-5) shows the property in an area with low susceptibility to liquefaction. Native soils at fairly shallow depth consists of dense to very dense glacial till. The risk of liquefaction at this site is considered low for the design level earthquake. Geotechnical Engineering Report SSGC LaFortuna Development 127th Avenue SE Renton, Washington SSGC Project No. 19061 July 31, 2019 10 Infiltration Characteristics Infiltration to control stormwater is not considered feasible at this site due to the presence of dense glacial till at shallow depths. Assessment of infiltration rates using small-scale Pilot Infiltration Test (PIT) procedures in similar soils in the area have shown negligible infiltration during the soak period of the test. Other detention/retention facilities will be required to control stormwater runoff at this site. Critical Areas Site slopes with heights of 10 feet or more have average inclinations between about 15 to 20 percent based on topographic information on the “Boundary and Topographic Survey” of the site completed by 4Site Surveying and Consulting, dated April 3, 2019. The site is not identified on the City of Renton GIS Landslide Hazard Severity map. Test pits on the site and geologic/soil maps indicate underlying native soils that comprise site slopes consist of glacial till. Slopes comprised of dense glacial till with inclinations of less than 20 percent are generally considered stable and not subject to significant movement. Evidence of recent or historic landslides was not observed on site slopes. We are unaware of any known deeper seated landslides within 300 feet of the site. The proposed development will not adversely impact site or neighboring slopes, in our opinion. REPORT CONDITIONS This report has been prepared for the exclusive use of Habitat for Humanity for specific application to the project discussed, and has been prepared in accordance with generally accepted geotechnical engineering practices in the area. No warranties, either express or implied, are intended or made. The analysis and recommendations presented in this report are based on observed soil conditions and test results at the indicated locations, and from other geologic information discussed. This report does not reflect variations that may occur across the site, or due to the modifying effects of construction or weather. The nature and extent of such variations may not become evident until during or after construction. If variations appear, we should be immediately notified so that further evaluation and supplemental recommendations can be provided. This report was prepared for the planned type of development of the site as discussed herein. It is not valid for third party entities or alternate types of development on the site without the express written consent of SSGC. If development plans change we should be notified to review those changes and modify our recommendations as necessary. N South Sound Geotechnical Consulting P.O. Box 39500 Lakewood, WA 98496 (253) 973-0515 Figure 1 – Exploration Plan LaFortuna Renton, WA SSGC Project #19061 Approximate Test Pit Location PIT - 1 TP - 1 TP-1 TP-1 Scale: NTS Base map from “Boundary and Topographic Survey of 12710 – 173rd Pl”, by 4Site Surveying and Consulting, dated 4-3-19. Legend TP-2 TP-1 TP-3 TP-1 TP-4 TP-1 Geotechnical Engineering Report SSGC LaFortuna Development 127th Avenue SE Renton, Washington SSGC Project No. 19061 July 31, 2019 A-1 Appendix A Field Exploration Procedures and Test Pit Logs Geotechnical Engineering Report SSGC LaFortuna Development 127th Avenue SE Renton, Washington SSGC Project No. 19061 July 31, 2019 Field Exploration Procedures Our field exploration for this project included four test pits completed on July 9, 2019. The approximate locations of the explorations are shown on Figure 1, Exploration Plan. The exploration locations were determined by pacing from site features. Ground surface elevations referenced on the logs were inferred from Google Earth satellite imagery. Exploration locations and elevations should be considered accurate only to the degree implied by the means and methods used. A client provided excavator dug the test pits. Soil samples were collected and stored in moisture tight containers for further assessment and laboratory testing. Explorations were backfilled with excavated soils and tamped when completed. Please note that backfill in the explorations will likely settle with time. Backfill material located in building areas should be re-excavated and recompacted, or replaced with structural fill. The following logs indicate the observed lithology of soils and other materials observed in the explorations at the time of excavation. Where a soil contact was observed to be gradational, our log indicates the average contact depth. Our logs also indicate the approximate depth to groundwater (where observed at the time of excavation), along with sample numbers and approximate sample depths. Soil descriptions on the logs are based on the Unified Soil Classification System. Project: LaFortuna SSGC Job # 19061 TEST PIT LOGS PAGE 1 OF 2 Location: Renton, WA TEST PIT LOGS FIGURE A-1 South Sound Geotechnical Consulting TP-1 TO TP-4 Logged by: THR Test Pit TP-1 Depth (feet) Material Description 0 – 0.5 0.5 – 4 Fill: Crushed Gravel Silty SAND with gravel and occasional cobble: Medium dense to dense, moist, brownish gray. (Glacial Till) Test pit completed at approximately 4 feet on 7/9/19. Groundwater not observed at time of excavation. Approximate surface elevation: 388 feet Test Pit TP-2 Depth (feet) Material Description 0 – 3 3 – 5 Fill: Silt, sand, gravel: Loose, damp, brown. Silty SAND with gravel and occasional cobble: Medium dense to dense, moist, brownish gray. (Glacial Till) Test pit completed at approximately 5 feet on 7/9/19. Groundwater not observed at time of excavation. Approximate surface elevation: 400 feet Test Pit TP-3 Depth (feet) Material Description 0 – 0.5 0.5 – 3.5 Topsoil Silty SAND with gravel and occasional cobble: Medium dense to dense, moist, light brown. (Glacial Till) Test pit completed at approximately 3.5 feet on 7/9/19. Groundwater not observed at time of excavation. Approximate surface elevation: 403 feet UNIFIED SOIL CLASSIFICATION SYSTEM Criteria for Assigning Group Symbols and Group Names Using Laboratory TestsA Soil Classification Group Symbol Group NameB Coarse Grained Soils More than 50% retained on No. 200 sieve Gravels More than 50% of coarse fraction retained on No. 4 sieve Clean Gravels Less than 5% finesC Cu 4 and 1 Cc 3E GW Well-graded gravelF Cu 4 and/or 1 Cc 3E GP Poorly graded gravelF Gravels with Fines More than 12% finesC Fines classify as ML or MH GM Silty gravelF,G, H Fines classify as CL or CH GC Clayey gravelF,G,H Sands 50% or more of coarse fraction passes No. 4 sieve Clean Sands Less than 5% finesD Cu 6 and 1 Cc 3E SW Well-graded sandI Cu 6 and/or 1 Cc 3E SP Poorly graded sandI Sands with Fines More than 12% finesD Fines classify as ML or MH SM Silty sandG,H,I Fines Classify as CL or CH SC Clayey sandG,H,I Fine-Grained Soils 50% or more passes the No. 200 sieve Silts and Clays Liquid limit less than 50 inorganic PI 7 and plots on or above “A” lineJ CL Lean clayK,L,M PI 4 or plots below “A” lineJ ML SiltK,L,M organic Liquid limit - oven dried 0.75 OL Organic clayK,L,M,N Liquid limit - not dried Organic siltK,L,M,O Silts and Clays Liquid limit 50 or more inorganic PI plots on or above “A” line CH Fat clayK,L,M PI plots below “A” line MH Elastic SiltK,L,M organic Liquid limit - oven dried 0.75 OH Organic clayK,L,M,P Liquid limit - not dried Organic siltK,L,M,Q Highly organic soils Primarily organic matter, dark in color, and organic odor PT Peat A Based on the material passing the 3-in. (75-mm) sieve B If field sample contained cobbles or boulders, or both, add “with cobbles or boulders, or both” to group name. C Gravels with 5 to 12% fines require dual symbols: GW-GM well-graded gravel with silt, GW-GC well-graded gravel with clay, GP-GM poorly graded gravel with silt, GP-GC poorly graded gravel with clay. D Sands with 5 to 12% fines require dual symbols: SW-SM well-graded sand with silt, SW-SC well-graded sand with clay, SP-SM poorly graded sand with silt, SP-SC poorly graded sand with clay E Cu = D60/D10 Cc = 6010 230 DxD )(D F If soil contains 15% sand, add “with sand” to group name. G If fines classify as CL-ML, use dual symbol GC-GM, or SC-SM. HIf fines are organic, add “with organic fines” to group name. I If soil contains 15% gravel, add “with gravel” to group name. J If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay. K If soil contains 15 to 29% plus No. 200, add “with sand” or “with gravel,” whichever is predominant. L If soil contains 30% plus No. 200 predominantly sand, add “sandy” to group name. M If soil contains 30% plus No. 200, predominantly gravel, add “gravelly” to group name. N PI 4 and plots on or above “A” line. O PI 4 or plots below “A” line. P PI plots on or above “A” line. Q PI plots below “A” line. Project: LaFortuna SSGC Job # 19061 TEST PIT LOGS PAGE 2 OF 2 Location: Renton, WA TEST PIT LOGS FIGURE A-1 South Sound Geotechnical Consulting TP-1 TO TP-4 Logged by: THR Test Pit TP-4 Depth (feet) Material Description 0 – 0.5 0.5 – 4 Topsoil Silty SAND with gravel and occasional cobble: Medium dense to dense, moist, light brown. (Glacial Till) Test pit completed at approximately 4 feet on 7/9/19. Groundwater not observed at time of excavation. Approximate surface elevation: 410 feet South Sound Geotechnical Consulting 1 September 20, 2019 Habitat for Humanity – Seattle/King County 560 Naches Avenue SW, Suite 110 Renton, WA 98057 Attention: Mr. Brett VanSlyke Subject: Ultrablock Retaining Wall Design LaFortuna Development 127th Avenue E. Renton, Washington SSGC Project No. 19061 Mr. VanSlyke, South Sound Geotechnical Consulting (SSGC) has completed designs for Ultrablock gravity block walls for the LaFortuna Development. We understand the City of Renton requires individual walls have a maximum exposed height of 6 feet. Based on information provided to us, wall heights of up to 10 feet will be needed in the northeast portion of the site. Therefore a tiered (terraced) wall system will be needed to maintain the city’s maximum height requirement for taller walls. DESIGN RECOMMENDATIONS Subgrade/Foundation Preparation Subgrades for wall foundations should consist of firm, undisturbed native glacial till or structural fill placed on firm native subgrades. Foundation excavations should extend deep enough to allow a minimum embedment depth of at least 1 foot for Ultrablock walls. We recommend a minimum 6 inch thick leveling pad of well-graded sand and gravel (e.g. base course) is placed on the prepared subgrade prior to Ultrablock placement. This pad should extend at least 6 inches beyond the edges of the blocks and be compacted to a firm condition. Wall Drainage Drainage should be provided behind all retaining walls to reduce the potential for hydrostatic pressure developing against the wall. We recommend a minimum 4-inch diameter perforated rigid plastic drain line is installed behind the base of the wall. The invert of the drain line should be placed near the base of the lowest block. The drain line should be sloped to provide positive flow to an approved storm drain receptor. The drain line should be encased in a minimum 12-inch wide zone of clean, free-draining granular material having less than 5 percent passing the No. 200 sieve or meeting Geotechnical Engineering Report SSGC Ultrablock Retaining Walls LaFortuna Development Renton, Washington SSGC Project No. 19061 December 17, 2019 2 the requirements of Section 9-03.12(2) “Gravel Backfill for Walls” in the 2018 WSDOT (M41-10) manual, or as approved by the engineer. This drainage zone should extend to within 1 foot of the top of the wall and capped by a low permeable soil. Cleanouts are recommended for maintenance of the drain system. A filter/separation fabric such as Mirafi 140N should be used between the drainage material and native cut or structural fill soils to limit the potential of siltation in the drain system. Ultrablock Walls Lateral earth pressures presented in our geotechnical engineering report for this project (dated July 31, 2019) were used in the designs of Ultrablock walls. Our analyses also used the following design parameters: Maximum exposed height of any individual walls is 6 feet (10 feet maximum tiered wall); Standard Ultrablock (H = 2.5 ft, W = 2.5 ft) An embedment depth of 1 foot; Separation of at least 2 feet behind lower and upper walls; Level backfill behind walls; Seismic acceleration of 0.2g; Ground surface in front of walls is level; NCMA 2009 analyses used for design. A schematic for an exposed 10 feet tiered wall system is attached. Block layouts for Ultrablock walls having exposed wall heights of 4 and 6 feet are included in Appendix A. Shorter walls (or walls not requiring tiered configuration) can be designed using the appropriate height design. Cap blocks can be substituted for standard blocks on the upper layer to minimize block “stick up” for shorter (or in-between) wall heights. REPORT CONDITIONS This report has been prepared for the exclusive use of Habitat for Humanity and their agents for specific application to the wall designs discussed and has been prepared in accordance with generally accepted geotechnical engineering practices in the area. No warranties, either express or implied, are intended or made. Should site conditions at the time of construction vary from those discussed in our July 2019 report the conclusions and designs contained herein shall not be considered valid unless SSGC reviews the new information and either verifies or modifies the designs in writing. South Sound Geotechnical Consulting 1 Appendix A UltraBlock Layout Sections (4 and 6 Feet Exposed Heights) September 10, 2018 Report Revisions: February 6, 2020 Brett VanSlyke Site Development Manager Habitat for Humanity Seattle – King County Via email: bvanslyke@habitatskc.org Phone: 206-391-5984 Re: Renton La Fortuna Townhome Property, Wetland Delineation Report The Watershed Company Reference Number: 180810 Dear Kelly: On August 21, 2018, ecologists Sam Payne and Logan Dougherty, visited the La Fortuna Townhome Property in Renton, Washington (parcel #3956210000) to screen for jurisdictional wetland and streams within a defined study area. This letter summarizes the findings of the study and details applicable federal, state, and local regulations. The following documents are enclosed: • Proposed Site Plan • Proposed Drainage Plan • Wetland Determination Data Forms • Ecology Rating Forms and Figures Methods Public-domain information on the subject properties was reviewed for this delineation study and include the following: • USDA Natural Resources Conservation Service, Web Soil Survey (WSS) application • U.S. Fish and Wildlife Service National Wetland Inventory (NWI) maps • Washington Department of Fish and Wildlife interactive mapping programs (PHS on the Web, SalmonScape) Wetland Delineation Report Habitat for Humanity September 10, 2018, Revised February 6, 2020 Page 2 • Washington Department of Natural Resources, Forest Practices Application Mapping Tool (FPARS) • Washington Department of Natural Resources, Wetlands of High Conservation Value Map Viewer • King County’s GIS mapping website (iMAP) • City of Renton (COR) maps Characterization of climatic conditions for precipitation was determined using the WETS table methodology from the USDA NRCS document Part 650 Engineering Field Handbook, National Engineering Handbook, Hydrology Tools for Wetland Identification and Analysis, Chapter 19 (September 2015). The Seattle-Tacoma International AP station as recorded by NOAA from 1981-2010 (http://agacis.rcc-acis.org/) was used as a source for precipitation data. The WETS table methodology uses climate data from the three months prior to the site visit month to determine if normal conditions are present. Wetlands The study area was evaluated for wetlands using methodology from the Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys, and Coast Region Version 2.0 (Regional Supplement) (US Army Corps of Engineers [Corps] May 2010). Wetland boundaries were determined on the basis of an examination of vegetation, soils, and hydrology. Areas meeting the criteria set forth in the Regional Supplement were determined to be wetland. Soil, vegetation, and hydrologic parameters were sampled at several locations along the wetland boundary to make the determination. Identified wetlands within the property were classified using the 2014 Update to the Western Washington Wetland Rating System (Publication #14-06-029) (Rating System). Streams The study area was evaluated for streams based on the presence or absence of an ordinary high water mark (OHWM) as defined by the Revised Code of Washington (RCW) 90.58.030 and the Washington Administrative Code (WAC) 220-660-030. The OHWM edge was located by examining the bed and bank physical characteristics and vegetation, using recent guidance from the Department of Ecology, Determining the Ordinary High Water Mark for Shoreline Management Act Compliance in Washington State (Publication no. 16-06-029). Findings The study area is within the Soos Creek sub-basin of the Duwamish-Green Water Resource Inventory Area (WRIA 9); Township 23 North, Range 05 East, Section 28. The Wetland Delineation Report Habitat for Humanity September 10, 2018, Revised February 6, 2020 Page 3 property is along a moderate gradient sloping downhill to the southwest. The developed area includes numerous attached townhome units, a private access road, lawns, and community gardens. The site also contains a large undeveloped area along the western side that includes numerous wetlands and forested land. Public-domain information on the subject properties was reviewed for this study and include the following, as summarized in Table 1. Table 1. Summary of online mapping and inventory resources. Resource Summary USDA Natural Resources Conservation Service, Web Soil Survey (WSS) application Alderwood gravelly sandy loam, 8 to 15 percent slopes; Arents, Alderwood material, 6 to 15 percent slopes; Seattle Muck. U.S. Fish and Wildlife Service National Wetland Inventory (NWI) maps Numerous wetlands identified on and adjacent to the property. Washington Department of Fish and Wildlife, Priority Habitats and Species (PHS on the Web) No priority habitat or species. Washington Department of Fish and Wildlife, SalmonScape No salmonids mapped within project site. Documented presence of salmonids, approx. 1,000 feet south of project area. Washington Department of Natural Resources, Forest Practices Application Mapping Tool (FPARS) No mapped streams. Nearest stream approximately 1,000 south. King County’s GIS mapping website (iMAP) Mapped wetlands in the subject parcel. City of Renton Maps Mapped wetland in the subject parcel. Wetland Delineation Report Habitat for Humanity September 10, 2018, Revised February 6, 2020 Page 4 WETS weather conditions based on precipitation from the prior three months Drier than normal. Table 2. Wetland A assessment summary. WETLAND A – Assessment Summary Location: City of Renton Parcel #3956210000 WRIA / Sub-basin: Soos Creek / WRIA 9 2014 Western WA Ecology Rating: Category II Local Jurisdiction Buffer Width and Buffer Setback: 100-Foot Buffer 15-Foot Setback Wetland Size: Approx. 5 Acres Cowardin Classification(s): Palustrine Forested HGM Classification(s): Depressional Wetland Data Sheet(s): DP-1 Upland Data Sheet (s): DP-2 Flag Color: Pink-and-black striped Flag Numbers: A-1 to A-41 Vegetation Tree stratum: Western red cedar, red alder, black cottonwood, Oregon ash, Pacific willow, Sitka willow Shrub stratum: Black twinberry, red-osier dogwood, Douglas spirea, vine maple, highbush cranberry, salmonberry Herb stratum: Skunk cabbage, slough sedge, small-fruited bulrush, lady fern, creeping buttercup Soils Soil survey: Alderwood gravelly sandy loam; Arents, Alderwood material; Seattle Muck Field data: Hydrogen sulfide (A4) Hydrology Source: Groundwater, piped and ditched runoff, precipitation Field data: High Water Table (A2), Saturation (A3), Hydrogen Sulfide Odor (C1) Wetland Functions Improving Water Quality Hydrologic Habitat 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 9 7 6 22 Wetland Delineation Report Habitat for Humanity September 10, 2018, Revised February 6, 2020 Page 5 WETLAND A – Assessment Summary Description and Comments Wetland A is a large forested wetland that drains to the south to an even larger wetland complex associated with Soos creek that is located south of SE Petrovitsky Road. Numerous stormwater pipes, culverts, and ditches flow into the wetland, likely providing much of the wetland hydrology. A ditched stormwater outlet draining into the wetland from the southern area of the parcel was not included in the wetland area because it is an intentionally constructed stormwater feature created from a non-wetland site. Table 3. Wetland B assessment summary. WETLAND B – Assessment Summary Location: City of Renton Parcel #3956210000 WRIA / Sub-basin: Soos Creek / WRIA 9 2014 Western WA Ecology Rating: Category III Local Jurisdiction Buffer Width and Buffer Setback: 50-Foot Buffer 15-Foot Setback Wetland Size: Approx. 4,000 SF Cowardin Classification(s): Palustrine Forested HGM Classification(s): Depressional Wetland Data Sheet(s): DP-3 Upland Data Sheet (s): DP-4 Flag Color: Pink-and-black striped Flag Numbers: B-1 to B-10 Vegetation Tree stratum: Red alder, Oregon ash, black cottonwood, Sitka spruce Shrub stratum: Vine maple, red-osier dogwood, black twinberry Herb stratum: Reed canarygrass, yellow-flag iris, giant horsetail, creeping buttercup Soils Soil survey: Seattle muck Field data: Redox Dark Surface (F6) Hydrology Source: Groundwater, precipitation Field data: Geomorphic Position (D2), FAC-Neutral Test (D5) Wetland Functions Improving Water Quality Hydrologic Habitat Site Potential H M L H M L H M L Landscape Potential H M L H M L H M L Wetland Delineation Report Habitat for Humanity September 10, 2018, Revised February 6, 2020 Page 6 WETLAND B – Assessment Summary Value H M L H M L H M L TOTAL Score Based on Ratings 7 5 4 16 Description and Comments Wetland B is a small forested wetland depressional wetland upslope from Wetland A. Recent mitigation projects have resulted in enhancement of Wetland A and Wetland B buffers. Table 4. Wetland C assessment summary. WETLAND C – Assessment Summary Location: City of Renton Parcel #0739000025 WRIA / Sub-basin: Soos Creek / WRIA 9 2014 Western WA Ecology Rating: Category III Local Jurisdiction Buffer Width and Buffer Setback: 50-Foot Buffer 15-Foot Setback Wetland Size: Approx. 4,000 SF Cowardin Classification(s): Palustrine Emergent HGM Classification(s): Depressional Wetland Data Sheet(s): N/A Upland Data Sheet (s): N/A Flag Color: Not Flagged Flag Numbers: Not Flagged Vegetation Tree stratum: N/A Shrub stratum: N/A Herb stratum: Soft rush, reed canarygrass, curly dock Soils Soil survey: Arents, Alderwood material Field data: N/A Hydrology Source: Groundwater, precipitation Field data: N/A Wetland Functions Improving Water Quality Hydrologic Habitat Site Potential H M L H M L H M L Wetland Delineation Report Habitat for Humanity September 10, 2018, Revised February 6, 2020 Page 7 WETLAND C – Assessment Summary 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 7 5 4 16 Description and Comments Wetland C located entirely offsite and not confirmed. It includes an area of hydrophytic emergent vegetation. Stormwater Features A recently excavated feature identified as a “filter / spreader” on site mitigation plans meets wetland criteria for hydrophytic plants, hydric soils, and wetland hydrology. However, it is clearly man-made stormwater feature and does not meet the Renton definition of a regulated wetland. According to RMC 4-3-050(B)(1), regulated wetlands do not include those artificial wetlands intentionally created from non-wetland sites. Non-wetland areas Areas outside of identified wetlands did not meet criteria for hydrophytic vegetation, hydric soils, and wetland hydrology. A wetland buffer enhancement has resulted in the establishment of wetland plants in the buffers of Wetland A and Wetland B, however, these areas exhibited neither hydric soil nor wetland hydrology indicators. One area between the stormwater outfall and Wetland A exhibits the three-parameter test for wetland. However, this area is not jurisdictional because it is an intentionally constructed stormwater feature created from a non-wetland site Streams The property lacked any watermarks, stained leaves, algae, bed, bank, or hydraulically sorted sediments. Based on these findings, there are no jurisdictional streams on the property. A stream can be seen on aerial photography connecting Wetland A, offsite to the Soos Creek wetland complex to the south. Local Regulations Wetland buffers in the City of Renton are determined by a combination of the wetland category and habitat score, as determined by the wetland rating system. Wetland A is a Category II wetland with a habitat score of 6 and therefore requires a standard buffer of 100 feet. Wetland B rated as Category III with a habitat score of 4 and therefore requires Wetland Delineation Report Habitat for Humanity September 10, 2018, Revised February 6, 2020 Page 8 a standard buffer of 50 feet. Wetland C, if verified, also rated as Category III with a habitat score of 4, and would require a buffer of 50 feet. An additional 15-foot structure setback is required beyond the limit of each buffer. According to Renton Municipal Code (RMC) Critical Areas Regulations 4-3-050B.g, sites that are separated from critical areas by pre-existing, lawfully created intervening lots/parcels, roads, or other substantial infrastructure shall not be regulated as a critical area buffer. This applies to features that separate the subject property from the critical area due to their height or width and substantially prevent delivery of all or most functions from the subject upland property to the critical area. As a legally established roadway that provides access to multi-family residential development, 127th Ave SE acts as one such functional break. Additionally, areas north of 127th Ave SE have been cleared, graded, and maintained as gravel platforms since approximately 2007, and do not add any function to the wetland buffer. The compact, gravel conditions do not allow for notable infiltration that reduces surface flow volumes and velocities, and the lack of vegetation precludes the ability of the area to trap and filter pollutants and sediments. The unvegetated condition of the areas north of 127th provide virtually no habitat functions for wildlife; there are no forage or cover opportunities available. Therefore, in accordance with RMC 4-3-050B.g, the Wetland A and Wetland B buffers do not extend beyond 127th Ave SE. Stormwater Infrastructure Under RMC 4-3-050C.3.9, surface water discharges in the form of dispersion trenches, outfalls, and bioswales are allowed in the outer 25 percent of Category III and IV wetland buffers, provided the discharge meets the requirements of RMC 4-6-030; no other location is feasible; and it will not degrade the functions or values of the wetland. The bioretention facility and flow control structure proposed under the Phase II plan of La Fortuna homes are both will be located outside the buffers associated with Wetlands A and B. However, a stormwater outfall and a stormwater flow path are proposed within wetland buffers in accordance with the above exemption. Stormwater discharge is proposed at two locations within wetland buffers. A gravel- filled dispersion trench is proposed adjacent but outside of the wetland buffer area. Runoff from the proposed “central” parking area will discharge via dispersion through minimum 100-foot flow path of native vegetation between Wetlands A and B. Neither the 100-foot dispersion flow path nor the dispersion trench is located within wetland areas; however, portions of the flow path are located within a wetland buffer. Discharge would flow through the vegetated buffer downgradient (westward) from the dispersion trench and towards Wetland A. By spreading the discharge evenly over a wide area, the proposed dispersion trench will ensure that channelization and erosion do not occur in the buffer. The flow will continue through a densely vegetated buffer prior to reaching Wetland Delineation Report Habitat for Humanity September 10, 2018, Revised February 6, 2020 Page 9 Wetland A, which will further slow any outflows from the dispersion trench. The stormwater dispersion is designed in accordance with required full dispersion implementation under Section C2.1 of the 2017 Renton Surface Water Design Manual. With these precautions, little to no impact on the critical area or its buffer will occur with these proposed stormwater infrastructure improvements. Stormwater runoff from proposed “east” parking area is collected via catch basin and routed to the bioretention facility, which provides enhanced water quality treatment per City of Renton stormwater manual requirements. This treated runoff is then routed into five-foot diameter pipe under the parking area, which is a detention tank, providing flow control per Renton stormwater manual requirements. Detained and treated stormwater runoff would be released from detention facility at flow rates matching pre- existing site conditions to a discharge pipe that would route runoff to a proposed outfall location in the outer 25 percent of the buffer for Wetland B, a Category III wetland. The discharge is designed to meet all requirements of RMC 4-6-030. Any incidental, construction-related vegetation removal within the Wetland B buffer would be restored in kind. Given the flow control, treatment, and dissipation, adverse impacts to Wetland B and its buffer are not anticipated. It is not feasible to route either of the above stormwater discharges to the existing storm drainage outfall location at the southwest corner of the project site. Routing the storm drainage discharge pipe around existing structures (buildings, storm vault) and improvements would result in more than 170 feet of additional storm drainage conveyance pipe, which would have to be located in the buffers of both Wetlands A and B. Not only would this lengthy connection to the existing outfall location add significant cost to the project for the additional material cost of pipe, but complicated trenching through sloping topography bordering the wetlands, and significant native vegetation impacts to clear the required trenching alignment and associated layback area on each side of the trench. The required routing to connect to the existing storm drainage outfall at the southwest corner of the site would have significant and detrimental impacts to the native vegetation within the wetland buffers. Additionally, the routing to the existing storm drainage outfall would require trenching for the storm piping on the downslope side of the proposed dispersion trench and would have significant impacts on the native vegetation within the dispersion area between wetlands A and B. None of the proposed improvements will result in any loss of wetland or buffer area or functions, and no adverse impacts are anticipated. Therefore, compensatory mitigation is not necessary to achieve no net loss of critical area and/or buffer functions. By achieving no net loss and maintaining compliance with the allowed provisions under RMC 4-3-050C.9, the proposed stormwater conveyances are exempt. A letter of exemption from the City, which states that the dispersion and outfall within buffers is Wetland Delineation Report Habitat for Humanity September 10, 2018, Revised February 6, 2020 Page 10 exempt from critical areas regulations, may be required for the dispersion flow path and outfall that are planned within the wetland buffers. State and Federal Regulations Wetlands and streams are regulated by the Corps under section 404 of the Clean Water Act. Any proposed filling or other direct impacts to Waters of the U.S., including wetlands (except isolated wetlands), would require notification and permits from the Corps. Unavoidable impacts are typically required to be compensated through implementation of an approved mitigation plan. Federally permitted actions that could affect endangered species may also require a biological assessment study and consultation with the U.S. Fish and Wildlife Service and/or the National Marine Fisheries Service. Compliance with the Endangered Species Act must be demonstrated for activities within jurisdictional wetlands and the 100-year floodplain. Application for Corps permits may also require an individual 401 Water Quality Certification and Coastal Zone Management Consistency determination from Ecology and a cultural resource study in accordance with Section 106 of the National Historic Preservation Act. Washington Department of Ecology Similar to the Corps, Ecology, under Section 401 of the Clean Water Act, is charged with reviewing, conditioning, and approving or denying certain federally permitted actions that result in discharges to state waters. However, Ecology review would only become necessary if a Section 404 permit from the Corps was issued. Therefore, if filling activities are avoided, authorization from Ecology would not be needed. If filling is proposed, a JARPA could be submitted to Ecology in order to obtain a Section 401 Water Quality Certification (WQC) and Coastal Zone Management Consistency Determination. Ecology permits are either issued concurrently with the Corps permit or within 90 days following the Corps permit. In general, neither the Corps nor Ecology or WDFW regulates wetland and stream buffers, unless direct impacts are proposed. When direct impacts are proposed, mitigated wetlands and streams may be required to employ buffers based on Corps and Ecology joint regulatory guidance. It is our understanding, based on the project plans, that no direct wetland or stream impacts are proposed. Therefore, state and federal permitting will not be required for the planned site development. Wetland Delineation Report Habitat for Humanity September 10, 2018, Revised February 6, 2020 Page 11 Disclaimer The information contained in this letter or report is based on the application of technical guidelines currently accepted as the best available science and in conjunction with the manuals and criteria outlined in the methods section. All discussions, conclusions and recommendations reflect the best professional judgment of the author(s) and are based upon information available at the time the study was conducted. All work was completed within the constraints of budget, scope, and timing. The findings of this report are subject to verification and agreement by the appropriate local, state and federal regulatory authorities. No other warranty, expressed or implied, is made. Please call if you have any questions or if we can provide you with any additional information. Sincerely, Revisions by: Sam Payne Ryan Kahlo, PWS Ecologist Senior Ecologist NATIVE VEGETATIONAREA MIN. AREAREQUIRED 28,700 SFSTORM DRAINAGEPLANIN COMPLIANCE WITH CITY OF RENTON STANDARDSÄ6*564''64'06109#.#(14670#2*++coterra321 3rd Ave South, Suite 406Seattle, Washington 98104ph 206.596.7115coterraengineering.comENGINEERING PLLC**.#(14670#2*++ 241)4'555'6Ä%+8+.%105647%6+102'4/+657$/+66#. NATIVE VEGETATIONAREA MIN. AREAREQUIRED 28,700 SFGRADING ANDDRAINAGE PLANIN COMPLIANCE WITH CITY OF RENTON STANDARDSÄ6*564''64'06109#.#(14670#2*++coterra321 3rd Ave South, Suite 406Seattle, Washington 98104ph 206.596.7115coterraengineering.comENGINEERING PLLC**.#(14670#2*++ 2'4/+65'6Ä%+8+.%105647%6+102'4/+657$/+66#.PROPOSEDSTORMOUTFALLLOCATIONFORTREATEDANDDETAINEDRUNOFFFROMEASTPARKINGAREA.WILLPRESENTOUTFALLLOCATIONINSTORMDRAINAGEREPORTOUTSIDEWETLANDABUFFER(100')ANDONLYUPTO25%OFWETLANDBBUFFERINFEASIBLESTORMDRAINAGECONVEYANCEOPTIONTOCONNECTTOEXISTINGSTORMOUTFALLTOWETLANDA.INFEASIBLEDUETOSIGNIFICANTIMPACTSTOWETLANDBUFFERSFORTRENCHINGANDADDITIONALCOSTSTOROUTEADDITIONAL170'TOEXISTINGOUTFALLLOCATION. US Army Corps of Engineers Western Mountains, Valleys, and Coast – Interim Version 750 Sixth Street South Kirkland, Washington 98033 (425) 822-5242 watershedco.com WETLAND DETERMINATION DATA FORM Western Mountains, Valleys, and Coast Supplement to the 1987 COE Wetlands Delineation Manual Project Site: 12710 SE 173rd St, Renton, WA Sampling date: August 21, 2018 Applicant/Owner: Habitat for Humanity Sampling Point: DP-1 Investigator: Logan Dougherty, Sam Payne City/County: Renton / King Sect., Township, Range: S 28 T 23N R 05E State: Washington Landform (hillslope, terrace, etc): Depression Slope (%): 0 Local relief (concave, convex, none): None Subregion (LRR): A Lat: Long: Datum: Soil Map Unit Name: Seattle Muck NWI classification: PFOC (Freshwater Forested/Shrub) Are climatic/hydrologic conditions on the site typical for this time of year? ☐Yes ☒ No (If no, explain in remarks.) Are “Normal Circumstances” present on the site? ☒Yes ☐ No (If needed, explain any answers in Remarks.) Are Vegetation☐, Soil ☐, or Hydrology ☐ significantly disturbed? Are Vegetation☐, Soil ☐, or Hydrology ☐ naturally problematic SUMMARY OF FINDINGS – Attach site map showing sampling point locations, transects, important features, etc. Hydrophytic Vegetation Present? Yes ☒ No ☐ Is the Sampling Point within a Wetland? Yes ☒ No ☐ Hydric Soils Present? Yes ☒ No ☐ Wetland Hydrology Present? Yes ☒ No ☐ Remarks: Drier than normal per WETS (Seattle-Tacoma International Airport) VEGETATION – Use scientific names of plants. Tree Stratum (Plot size: 5m diam.) Absolute % Cover Dominant Species? Indicator Status Dominance Test Worksheet 1. Alnus rubra 90 Y FAC Number of Dominant Species that are OBL, FACW, or FAC: 5 (A) 2. Populus balsamifera 30 Y FAC 3. Total Number of Dominant Species Across All Strata: 5 (B) 4. 120 = Total Cover Percent of Dominant Species that are OBL, FACW, or FAC: 100 (A/B) Sapling/Shrub Stratum (Plot size: 3m diam.) 1. Cornus sericea 70 Y FACW Prevalence Index Worksheet 2. Lonicera involucrata 60 Y FAC Total % Cover of Multiply by 3. OBL species x 1 = 4. FACW species x 2 = 5. FAC species x 3 = 130 = Total Cover FACU species x 4 = UPL species x 5 = Herb Stratum (Plot size: 1m diam.) Column totals (A) (B) 1. Carex obnupta 70 Y OBL 2. Prevalence Index = B / A = 3. 4. Hydrophytic Vegetation Indicators 5. ☒ Dominance test is > 50% 6. ☐ Prevalence test is ≤ 3.0 * 7. Morphological Adaptations * (provide supporting 8. ☐ data in remarks or on a separate sheet) 9. ☐ Wetland Non-Vascular Plants * 10. ☐ Problematic Hydrophytic Vegetation * (explain) 11. 70 = Total Cover * Indicators of hydric soil and wetland hydrology must be present, unless disturbed or problematic Woody Vine Stratum (Plot size: ) Hydrophytic Vegetation Present? Yes ☒No ☐ 1. 2. 0 = Total Cover % Bare Ground in Herb Stratum: 30 Remarks: DP- 1 US Army Corps of Engineers Western Mountains, Valleys, and Coast – Interim Version SOIL Sampling Point – DP- 1 HYDROLOGY Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.) Depth Matrix Redox Features (inches) Color (moist) % Color (moist) % Type1 Loc2 Texture Remarks 0-1 10YR 2/1 100 Muck High organic matter content 1-16 10YR 2/2 100 Silt loam Abundant non-decomposed organic matter 1Type: C=Concentration, D=Depletion, RM=Reduced Matrix, CS=Covered or Coated Sand Grains 2Loc: 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) ☐2cm 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) ☐Thick Dark Surface (A12) ☐ Redox Dark Surface (F6) 3 Indicators of hydrophytic vegetation and wetland hydrology must be present, unless disturbed or problematic ☐Sandy Mucky Mineral (S1) ☐ Depleted Dark Surface (F7) ☐Sandy Gleyed Matrix (S4) ☐ Redox Depressions (F8) Restrictive Layer (if present): Hydric soil present? Yes ☒ No ☐ Type: Depth (inches): Remarks: Wetland Hydrology Indicators: Primary Indicators (minimum of one required: check all that apply): Secondary Indicators (2 or more required): ☐ Surface water (A1) ☐ Sparsely Vegetated Concave Surface (B8) ☒Water-Stained Leaves (B9) (MLRA 1, 2, 4A & 4B) ☒ High Water Table (A2) ☐ Water-Stained Leaves (except MLRA 1, 2, 4A & 4B) (B9) ☐Drainage Patterns (B10) ☒ Saturation (A3) ☐ Salt Crust (B11) ☐Dry-Season Water Table (C2) ☐ Water Marks (B1) ☐ Aquatic Invertebrates (B13) ☐Saturation Visible on Aerial Imagery (C9) ☐ Sediment Deposits (B2) ☒ Hydrogen Sulfide Odor (C1) ☒Geomorphic Position (D2) ☐ Drift Deposits (B3) ☐ Oxidized Rhizospheres along Living Roots (C3) ☐Shallow Aquitard (D3) ☐ Algal Mat or Crust (B4) ☐ Presence of Reduced Iron (C4) ☒FAC-Neutral Test (D5) ☐ Iron Deposits (B5) ☐ Recent Iron Reduction in Tilled Soils (C6) ☐Raised Ant Mounds (D6) (LRR A) ☐ Surface Soil Cracks (B6) ☐ Stunted or Stressed Plants (D1) (LRR A) ☐Frost-Heave Hummocks ☐ Inundation Visible on Aerial Imagery (B7) ☐ Other (explain in remarks) Field Observations Wetland Hydrology Present? Yes ☒ No ☐ Surface Water Present? Yes ☐ No ☒ Depth (in): Water Table Present? Yes ☒ No ☐ Depth (in): 0 Saturation Present? (includes capillary fringe) Yes ☒ No ☐ Depth (in): 0 Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available: Remarks: US Army Corps of Engineers Western Mountains, Valleys, and Coast – Interim Version 750 Sixth Street South Kirkland, Washington 98033 (425) 822-5242 watershedco.com WETLAND DETERMINATION DATA FORM Western Mountains, Valleys, and Coast Supplement to the 1987 COE Wetlands Delineation Manual Project Site: 12710 SE 173rd St, Renton, WA Sampling date: August 21, 2018 Applicant/Owner: Habitat for Humanity Sampling Point: DP-2 Investigator: Logan Dougherty, Sam Payne City/County: Renton / King Sect., Township, Range: S 28 T 23N R 05E State: Washington Landform (hillslope, terrace, etc): Hillslope Slope (%): 5-10 Local relief (concave, convex, none): None Subregion (LRR): A Lat: Long: Datum: Soil Map Unit Name: Seattle Muck NWI classification: PFOC (Freshwater Forested/Shrub) Are climatic/hydrologic conditions on the site typical for this time of year? ☐Yes ☒ No (If no, explain in remarks.) Are “Normal Circumstances” present on the site? ☒Yes ☐ No (If needed, explain any answers in Remarks.) Are Vegetation☐, Soil ☐, or Hydrology ☐ significantly disturbed? Are Vegetation☐, Soil ☐, or Hydrology ☐ naturally problematic SUMMARY OF FINDINGS – Attach site map showing sampling point locations, transects, important features, etc. Hydrophytic Vegetation Present? Yes ☒ No ☐ Is the Sampling Point within a Wetland? Yes ☐ No ☒ Hydric Soils Present? Yes ☐ No ☒ Wetland Hydrology Present? Yes ☐ No ☒ Remarks: Drier than normal per WETS (Seattle-Tacoma International Airport) VEGETATION – Use scientific names of plants. Tree Stratum (Plot size: 5m diam.) Absolute % Cover Dominant Species? Indicator Status Dominance Test Worksheet 1. Betula nigra 80 Y FACW Number of Dominant Species that are OBL, FACW, or FAC: 5 (A) 2. 3. Total Number of Dominant Species Across All Strata: 6 (B) 4. 80 = Total Cover Percent of Dominant Species that are OBL, FACW, or FAC: 83 (A/B) Sapling/Shrub Stratum (Plot size: 3m diam.) 1. Fraxinus latifolia 15 Y FACW Prevalence Index Worksheet 2. Thuja plicata 5 N FAC Total % Cover of Multiply by 3. Corylus cornuta 20 Y FACU OBL species x 1 = 4. Rubus armeniacus 15 Y FAC FACW species x 2 = 5. FAC species x 3 = 55 = Total Cover FACU species x 4 = UPL species x 5 = Herb Stratum (Plot size: 1m diam.) Column totals (A) (B) 1. Ranunculus repens 50 Y FAC 2. Poaceae sp. 40 Y FAC* Prevalence Index = B / A = 3. 4. Hydrophytic Vegetation Indicators 5. ☒ Dominance test is > 50% 6. ☐ Prevalence test is ≤ 3.0 * 7. Morphological Adaptations * (provide supporting 8. ☐ data in remarks or on a separate sheet) 9. ☐ Wetland Non-Vascular Plants * 10. ☐ Problematic Hydrophytic Vegetation * (explain) 11. 90 = Total Cover * Indicators of hydric soil and wetland hydrology must be present, unless disturbed or problematic Woody Vine Stratum (Plot size: ) Hydrophytic Vegetation Present? Yes ☒No ☐ 1. 2. 0 = Total Cover % Bare Ground in Herb Stratum: 10 Remarks: *Presumed indicator status DP- 2 US Army Corps of Engineers Western Mountains, Valleys, and Coast – Interim Version SOIL Sampling Point – DP- 2 HYDROLOGY Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.) Depth Matrix Redox Features (inches) Color (moist) % Color (moist) % Type1 Loc2 Texture Remarks 0-12 10YR 2/2 100 Sandy loam 1Type: C=Concentration, D=Depletion, RM=Reduced Matrix, CS=Covered or Coated Sand Grains 2Loc: 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) ☐2cm 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) ☐Thick Dark Surface (A12) ☐ Redox Dark Surface (F6) 3 Indicators of hydrophytic vegetation and wetland hydrology must be present, unless disturbed or problematic ☐Sandy Mucky Mineral (S1) ☐ Depleted Dark Surface (F7) ☐Sandy Gleyed Matrix (S4) ☐ Redox Depressions (F8) Restrictive Layer (if present): Hydric soil present? Yes ☐ No ☒ Type: Depth (inches): Remarks: Very hard to dig soils. Wetland Hydrology Indicators: Primary Indicators (minimum of one required: check all that apply): Secondary Indicators (2 or more required): ☐ Surface water (A1) ☐ Sparsely Vegetated Concave Surface (B8) ☐Water-Stained Leaves (B9) (MLRA 1, 2, 4A & 4B) ☐ High Water Table (A2) ☐ Water-Stained Leaves (except MLRA 1, 2, 4A & 4B) (B9) ☐Drainage Patterns (B10) ☐ Saturation (A3) ☐ Salt Crust (B11) ☐Dry-Season Water Table (C2) ☐ Water Marks (B1) ☐ Aquatic Invertebrates (B13) ☐Saturation Visible on Aerial Imagery (C9) ☐ Sediment Deposits (B2) ☐ Hydrogen Sulfide Odor (C1) ☐Geomorphic Position (D2) ☐ Drift Deposits (B3) ☐ Oxidized Rhizospheres along Living Roots (C3) ☐Shallow Aquitard (D3) ☐ Algal Mat or Crust (B4) ☐ Presence of Reduced Iron (C4) ☐FAC-Neutral Test (D5) ☐ Iron Deposits (B5) ☐ Recent Iron Reduction in Tilled Soils (C6) ☐Raised Ant Mounds (D6) (LRR A) ☐ Surface Soil Cracks (B6) ☐ Stunted or Stressed Plants (D1) (LRR A) ☐Frost-Heave Hummocks ☐ Inundation Visible on Aerial Imagery (B7) ☐ Other (explain in remarks) Field Observations Wetland Hydrology Present? Yes ☐ No ☒ Surface Water Present? Yes ☐ No ☒ Depth (in): Water Table Present? Yes ☐ No ☒ Depth (in): Saturation Present? (includes capillary fringe) Yes ☐ No ☒ Depth (in): Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available: Remarks: Completely dry US Army Corps of Engineers Western Mountains, Valleys, and Coast – Interim Version 750 Sixth Street South Kirkland, Washington 98033 (425) 822-5242 watershedco.com WETLAND DETERMINATION DATA FORM Western Mountains, Valleys, and Coast Supplement to the 1987 COE Wetlands Delineation Manual Project Site: 12710 SE 173rd St, Renton, WA Sampling date: August 21, 2018 Applicant/Owner: Habitat for Humanity Sampling Point: DP-3 Investigator: Logan Dougherty, Sam Payne City/County: Renton / King Sect., Township, Range: S 28 T 23N R 05E State: Washington Landform (hillslope, terrace, etc): Depression Slope (%): 0 Local relief (concave, convex, none): None Subregion (LRR): A Lat: Long: Datum: Soil Map Unit Name: Seattle Muck NWI classification: PFOC (Freshwater Forested/Shrub) Are climatic/hydrologic conditions on the site typical for this time of year? ☐Yes ☒ No (If no, explain in remarks.) Are “Normal Circumstances” present on the site? ☒Yes ☐ No (If needed, explain any answers in Remarks.) Are Vegetation☐, Soil ☐, or Hydrology ☐ significantly disturbed? Are Vegetation☐, Soil ☐, or Hydrology ☐ naturally problematic SUMMARY OF FINDINGS – Attach site map showing sampling point locations, transects, important features, etc. Hydrophytic Vegetation Present? Yes ☒ No ☐ Is the Sampling Point within a Wetland? Yes ☒ No ☐ Hydric Soils Present? Yes ☒ No ☐ Wetland Hydrology Present? Yes ☒ No ☐ Remarks: Drier than normal per WETS (Seattle-Tacoma International Airport) VEGETATION – Use scientific names of plants. Tree Stratum (Plot size: 5m diam.) Absolute % Cover Dominant Species? Indicator Status Dominance Test Worksheet 1. Alnus rubra 95 Y FAC Number of Dominant Species that are OBL, FACW, or FAC: 5 (A) 2. 3. Total Number of Dominant Species Across All Strata: 5 (B) 4. 95 = Total Cover Percent of Dominant Species that are OBL, FACW, or FAC: 100 (A/B) Sapling/Shrub Stratum (Plot size: 3m diam.) 1. Cornus sericea 40 Y FACW Prevalence Index Worksheet 2. Lonicera involucrata 20 Y FAC Total % Cover of Multiply by 3. OBL species x 1 = 4. FACW species x 2 = 5. FAC species x 3 = 60 = Total Cover FACU species x 4 = UPL species x 5 = Herb Stratum (Plot size: 1m diam.) Column totals (A) (B) 1. Phalaris arundinacea 50 Y FACW 2. Ranunculus repens 30 Y FAC Prevalence Index = B / A = 3. Equisetum telmateia 5 N FACW 4. Hydrophytic Vegetation Indicators 5. ☒ Dominance test is > 50% 6. ☐ Prevalence test is ≤ 3.0 * 7. Morphological Adaptations * (provide supporting 8. ☐ data in remarks or on a separate sheet) 9. ☐ Wetland Non-Vascular Plants * 10. ☐ Problematic Hydrophytic Vegetation * (explain) 11. 85 = Total Cover * Indicators of hydric soil and wetland hydrology must be present, unless disturbed or problematic Woody Vine Stratum (Plot size: ) Hydrophytic Vegetation Present? Yes ☒No ☐ 1. 2. 0 = Total Cover % Bare Ground in Herb Stratum: 15 Remarks: DP- 3 US Army Corps of Engineers Western Mountains, Valleys, and Coast – Interim Version SOIL Sampling Point – DP- 3 HYDROLOGY Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.) Depth Matrix Redox Features (inches) Color (moist) % Color (moist) % Type1 Loc2 Texture Remarks 0-6 10YR 2/2 100 Sandy loam 6-16 10YR 2/2 90 10YR 4/6 5Y 5/1 5 5 C D M Sandy loam 1Type: C=Concentration, D=Depletion, RM=Reduced Matrix, CS=Covered or Coated Sand Grains 2Loc: 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) ☐2cm 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) ☐Thick Dark Surface (A12) ☒ Redox Dark Surface (F6) 3 Indicators of hydrophytic vegetation and wetland hydrology must be present, unless disturbed or problematic ☐Sandy Mucky Mineral (S1) ☐ Depleted Dark Surface (F7) ☐Sandy Gleyed Matrix (S4) ☐ Redox Depressions (F8) Restrictive Layer (if present): Hydric soil present? Yes ☒ No ☐ Type: Depth (inches): Remarks: Wetland Hydrology Indicators: Primary Indicators (minimum of one required: check all that apply): Secondary Indicators (2 or more required): ☐ Surface water (A1) ☐ Sparsely Vegetated Concave Surface (B8) ☐Water-Stained Leaves (B9) (MLRA 1, 2, 4A & 4B) ☐ High Water Table (A2) ☐ Water-Stained Leaves (except MLRA 1, 2, 4A & 4B) (B9) ☐Drainage Patterns (B10) ☐ Saturation (A3) ☐ Salt Crust (B11) ☐Dry-Season Water Table (C2) ☐ Water Marks (B1) ☐ Aquatic Invertebrates (B13) ☐Saturation Visible on Aerial Imagery (C9) ☐ Sediment Deposits (B2) ☐ Hydrogen Sulfide Odor (C1) ☒Geomorphic Position (D2) ☐ Drift Deposits (B3) ☐ Oxidized Rhizospheres along Living Roots (C3) ☐Shallow Aquitard (D3) ☐ Algal Mat or Crust (B4) ☐ Presence of Reduced Iron (C4) ☒FAC-Neutral Test (D5) ☐ Iron Deposits (B5) ☐ Recent Iron Reduction in Tilled Soils (C6) ☐Raised Ant Mounds (D6) (LRR A) ☐ Surface Soil Cracks (B6) ☐ Stunted or Stressed Plants (D1) (LRR A) ☐Frost-Heave Hummocks ☐ Inundation Visible on Aerial Imagery (B7) ☐ Other (explain in remarks) Field Observations Wetland Hydrology Present? Yes ☒ No ☐ Surface Water Present? Yes ☐ No ☒ Depth (in): Water Table Present? Yes ☐ No ☒ Depth (in): Saturation Present? (includes capillary fringe) Yes ☐ No ☒ Depth (in): Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available: Remarks: US Army Corps of Engineers Western Mountains, Valleys, and Coast – Interim Version 750 Sixth Street South Kirkland, Washington 98033 (425) 822-5242 watershedco.com WETLAND DETERMINATION DATA FORM Western Mountains, Valleys, and Coast Supplement to the 1987 COE Wetlands Delineation Manual Project Site: 12710 SE 173rd St, Renton, WA Sampling date: August 21, 2018 Applicant/Owner: Habitat for Humanity Sampling Point: DP -4 Investigator: Logan Dougherty, Sam Payne City/County: Renton / King Sect., Township, Range: S 28 T 23N R 05E State: Washington Landform (hillslope, terrace, etc): Hillslope Slope (%): 2 Local relief (concave, convex, none): None Subregion (LRR): A Lat: Long: Datum: Soil Map Unit Name: Seattle Muck NWI classification: PFOC (Freshwater Forested/Shrub) Are climatic/hydrologic conditions on the site typical for this time of year? ☐Yes ☒ No (If no, explain in remarks.) Are “Normal Circumstances” present on the site? ☒Yes ☐ No (If needed, explain any answers in Remarks.) Are Vegetation☐, Soil ☐, or Hydrology ☐ significantly disturbed? Are Vegetation☐, Soil ☐, or Hydrology ☐ naturally problematic SUMMARY OF FINDINGS – Attach site map showing sampling point locations, transects, important features, etc. Hydrophytic Vegetation Present? Yes ☒ No ☐ Is the Sampling Point within a Wetland? Yes ☐ No ☒ Hydric Soils Present? Yes ☐ No ☒ Wetland Hydrology Present? Yes ☐ No ☒ Remarks: Drier than normal per WETS (Seattle-Tacoma International Airport) VEGETATION – Use scientific names of plants. Tree Stratum (Plot size: 5m diam.) Absolute % Cover Dominant Species? Indicator Status Dominance Test Worksheet 1. Betula nigra 40 Y FACW Number of Dominant Species that are OBL, FACW, or FAC: 3 (A) 2. 3. Total Number of Dominant Species Across All Strata: 3 (B) 4. 40 = Total Cover Percent of Dominant Species that are OBL, FACW, or FAC: 100 (A/B) Sapling/Shrub Stratum (Plot size: 3m diam.) 1. Cornus sericea 40 Y FACW Prevalence Index Worksheet 2. Populus balsamifera 5 N FAC Total % Cover of Multiply by 3. OBL species x 1 = 4. FACW species x 2 = 5. FAC species x 3 = 45 = Total Cover FACU species x 4 = UPL species x 5 = Herb Stratum (Plot size: 1m diam.) Column totals (A) (B) 1. Poaceae sp. 60 Y FAC* 2. Ranunculus repens 20 N FAC Prevalence Index = B / A = 3. Phalaris arundinacea 20 N FACW 4. Geranium robertianum 5 N FACU Hydrophytic Vegetation Indicators 5. ☒ Dominance test is > 50% 6. ☐ Prevalence test is ≤ 3.0 * 7. Morphological Adaptations * (provide supporting 8. ☐ data in remarks or on a separate sheet) 9. ☐ Wetland Non-Vascular Plants * 10. ☐ Problematic Hydrophytic Vegetation * (explain) 11. 105 = Total Cover * Indicators of hydric soil and wetland hydrology must be present, unless disturbed or problematic Woody Vine Stratum (Plot size: ) Hydrophytic Vegetation Present? Yes ☒No ☐ 1. 2. 0 = Total Cover % Bare Ground in Herb Stratum: 0 Remarks: *Presumed indicator status DP- 4 US Army Corps of Engineers Western Mountains, Valleys, and Coast – Interim Version SOIL Sampling Point – DP- 4 HYDROLOGY Profile Description: (Describe to the depth needed to document the indicator or confirm the absence of indicators.) Depth Matrix Redox Features (inches) Color (moist) % Color (moist) % Type1 Loc2 Texture Remarks 0-10 10YR 2/2 Sandy loam 10-14 10YR 2/2 Gravelly sandy loam 1Type: C=Concentration, D=Depletion, RM=Reduced Matrix, CS=Covered or Coated Sand Grains 2Loc: 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) ☐2cm 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) ☐Thick Dark Surface (A12) ☐ Redox Dark Surface (F6) 3 Indicators of hydrophytic vegetation and wetland hydrology must be present, unless disturbed or problematic ☐Sandy Mucky Mineral (S1) ☐ Depleted Dark Surface (F7) ☐Sandy Gleyed Matrix (S4) ☐ Redox Depressions (F8) Restrictive Layer (if present): Hydric soil present? Yes ☐ No ☒ Type: Depth (inches): Remarks: Wetland Hydrology Indicators: Primary Indicators (minimum of one required: check all that apply): Secondary Indicators (2 or more required): ☐ Surface water (A1) ☐ Sparsely Vegetated Concave Surface (B8) ☐Water-Stained Leaves (B9) (MLRA 1, 2, 4A & 4B) ☐ High Water Table (A2) ☐ Water-Stained Leaves (except MLRA 1, 2, 4A & 4B) (B9) ☐Drainage Patterns (B10) ☐ Saturation (A3) ☐ Salt Crust (B11) ☐Dry-Season Water Table (C2) ☐ Water Marks (B1) ☐ Aquatic Invertebrates (B13) ☐Saturation Visible on Aerial Imagery (C9) ☐ Sediment Deposits (B2) ☐ Hydrogen Sulfide Odor (C1) ☐Geomorphic Position (D2) ☐ Drift Deposits (B3) ☐ Oxidized Rhizospheres along Living Roots (C3) ☐Shallow Aquitard (D3) ☐ Algal Mat or Crust (B4) ☐ Presence of Reduced Iron (C4) ☐FAC-Neutral Test (D5) ☐ Iron Deposits (B5) ☐ Recent Iron Reduction in Tilled Soils (C6) ☐Raised Ant Mounds (D6) (LRR A) ☐ Surface Soil Cracks (B6) ☐ Stunted or Stressed Plants (D1) (LRR A) ☐Frost-Heave Hummocks ☐ Inundation Visible on Aerial Imagery (B7) ☐ Other (explain in remarks) Field Observations Wetland Hydrology Present? Yes ☐ No ☒ Surface Water Present? Yes ☐ No ☐ Depth (in): Water Table Present? Yes ☐ No ☐ Depth (in): Saturation Present? (includes capillary fringe) Yes ☐ No ☐ Depth (in): Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available: Remarks: Wetland Rating System forWestern WA: 2014Update Rating Form – Effective January 1, 2015 1 Wetland name or number: Wetland A RATING SUMMARY – Western Washington Name of wetland (or ID #): Wetland A Date of site visit: August 21, 2018 Rated by: Sam Payne, Logan Dougherty Trained by Ecology? ☒Y ☐N Date of training: June 2017 HGM Class used for rating: Depressional 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: King County iMap, Bing Maps 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 9 7 6 22 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 ☒ 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 Wetland Rating System forWestern WA: 2014Update Rating Form – Effective January 1, 2015 2 Wetland name or number: Wetland A 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 1 Hydroperiods D 1.4, H 1.2 2 Location of outlet (can be added to map of hydroperiods)D 1.1, D 4.1 2 Boundary of area within 150 ft of the wetland (can be added to another figure)D 2.2, D 5.2 2 Map of the contributing basin D 4.3, D 5.3 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 6 Screen capture of map of 303(d) listed waters in basin (from Ecology website)D 3.1, D 3.2 7 Screen capture of list of TMDLs for WRIA in which unit is found (from web)D 3.3 8 Wetland Rating System for Western WA: 2014 Update Rating Form – Effective January 1, 2015 3 Wetland name or number: Wetland A 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. Wetland Rating System for Western WA: 2014 Update Rating Form – Effective January 1, 2015 4 Wetland name or number: Wetland A ☒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 Rating System for Western WA: 2014 Update Rating Form – Effective January 1, 2015 5 Wetland name or number: Wetland A DEPRESSIONAL AND FLATS WETLANDS Water Quality Functions ‐ Indicators that the site functions to improve water quality D 1.0. Does the site have the potential to improve water quality? D 1.1. Characteristics of surface water outflows from the wetland: ☐ Wetland is a depression or flat depression (QUESTION 7 on key) with no surface water leaving it (no outlet). points = 3 ☐ Wetland has an intermittently flowing stream or ditch, OR highly constricted permanently flowing outlet. points = 2 ☒ Wetland has an unconstricted, or slightly constricted, surface outlet that is permanently flowing. points = 1 ☐ Wetland is a flat depression (QUESTION 7 on key), whose outlet is a permanently flowing ditch. points = 1 1 D 1.2. The soil 2 in below the surface (or duff layer) is true clay or true organic (use NRCS definitions).☒Yes = 4 ☐No = 0 4 D 1.3. Characteristics and distribution of persistent plants (Emergent, Scrub‐shrub, and/or Forested Cowardin classes): ☒ Wetland has persistent, ungrazed, plants > 95% of area points = 5 ☐ Wetland has persistent, ungrazed, plants > 1/2 of area points = 3 ☐ Wetland has persistent, ungrazed plants > 1/10 of area points = 1 ☐ Wetland has persistent, ungrazed plants < 1/10 of area points = 0 5 D 1.4. Characteristics of seasonal ponding or inundation: This is the area that is ponded for at least 2 months. See description in manual. ☒ Area seasonally ponded is > ½ total area of wetland points = 4 ☐ Area seasonally ponded is > ¼ total area of wetland points = 2 ☐ Area seasonally ponded is < ¼ total area of wetland points = 0 4 Total for D 1 Add the points in the boxes above 14 Rating of Site Potential If score is: ☒12‐16 = H ☐6‐11 = M ☐0‐5 = L Record the rating on the first page D 2.0. Does the landscape have the potential to support the water quality function of the site? D 2.1. Does the wetland unit receive stormwater discharges? ☒Yes = 1 ☐No = 0 1 D 2.2. Is > 10% of the area within 150 ft of the wetland in land uses that generate pollutants? ☒Yes = 1 ☐No = 0 1 D 2.3. Are there septic systems within 250 ft of the wetland? ☒Yes = 1 ☐No = 0 1 D 2.4. Are there other sources of pollutants coming into the wetland that are not listed in questions D 2.1‐D 2.3? Source: Click here to enter text.☐Yes = 1 ☒No =0 0 Total for D 2 Add the points in the boxes above 3 Rating of Landscape Potential If score is: ☒3 or 4 = H ☐1 or 2 = M ☐0 = L Record the rating on the first page D 3.0. Is the water quality improvement provided by the site valuable to society? D 3.1. Does the wetland discharge directly (i.e., within 1 mi) to a stream, river, lake, or marine water that is on the 303(d) list? ☐Yes = 1 ☒No = 0 0 D 3.2. Is the wetland in a basin or sub‐basin where an aquatic resource is on the 303(d) list? ☒Yes = 1 ☐No = 0 1 D 3.3. Has the site been identified in a watershed or local plan as important for maintaining water quality (answer YES if there is a TMDL for the basin in which the unit is found)? ☒Yes = 2 ☐No = 0 2 Total for D 3 Add the points in the boxes above 3 Rating of Value If score is: ☒2‐4 = H ☐1 = M ☐0 = L Record the rating on the first page Wetland Rating System for Western WA: 2014 Update Rating Form – Effective January 1, 2015 6 Wetland name or number: Wetland A DEPRESSIONAL AND FLATS WETLANDS Hydrologic Functions ‐ Indicators that the site functions to reduce flooding and stream degradation D 4.0. Does the site have the potential to reduce flooding and erosion? D 4.1. Characteristics of surface water outflows from the wetland: ☐ Wetland is a depression or flat depression with no surface water leaving it (no outlet). points = 4 ☐ Wetland has an intermittently flowing stream or ditch, OR highly constricted permanently flowing outlet. points = 2 ☐ Wetland is a flat depression (QUESTION 7 on key), whose outlet is a permanently flowing ditch. points = 1 ☒ Wetland has an unconstricted, or slightly constricted, surface outlet that is permanently flowing. points = 0 0 D 4.2. Depth of storage during wet periods: Estimate the height of ponding above the bottom of the outlet. For wetlands with no outlet, measure from the surface of permanent water or if dry, the deepest part. ☐ Marks of ponding are 3 ft or more above the surface or bottom of outlet. points = 7 ☐ Marks of ponding between 2 ft to < 3 ft from surface or bottom of outlet. points = 5 ☒ Marks are at least 0.5 ft to < 2 ft from surface or bottom of outlet. points = 3 ☐ The wetland is a “headwater” wetland. points = 3 ☐ Wetland is flat but has small depressions on the surface that trap water. points = 1 ☐ Marks of ponding less than 0.5 ft (6 in). points = 0 3 D 4.3. Contribution of the wetland to storage in the watershed: Estimate the ratio of the area of upstream basin contributing surface water to the wetland to the area of the wetland unit itself. ☐ The area of the basin is less than 10 times the area of the unit. points = 5 ☒ The area of the basin is 10 to 100 times the area of the unit. points = 3 ☐ The area of the basin is more than 100 times the area of the unit. points = 0 ☐ Entire wetland is in the Flats class. points = 5 3 Total for D 4 Add the points in the boxes above 6 Rating of Site Potential If score is: ☐12‐16 = H ☒6‐11 = M ☐0‐5 = L Record the rating on the first page D 5.0. Does the landscape have the potential to support hydrologic functions of the site? D 5.1. Does the wetland receive stormwater discharges? ☒Yes = 1 ☐No = 0 1 D 5.2. Is >10% of the area within 150 ft of the wetland in land uses that generate excess runoff? ☒Yes = 1 ☐No = 0 1 D 5.3. Is more than 25% of the contributing basin of the wetland covered with intensive human land uses (residential at >1 residence/ac, urban, commercial, agriculture,etc.)?☒Yes = 1 ☐No =0 1 Total for D 5 Add the points in the boxes above 3 Rating of Landscape Potential If score is: ☒3 = H ☐1 or 2 = M ☐0 = L Record the rating on the first page D 6.0. Are the hydrologic functions provided by the site valuable to society? D 6.1. The unit is in a landscape that has flooding problems. Choose the description that best matches conditions around the wetland unit being rated. Do not add points. Choose the highest score if more than one condition is met. The wetland captures surface water that would otherwise flow down‐gradient into areas where flooding has damaged human or natural resources (e.g., houses or salmon redds): ☐ Flooding occurs in a sub‐basin that is immediately down‐gradient of unit. points = 2 ☒ Surface flooding problems are in a sub‐basin farther down‐gradient. points = 1 ☐ Flooding from groundwater is an issue in the sub‐basin. points = 1 ☐ The existing or potential outflow from the wetland is so constrained by human or natural conditions that the water stored by the wetland cannot reach areas that flood. Explain why: …. points = 0 ☐There are no problems with flooding downstream of the wetland. points = 0 1 D 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 0 Total for D 6 Add the points in the boxes above 1 Rating of Value If score is: ☐2‐4 = H ☒1 = M ☐0 = L Record the rating on the first page Wetland name or number: Wetland A Wetland Rating System for Western WA: 2014 Update Rating Form – Effective January 1, 2015 7 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 1 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 2 H 1.3. Richness of plant species Count the number of plant species in the wetland that cover at least 10 ft2. Different patches of the same species can be combined to meet the size threshold and you do not have to name the species. Do not include Eurasian milfoil, reed canarygrass, purple loosestrife, Canadian thistle If you counted: ☒ > 19 species points = 2 ☐ 5 ‐ 19 species points = 1 ☐ < 5 species points = 0 2 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 0 Wetland name or number: Wetland A Wetland Rating System for Western WA: 2014 Update Rating Form – Effective January 1, 2015 8 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). 5 Total for H 1 Add the points in the boxes above 10 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] = 1% + (0%/2) = 0.5% 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 0 H 2.2. Undisturbed habitat in 1 km Polygon around the wetland. Calculate: % undisturbed habitat + [(%moderate and low intensity land uses)/2 = 35% + (4%/2) = 37% ☐ 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 2 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 ‐2 Total for H 2 Add the points in the boxes above 0 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 2 Rating of Value If score is: ☒2 = H ☐1 = M ☐0 = L Record the rating on the first page Wetland name or number: Wetland A Wetland Rating System for Western WA: 2014 Update Rating Form – Effective January 1, 2015 9 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. Wetland name or number: Wetland A Wetland Rating System for Western WA: 2014 Update Rating Form – Effective January 1, 2015 10 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? http://www.dnr.wa.gov/NHPwetlandviewer ☐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://file.dnr.wa.gov/publications/amp_nh_wetlands_trs.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 Cat. I Wetland name or number: Wetland A Wetland Rating System for Western WA: 2014 Update Rating Form – Effective January 1, 2015 11 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 Rating System forWestern WA: 2014Update Rating Form – Effective January 1, 2015 1 Wetland name or number: Wetland B RATING SUMMARY – Western Washington Name of wetland (or ID #): Wetland B Date of site visit: August 21, 2018 Rated by: Sam Payne, Logan Dougherty Trained by Ecology? ☒Y ☐N Date of training: June 2017 HGM Class used for rating: Depressional 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: King County iMap, Bing Maps 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 7 5 4 16 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 ☒ 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 Wetland Rating System forWestern WA: 2014Update Rating Form – Effective January 1, 2015 2 Wetland name or number: Wetland B 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 1 Hydroperiods D 1.4, H 1.2 2 Location of outlet (can be added to map of hydroperiods)D 1.1, D 4.1 2 Boundary of area within 150 ft of the wetland (can be added to another figure)D 2.2, D 5.2 2 Map of the contributing basin D 4.3, D 5.3 4 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 6 Screen capture of map of 303(d) listed waters in basin (from Ecology website)D 3.1, D 3.2 7 Screen capture of list of TMDLs for WRIA in which unit is found (from web)D 3.3 8 Wetland Rating System for Western WA: 2014 Update Rating Form – Effective January 1, 2015 3 Wetland name or number: Wetland B 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. Wetland Rating System for Western WA: 2014 Update Rating Form – Effective January 1, 2015 4 Wetland name or number: Wetland B ☒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 Rating System for Western WA: 2014 Update Rating Form – Effective January 1, 2015 5 Wetland name or number: Wetland B DEPRESSIONAL AND FLATS WETLANDS Water Quality Functions ‐ Indicators that the site functions to improve water quality D 1.0. Does the site have the potential to improve water quality? D 1.1. Characteristics of surface water outflows from the wetland: ☐ Wetland is a depression or flat depression (QUESTION 7 on key) with no surface water leaving it (no outlet). points = 3 ☒ Wetland has an intermittently flowing stream or ditch, OR highly constricted permanently flowing outlet. points = 2 ☐ Wetland has an unconstricted, or slightly constricted, surface outlet that is permanently flowing. points = 1 ☐ Wetland is a flat depression (QUESTION 7 on key), whose outlet is a permanently flowing ditch. points = 1 2 D 1.2. The soil 2 in below the surface (or duff layer) is true clay or true organic (use NRCS definitions).☐Yes = 4 ☒No = 0 0 D 1.3. Characteristics and distribution of persistent plants (Emergent, Scrub‐shrub, and/or Forested Cowardin classes): ☒ Wetland has persistent, ungrazed, plants > 95% of area points = 5 ☐ Wetland has persistent, ungrazed, plants > 1/2 of area points = 3 ☐ Wetland has persistent, ungrazed plants > 1/10 of area points = 1 ☐ Wetland has persistent, ungrazed plants < 1/10 of area points = 0 5 D 1.4. Characteristics of seasonal ponding or inundation: This is the area that is ponded for at least 2 months. See description in manual. ☐ Area seasonally ponded is > ½ total area of wetland points = 4 ☐ Area seasonally ponded is > ¼ total area of wetland points = 2 ☒ Area seasonally ponded is < ¼ total area of wetland points = 0 0 Total for D 1 Add the points in the boxes above 7 Rating of Site Potential If score is: ☐12‐16 = H ☒6‐11 = M ☐0‐5 = L Record the rating on the first page D 2.0. Does the landscape have the potential to support the water quality function of the site? D 2.1. Does the wetland unit receive stormwater discharges? ☐Yes = 1 ☒No = 0 0 D 2.2. Is > 10% of the area within 150 ft of the wetland in land uses that generate pollutants? ☒Yes = 1 ☐No = 0 1 D 2.3. Are there septic systems within 250 ft of the wetland? ☒Yes = 1 ☐No = 0 1 D 2.4. Are there other sources of pollutants coming into the wetland that are not listed in questions D 2.1‐D 2.3? Source: Click here to enter text.☐Yes = 1 ☒No =0 Total for D 2 Add the points in the boxes above 2 Rating of Landscape Potential If score is: ☐3 or 4 = H ☒1 or 2 = M ☐0 = L Record the rating on the first page D 3.0. Is the water quality improvement provided by the site valuable to society? D 3.1. Does the wetland discharge directly (i.e., within 1 mi) to a stream, river, lake, or marine water that is on the 303(d) list? ☐Yes = 1 ☒No = 0 0 D 3.2. Is the wetland in a basin or sub‐basin where an aquatic resource is on the 303(d) list? ☒Yes = 1 ☐No = 0 1 D 3.3. Has the site been identified in a watershed or local plan as important for maintaining water quality (answer YES if there is a TMDL for the basin in which the unit is found)? ☒Yes = 2 ☐No = 0 2 Total for D 3 Add the points in the boxes above 3 Rating of Value If score is: ☒2‐4 = H ☐1 = M ☐0 = L Record the rating on the first page Wetland Rating System for Western WA: 2014 Update Rating Form – Effective January 1, 2015 6 Wetland name or number: Wetland B DEPRESSIONAL AND FLATS WETLANDS Hydrologic Functions ‐ Indicators that the site functions to reduce flooding and stream degradation D 4.0. Does the site have the potential to reduce flooding and erosion? D 4.1. Characteristics of surface water outflows from the wetland: ☐ Wetland is a depression or flat depression with no surface water leaving it (no outlet). points = 4 ☒ Wetland has an intermittently flowing stream or ditch, OR highly constricted permanently flowing outlet. points = 2 ☐ Wetland is a flat depression (QUESTION 7 on key), whose outlet is a permanently flowing ditch. points = 1 ☐ Wetland has an unconstricted, or slightly constricted, surface outlet that is permanently flowing. points = 0 2 D 4.2. Depth of storage during wet periods: Estimate the height of ponding above the bottom of the outlet. For wetlands with no outlet, measure from the surface of permanent water or if dry, the deepest part. ☐ Marks of ponding are 3 ft or more above the surface or bottom of outlet. points = 7 ☐ Marks of ponding between 2 ft to < 3 ft from surface or bottom of outlet. points = 5 ☐ Marks are at least 0.5 ft to < 2 ft from surface or bottom of outlet. points = 3 ☐ The wetland is a “headwater” wetland. points = 3 ☐ Wetland is flat but has small depressions on the surface that trap water. points = 1 ☒ Marks of ponding less than 0.5 ft (6 in). points = 0 0 D 4.3. Contribution of the wetland to storage in the watershed: Estimate the ratio of the area of upstream basin contributing surface water to the wetland to the area of the wetland unit itself. ☐ The area of the basin is less than 10 times the area of the unit. points = 5 ☒ The area of the basin is 10 to 100 times the area of the unit. points = 3 ☐ The area of the basin is more than 100 times the area of the unit. points = 0 ☐ Entire wetland is in the Flats class. points = 5 3 Total for D 4 Add the points in the boxes above 5 Rating of Site Potential If score is: ☐12‐16 = H ☐6‐11 = M ☒0‐5 = L Record the rating on the first page D 5.0. Does the landscape have the potential to support hydrologic functions of the site? D 5.1. Does the wetland receive stormwater discharges? ☐Yes = 1 ☒No = 0 0 D 5.2. Is >10% of the area within 150 ft of the wetland in land uses that generate excess runoff? ☒Yes = 1 ☐No = 0 1 D 5.3. Is more than 25% of the contributing basin of the wetland covered with intensive human land uses (residential at >1 residence/ac, urban, commercial, agriculture,etc.)?☒Yes = 1 ☐No =0 1 Total for D 5 Add the points in the boxes above 2 Rating of Landscape Potential If score is: ☐3 = H ☒1 or 2 = M ☐0 = L Record the rating on the first page D 6.0. Are the hydrologic functions provided by the site valuable to society? D 6.1. The unit is in a landscape that has flooding problems. Choose the description that best matches conditions around the wetland unit being rated. Do not add points. Choose the highest score if more than one condition is met. The wetland captures surface water that would otherwise flow down‐gradient into areas where flooding has damaged human or natural resources (e.g., houses or salmon redds): ☐ Flooding occurs in a sub‐basin that is immediately down‐gradient of unit. points = 2 ☒ Surface flooding problems are in a sub‐basin farther down‐gradient. points = 1 ☐ Flooding from groundwater is an issue in the sub‐basin. points = 1 ☐ The existing or potential outflow from the wetland is so constrained by human or natural conditions that the water stored by the wetland cannot reach areas that flood. Explain why: …. points = 0 ☐There are no problems with flooding downstream of the wetland. points = 0 1 D 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 0 Total for D 6 Add the points in the boxes above 1 Rating of Value If score is: ☐2‐4 = H ☒1 = M ☐0 = L Record the rating on the first page Wetland name or number: Wetland B Wetland Rating System for Western WA: 2014 Update Rating Form – Effective January 1, 2015 7 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 1 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 1 H 1.3. Richness of plant species Count the number of plant species in the wetland that cover at least 10 ft2. Different patches of the same species can be combined to meet the size threshold and you do not have to name the species. Do not include Eurasian milfoil, reed canarygrass, purple loosestrife, Canadian thistle If you counted: ☒ > 19 species points = 2 ☐ 5 ‐ 19 species points = 1 ☐ < 5 species points = 0 2 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 0 Wetland name or number: Wetland B Wetland Rating System for Western WA: 2014 Update Rating Form – Effective January 1, 2015 8 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). 1 Total for H 1 Add the points in the boxes above 5 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] = 3% + (0%/2) = 1.5% 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 0 H 2.2. Undisturbed habitat in 1 km Polygon around the wetland. Calculate: % undisturbed habitat + [(%moderate and low intensity land uses)/2 = 35% + (4%/2) = 37% ☐ 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 2 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 ‐2 Total for H 2 Add the points in the boxes above 0 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 1 Rating of Value If score is: ☐2 = H ☒1 = M ☐0 = L Record the rating on the first page Wetland name or number: Wetland B Wetland Rating System for Western WA: 2014 Update Rating Form – Effective January 1, 2015 9 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. Wetland name or number: Wetland B Wetland Rating System for Western WA: 2014 Update Rating Form – Effective January 1, 2015 10 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? http://www.dnr.wa.gov/NHPwetlandviewer ☐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://file.dnr.wa.gov/publications/amp_nh_wetlands_trs.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 Cat. I Wetland name or number: Wetland B Wetland Rating System for Western WA: 2014 Update Rating Form – Effective January 1, 2015 11 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 Rating System forWestern WA: 2014Update Rating Form – Effective January 1, 2015 1 Wetland name or number: Wetland C RATING SUMMARY – Western Washington Name of wetland (or ID #): Wetland C Date of site visit: August 21, 2018 Rated by: Sam Payne, Logan Dougherty Trained by Ecology? ☒Y ☐N Date of training: June 2017 HGM Class used for rating: Depressional 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: King County iMap, Bing Maps 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 7 5 4 16 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 ☒ 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 Wetland Rating System forWestern WA: 2014Update Rating Form – Effective January 1, 2015 2 Wetland name or number: Wetland C 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 1 Hydroperiods D 1.4, H 1.2 2 Location of outlet (can be added to map of hydroperiods)D 1.1, D 4.1 2 Boundary of area within 150 ft of the wetland (can be added to another figure)D 2.2, D 5.2 2 Map of the contributing basin D 4.3, D 5.3 5 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 6 Screen capture of map of 303(d) listed waters in basin (from Ecology website)D 3.1, D 3.2 7 Screen capture of list of TMDLs for WRIA in which unit is found (from web)D 3.3 8 Wetland Rating System for Western WA: 2014 Update Rating Form – Effective January 1, 2015 3 Wetland name or number: Wetland 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. Wetland Rating System for Western WA: 2014 Update Rating Form – Effective January 1, 2015 4 Wetland name or number: Wetland ☒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 Rating System for Western WA: 2014 Update Rating Form – Effective January 1, 2015 5 Wetland name or number: Wetland DEPRESSIONAL AND FLATS WETLANDS Water Quality Functions ‐ Indicators that the site functions to improve water quality D 1.0. Does the site have the potential to improve water quality? D 1.1. Characteristics of surface water outflows from the wetland: ☐ Wetland is a depression or flat depression (QUESTION 7 on key) with no surface water leaving it (no outlet). points = 3 ☒ Wetland has an intermittently flowing stream or ditch, OR highly constricted permanently flowing outlet. points = 2 ☐ Wetland has an unconstricted, or slightly constricted, surface outlet that is permanently flowing. points = 1 ☐ Wetland is a flat depression (QUESTION 7 on key), whose outlet is a permanently flowing ditch. points = 1 2 D 1.2. The soil 2 in below the surface (or duff layer) is true clay or true organic (use NRCS definitions).☐Yes = 4 ☒No = 0 0 D 1.3. Characteristics and distribution of persistent plants (Emergent, Scrub‐shrub, and/or Forested Cowardin classes): ☒ Wetland has persistent, ungrazed, plants > 95% of area points = 5 ☐ Wetland has persistent, ungrazed, plants > 1/2 of area points = 3 ☐ Wetland has persistent, ungrazed plants > 1/10 of area points = 1 ☐ Wetland has persistent, ungrazed plants < 1/10 of area points = 0 5 D 1.4. Characteristics of seasonal ponding or inundation: This is the area that is ponded for at least 2 months. See description in manual. ☐ Area seasonally ponded is > ½ total area of wetland points = 4 ☐ Area seasonally ponded is > ¼ total area of wetland points = 2 ☒ Area seasonally ponded is < ¼ total area of wetland points = 0 0 Total for D 1 Add the points in the boxes above 7 Rating of Site Potential If score is: ☐12‐16 = H ☒6‐11 = M ☐0‐5 = L Record the rating on the first page D 2.0. Does the landscape have the potential to support the water quality function of the site? D 2.1. Does the wetland unit receive stormwater discharges? ☐Yes = 1 ☒No = 0 0 D 2.2. Is > 10% of the area within 150 ft of the wetland in land uses that generate pollutants? ☒Yes = 1 ☐No = 0 1 D 2.3. Are there septic systems within 250 ft of the wetland? ☒Yes = 1 ☐No = 0 1 D 2.4. Are there other sources of pollutants coming into the wetland that are not listed in questions D 2.1‐D 2.3? Source: Click here to enter text.☐Yes = 1 ☒No =0 0 Total for D 2 Add the points in the boxes above 2 Rating of Landscape Potential If score is: ☐3 or 4 = H ☒1 or 2 = M ☐0 = L Record the rating on the first page D 3.0. Is the water quality improvement provided by the site valuable to society? D 3.1. Does the wetland discharge directly (i.e., within 1 mi) to a stream, river, lake, or marine water that is on the 303(d) list? ☐Yes = 1 ☒No = 0 0 D 3.2. Is the wetland in a basin or sub‐basin where an aquatic resource is on the 303(d) list? ☒Yes = 1 ☐No = 0 1 D 3.3. Has the site been identified in a watershed or local plan as important for maintaining water quality (answer YES if there is a TMDL for the basin in which the unit is found)? ☒Yes = 2 ☐No = 0 2 Total for D 3 Add the points in the boxes above 3 Rating of Value If score is: ☒2‐4 = H ☐1 = M ☐0 = L Record the rating on the first page Wetland Rating System for Western WA: 2014 Update Rating Form – Effective January 1, 2015 6 Wetland name or number: Wetland DEPRESSIONAL AND FLATS WETLANDS Hydrologic Functions ‐ Indicators that the site functions to reduce flooding and stream degradation D 4.0. Does the site have the potential to reduce flooding and erosion? D 4.1. Characteristics of surface water outflows from the wetland: ☐ Wetland is a depression or flat depression with no surface water leaving it (no outlet). points = 4 ☒ Wetland has an intermittently flowing stream or ditch, OR highly constricted permanently flowing outlet. points = 2 ☐ Wetland is a flat depression (QUESTION 7 on key), whose outlet is a permanently flowing ditch. points = 1 ☐ Wetland has an unconstricted, or slightly constricted, surface outlet that is permanently flowing. points = 0 2 D 4.2. Depth of storage during wet periods: Estimate the height of ponding above the bottom of the outlet. For wetlands with no outlet, measure from the surface of permanent water or if dry, the deepest part. ☐ Marks of ponding are 3 ft or more above the surface or bottom of outlet. points = 7 ☐ Marks of ponding between 2 ft to < 3 ft from surface or bottom of outlet. points = 5 ☐ Marks are at least 0.5 ft to < 2 ft from surface or bottom of outlet. points = 3 ☐ The wetland is a “headwater” wetland. points = 3 ☐ Wetland is flat but has small depressions on the surface that trap water. points = 1 ☒ Marks of ponding less than 0.5 ft (6 in). points = 0 0 D 4.3. Contribution of the wetland to storage in the watershed: Estimate the ratio of the area of upstream basin contributing surface water to the wetland to the area of the wetland unit itself. ☐ The area of the basin is less than 10 times the area of the unit. points = 5 ☒ The area of the basin is 10 to 100 times the area of the unit. points = 3 ☐ The area of the basin is more than 100 times the area of the unit. points = 0 ☐ Entire wetland is in the Flats class. points = 5 3 Total for D 4 Add the points in the boxes above 5 Rating of Site Potential If score is: ☐12‐16 = H ☐6‐11 = M ☒0‐5 = L Record the rating on the first page D 5.0. Does the landscape have the potential to support hydrologic functions of the site? D 5.1. Does the wetland receive stormwater discharges? ☐Yes = 1 ☒No = 0 0 D 5.2. Is >10% of the area within 150 ft of the wetland in land uses that generate excess runoff? ☒Yes = 1 ☐No = 0 1 D 5.3. Is more than 25% of the contributing basin of the wetland covered with intensive human land uses (residential at >1 residence/ac, urban, commercial, agriculture,etc.)?☒Yes = 1 ☐No =0 1 Total for D 5 Add the points in the boxes above 2 Rating of Landscape Potential If score is: ☐3 = H ☒1 or 2 = M ☐0 = L Record the rating on the first page D 6.0. Are the hydrologic functions provided by the site valuable to society? D 6.1. The unit is in a landscape that has flooding problems. Choose the description that best matches conditions around the wetland unit being rated. Do not add points. Choose the highest score if more than one condition is met. The wetland captures surface water that would otherwise flow down‐gradient into areas where flooding has damaged human or natural resources (e.g., houses or salmon redds): ☐ Flooding occurs in a sub‐basin that is immediately down‐gradient of unit. points = 2 ☒ Surface flooding problems are in a sub‐basin farther down‐gradient. points = 1 ☐ Flooding from groundwater is an issue in the sub‐basin. points = 1 ☐ The existing or potential outflow from the wetland is so constrained by human or natural conditions that the water stored by the wetland cannot reach areas that flood. Explain why: …. points = 0 ☐There are no problems with flooding downstream of the wetland. points = 0 1 D 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 0 Total for D 6 Add the points in the boxes above 1 Rating of Value If score is: ☐2‐4 = H ☒1 = M ☐0 = L Record the rating on the first page Wetland name or number: Wetland Wetland Rating System for Western WA: 2014 Update Rating Form – Effective January 1, 2015 7 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 0 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 0 H 1.3. Richness of plant species Count the number of plant species in the wetland that cover at least 10 ft2. Different patches of the same species can be combined to meet the size threshold and you do not have to name the species. Do not include Eurasian milfoil, reed canarygrass, purple loosestrife, Canadian thistle If you counted: ☐ > 19 species points = 2 ☒ 5 ‐ 19 species points = 1 ☐ < 5 species points = 0 1 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 0 Wetland name or number: Wetland Wetland Rating System for Western WA: 2014 Update Rating Form – Effective January 1, 2015 8 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). 0 Total for H 1 Add the points in the boxes above 1 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] = 3% + (0%/2) = 1.5% 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 0 H 2.2. Undisturbed habitat in 1 km Polygon around the wetland. Calculate: % undisturbed habitat + [(%moderate and low intensity land uses)/2 = 35% + (4%/2) = 37% ☐ 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 2 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 ‐2 Total for H 2 Add the points in the boxes above 0 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 1 Rating of Value If score is: ☐2 = H ☒1 = M ☐0 = L Record the rating on the first page Wetland name or number: Wetland Wetland Rating System for Western WA: 2014 Update Rating Form – Effective January 1, 2015 9 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. Wetland name or number: Wetland Wetland Rating System for Western WA: 2014 Update Rating Form – Effective January 1, 2015 10 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? http://www.dnr.wa.gov/NHPwetlandviewer ☐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://file.dnr.wa.gov/publications/amp_nh_wetlands_trs.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 Cat. I Wetland name or number: Wetland Wetland Rating System for Western WA: 2014 Update Rating Form – Effective January 1, 2015 11 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 Features depicted are not to scale. Sketches are based on available data and best professional judgment. Wetland Figures ‐ 1 WETLAND A (DEPRESSIONAL) Figure 1. Cowardin plant classes – D1.3, H1.1, H1.4 I Features depicted are not to scale. Sketches are based on available data and best professional judgment. Wetland Figures ‐ 2 Figure 2. Hydroperiods, outlet(s), and 150‐ft area – D1.1, D1.4, H1.2, D2.2, D5.2 I Outlet Outlet Outlet Features depicted are not to scale. Sketches are based on available data and best professional judgment. Wetland Figures ‐ 3 Figure 3. Map of the contributing basin for Wetland A – D4.3, D5.3 I Features depicted are not to scale. Sketches are based on available data and best professional judgment. Wetland Figures ‐ 4 Figure 4. Map of the contributing basin for Wetland B – D4. 3, D5.3 I Features depicted are not to scale. Sketches are based on available data and best professional judgment. Wetland Figures ‐ 5 Figure 5. Map of the contributing basin for Wetland C – D4. 3, D5.3 I Features depicted are not to scale. Sketches are based on available data and best professional judgment. Wetland Figures ‐ 6 Figure 6. Undisturbed habitat and moderate‐low intensity land uses within 1 km from wetland edge including polygon for accessible habitat – H2.1, H2.2, H2.3 I Features depicted are not to scale. Sketches are based on available data and best professional judgment. Wetland Figures ‐ 7 Figure 7. Screen‐capture of 303(d) listed waters in basin – D3.1, D3.2 Wetland Units, drain south Features depicted are not to scale. Sketches are based on available data and best professional judgment. Wetland Figures ‐ 8 Figure 8. Screen‐capture of TMDL list for WRIA in which unit is found – D3.3