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HomeMy WebLinkAboutRS_TIR_251106_V1 Western Washington Division Eastern Washington Division 165 NE Juniper St., Ste 201, Issaquah, WA 98027 407 Swiftwater Blvd, Cle Elum, WA 98922 Phone: (425) 392-0250 Fax: (425) 391-3055 Phone: (509) 674-7433 Fax: (509) 674-7419 www.EncompassES.net TECHNICAL INFORMATION REPORT For Vision House 4XX Bremerton Ave NE Renton, WA 98059 November 6th, 2025 Prepared by: Gabe Garner Encompass Engineering Job No. 22514 Prepared For: Steven Jewett Vision House C/O Pavilion 8201 164th Avenue NE #200 Redmond, WA 98052 Vision House Technical Information Report 11/06/2025 P a g e | i Table of Contents List of Figures ................................................................................................................................. i I. PROJECT OVERVIEW .............................................................................................................. 1 II. CONDITIONS AND REQUIREMENTS SUMMARY ..................................................................... 6 III. DOWNSTREAM ANALYSIS .................................................................................................... 10 IV. FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN ........................... 15 V. CONVEYANCE SYSTEM ANALYSIS AND DESIGN .................................................................... 17 VI. SPECIAL REPORTS AND STUDIES .......................................................................................... 18 VII. OTHER PERMITS ................................................................................................................... 18 VIII. CSWPP ANALYSIS AND DESIGN ............................................................................................ 18 IX. BOND QUANTITIES, FACILITY SUMMARIES AND DECLARATION of COVENANT ................... 18 X. OPERATION AND MAINTENANCE MANUAL ......................................................................... 18 List of Figures Figure 1 – TIR Worksheet Figure 2 – Vicinity Map Figure 3 – Soils Map and Legend Figure 4 – Existing Conditions Map Figure 5 – Developed Conditions Map Figure 6 – Drainage Review Flow Chart Figure 7 – Downstream Map Appendix A Geotechnical Report by Terra Associates, Inc. dated April 15, 2022 Appendix B Critical Area Delineation and Rating Report: Wetlands and Streams by Evergreen Aquatic Resource Consultants, LLC dated October 14, 2025 Appendix C WWHM Output Appendix D Operations and Maintenance CITY OF RENTON SURFACE WATER DESIGN MANUAL 2022 City of Renton Surface Water Design Manual 6/22/2022 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 __________________ __________________ __________________ REFERENCE 8: PLAN REVIEW FORMS AND WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 6/22/2022 2022 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 ______________________  _____________________________________ REFERENCE 8-A: TECHNICAL INFORMATION REPORT (TIR) WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 2022 City of Renton Surface Water Design Manual 6/22/2022 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 9 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: ____________ Conveyance System Spill containment located at: _____________________________ Erosion and Sediment Control / Construction Stormwater Pollution Prevention CSWPP/CESCL/ESC Site Supervisor: _____________________ Contact Phone: _________________________ After Hours Phone: _________________________ Maintenance and Operation Responsibility (circle one): Private / Public If Private, Maintenance Log Required: Yes / No Financial Guarantees and Liability Provided: Yes / No REFERENCE 8: PLAN REVIEW FORMS AND WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 6/22/2022 2022 City of Renton Surface Water Design Manual 8-A-4 Part 12 TIR SUMMARY SHEET (provide one TIR Summary Sheet per Threshold Discharge Area) Water Quality (include facility summary sheet) Type (circle one): Basic / Sens. Lake / Enhanced Basic / Bog or Exemption No. _______________________ On-site BMPs Describe: 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: REFERENCE 8-A: TECHNICAL INFORMATION REPORT (TIR) WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 2022 City of Renton Surface Water Design Manual 6/22/2022 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 Description Water Quality Description On-site BMPs Description  Detention  Infiltration  Regional Facility  Shared Facility  Other _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________  Vegetated Flowpath  Wetpool  Filtration  Oil Control  Spill Control  Other _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________  Full Dispersion  Full Infiltration  Limited Infiltration  Rain Gardens  Bioretention  Permeable Pavement  Basic Dispersion  Soil Amendment  Perforated Pipe Connection  Other _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ REFERENCE 8: PLAN REVIEW FORMS AND WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 6/22/2022 2022 City of Renton Surface Water Design Manual 8-A-6 Part 15 EASEMENTS/TRACTS Part 16 STRUCTURAL ANALYSIS  Drainage Easement  Covenant  Native Growth Protection Covenant  Tract  Other ____________________________  Cast in Place Vault  Retaining Wall  Rockery > 4′ High  Structural on Steep Slope  Other _______________________________ Part 17 SIGNATURE OF PROFESSIONAL ENGINEER I, or a civil engineer under my supervision, have visited the site. Actual site conditions as observed were incorporated into this worksheet and the attached Technical Information Report. To the best of my knowledge the information provided here is accurate. ____________________________________________________________________________________ Signed/Date Vision House Technical Information Report 11/06/2025 P a g e | 1 I. PROJECT OVERVIEW Project: Vision House Site Address: 4XX Bremerton Ave NE, Renton, WA 98059 (See Vicinity Map) Tax Parcel: 102305-9086 Zoning District: Commercial Arterial (CA) Site Area: 53,578 SF (1.23 AC) Figure 2: Vicinity Map Pre-developed Site Conditions: The project site is located in the City of Renton on a 53,578 SF (1.23 AC) lot that is zoned as Commercial Arterial (CA). The property may be accessed off the eastern side of Bremerton Avenue NE (located behind the existing Vision House group homes found on parcels 102305-9066 & 102305-9065). It appears that the existing site is currently being utilized for Vision House parking. The site is bordered to the north by single-family residential properties, to the east by Shooting Star Preschool and the Highland Professional Plaza, to the south by a vacant lot owned by Vision House, and to the west by the existing Vision House mixed use building. The site is currently developed with gravel parking, miscellaneous concrete, a small structure, and a play area. Stormwater runoff produced from the existing site sheet flows over moderate slopes ranging from 2-35% towards the natural discharge area (NDA) which is generally located along the eastern portion of the site. The property is located within the Lower Cedar River drainage basin, within the Cedar River/Lake Washington watershed. See the full downstream analysis in Section III of this Technical Information Report (TIR) for more information. An Existing Conditions Map is included as Figure 4 at the end of this Section. Vision House Technical Information Report 11/06/2025 P a g e | 2 Critical Areas: Per the City of Renton GIS Mapping System and the ‘Critical Area Delineation and Rating Report: Wetlands and Streams’ by Evergreen Aquatic Resource Consultants, LLC (Appendix B), there is a Category III wetland and a Type N stream that exists south and east of the project site. A 75-foot buffer is required for the wetland, and a 50-foot buffer is required for the stream. An additional 15-foot building setback is required from the outer limits of the buffers. Soils: Per the US Department of Agriculture (USDA) Natural Resources Conservation Service (NRCS) Web Soil Survey (WSS) information, the project site is underlain with Alderwood gravelly sandy loam (See Figure 3 below). The Geotechnical Report prepared by Terra Associates, Inc. (Appendix A) states that stormwater management at the site should not be managed with infiltration facilities, as the soils underling the site generally consist of silty sand glacial till soils that would impede the downward migration of any site stormwater. Figure 3: Soil Map and Legend Vision House Technical Information Report 11/06/2025 P a g e | 3 Developed Site Conditions This project proposes the demolition of all existing structures/appurtenances on-site (apart from the existing play area located in the northern portion of the site), and the construction of a new commercial structure. The proposed on-site impervious surfaces will include an 18,814 SF building (roof area), 13,839 SF of asphalt driveway & parking areas, and 2,722 SF of concrete walkways/steps/ramps. The proposed off-site impervious surfaces include 1,574 SF of asphalt aprons & parking areas and 546 SF of concrete walkways/ramps. The total proposed impervious surface area associated with the project is 37,495 SF, of which 35,375 SF is located on-site. Runoff produced from the proposed development will be collected and conveyed into a 24 FT x 134 FT x 7 FT deep detention vault located in the eastern portion of the site. A Contech Filterra manhole is proposed post-detention to provide water quality. Water and sewer services will be provided by the City of Renton. Gas and electrical utility connections will be provided by Puget Sound Energy. Please refer to Core Requirement #9 in Section II and Section IV of this TIR for additional discussion on stormwater BMPs and flow control. A Developed Conditions Map is provided as Figure 5 at this end of this Section. NORTH V. E . K . O N A B E R D E E N 95 7 A B E R D E E N A V E N E RE N T O N , W A 9 8 0 5 6 RE V I S I O N S JO B N O . DA T E SC A L E SH E E T En c o m p a s s Ea s t e r n W a s h i n g t o n D i v i s i o n 40 7 S w i f t w a t e r B l v d . ▪ Cl e E l u m , W A 9 8 9 2 2 ▪ Ph o n e : ( 5 0 9 ) 6 7 4 - 7 4 3 3 We s t e r n W a s h i n g t o n D i v i s i o n 16 5 N E J u n i p e r S t r e e t , S u i t e 2 0 1 ▪ Is s a q u a h , W A 9 8 0 2 7 ▪ Ph o n e : ( 4 2 5 ) 3 9 2 - 0 2 5 0 EN G I N E E R I N G & S U R V E Y I N G 1 O F 1 EX I S T I N G C O N D I T I O N S ON-SITE EXISTING IMPERVIOUS SURFACE:OFF-SITE EXISTING IMPERVIOUS SURFACE: NORTH V. E . K . O N A B E R D E E N 95 7 A B E R D E E N A V E N E RE N T O N , W A 9 8 0 5 6 RE V I S I O N S JO B N O . DA T E SC A L E SH E E T En c o m p a s s Ea s t e r n W a s h i n g t o n D i v i s i o n 40 7 S w i f t w a t e r B l v d . ▪ Cl e E l u m , W A 9 8 9 2 2 ▪ Ph o n e : ( 5 0 9 ) 6 7 4 - 7 4 3 3 We s t e r n W a s h i n g t o n D i v i s i o n 16 5 N E J u n i p e r S t r e e t , S u i t e 2 0 1 ▪ Is s a q u a h , W A 9 8 0 2 7 ▪ Ph o n e : ( 4 2 5 ) 3 9 2 - 0 2 5 0 EN G I N E E R I N G & S U R V E Y I N G 1 O F 1 PR O P O S E D C O N D I T I O N S ON-SITE PROPOSED IMPERVIOUS SURFACE:ON-SITE PROPOSED LANDSCAPE: OFF-SITE PROPOSED IMPERVIOUS SURFACE: Vision House Technical Information Report 11/06/2025 P a g e | 6 II. CONDITIONS AND REQUIREMENTS SUMMARY The 2022 City of Renton Surface Water Design Manual (RSWDM) was utilized to determine and address all core and special requirements. Based on the criteria specified in Figure 1.1.2.A of the RSWDM, the project falls under Full Drainage Review. Per Section 1.1.2.4 of the RSWDM, the project must meet all nine (9) core and all six (6) special requirements. See Figure 6 below for more information on how the type of drainage review was determined. Figure 6: Drainage Review Flow Chart Vision House Technical Information Report 11/06/2025 P a g e | 7 Core Requirements Core Requirement #1: Discharge at the Natural Location Runoff from the proposed development will follow existing drainage patterns. After being conveyed through the proposed 24 FT x 134 FT x 7 FT deep detention vault, runoff will be conveyed to a 10-foot dispersion trench outfall located south of the site. This dispersion trench will route runoff towards the stream and wetland to the south of the site where it converges with the natural discharge location for the site. Please refer to the full Downstream Analysis provided in Section III of this TIR. Core Requirement #2: Downstream Analysis A Level 1 Downstream Analysis has been completed for the site and no existing or potential problems have been identified. This analysis is included in Section III of this TIR. Core Requirement #3: Flow Control Facilities Based on the City of Renton’s flow control application map, the project site is located within the Duration Flow Control Standard (Forested Conditions). Flow control facilities are required to match the developed peak discharge rates to historical (forested) site conditions over the range of flows extending form 50% of the 2-year up to the full 50-year flow and match the peaks for the 2- and 10-year return periods. A 24 FT x 134 FT x 7 FT deep detention vault is proposed to meet stormwater requirements. This stormwater facility will be located in the eastern portion of the site. Please refer to Section IV of this TIR for additional discussion. Core Requirement #4: Conveyance System Conveyance in compliance with the requirements detailed in Section 1.2.4.1 of the City of Renton 2022 SWDM is provided in Section V of this report. Core Requirement #5: Construction Stormwater Pollution Prevention A temporary erosion and sediment control (TESC) plan providing details on best management practices (BMPs) to be implemented during construction is included in the engineering plan set. A Construction Stormwater Pollution Prevention Plan (CSWPPP) has been included with the submittal package. Please refer to Section VIII of this TIR for additional discussion. Core Requirement #6: Maintenance and Operations An Operation and Maintenance Manual is provided as Appendix D of this TIR. Core Requirement #7: Financial Guarantees and Liability The owner will arrange for any financial guarantees and liabilities required by the permit. Core Requirement #8: Water Quality Facilities In accordance with Section 1.2.8.1.B and 6.1.2 of the RSWDM, Enhanced Basic Water Quality Treatment is required for this project as new plus replaced pollution generating impervious surfaces (PGIS) exceed 5,000 SF. To address water quality requirements, a Contech Filterra manhole is proposed post-detention. Vision House Technical Information Report 11/06/2025 P a g e | 8 Core Requirement #9: Flow Control BMPs This project is classified as a Large Lot; therefore, it is subject to the Large Lot BMP Requirements detailed in Section 1.2.9.2.2 in the RSWDM. 1.2.9.2.2 Large Lot BMP Requirements Full Dispersion: Infeasible. A 100-foot native vegetated flowpath segment is not available on-site. Full Infiltration / Bioretention / Limited Infiltration / Permeable Pavement: Infeasible. The Geotechnical Report prepared by Terra Associates, Inc. (Appendix A) states that stormwater management at the site should not be managed with infiltration facilities, as the soils underlying the site generally consist of silty sand glacial till soils that would impede the downward migration of any site stormwater. Basic Dispersion: Infeasible. A 25-foot vegetated flowpath is not available on-site. Soil Moisture Holding Capacity: The soil moisture holding capacity of new pervious surfaces must be protected in accordance with KCC 16.82.100 (F) and (G). KCC 16.82.100(F) requires that the duff layer or native topsoil be retained to the maximum extent practicable. KCC 16.82.100(G) requires soil amendment to mitigate for lost moisture holding capacity where compaction or removal of some or all of the duff layer or underlying topsoil has occurred. The amendment must be such that the replaced topsoil is a minimum of 8 inches thick, unless the applicant demonstrates that a different thickness will provide conditions equivalent to the soil moisture holding capacity native to the site. The replaced topsoil must have an organic content of 5-10% dry weight and a pH suitable for the proposed surface vegetation (for most soils in King County, 4 inches of well-rotted compost tilled into the top 8 inches of soil is sufficient to achieve the organic content standard.) The amendment must take place between May 1 and October 1. As no BMPs are feasible for the mitigation of the 37,459 SF of impervious surfaces to be constructed with the project, stormwater runoff will be collected and conveyed into a 24 FT x 134 FT x 7 FT deep detention vault located in the eastern portion of the site. Please refer to Section IV of this TIR for additional information on the detention vault. A Developed Conditions Map is provided as Figure 5 of this TIR. Vision House Technical Information Report 11/06/2025 P a g e | 9 Special Requirements Special Requirement #1: Other Adopted Area-Specific Requirements Critical Drainage Area – N/A Master Drainage Plan – N/A Basin Plan – N/A Lake management Plan – N/A Shared Facility Drainage Plan – N/A Special Requirement #2: Flood Hazard Area Delineation The limits of this project do not lie within a delineated FEMA 100-year floodplain. Special Requirement #3: Flood Protection Facilities This project does not rely on or propose to modify/construct a new flood protection facility. Special Requirement #4: Source controls Source controls for the proposed short plat development are not applicable. Special Requirement #5: Oil Control This project is not considered high-use in need of oil control. Special Requirement #6: Aquifer Protection Area The site is not located within an Aquifer Protection Area per the Groundwater Protection Areas Map in the RSWDM. Vision House Technical Information Report 11/06/2025 P a g e | 10 III. DOWNSTREAM ANALYSIS A Level 1 Downstream analysis has been conducted per the requirements in Section 1.2.2.1 of the RSWDM. Please see Tasks 1 through 4 below for a summary of the results. Task 1: Define and Map the Study Area The area of analysis extends approximately a quarter-mile downstream from the natural discharge area (NDA). This site includes one NDA in the eastern portion of the site, therefore creating one threshold discharge area. A Downstream Map is provided in Figure 7 below. Figure 7: Downstream Map Task 2: Review All Available Information on the Study Area Per the City of Renton GIS Mapping System and the ‘Critical Area Delineation and Rating Report: Wetlands and Streams’ by Evergreen Aquatic Resource Consultants, LLC (Appendix B), there is a Category III wetland and a Type N stream that exist south and east of the project site. Additionally, a review of King County iMap found that there are no significant drainage complaints within a quarter mile downstream of the site. Task 3: Field Inspect the Study Area A field inspection was performed by Encompass Engineering & Surveying on November 4th, 2025. Please refer to Task 4 for a detailed description of the downstream drainage system and analysis. Vision House Technical Information Report 11/06/2025 P a g e | 11 Task 4: Describe the Drainage System Stormwater runoff in the existing conditions leaves the site from one natural discharge area located along the eastern side of the property. Runoff begins by sheet flowing over flat to moderate slopes ranging from 2-35% until passing through the eastern property limits (A). Once exiting the site, runoff continues to follow the natural topography eastward until reaching the Highland Professional Plaza parking lot. Stormwater would then enter the stormwater system located in the western portion of the Highland Professional Plaza which contains a detention pond in the southwestern portion of the property (B). Per Renton’s GIS Mapping System, this detention pond discharges runoff to the south where it then would converge with an unnamed stream/ditch that flows in the western direction (C). After travelling west within this stream for approximately 300 feet, runoff is conveyed into the public stormwater system which travels westward beneath Bremerton Avenue NE (D). The storm system continues travelling to the west, passing through ‘The Windsor’ apartment complex (E). After another 350 feet, the storm system continues travelling west until reaching a Safeway parking lot within TPN 880500-0030 (F). The system continues conveying runoff in the western/southwestern direction until reaching a bioswale facility located south of an AutoZone. The storm system does not appear to discharge runoff into the bioswale; per Renton’s GIS Mapping System, it appears the bioswale system outlets runoff into the stormwater system in which the subject downstream flowpath is located (G). From here, the system would convey runoff to the southern side of NE 4th Street. This is where the ¼ mile downstream limit was reached. No drainage related issues were observed downstream of the site, and no relevant drainage complaints were identified on the King County iMap system within a quarter mile of the site discharge location. Please refer to Figure 7 on the previous page for the approximate location of identified drainage features. Photographs from the site visit are included below. Element A – Runoff sheet flows towards the eastern property limits. Once exiting the site, stormwater continues sheet flowing into the Highland Professional Plaza that borders the subject site to the east. Vision House Technical Information Report 11/06/2025 P a g e | 12 Element B/C – Runoff eventually converges with a detention pond facility located southwest of the Highland Professional Plaza (could not be photographed – within private property). Per Renton’s GIS Mapping System, this pond discharges runoff south where it enters an unnamed stream/ditch. Element D – The unnamed stream/ditch eventually conveys runoff into the public stormwater system that travels west beneath Bremerton Ave NE. Vision House Technical Information Report 11/06/2025 P a g e | 13 Element E – The public stormwater system continues travelling in the western direction through ‘The Windsor’ apartment complex. Element F – The public stormwater system continues travelling in the western direction where it passes through TPN 880500-0030 (Safeway parking lot). Vision House Technical Information Report 11/06/2025 P a g e | 14 Element G – The public stormwater system reaches the south side of an AutoZone, where a bioswale facility is located (per Renton GIS Mapping System). The storm system does not appear to discharge runoff into this bioswale (instead it appears to convey runoff to the southern side of NE 4th Street). Vision House Technical Information Report 11/06/2025 P a g e | 15 IV. FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN Part A: Existing Site Hydrology This property is located within the Lower Cedar River drainage basin, within the Cedar River/Lake Washington watershed. The 53,578 SF (1.23 AC) site is currently developed with gravel parking, miscellaneous concrete, a small structure, and a play area. Stormwater runoff produced from the existing site sheet flows over moderate slopes ranging from 2-35% towards the natural discharge area (NDA) which is generally located along the eastern portion of the site. See the full Downstream Analysis in Section III of this Technical Information Report (TIR). The Geotechnical Report prepared by Terra Associates, Inc. (Appendix A) states that stormwater management at the site should not be managed with infiltration facilities, as the soils underling the site generally consist of silty sand glacial till soils that would impede the downward migration of any site stormwater. Part B: Developed Site Hydrology This project proposes the demolition of all existing structures/appurtenances on-site (apart from the existing play area located in the northern portion of the site), and the construction of a new commercial structure. The proposed on-site impervious surfaces will include an 18,814 SF building (roof area), 13,839 SF of asphalt driveway & parking areas, and 2,722 SF of concrete walkways/steps/ramps. The proposed off-site impervious surfaces include 1,574 SF of asphalt aprons & parking areas and 546 SF of concrete walkways/ramps. The total proposed impervious surface area associated with the project is 37,495 SF, of which 35,375 SF is located on-site. Runoff produced from the proposed development will be collected and conveyed into a 24 FT x 134 FT x 7 FT deep detention vault located in the eastern portion of the site. WWHM 2012 was used to model the proposed condition using target surfaces per Section 1.2.3 of the 2022 RSWDM. A summary of the existing and developed analyses is provided in the table below: Existing Developed Condition Measured Modeled Measured Modeled C, Forest, Mod: 1.20 AC 1.20 AC C, Lawn, Flat: 0.35 AC 0.35 AC Roof Tops/Flat: 0.43 AC 0.43 AC Driveways/Flat: 0.35 AC 0.35 AC Sidewalks/Flat: 0.07 AC 0.07 AC Total Area: 1.20 AC 1.20 AC 1.20 AC 1.20 AC WWHM Conditions Model Vision House Technical Information Report 11/06/2025 P a g e | 16 Part C: Performance Standards Based on the City of Renton’s flow control application map, the project site is located within the Duration Flow Control Standard (Forested Conditions). Flow control facilities are required to match the developed peak discharge rates to historical (forested) site conditions over the range of flows extending form 50% of the 2-year up to the full 50-year flow and match the peaks for the 2- and 10-year return periods. This project is classified as a Large Lot; therefore, it is subject to the Large Lot BMP Requirements detailed in Section 1.2.9.2.2 in the RSWDM. The site falls within an Enhanced Basic Water Quality treatment area in accordance with Section 1.2.8.1.B and 6.1.2 of the RSWDM. Part D: Flow Control System Flow control will be provided by a 24 FT x 134 FT x 7 FT deep detention vault located in the eastern portion of the site. A Contech Filterra manhole is proposed post-detention to provide water quality. After being conveyed through the proposed detention vault and water quality manhole, runoff will be conveyed to a 10-foot dispersion trench outfall located south of the site. This dispersion trench will route runoff towards the stream and wetland to the south of the site where it converges with the natural discharge location for the site. Per WWHM modeling, the required storage volume of the system is 19,863 CF (0.456 ac-ft). The proposed tank has a provided volume of 20,904 CF. Please refer to Appendix B for a copy of the full WWHM data output. Part E: Water Quality System In accordance with Section 1.2.8.1.B and 6.1.2 of the RSWDM, Enhanced Basic Water Quality Treatment is required for this project as new plus replaced pollution generating impervious surfaces (PGIS) exceed 5,000 SF. To address water quality requirements, a Contech Filterra manhole is proposed post-detention. Please see the engineering plans for specifications on the Contech Filterra manhole, and the WWHM Output in Appendix B for water quality flow rates. Vision House Technical Information Report 11/06/2025 P a g e | 17 V. CONVEYANCE SYSTEM ANALYSIS AND DESIGN According to the WWHM Output in Appendix C, the 100-yr developed conditions flow rate produced from the site is 0.069726 CFS. This represents the highest possible flow through any component of the proposed stormwater system. WWHM Conveyance Analysis Conveyance analysis has been completed for the proposed storm with Manning’s Equation. The pipe which is assumed to endure the highest flows is a 12” PVC pipe sloped at 0.27% located prior to the detention system in the western portion of the site. This pipe was analyzed to see if it can support the 100-yr flow rate of 0.069726 CFS (worst case scenario). Using Manning’s Equation (see table below), a 12” storm pipe sloped at 0.27% can support a flow rate of 1.91 CFS, which exceeds the 100-year flow rate into the storm system (1.91 CFS > 0.069726 CFS). In addition, the velocity at full flow is 2.692 ft/s, which meets the minimum velocity requirement per Section 4.2.1.1 of the 2022 RSWDM. Conveyance Capacity for 12” PVC @ 0.27% Slope Vision House Technical Information Report 11/06/2025 P a g e | 18 VI. SPECIAL REPORTS AND STUDIES · Geotechnical Report by Terra Associates, Inc. dated April 15, 2025 (Appendix A) · Critical Area Delineation and Rating Report: Wetlands and Streams by Evergreen Aquatic Resource Consultants, LLC dated October 14, 2025 (Appendix B) VII. OTHER PERMITS · Civil Construction Permit · Building Permits VIII. CSWPP ANALYSIS AND DESIGN A CSWPPP has been included with the submittal package. IX. BOND QUANTITIES, FACILITY SUMMARIES AND DECLARATION of COVENANT Bond Quantities, Facility Summaries, and a Declaration of Covenant will be included with the future building permit. X. OPERATION AND MAINTENANCE MANUAL An Operation and Maintenance Manual is provided as Appendix D of this TIR. Appendix A Geotechnical Report by Terra Associates, Inc. dated April 15, 2025 Appendix B Critical Area Delineation and Rating Report: Wetlands and Streams by Evergreen Aquatic Resource Consultants, LLC dated October 14, 2025 Wetland Delineation • Mitigation Design • Compliance Monitoring Ocvtober 14, 2025 Project No. 22003 Pavillon, LLC Attention: Steven Jewett 8201 164th Avenue NE, Suite 260 Redmond, Washington 98052 Regarding: Critical Area Delineation and Rating Report: Wetlands and Streams Vision House Phase 4 King County Tax Parcel Number 102305-9086 Steven, INTRODUCTION This critical area delineation and rating report has been prepared for the proposed Vision House – Phase 4 project located in Renton, Washington. On February 2, 2022, I screened the project site and vicinity for wetlands and streams. As a result of this work, I determined that a Category III wetland and Type Ns stream exist south and east of the site. The buffer and building setback associated with the wetland encroaches the extreme southeast corner of the site. This letter summarizes my findings. AUTHORIZATION AND SCOPE OF SERVICES Authorization to proceed and all rights-of-entry to complete the work covered by this report were granted by Melissa Gehrig on January 18, 2022. This report has been prepared per the stream study and wetland assessment requirements established in Renton Municipal Code (RMC) 4-3-050F. The general scope of services for this report was to identify and classify wetlands and streams that exist within and/or otherwise affect the project site. The purpose of the work is to assist with project planning. All work was conducted per City of Renton standards. QUALIFICATIONS OF REPORT AUTHOR I am a certified Professional Wetland Scientist (PWS). My educational and training background includes a Bachelor of Science in Environmental Science from Washington State University, a Certificate in Wetland Science and Management from the University of Washington, and continuing education specific to wetland delineation, classification, functional assessment, and impact mitigation. I maintain nearly 26 years of critical area consulting experience in the King County area of western Washington. I have previously completed similar unrelated studies at 451 Duvall Avenue NE and 4502 NE 4th Street. Both unrelated studies included analysis of the same wetland and stream discussed in this report. PO Box 1721 Issaquah, Washington 98027 (425) 677-7166 www.evergreenarc.com Critical Area Delineation and Rating Report: Wetlands and Streams Vision House – Phase 4 Page 2 PROJECT SITE The project site is an undeveloped commercial arterial (CA) zoned parcel located west of Duvall Avenue NE, east of Bremerton Avenue NE, and north of NE 4th Street in Renton, Washington. The site is situated in the southwest quarter of Section 10, Township 23 North, Range 5 East, Willamette Meridian and is described as King County tax parcel number 102305-9086. The site has a total area of 53,578 sf (1.23 acres) and measures roughly 161 feet east to west by 333 feet north to south. Currently a fenced children’s playground exists in the northern portion of the site and an informal vehicle parking area exists in the central portion of the site. PRELIMINARY DATA GATHERING AND SYNTHESIS The wetlands and streams discussed in this report have been extensively studied over the last approximately 20 years. The scope of these studies has varied, but collectively this work has largely concluded that a Category III or IV wetland and a Type Ns stream exists south and east of the project site. Table 1 below summarizes existing studies and findings. TABLE 1 – SUMMARY OF EXISTING STUDIES AND FINDINGS PERMIT NUMBER PROJECT NAME CONSULTANT WORK PRODUCT FINDINGS NOTES LUA02- 003 Highlands Professional Plaza Coughlin Porter Lundeen Site plan Category IV wetland Type Ns stream 1. Older code. 2. Out-of-date methods. 3. Best mapping of wetland and stream. LUA19- 000153 4th Dimension Mixed Use Raedeke Associates, Inc. Technical memorandum dated 07/25/2019 and response letter dated 10/27/2019 Category III wetland (4 habitat points) Type Ns stream 1. Off-site analysis only. 2. Similar code 3. Prior revision to current assessment methods. PRE21- 000462 Soyam Commercial Building The Watershed Company Ecological critical area reconnaissance study dated 12/08/2021 Category IV wetland (4 habitat points) Type Ns stream 1. On & off-site analysis. 2. Current code. 3. Current assessment methods. Could not verify application. Sewall Wetland Consultants, Inc Critical area report dated 02/29/2016 Category IV wetland (4 habitat points) Type Ns stream 1. On & off-site analysis 2. Similar code 3. Prior revision to current assessment methods. LUA25- 000193 4th Dimension Building Raedeke Associates, Inc. Technical memorandum dated 07/25/2019 and response letter dated 10/27/2019. Category III wetland (4 habitat points) Type Ns stream 1. Off-site analysis only. 2. Similar code 3. Prior revision to current assessment methods. LUA25- 000195 Oasis Home Daycare Altman Oliver Associates, LLC Wetland and stream study dated 05/21/2025 Category III wetland (5 habitat points) Type Ns stream 1. Off-site analysis only. 2. Current code 3. Current assessment methods, but incorrect application. Critical Area Delineation and Rating Report: Wetlands and Streams Vision House – Phase 4 Page 3 BASELINE CONDITIONS FOR CRITICAL AREA DETERMINATIONS: 1. Weather and Climatic Conditions: Critical areas determinations were made during the statistical wet season at the time when the drought index was classified as “mild wetness” and when precipitation was considered “drier than normal”. Weather conditions at the time of the determinations included overcast sky conditions with ambient air temperatures ranging to approximately 45 °F. Antecedent precipitation and/or the weather conditions at the time of critical area determinations did not prevent or otherwise limit the ability to make accurate critical area determinations. 2. Normal Circumstances: For the purposes of wetland determinations, normal circumstances (conditions) were assumed throughout the site. The site has been altered from natural conditions. These alterations include native vegetation removal, soil excavation and grading, and historic building construction. In general, these alterations are not recent and have a time scale of relative permanence. Atypical or naturally problematic and/or difficult wetland conditions were not encountered or are not known to exist within the site. 3. Off-Site Access Limitations: At the time of the on-site determinations, access was not granted to review adjacent private properties. As necessary, off-site areas were assessed by viewing conditions from the project site, private easements, and public right-of-way and then correlating observations to remote sensing data such as topographic contours derived from publicly available LIDAR data. Where assessed, off-site wetlands and aquatic areas were noted only to the degree necessary to determine buffer widths and any related buffer encroachment onto the project site. ON-SITE WETLAND AND STREAM DETERMINATION Summary: Wetlands and streams do not exist within the site. A wetland determination form for the project site is attached to this report. Methodology: On-site wetland determinations were made using the “routine determination” methods required for “on-site inspections” as described in the 1987 Corps of Engineers Wetlands Delineation Manual (Environmental Laboratory 1987). Vegetation, soil, and hydrology characteristics were examined at multiple locations and then compared to the specific criteria established for the three wetland indicators described in the Regional Supplement To The Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys, and Coast Region - Version 2.0 (US Army Corps of Engineers 2010). When hydrophytic vegetation, hydric soil, and wetland hydrology indicators were present, an area was determined to be a wetland. In the absence of all three indicators or when exclusionary situations apply, an area was considered non-wetland, or “upland”. On-site stream determinations utilized the definitions and related water typing criteria described in Washington Administrative Code (WAC) 222-16-030 (Water Typing System) and RMC 4-3-50 (Critical Critical Area Delineation and Rating Report: Wetlands and Streams Vision House – Phase 4 Page 4 Areas Regulations). Fisheries utilization within a stream considered the physical characteristics of the stream such as width and gradient as well as records of any known fish use or natural blockages within the stream and/or connected downstream waters, including wetlands. Findings: The northern and central portion of the project site is relatively flat to gently sloping with a base elevation of approximately 410 feet (NAVD 88). The southern portion of the site includes sloping topography that trends to the south and east. The highest elevation on the site is located near the center point of the western property line at an elevation of approximately 417 feet (NAVD 88). The lowest elevation of the site is near the southeast property corner at an elevation of approximately 396 feet (NAVD 88). Vegetation in the northern and central portions of the site includes scattered Douglas- fir (Pseudotsuga menziesii, FACU) with occasional bigleaf maple (Acer macrophyllum, FACU) and western redcedar (Thuja plicata, FAC) over mainly mowed grasses with a perimeter of moderately dense Himalayan blackberry (Rubus aremeniacus, FAC) with occasional butterfly bush (Buddleja sp.). The sloping area in the southern portion of the site includes mostly young black cottonwood (Populus balsamifera, FAC) over moderately dense Himalayan blackberry. Soil present within the topographically lowest portion of the site was generally a very dark brown (10YR 2/2) gravelly sandy loam overlying a dark brown (7.5YR 3/2) to brown (7.5YR 4/3) gravelly sandy loam. Wetland hydrology indicators were not present within the project site. OFF-SITE WETLAND AND STREAM DETERMINATION Summary: A Category III wetland and a Type Ns stream exist south and east of the project site. A 75 foot buffer is required the wetland and a 50 foot buffer is required from the Type Ns stream. Wetland rating forms for the wetland are attached to this report. Findings: A seasonally flooded palustrine persistent emergent (PEM1C) and seasonally flooded palustrine scrub- shrub (PSSC) wetland exists within a riverine hydrogeomorphic (HGM) landform located south and east of the project site. Dominant plant species within the wetland include Himalayan blackberry and reed canarygrass (Phalaris arundinacea, FACW). Sub-dominant plant species include small Oregon ash (Fraxinus latifolia, FACW), salmonberry (Rubus spectabilis, FAC), Nootka rose (Rosa nutkana, FAC), Pacific willow (Salix lucida, FACW), Sitka willow (Salix sitchensis, FACW), and creeping buttercup (Ranunculus repens, FACW). The wetland is topographically confined and drains to the west via a narrow-excavated channel. The wetland was assigned a Category III rating based on the total score of “16” that the wetland received for functions. Based on classification and a habitat score of “4”, a 75 foot standard width buffer is required from the delineated wetland limits for all land uses except low impact land uses. An additional 15 foot setback is required from the outer limits of the buffer for buildings and other structures. A stream exists southeast of the project site interior to the off-site wetland. The stream originates east Critical Area Delineation and Rating Report: Wetlands and Streams Vision House – Phase 4 Page 5 of Duvall Avenue NE within a large critical area tract. The stream then drains west and south under Duvall Avenue NE and then through the off-site Category III wetland to an existing 24 inch diameter pipe located south of the project site. The stream is classified a Type Ns (non-fish bearing seasonal seasonally flowing) stream. A 50 foot standard width buffer is required from the OHWM of the stream or the top of bank of the stream if the OHWM cannot be determined. An additional 15 foot setback from the outer limits of the buffer for buildings and other structures. DISCUSSION OF RESULTS The presence of a wetland located south and east of the project site is well established. The wetland classification presented in this report, including a habitat score of “4”, is consistent with work reviewed by the City of Renton under LUA19-000153 and LUA25-000193. In addition, a habitat score of “4” has is also consistent with reporting submitted to the City of Renton under PRE21-000462. The only outlier is a recent study submitted under LUA25-000195, which assigns a similar Category III rating to the wetland but reports a habitat score of “5”. The habitat score of “5” is incorrect because it relies on a characterization of wetland conditions that do not exist. A habitat score of “4” is the correct determination because the wetland has only scrub-shrub and emergent Cowardin classes and two hydroperiods (seasonally flooded and seasonal stream) present. A detailed map showing the limits of vegetation types and hydroperiods is included on the wetland rating forms attached to this report. The presence of a stream located south and east of the project site is well established; however, unlike the findings of this report, some studies refer to the excavated outlet of the Category III wetland as a continuation of the mapped stream either in whole or part. There is no need to clarify if a stream exists in this location because the 50 foot buffer from a Type Ns stream, if present within the outlet, would be fully contained within the 75 foot buffer from the wetland. REPORT LIMITATIONS Within the limitations of scope, schedule, and budget, the critical area consulting services summarized in this report conform to the generally accepted standard of care in effect at the time the work was conducted. No other warranty, express or implied, is made. The collection, assessment, and determinations made, if any, related to soil characteristics and groundwater conditions are for the sole purpose of wetland identification/delineation and have been conducted in accordance with the wetland delineation methods adopted under Revised Code of Washington (RCW) 90.58.380 and WAC 173-22- 035. The purpose of the work summarized by this report is to describe site conditions per City of Renton critical area regulations in effect at the time of report preparation. All opinions presented in this report should be considered preliminary until reviewed and confirmed by the City of Renton. CLOSURE Based on my review of the proposed Vision House – Phase 4 project site located in Renton, Washington, I determined that wetlands or streams do not exist within the project site and a Category III wetland and Type Ns stream exist south and east of the project site. A standard width 75 foot buffer is required from the Category III wetland and a standard width 50 foot buffer is required from the Type Ns stream. An Critical Area Delineation and Rating Report: Wetlands and Streams Vision House – Phase 4 Page 6 additional 15 foot setback is required from the outer limits of both buffers for buildings and other structures. Please contact me if you require clarification, additional site analysis, or assistance with permitting. I am available at (425) 677-7166 or psuper@evergreenarc.com. EVERGREEN AQUATIC RESOURCE CONSULTANTS, LLC Issaquah, Washington Peter P. Super Professional Wetland Scientist Attachment 1 – Critical Area Map: Wetlands and Streams Attachment 2 – Wetland Determination Forms Attachment 3 – Wetland Rating Forms REFERENCES Environmental Laboratory (1987) Corps of Engineers Wetlands Delineation Manual. Vicksburg, MS: Technical Report Y-87-1. US Army Engineer Waterway Experiment Station. Hruby, T. (2014) Washington State Wetland Rating System for Western Washington: 2014 Update. Washington State Department of Ecology Publication #14-06-029. Olympia, Washington. United States Army Corps of Engineers. (2010). Regional Supplement to the Corps of Engineers Wetland Delineation Manual: Western Mountains, Valleys, and Coast Region (Version 2.0.). Vicksburg, MS: US Army Engineer Research and Development Center: ed. J.S. Wakeley, R.W. Lichvar, and C.V. Noble. ERDC/EL TR-10-3. May 2010. STORM WATER POND PER RENON GIS & #LUA02-003 DP1 75' BUFFER 15' BSBL Catego r y I I I W e t l a n d Evergreen Aquatic Wetland Delineation Mitigation Design Compliance Monitoring Resource Consultants, LLC03060 N Critical Area Map: Wetlands and Streams 10/14/2025 Vision House Phase 4 - TPN 102305-9086 Renton, Washington Figure 1 Legend: Wetland Standard Width Wetland Buffer 15' Building Setback Wetland Determination Point DP1 WETLAND DETERMINATION DATA FORM – Western Mountains, Valleys, and Coast Region VEGETATION Tree Stratum (Plot Size: 10 meter) Absolute % Cover Dominant Species? Indicator Status Dominance Test Worksheet: 1. Populus balsamifera 70 YES FAC Number of Dominant Species That Are OBL, FACW, or FAC: 2 (A) 2. 3. Total Number of Dominant Species Across All Strata: 1 (B) 4. 70 = Total Cover Percent of Dominant Species That Are OBL, FACW, or FAC: 100 (A/B) Sapling/Shrub Stratum (Plot Size: 5 meter) 1. Prevalence Index worksheet: 2. Total % Cover of: Multiply by: 3. OBL species x1 = 4. FACW species x2 = 5. FAC species x3 = n/a = Total Cover FACU species x4 = Herb Stratum (Plot Size: 1 meter) UPL species x5 = 1. Column Totals: (A) (B) 2. Prevalence Index = 3. Hydrophytic Vegetation Indicators: 4. YES Dominance Test is >50% 5. Prevalence Index is <3.01 6. Morphological Adaptations1 (Provide supporting data in Remarks or on a separate sheet) 7. 8. Wetland Non-Vascular Plants1 9. Problematic Hydrophytic Vegetation1 (Explain) 10. 1 Indicators of hydric soil and wetland hydrology must be present, unless disturbed or problematic. 11. n/a = Total Cover Woody Vine Stratum (Plot Size: 1 meter) Hydrophytic Vegetation Present? Yes No 1. Rubus armeniacus 100 YES FAC 2. 100 = Total Cover % Bare Ground in Herb Stratum – n/a Remarks: Plant species scientific names and wetland indicator statuses are per USDA PLANTS online database available on 02/03/2022 at: http://plants.usda.gov. Project Site: TPN 102305-9086 City/County: Renton Sampling Date: 02/03/2022 Applicant/Owner: Vision House State: WA Sampling Point: DP 1 Investigator(s): Peter P. Super – Professional Wetland Scientist Section, Township, Range: 10-23-05 Landform (hillslope, terrace, etc.): Hillslope Local relief (concave, convex, none): Slope (%): 15% Subregion (LRR): A Lat: 14.48986 Long: -122.15797 Datum: NAD 88 Soil Map Unit Name: NWI classification: Are climatic / hydrologic conditions on the site typical for this time of year? Yes No (If no, explain in Remarks.) Are Vegetation , Soil , Or Hydrology , significantly disturbed? Are “Normal Circumstances” present? Yes No Are Vegetation , Soil , Or Hydrology , naturally problematic? (If needed, explain any answers in Remarks.) SUMMARY OF FINDINGS Hydrophytic Vegetation Present? Yes No Is the Sampling Area within a Wetland? Hydric Soil Present? Yes No Wetland Hydrology Present? Yes No Remarks: NO SOIL DP 1 Profile Description: Depth (inches) Matrix Redox Features Color (moist) % Color (Moist) % Type1 Loc2 Texture Remarks 0 to 6 10YR 2/2 100 gravelly sandy loam 6 to 14 7.5YR 3/2 100 gravelly sandy loam 14 to 18 7.5YR 4/3 100 gravelly sandy loam 1Type: C= Concentration, D=Depletion, RM=Reduced Matrix, CS=Covered or Coated Sand Grains. 2Location: PL=Pore Lining, M=Matrix Hydric Soil Indicators: (Applicable to all LRRs, unless otherwise noted.) Indicators for Problematic Hydric Soils3: Histosol (A1) Sandy Redox (S5) 2 cm Muck (A10) Histic Epipedon (A2) Stripped Matrix (S6) Red Parent Material (TF2) Black Histic (A3) Loamy Mucky Mineral (F1) (except MLRA 1) Other (Explain in Remarks) Hydrogen Sulfide (A4) Loamy Gleyed Matrix (F2) Depleted Below Dark Surface (A11) Depleted Matrix (F3) 3 Indicators of hydrophytic vegetation and wetland hydrology must be present, unless disturbed or problematic. Thick Dark Surface (A12) Redox Dark Surface (F6) Sandy Mucky Mineral (S1) Depleted Dark Surface (F7) Sandy Gleyed Matrix (S4) Redox Depressions (F8) Restrictive Layer (if present): None Present Hydric Soils Present? Yes No Type: Depth (Inches): Remarks: Soil textures stated are apparent field textures. Soil colors are for moist soil per Munsell Soil Color Charts (GretagMacbeth 2001 with updated color charts). HYDROLOGY Wetland Hydrology Indicators: Primary Indicators (minimum of one required; check all that apply) Secondary Indicators (2 or more required) Surface Water (A1) Water-Stained Leaves (B9) Water-Stained Leaves (B9) High Water Table (A2) (except MLRA 1, 2, 4A, and 4B) (MLRA 1, 2, 4A, and 4B) Saturation (A3) Salt Crust (B11) Drainage Patterns (B10) Water Marks (B1) Aquatic Invertebrates (B13) Dry-Season Water Table (C2) Sediment Deposits (B2) Hydrogen Sulfide Odor (C1) Saturation Visible on Aerial Imagery (C9) Drift Deposits (B3) Oxidized Rhizospheres along Living Roots (C3) Geomorphic Position (D2) Algal Mat or Crust (B4) Presence of Reduced Iron (C4) Shallow Aquitard (D3) Iron Deposits (B5) Recent Iron Reduction in Tilled Soils (C6) FAC-Neutral Test (D5) Surface Soil Cracks (B6) Stunted or Stresses Plants (D1) (LRR A) Raised Ant Mounds (D6) (LRR A) Inundation Visible on Aerial Imagery (B7) Other (Explain in Remarks) Frost-Heave Hummocks (D7) Sparsely Vegetated Concave Surface (B8) Field Observations: Surface Water Present? Yes No Depth (inches): n/a Wetland Hydrology Present? Yes No Water Table Present? Yes No Depth (inches): n/a Saturation Present? (includes capillary fringe) Yes No Depth (inches): n/a Describe Recorded Data (stream gauge, monitoring well, aerial photos, previous inspections), if available: Remarks: Project Site: TPN 102305-9086 Vegetation Conditions at DP1 Soil Conditions at DP1 Wetland name or number ______ Wetland Rating System for Western WA: 2014 Update 1 Rating Form – Version 2, July 2023 RATING SUMMARY – Western Washington Name of wetland (or ID #): _________________________________ Date of site visit: _____ Rated by____________________________ Trained by Ecology?__ Yes ___No Date of training______ HGM Class used for rating_________________ Wetland has multiple HGM classes?___Y ____N NOTE: Form is not complete without the required figures (figures can be combined). Source of base aerial photo/map ______________________________________ OVERALL WETLAND CATEGORY ____ (based on functions___ or special characteristics__) 1. Category of wetland based on FUNCTIONS _______Category I – Total score = 23 - 27 _______Category II – Total score = 20 - 22 _______Category III – Total score = 16 - 19 _______Category IV – Total score = 9 - 15 FUNCTION Improving Water Quality Hydrologic Habitat Circle the appropriate ratings Site Potential H M L H M L H M L Landscape Potential H M L H M L H M L Value H M L H M L H M L TOTAL Score Based on Ratings 2. Category based on SPECIAL CHARACTERISTICS of wetland CHARACTERISTIC CATEGORY Estuarine I II Wetland of High Conservation Value I Bog I Mature Forest I Old Growth Forest I Coastal Lagoon I II Interdunal I II III IV None of the above 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 Peter Super X King County Off-site Wetland Off-site Wetland Caution: Wetland is located off-site. Conditions may be estimated or assumed. 02/03/2022 XRiverine 5 4 X X X 7 III 16 Wetland name or number ______ Wetland Rating System for Western WA: 2014 Update 2 Rating Form – Version 2, July 2023 Maps and figures required to answer questions correctly for Western Washington Depressional Wetlands Map of: To answer questions: Figure # Cowardin plant classes D 1.3, H 1.1, H 1.4 Hydroperiods D 1.4, H 1.2 Location of outlet (can be added to map of hydroperiods) D 1.1, D 4.1 Boundary of area within 150 ft of the wetland (can be added to another figure) D 2.2, D 5.2 Map of the contributing basin D 4.3, D 5.3 1 km Polygon: Area that extends 1 km from entire wetland edge - including polygons for accessible habitat and total habitat H 2.1, H 2.2, H 2.3 Screen capture of map of 303(d) listed waters in basin (from Ecology website) D 3.1, D 3.2 Screen capture of list of TMDLs for WRIA in which unit is found (from web) D 3.3 Riverine Wetlands Map of: To answer questions: Figure # Cowardin plant classes H 1.1, H 1.4 Hydroperiods H 1.2 Ponded depressions R 1.1 Boundary of area within 150 ft of the wetland (can be added to another figure) R 2.4 Plant cover of trees, shrubs, and herbaceous plants R 1.2, R 4.2 Width of unit vs. width of stream (can be added to another figure) R 4.1 Map of the contributing basin R 2.2, R 2.3, R 5.2 1 km Polygon: Area that extends 1 km from entire wetland edge - including polygons for accessible habitat and total habitat H 2.1, H 2.2, H 2.3 Screen capture of map of 303(d) listed waters in basin (from Ecology website) R 3.1 Screen capture of list of TMDLs for WRIA in which unit is found (from web) R 3.2, R 3.3 Lake Fringe Wetlands Map of: To answer questions: Figure # Cowardin plant classes L 1.1, L 4.1, H 1.1, H 1.4 Plant cover of trees, shrubs, and herbaceous plants L 1.2 Boundary of area within 150 ft of the wetland (can be added to another figure) L 2.2 1 km Polygon: Area that extends 1 km from entire wetland edge - including polygons for accessible habitat and total habitat H 2.1, H 2.2, H 2.3 Screen capture of map of 303(d) listed waters in basin (from Ecology website) L 3.1, L 3.2 Screen capture of list of TMDLs for WRIA in which unit is found (from web) L 3.3 Slope Wetlands Map of: To answer questions: Figure # Cowardin plant classes H 1.1, H 1.4 Hydroperiods H 1.2 Plant cover of dense trees, shrubs, and herbaceous plants S 1.3 Plant cover of dense, rigid trees, shrubs, and herbaceous plants (can be added to figure above) S 4.1 Boundary of 150 ft buffer (can be added to another figure) S 2.1, S 5.1 1 km Polygon: Area that extends 1 km from entire wetland edge - including polygons for accessible habitat and total habitat H 2.1, H 2.2, H 2.3 Screen capture of map of 303(d) listed waters in basin (from Ecology website) S 3.1, S 3.2 Screen capture of list of TMDLs for WRIA in which unit is found (from web) S 3.3 Figure 1 Figure 1 Figure 1 Figure 1 Figure 1 Attached Attached Figure 2 Wetland name or number ______ Wetland Rating System for Western WA: 2014 Update 3 Rating Form – Version 2, July 2023 HGM Classification of Wetlands in Western Washington 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. 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 sheet flow, 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). Wetland name or number ______ Wetland Rating System for Western WA: 2014 Update 4 Rating Form – Version 2, July 2023 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. 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. 6 X X Wetland name or number ______ Wetland Rating System for Western WA: 2014 Update 7 Rating Form – Version 2, July 2023 RIVERINE AND FRESHWATER TIDAL FRINGE WETLANDS Water Quality Functions - Indicators that the site functions to improve water quality R 1.0. Does the site have the potential to improve water quality? R 1.1. Area of surface depressions within the Riverine wetland that can trap sediments during a flooding event: Depressions cover >3/4 area of wetland points = 8 Depressions cover > ½ area of wetland points = 4 Depressions present but cover ч ½ area of wetland points = 2 No depressions present points = 0 R 1.2. Structure of plants in the wetland (areas with >90% cover at person height, not Cowardin classes) Trees or shrubs > 2/3 area of the wetland points = 8 Trees or shrubs > 1/3 area of the wetland points = 6 Herbaceous plants (> 6 in. high) > 2/3 area of the wetland points = 6 Herbaceous plants (> 6 in. high) > 1/3 area of the wetland points = 3 Trees, shrubs, and ungrazed herbaceous < 1/3 area of the wetland points = 0 Total for R 1 Add the points in the boxes above Rating of Site Potential If score is: 12-16 = H 6-11 = M 0-5 = L Record the rating on the first page R 2.0. Does the landscape have the potential to support the water quality function of the site? R 2.1. Is the wetland within an incorporated city or within its UGA? Yes = 2 No = 0 R 2.2. Does the contributing basin to the wetland include a UGA or incorporated area? Yes = 1 No = 0 R 2.3. Does at least 10% of the contributing basin contain tilled fields, pastures, or forests that have been clearcut within the last 5 years? Yes = 1 No = 0 R 2.4. Is > 10% of the area within 150 ft of the wetland in land uses that generate pollutants? Yes = 1 No = 0 R 2.5. Are there other sources of pollutants coming into the wetland that are not listed in questions R 2.1-R 2.4? Other sources ____________________ Yes = 1 No = 0 Total for R 2 Add the points in the boxes above Rating of Landscape Potential If score is: 3-6 = H 1 or 2 = M 0 = L Record the rating on the first page R 3.0. Is the water quality improvement provided by the site valuable to society? R 3.1. Is the wetland along a stream or river that is on the 303(d) list or on a tributary that drains to one within 1 mi? Yes = 1 No = 0 R 3.2. Is the wetland along a stream or river that has TMDL limits for nutrients, toxics, or pathogens? Yes = 1 No = 0 R 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 in development or in effect for the drainage in which the unit is found.) Yes = 2 No = 0 Total for R 3 Add the points in the boxes above Rating of Value If score is: 2-4 = H 1 = M 0 = L Record the rating on the first page 6 2 1 0 1 0 3 X X 0 basin - Cedar River subbasin - Maplewood Creek 0 6 0 1 1 X Wetland name or number ______ Wetland Rating System for Western WA: 2014 Update 8 Rating Form – Version 2, July 2023 RIVERINE AND FRESHWATER TIDAL FRINGE WETLANDS Hydrologic Functions - Indicators that site functions to reduce flooding and stream erosion R 4.0. Does the site have the potential to reduce flooding and erosion? R 4.1. Characteristics of the overbank storage the wetland provides: Estimate the average width of the wetland perpendicular to the direction of the flow and the width of the stream or river channel (distance between banks). Calculate the ratio: (average width of wetland)/(average width of stream between banks). If the ratio is more than 20 points = 9 If the ratio is 10-20 points = 6 If the ratio is 5-<10 points = 4 If the ratio is 1-<5 points = 2 If the ratio is < 1 points = 1 R 4.2. Characteristics of plants that slow down water velocities during floods: Treat large woody debris as forest or shrub. Choose the points appropriate for the best description (polygons need to have >90% cover at person height. These are NOT Cowardin classes). Forest or shrub for >1/3 area OR emergent plants > 2/3 area points = 7 Forest or shrub for > 1/10 area OR emergent plants > 1/3 area points = 4 Plants do not meet above criteria points = 0 Total for R 4 Add the points in the boxes above Rating of Site Potential If score is: 12-16 = H 6-11 = M 0-5 = L Record the rating on the first page R 5.0. Does the landscape have the potential to support the hydrologic functions of the site? R 5.1. Is the stream or river adjacent to the wetland downcut? Yes = 0 No = 1 R 5.2. Does the upgradient watershed include a UGA or incorporated area? Yes = 1 No = 0 R 5.3. Is the upgradient stream or river controlled by dams? Yes = 0 No = 1 Total for R 5 Add the points in the boxes above Rating of Landscape Potential If score is: 3 = H 1 or 2 = M 0 = L Record the rating on the first page R 6.0. Are the hydrologic functions provided by the site valuable to society? R 6.1. Distance to the nearest areas downstream that have flooding problems? Choose the description that best fits the site. The sub-basin immediately downgradient of the wetland has flooding problems that result in damage to human or natural resources (e.g., houses or salmon redds) points = 2 Surface flooding problems are in a sub-basin farther downgradient points = 1 No flooding problems anywhere downstream points = 0 R 6.2. Has the site been identified as important for flood storage or flood conveyance in a regional flood control plan? Yes = 2 No = 0 Total for R 6 Add the points in the boxes above Rating of Value If score is: 2-4 = H 1 = M 0 = L Record the rating on the first page 4 7 11 X 0 1 0 1 X 0 0 0 X basin - Cedar River subbasin - Maplewood Creek Wetland name or number ______ Wetland Rating System for Western WA: 2014 Update 13 Rating Form – Version 2, July 2023 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 if the unit is at least 2.5 ac, or more than 10% of the unit if it is smaller than 2.5 ac. ____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/groundcover) that each cover 20% within the Forested polygon H 1.2. Hydroperiods Check the types of water regimes (hydroperiods) present within the wetland. The water regime has to cover more than 10% of the wetland if the unit is < 2.5 ac, or ¼ ac if the unit is at least 2.5 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 ____Intermittently or seasonally flowing stream in, or adjacent to, the wetland ____Lake Fringe wetland 2 points ____Freshwater tidal wetland 2 points H 1.3. Richness of plant species Count the number of plant species in the wetland that cover at least 10 ft2. Different patches of the same species can be combined to meet the size threshold and you do not have to name the species. Do not include Eurasian milfoil, reed canarygrass, purple loosestrife, Canada thistle If you counted: > 19 species points = 2 5 - 19 species points = 1 < 5 species points = 0 H 1.4. Interspersion of habitats Decide from the diagrams below whether interspersion among Cowardin plants classes (described in H 1.1), or the classes and unvegetated areas (can include open water or mudflats) is high, moderate, low, or none. If you have four or more plant classes or three classes and open water, the rating is always high. 1 1 X 1 X X X PHAR, RUAR, RUSP, SPDO, RONU, SALA, SASI, COSE, CAOB, RARE, OESA, 1 PSS PEMPEM Wetland name or number ______ Wetland Rating System for Western WA: 2014 Update 14 Rating Form – Version 2, July 2023 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 extend at least 3.3 ft (1 m) over open water or 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 above for the list of strata and H 1.5 in the manual for the list of aggressive plant species) Total for H 1 Add the points in the boxes above Rating of Site Potential If score is: 15-18 = H 7-14 = M 0-6 = L Record the rating on the first page H 2.0. Does the landscape have the potential to support the habitat functions of the site? H 2.1. Accessible habitat (include only habitat polygons accessible from the wetland. Calculate: % relatively undisturbed habitat + [(% moderate and low intensity land uses)/2] = _______% Total accessible habitat is: > 1/3 (33.3%) of 1 km Polygon points = 3 20-33% of 1 km Polygon points = 2 10-19% of 1 km Polygon points = 1 < 10% of 1 km Polygon points = 0 H 2.2. Total habitat in 1 km Polygon around the wetland. Calculate: % relatively undisturbed habitat + [(% moderate and low intensity land uses)/2] = _______% Total habitat > 50% of Polygon points = 3 Total habitat 10-50% and in 1-3 patches points = 2 Total habitat 10-50% and > 3 patches points = 1 Total habitat < 10% of 1 km Polygon points = 0 H 2.3. Land use intensity in 1 km Polygon: > 50% of 1 km Polygon is high intensity land use points = (- 2) ч50% of 1 km Polygon is high intensity points = 0 Total for H 2 Add the points in the boxes above Rating of Landscape Potential If score is: 4-6 = H 1-3 = M < 1 = L Record the rating on the first page H 3.0. Is the habitat provided by the site valuable to society? H 3.1. Does the site provide habitat for species valued in laws, regulations, or policies? Choose only the highest score that applies to the wetland being rated. Site meets ANY of the following criteria: points = 2  It has 3 or more Priority Habitats within 100 m (see next page)  It provides habitat for Threatened or Endangered species (any plant or animal on the state or federal lists)  It is mapped as a location for an individual WDFW Priority Species  It is a Wetland of High Conservation Value as determined by the Department of Natural Resources data  It has been categorized as an important habitat site in a local or regional comprehensive plan, in a Shoreline Master Plan, or in a watershed plan Site has 1 or 2 Priority Habitats (listed on next page) within 100 m points = 1 Site does not meet any of the criteria above points = 0 Rating of Value If score is: 2 = H 1 = M 0 = L Record the rating on the first page 0 0 X X 1 1 1 9 0 -2 -2 X X 1 2 X 6 8 PHAR DOMINANT PSS = 6,000 sf Wetland name or number ______ Wetland Rating System for Western WA: 2014 Update 15 Rating Form – Version 2, July 2023 WDFW Priority Habitats See complete descriptions of Priority Habitats listed by WDFW, and the counties in which they can be found, in: Washington Department of Fish and Wildlife. 2008 (current year, as revised). Priority Habitat and Species List.133 This list was updated for consistency with guidance from WDFW. This question is independent of the land use between the wetland unit and the Priority Habitat. All vegetated wetlands are by definition a Priority Habitat but are not included in this list because they are addressed by this rating system. Count how many of the following Priority Habitats are within 330 ft (100 m) of the wetland unit:  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. This habitat automatically counts if mapped on the PHS online map within 100m of the wetland. If not mapped, a determination can be made in the field.  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.  Fresh Deepwater: Lands permanently flooded with freshwater, including environments where surface water is permanent and often deep, so that water, rather than air, is the principal medium within which the dominant organisms live. Substrate does not support emergent vegetation. Do not select if Instream habitat is also present, or if the entire Deepwater feature is included in the wetland unit being rated (such as a pond with a vegetated fringe).  Herbaceous Balds: Variable size patches of grass and forbs on shallow soils over bedrock.  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. Do not select if Fresh Deepwater habitat is also present.  Nearshore: Relatively undisturbed nearshore habitats. These include Coastal Nearshore, Open Coast Nearshore, and Puget Sound Nearshore.  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) diameter at breast height (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. 133 http://wdfw.wa.gov/publications/00165/wdfw00165.pdf X Wetland name or number ______ Wetland Rating System for Western WA: 2014 Update 16 Rating Form – Version 2, July 2023  Oregon White Oak: Woodland stands of pure oak or oak/conifer associations where canopy coverage of the oak component is important. For single oaks or oak stands <0.4 ha in urban areas, WDFW’s Management Recommendations for Oregon White Oak 134 provides more detail for determining if they are Priority Habitats  Riparian: The area adjacent to freshwater aquatic systems with flowing or standing water that contains elements of both aquatic and terrestrial ecosystems which mutually influence each other.  Snags and Logs: Trees are considered snags if they are dead or dying and exhibit sufficient decay characteristics to enable cavity excavation/use by wildlife. Priority snags have a diameter at breast height of > 20 in. (51 cm) in western Washington and are > 6.5 ft (2 m) in height. Priority logs are > 12 in. (30 cm) in diameter at the largest end, and > 20 ft (6 m) long.  Talus: Homogenous areas of rock rubble ranging in average size 0.5 - 6.5 ft (0.15 - 2.0 m), composed of basalt, andesite, and/or sedimentary rock, including riprap slides and mine tailings. May be associated with cliffs.  Westside Prairies: Herbaceous, non-forested plant communities that can either take the form of a dry prairie or a wet prairie. 134 https://wdfw.wa.gov/publications/00030/wdfw00030.pdf X Wetland name or number ______ Wetland Rating System for Western WA: 2014 Update 17 Rating Form – Version 2, July 2023 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 chapter 4.8 in the manual.  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. Does the wetland overlap with any known or historical rare plant or rare & high-quality ecosystem polygons on the WNHP Data Explorer?135 Yes = Category I No – Go to SC 2.2 SC 2.2. Does the wetland have a rare plant species, rare ecosystem (e.g., plant community), or high-quality common ecosystem that may qualify the site as a WHCV? Contact WNHP for resources to help determine the presence of these elements. Yes – Submit data to WA Natural Heritage Program for determination,136 Go to SC 2.3 No = Not a WHCV SC 2.3. Did WNHP review the site within 30 days and determine that it has a rare plant or ecosystem that meets their criteria? 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 = 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 = 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 = Category I bog No = Not a bog Cat. I 135 https://www.dnr.wa.gov/NHPdata 136 https://www.dnr.wa.gov/Publications/amp_nh_sighting_form.pdf Wetland name or number ______ Wetland Rating System for Western WA: 2014 Update 18 Rating Form – Version 2, July 2023 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)  The lagoon retains some of its surface water at low tide during spring tides 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 in H 1.5 in the manual).  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 and Ocean Shores Blvd SW, including lands west of E. Oceans Shores Blvd SW. 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 Evergreen Aquatic Wetland Delineation Mitigation Design Compliance Monitoring Resource Consultants, LLC Wetland Unit Including 150 ft Off-Set Vision House Phase 4 Renton, Washington 0 50 100 N WETLAND UNIT AREA THAT CAN GENERATEPOLLUTANTS AND EXCESSRUNOFF Figure 1 150 FT OFFSET 150 FT OFFSET FIGURE NOTES: 1. 24"CCP PIPE (CULVERT). LOCATION PER CITY OF RENTON GIS.SIZE AND MATERIAL REFERENCE = LUA19-000153 + LUA25-000193).2. WETLAND OUTLET = 24' CCP PIPE 3. EXCAVATED VEGETATED SHALLOW DITCH DRAINS WETLAND. NO EVIDENCE OF NATURAL CHANNEL FORMATION (REFERENCE: THE WATERSHED CO. 2021; PRE21-000462). ALTMAN OLIVER ASSOCIATES REPORT (2025; LUA25-000195)WAS DISREGARDED BECAUSE IT APPROXIMATES WETLAND/STREAM LOCATIONS AND IS NOT CONSISTENT PRE21-000462.4. WETLAND AND STREAM LOCATION PER LUA02-003.5. STORM POND PER LUA02-003. LOCATION PER RENTON GIS. 6. WETLAND INLET - 48' CMP + 12" PIPE (UNKNOWN MATERIAL). 7. NO FISH PER RAEDEKE, ASSOCIATES, INC. 2019 (REFERENCE: LUA19-000153). PEM 1 C PSSC TYPE Ns STREAM (RIVERINE) PEM1Cx(RIVERINE) 1 2 3 4 5 6 6 COTTONWOODTREES ARE LOCATEDOUTSIDE OFWETLAND COTTONWOODTREES ARELOCATED OUTSIDEOF WETLAND TREES ROOTEDOUTSIDE OFWETLAND RIVERINE PSSC(RIVERINE) COTTONWOODTREE IS LOCATEDOUTSIDE OFWETLAND Accessible Habitat, Relative Undist. Habitat, & Low Intensity Land Use within 1 km of Wetland Evergreen Aquatic Wetland Delineation Mitigation Design Compliance Monitoring Resource Consultants, LLC 0 500 1000 N Wetland unit Accessible Undisturbed Habitat (<1%) Relatively Undisturbed Habitat (7%) Moderate/Low Intensity Land Use (1%) Figure 2 Vision House Phase 4 Renton, Washington LIMITS OFACCESSIBLEHABITAT LIMITS OF 1 KMPOLYGON 9,028 752 Legend 0 256 Notes 512 WGS_1984_Web_Mercator_Auxiliary_Sphere All data, information, and maps are provided "as is" without warranty or any representation of accuracy, timeliness of completeness. The burden for determining accuracy, completeness, timeliness, merchantability and fitness for or the appropriateness for use rests solely on the user. 512 Feet Pipe Public Pipe Private Pipe Public Culvert Private Culvert Public Roofdrain Private Roofdrain Open Drains Facility Outline Vegetated Non-Vegetated Streets 2023.sid Red: Band_1 Green: Band_2 Blue: Band_3 7,691.48 ft 303d-TMDL Map WSU Facilities Services GIS, King County, WA State Parks GIS, Esri, TomTom, Garmin, SafeGraph, GeoTechnologies, Inc, METI/NASA, USGS, Bureau of Land Management, EPA, NPS, US Census Bureau, USDA, October 13, 2025 0 0.45 0.90.23 Miles K Assessed Water/Sediment Water Category 5 - 303d Category 4C Category 4B Category 4A Category 2 Category 1 Sediment Category 5 - 303d Category 4C Category 4B Category 4A Category 2 Category 1 WQ Improvement Projects TMDL - Approved 4B - Approved STI - Approved ARP - Approved TMDL - In Development STI - In Development ARP - In Development Appendix C WWHM Output WWHM2012 PROJECT REPORT WWHM Model_Vision House_VAULT 11/7/2025 7:56:39 AM Page 2 General Model Information WWHM2012 Project Name:WWHM Model_Vision House_VAULT Site Name: Site Address: City: Report Date:11/7/2025 Gage:Seatac Data Start:1948/10/01 Data End:2009/09/30 Timestep:15 Minute Precip Scale:1.000 Version Date:2025/05/13 Version:4.3.2 POC Thresholds Low Flow Threshold for POC1:50 Percent of the 2 Year High Flow Threshold for POC1:50 Year WWHM Model_Vision House_VAULT 11/7/2025 7:56:39 AM Page 3 Landuse Basin Data Predeveloped Land Use Basin 1 Bypass:No GroundWater:No Pervious Land Use acre C, Forest, Mod 1.2 Pervious Total 1.2 Impervious Land Use acre Impervious Total 0 Basin Total 1.2 Element Flow Componants: Surface Interflow Groundwater Componant Flows To: POC 1 POC 1 WWHM Model_Vision House_VAULT 11/7/2025 7:56:39 AM Page 4 Mitigated Land Use Basin 1 Bypass:No GroundWater:No Pervious Land Use acre C, Lawn, Flat 0.35 Pervious Total 0.35 Impervious Land Use acre ROOF TOPS FLAT 0.43 DRIVEWAYS FLAT 0.35 SIDEWALKS FLAT 0.07 Impervious Total 0.85 Basin Total 1.2 Element Flow Componants: Surface Interflow Groundwater Componant Flows To: Vault 1 Vault 1 WWHM Model_Vision House_VAULT 11/7/2025 7:56:39 AM Page 5 Routing Elements Predeveloped Routing WWHM Model_Vision House_VAULT 11/7/2025 7:56:39 AM Page 6 Mitigated Routing Vault 1 Width:57.5608188512775 ft. Length:57.5608188512775 ft. Depth:7 ft. Discharge Structure Riser Height:6 ft. Riser Diameter:18 in. Notch Type:Rectangular Notch Width:0.011 ft. Notch Height:1.562 ft. Orifice 1 Diameter:0.600 in.Elevation:0 ft. Element Outlets: Outlet 1 Outlet 2 Outlet Flows To: Vault Hydraulic Table Stage(feet)Area(ac.)Volume(ac-ft.)Discharge(cfs)Infilt(cfs) 0.0000 0.076 0.000 0.000 0.000 0.0778 0.076 0.005 0.002 0.000 0.1556 0.076 0.011 0.003 0.000 0.2333 0.076 0.017 0.004 0.000 0.3111 0.076 0.023 0.005 0.000 0.3889 0.076 0.029 0.006 0.000 0.4667 0.076 0.035 0.006 0.000 0.5444 0.076 0.041 0.007 0.000 0.6222 0.076 0.047 0.007 0.000 0.7000 0.076 0.053 0.008 0.000 0.7778 0.076 0.059 0.008 0.000 0.8556 0.076 0.065 0.009 0.000 0.9333 0.076 0.071 0.009 0.000 1.0111 0.076 0.076 0.009 0.000 1.0889 0.076 0.082 0.010 0.000 1.1667 0.076 0.088 0.010 0.000 1.2444 0.076 0.094 0.010 0.000 1.3222 0.076 0.100 0.011 0.000 1.4000 0.076 0.106 0.011 0.000 1.4778 0.076 0.112 0.011 0.000 1.5556 0.076 0.118 0.012 0.000 1.6333 0.076 0.124 0.012 0.000 1.7111 0.076 0.130 0.012 0.000 1.7889 0.076 0.136 0.013 0.000 1.8667 0.076 0.142 0.013 0.000 1.9444 0.076 0.147 0.013 0.000 2.0222 0.076 0.153 0.013 0.000 2.1000 0.076 0.159 0.014 0.000 2.1778 0.076 0.165 0.014 0.000 2.2556 0.076 0.171 0.014 0.000 2.3333 0.076 0.177 0.014 0.000 2.4111 0.076 0.183 0.015 0.000 2.4889 0.076 0.189 0.015 0.000 2.5667 0.076 0.195 0.015 0.000 2.6444 0.076 0.201 0.015 0.000 2.7222 0.076 0.207 0.016 0.000 WWHM Model_Vision House_VAULT 11/7/2025 7:56:39 AM Page 7 2.8000 0.076 0.213 0.016 0.000 2.8778 0.076 0.218 0.016 0.000 2.9556 0.076 0.224 0.016 0.000 3.0333 0.076 0.230 0.017 0.000 3.1111 0.076 0.236 0.017 0.000 3.1889 0.076 0.242 0.017 0.000 3.2667 0.076 0.248 0.017 0.000 3.3444 0.076 0.254 0.017 0.000 3.4222 0.076 0.260 0.018 0.000 3.5000 0.076 0.266 0.018 0.000 3.5778 0.076 0.272 0.018 0.000 3.6556 0.076 0.278 0.018 0.000 3.7333 0.076 0.284 0.018 0.000 3.8111 0.076 0.289 0.019 0.000 3.8889 0.076 0.295 0.019 0.000 3.9667 0.076 0.301 0.019 0.000 4.0444 0.076 0.307 0.019 0.000 4.1222 0.076 0.313 0.019 0.000 4.2000 0.076 0.319 0.020 0.000 4.2778 0.076 0.325 0.020 0.000 4.3556 0.076 0.331 0.020 0.000 4.4333 0.076 0.337 0.020 0.000 4.5111 0.076 0.343 0.021 0.000 4.5889 0.076 0.349 0.022 0.000 4.6667 0.076 0.355 0.024 0.000 4.7444 0.076 0.360 0.026 0.000 4.8222 0.076 0.366 0.029 0.000 4.9000 0.076 0.372 0.031 0.000 4.9778 0.076 0.378 0.034 0.000 5.0556 0.076 0.384 0.037 0.000 5.1333 0.076 0.390 0.039 0.000 5.2111 0.076 0.396 0.042 0.000 5.2889 0.076 0.402 0.045 0.000 5.3667 0.076 0.408 0.048 0.000 5.4444 0.076 0.414 0.051 0.000 5.5222 0.076 0.420 0.054 0.000 5.6000 0.076 0.425 0.058 0.000 5.6778 0.076 0.431 0.062 0.000 5.7556 0.076 0.437 0.066 0.000 5.8333 0.076 0.443 0.070 0.000 5.9111 0.076 0.449 0.090 0.000 5.9889 0.076 0.455 0.096 0.000 6.0667 0.076 0.461 0.370 0.000 6.1444 0.076 0.467 0.966 0.000 6.2222 0.076 0.473 1.734 0.000 6.3000 0.076 0.479 2.598 0.000 6.3778 0.076 0.485 3.483 0.000 6.4556 0.076 0.491 4.313 0.000 6.5333 0.076 0.496 5.022 0.000 6.6111 0.076 0.502 5.566 0.000 6.6889 0.076 0.508 5.946 0.000 6.7667 0.076 0.514 6.303 0.000 6.8444 0.076 0.520 6.610 0.000 6.9222 0.076 0.526 6.904 0.000 7.0000 0.076 0.532 7.185 0.000 7.0778 0.076 0.538 7.455 0.000 7.1556 0.000 0.000 7.716 0.000 WWHM Model_Vision House_VAULT 11/7/2025 7:56:39 AM Page 8 WWHM Model_Vision House_VAULT 11/7/2025 7:56:39 AM Page 9 Analysis Results POC 1 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area:1.2 Total Impervious Area:0 Mitigated Landuse Totals for POC #1 Total Pervious Area:0.35 Total Impervious Area:0.85 Flow Frequency Method:Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.03573 5 year 0.058547 10 year 0.073218 25 year 0.09067 50 year 0.102758 100 year 0.114049 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.018564 5 year 0.026691 10 year 0.033314 25 year 0.043271 50 year 0.051968 100 year 0.061871 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 0.041 0.015 1950 0.049 0.018 1951 0.078 0.047 1952 0.024 0.014 1953 0.020 0.017 1954 0.030 0.016 1955 0.049 0.016 1956 0.039 0.020 1957 0.032 0.016 1958 0.035 0.017 WWHM Model_Vision House_VAULT 11/7/2025 7:57:20 AM Page 10 1959 0.030 0.015 1960 0.054 0.028 1961 0.030 0.019 1962 0.018 0.014 1963 0.025 0.017 1964 0.036 0.018 1965 0.024 0.020 1966 0.023 0.016 1967 0.055 0.018 1968 0.031 0.016 1969 0.030 0.016 1970 0.024 0.017 1971 0.027 0.017 1972 0.059 0.035 1973 0.026 0.020 1974 0.029 0.017 1975 0.041 0.015 1976 0.029 0.016 1977 0.004 0.014 1978 0.024 0.018 1979 0.015 0.013 1980 0.070 0.046 1981 0.022 0.017 1982 0.045 0.020 1983 0.039 0.017 1984 0.023 0.014 1985 0.014 0.014 1986 0.061 0.018 1987 0.054 0.021 1988 0.021 0.015 1989 0.014 0.014 1990 0.129 0.028 1991 0.069 0.024 1992 0.028 0.018 1993 0.027 0.014 1994 0.009 0.012 1995 0.039 0.019 1996 0.091 0.043 1997 0.070 0.065 1998 0.017 0.014 1999 0.077 0.036 2000 0.027 0.018 2001 0.005 0.011 2002 0.032 0.019 2003 0.047 0.016 2004 0.050 0.040 2005 0.037 0.016 2006 0.042 0.021 2007 0.098 0.069 2008 0.119 0.038 2009 0.056 0.019 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.1294 0.0687 2 0.1192 0.0647 3 0.0978 0.0466 WWHM Model_Vision House_VAULT 11/7/2025 7:57:20 AM Page 11 4 0.0906 0.0461 5 0.0781 0.0435 6 0.0767 0.0404 7 0.0699 0.0380 8 0.0698 0.0359 9 0.0686 0.0346 10 0.0612 0.0282 11 0.0593 0.0277 12 0.0556 0.0237 13 0.0549 0.0212 14 0.0540 0.0206 15 0.0539 0.0204 16 0.0504 0.0200 17 0.0488 0.0199 18 0.0486 0.0196 19 0.0471 0.0192 20 0.0452 0.0189 21 0.0420 0.0188 22 0.0411 0.0188 23 0.0405 0.0183 24 0.0392 0.0182 25 0.0391 0.0181 26 0.0387 0.0181 27 0.0374 0.0180 28 0.0359 0.0179 29 0.0351 0.0179 30 0.0316 0.0174 31 0.0316 0.0174 32 0.0309 0.0173 33 0.0304 0.0171 34 0.0301 0.0171 35 0.0301 0.0170 36 0.0296 0.0169 37 0.0291 0.0168 38 0.0290 0.0165 39 0.0280 0.0165 40 0.0274 0.0164 41 0.0272 0.0162 42 0.0272 0.0162 43 0.0263 0.0162 44 0.0253 0.0161 45 0.0245 0.0160 46 0.0245 0.0157 47 0.0241 0.0153 48 0.0239 0.0153 49 0.0233 0.0151 50 0.0229 0.0151 51 0.0219 0.0145 52 0.0213 0.0143 53 0.0198 0.0138 54 0.0184 0.0138 55 0.0171 0.0137 56 0.0148 0.0137 57 0.0141 0.0136 58 0.0138 0.0136 59 0.0092 0.0126 60 0.0049 0.0123 61 0.0042 0.0114 WWHM Model_Vision House_VAULT 11/7/2025 7:57:20 AM Page 12 WWHM Model_Vision House_VAULT 11/7/2025 7:57:20 AM Page 13 Duration Flows The Facility PASSED Flow(cfs)Predev Mit Percentage Pass/Fail 0.0179 17085 15368 89 Pass 0.0187 15488 10780 69 Pass 0.0196 14065 6921 49 Pass 0.0204 12805 3987 31 Pass 0.0213 11569 3255 28 Pass 0.0222 10515 2997 28 Pass 0.0230 9561 2740 28 Pass 0.0239 8754 2505 28 Pass 0.0247 8036 2329 28 Pass 0.0256 7347 2171 29 Pass 0.0264 6731 2015 29 Pass 0.0273 6192 1872 30 Pass 0.0282 5730 1700 29 Pass 0.0290 5309 1584 29 Pass 0.0299 4924 1511 30 Pass 0.0307 4569 1434 31 Pass 0.0316 4237 1351 31 Pass 0.0324 3951 1238 31 Pass 0.0333 3643 1113 30 Pass 0.0342 3390 1004 29 Pass 0.0350 3133 903 28 Pass 0.0359 2915 814 27 Pass 0.0367 2701 728 26 Pass 0.0376 2490 662 26 Pass 0.0384 2314 584 25 Pass 0.0393 2136 526 24 Pass 0.0402 1972 474 24 Pass 0.0410 1825 430 23 Pass 0.0419 1702 399 23 Pass 0.0427 1577 364 23 Pass 0.0436 1442 320 22 Pass 0.0444 1325 295 22 Pass 0.0453 1232 270 21 Pass 0.0462 1147 226 19 Pass 0.0470 1083 209 19 Pass 0.0479 1020 203 19 Pass 0.0487 947 196 20 Pass 0.0496 886 181 20 Pass 0.0505 823 168 20 Pass 0.0513 760 158 20 Pass 0.0522 725 153 21 Pass 0.0530 674 147 21 Pass 0.0539 623 142 22 Pass 0.0547 589 137 23 Pass 0.0556 549 131 23 Pass 0.0565 506 120 23 Pass 0.0573 469 106 22 Pass 0.0582 427 88 20 Pass 0.0590 388 82 21 Pass 0.0599 356 75 21 Pass 0.0607 328 69 21 Pass 0.0616 298 63 21 Pass 0.0625 270 55 20 Pass WWHM Model_Vision House_VAULT 11/7/2025 7:57:20 AM Page 14 0.0633 241 48 19 Pass 0.0642 218 41 18 Pass 0.0650 198 34 17 Pass 0.0659 173 31 17 Pass 0.0667 152 27 17 Pass 0.0676 130 12 9 Pass 0.0685 119 5 4 Pass 0.0693 104 0 0 Pass 0.0702 95 0 0 Pass 0.0710 83 0 0 Pass 0.0719 74 0 0 Pass 0.0727 69 0 0 Pass 0.0736 61 0 0 Pass 0.0745 53 0 0 Pass 0.0753 46 0 0 Pass 0.0762 39 0 0 Pass 0.0770 29 0 0 Pass 0.0779 25 0 0 Pass 0.0787 22 0 0 Pass 0.0796 20 0 0 Pass 0.0805 17 0 0 Pass 0.0813 14 0 0 Pass 0.0822 12 0 0 Pass 0.0830 8 0 0 Pass 0.0839 7 0 0 Pass 0.0848 7 0 0 Pass 0.0856 7 0 0 Pass 0.0865 6 0 0 Pass 0.0873 6 0 0 Pass 0.0882 6 0 0 Pass 0.0890 6 0 0 Pass 0.0899 6 0 0 Pass 0.0908 5 0 0 Pass 0.0916 5 0 0 Pass 0.0925 5 0 0 Pass 0.0933 5 0 0 Pass 0.0942 5 0 0 Pass 0.0950 5 0 0 Pass 0.0959 5 0 0 Pass 0.0968 4 0 0 Pass 0.0976 4 0 0 Pass 0.0985 3 0 0 Pass 0.0993 3 0 0 Pass 0.1002 3 0 0 Pass 0.1010 3 0 0 Pass 0.1019 3 0 0 Pass 0.1028 3 0 0 Pass WWHM Model_Vision House_VAULT 11/7/2025 7:57:20 AM Page 15 Water Quality Water Quality BMP Flow and Volume for POC #1 On-line facility volume:0.0198 acre-feet On-line facility target flow:0.0096 cfs. Adjusted for 15 min:0.0096 cfs. Off-line facility target flow:0.0074 cfs. Adjusted for 15 min:0.0074 cfs. WWHM Model_Vision House_VAULT 11/7/2025 7:57:20 AM Page 16 Model Default Modifications Total of 0 changes have been made. PERLND Changes No PERLND changes have been made. IMPLND Changes No IMPLND changes have been made. WWHM Model_Vision House_VAULT 11/7/2025 7:57:21 AM Page 17 Appendix Predeveloped Schematic WWHM Model_Vision House_VAULT 11/7/2025 7:57:23 AM Page 18 Mitigated Schematic WWHM Model_Vision House_VAULT 11/7/2025 7:57:24 AM Page 19 Predeveloped UCI File RUN GLOBAL WWHM4 model simulation START 1948 10 01 END 2009 09 30 RUN INTERP OUTPUT LEVEL 3 0 RESUME 0 RUN 1 UNIT SYSTEM 1 END GLOBAL FILES <File> <Un#> <-----------File Name------------------------------>*** <-ID-> *** WDM 26 WWHM Model_Vision House_VAULT.wdm MESSU 25 PreWWHM Model_Vision House_VAULT.MES 27 PreWWHM Model_Vision House_VAULT.L61 28 PreWWHM Model_Vision House_VAULT.L62 30 POCWWHM Model_Vision House_VAULT1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 11 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Basin 1 MAX 1 2 30 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 501 1 1 END TIMESERIES END COPY GENER OPCODE # # OPCD *** END OPCODE PARM # # K *** END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 11 C, Forest, Mod 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 11 0 0 1 0 0 0 0 0 0 0 0 0 END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* 11 0 0 4 0 0 0 0 0 0 0 0 0 1 9 END PRINT-INFO WWHM Model_Vision House_VAULT 11/7/2025 7:57:24 AM Page 20 PWAT-PARM1 <PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 11 0 0 0 0 0 0 0 0 0 0 0 END PWAT-PARM1 PWAT-PARM2 <PLS > PWATER input info: Part 2 *** # - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC 11 0 4.5 0.08 400 0.1 0.5 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 11 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 11 0.2 0.5 0.35 6 0.5 0.7 END PWAT-PARM4 PWAT-STATE1 <PLS > *** Initial conditions at start of simulation ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 *** # - # *** CEPS SURS UZS IFWS LZS AGWS GWVS 11 0 0 0 0 2.5 1 0 END PWAT-STATE1 END PERLND IMPLND GEN-INFO <PLS ><-------Name-------> Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** END GEN-INFO *** Section IWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** END ACTIVITY PRINT-INFO <ILS > ******** Print-flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* END PRINT-INFO IWAT-PARM1 <PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI *** END IWAT-PARM1 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS END IWAT-STATE1 WWHM Model_Vision House_VAULT 11/7/2025 7:57:24 AM Page 21 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Basin 1*** PERLND 11 1.2 COPY 501 12 PERLND 11 1.2 COPY 501 13 ******Routing****** END SCHEMATIC NETWORK <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 501 OUTPUT MEAN 1 1 48.4 DISPLY 1 INPUT TIMSER 1 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** END NETWORK RCHRES GEN-INFO RCHRES Name Nexits Unit Systems Printer *** # - #<------------------><---> User T-series Engl Metr LKFG *** in out *** END GEN-INFO *** Section RCHRES*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR ********* END PRINT-INFO HYDR-PARM1 RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** END HYDR-PARM1 HYDR-PARM2 # - # FTABNO LEN DELTH STCOR KS DB50 *** <------><--------><--------><--------><--------><--------><--------> *** END HYDR-PARM2 HYDR-INIT RCHRES Initial conditions for each HYDR section *** # - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> END HYDR-INIT END RCHRES SPEC-ACTIONS END SPEC-ACTIONS FTABLES END FTABLES EXT SOURCES <-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1 IMPLND 1 999 EXTNL PREC WWHM Model_Vision House_VAULT 11/7/2025 7:57:24 AM Page 22 WDM 1 EVAP ENGL 0.76 PERLND 1 999 EXTNL PETINP WDM 1 EVAP ENGL 0.76 IMPLND 1 999 EXTNL PETINP END EXT SOURCES EXT TARGETS <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg*** COPY 501 OUTPUT MEAN 1 1 48.4 WDM 501 FLOW ENGL REPL END EXT TARGETS MASS-LINK <Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** <Name> <Name> # #<-factor-> <Name> <Name> # #*** MASS-LINK 12 PERLND PWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 12 MASS-LINK 13 PERLND PWATER IFWO 0.083333 COPY INPUT MEAN END MASS-LINK 13 END MASS-LINK END RUN WWHM Model_Vision House_VAULT 11/7/2025 7:57:24 AM Page 23 Mitigated UCI File RUN GLOBAL WWHM4 model simulation START 1948 10 01 END 2009 09 30 RUN INTERP OUTPUT LEVEL 3 0 RESUME 0 RUN 1 UNIT SYSTEM 1 END GLOBAL FILES <File> <Un#> <-----------File Name------------------------------>*** <-ID-> *** WDM 26 WWHM Model_Vision House_VAULT.wdm MESSU 25 MitWWHM Model_Vision House_VAULT.MES 27 MitWWHM Model_Vision House_VAULT.L61 28 MitWWHM Model_Vision House_VAULT.L62 30 POCWWHM Model_Vision House_VAULT1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 16 IMPLND 4 IMPLND 5 IMPLND 8 RCHRES 1 COPY 1 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Vault 1 MAX 1 2 30 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 501 1 1 END TIMESERIES END COPY GENER OPCODE # # OPCD *** END OPCODE PARM # # K *** END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 16 C, Lawn, Flat 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 16 0 0 1 0 0 0 0 0 0 0 0 0 END ACTIVITY PRINT-INFO WWHM Model_Vision House_VAULT 11/7/2025 7:57:24 AM Page 24 <PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* 16 0 0 4 0 0 0 0 0 0 0 0 0 1 9 END PRINT-INFO PWAT-PARM1 <PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 16 0 0 0 0 0 0 0 0 0 0 0 END PWAT-PARM1 PWAT-PARM2 <PLS > PWATER input info: Part 2 *** # - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC 16 0 4.5 0.03 400 0.05 0.5 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 16 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 16 0.1 0.25 0.25 6 0.5 0.25 END PWAT-PARM4 PWAT-STATE1 <PLS > *** Initial conditions at start of simulation ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 *** # - # *** CEPS SURS UZS IFWS LZS AGWS GWVS 16 0 0 0 0 2.5 1 0 END PWAT-STATE1 END PERLND IMPLND GEN-INFO <PLS ><-------Name-------> Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 4 ROOF TOPS/FLAT 1 1 1 27 0 5 DRIVEWAYS/FLAT 1 1 1 27 0 8 SIDEWALKS/FLAT 1 1 1 27 0 END GEN-INFO *** Section IWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** 4 0 0 1 0 0 0 5 0 0 1 0 0 0 8 0 0 1 0 0 0 END ACTIVITY PRINT-INFO <ILS > ******** Print-flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* 4 0 0 4 0 0 4 1 9 5 0 0 4 0 0 0 1 9 8 0 0 4 0 0 0 1 9 END PRINT-INFO IWAT-PARM1 <PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI *** 4 0 0 0 0 0 5 0 0 0 0 0 8 0 0 0 0 0 WWHM Model_Vision House_VAULT 11/7/2025 7:57:24 AM Page 25 END IWAT-PARM1 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC 4 400 0.01 0.1 0.1 5 400 0.01 0.1 0.1 8 400 0.01 0.1 0.1 END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN 4 0 0 5 0 0 8 0 0 END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS 4 0 0 5 0 0 8 0 0 END IWAT-STATE1 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Basin 1*** PERLND 16 0.35 RCHRES 1 2 PERLND 16 0.35 RCHRES 1 3 IMPLND 4 0.43 RCHRES 1 5 IMPLND 5 0.35 RCHRES 1 5 IMPLND 8 0.07 RCHRES 1 5 ******Routing****** PERLND 16 0.35 COPY 1 12 IMPLND 4 0.43 COPY 1 15 IMPLND 5 0.35 COPY 1 15 IMPLND 8 0.07 COPY 1 15 PERLND 16 0.35 COPY 1 13 RCHRES 1 1 COPY 501 16 END SCHEMATIC NETWORK <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 501 OUTPUT MEAN 1 1 48.4 DISPLY 1 INPUT TIMSER 1 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** END NETWORK RCHRES GEN-INFO RCHRES Name Nexits Unit Systems Printer *** # - #<------------------><---> User T-series Engl Metr LKFG *** in out *** 1 Vault 1 1 1 1 1 28 0 1 END GEN-INFO *** Section RCHRES*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** WWHM Model_Vision House_VAULT 11/7/2025 7:57:24 AM Page 26 1 1 0 0 0 0 0 0 0 0 0 END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR ********* 1 4 0 0 0 0 0 0 0 0 0 1 9 END PRINT-INFO HYDR-PARM1 RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** 1 0 1 0 0 4 0 0 0 0 0 0 0 0 0 2 2 2 2 2 END HYDR-PARM1 HYDR-PARM2 # - # FTABNO LEN DELTH STCOR KS DB50 *** <------><--------><--------><--------><--------><--------><--------> *** 1 1 0.01 0.0 0.0 0.5 0.0 END HYDR-PARM2 HYDR-INIT RCHRES Initial conditions for each HYDR section *** # - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> 1 0 4.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 END HYDR-INIT END RCHRES SPEC-ACTIONS END SPEC-ACTIONS FTABLES FTABLE 1 92 4 Depth Area Volume Outflow1 Velocity Travel Time*** (ft) (acres) (acre-ft) (cfs) (ft/sec) (Minutes)*** 0.000000 0.076062 0.000000 0.000000 0.077778 0.076062 0.005916 0.002725 0.155556 0.076062 0.011832 0.003853 0.233333 0.076062 0.017748 0.004719 0.311111 0.076062 0.023664 0.005449 0.388889 0.076062 0.029580 0.006092 0.466667 0.076062 0.035495 0.006674 0.544444 0.076062 0.041411 0.007208 0.622222 0.076062 0.047327 0.007706 0.700000 0.076062 0.053243 0.008174 0.777778 0.076062 0.059159 0.008616 0.855556 0.076062 0.065075 0.009036 0.933333 0.076062 0.070991 0.009438 1.011111 0.076062 0.076907 0.009823 1.088889 0.076062 0.082823 0.010194 1.166667 0.076062 0.088739 0.010552 1.244444 0.076062 0.094655 0.010898 1.322222 0.076062 0.100570 0.011233 1.400000 0.076062 0.106486 0.011559 1.477778 0.076062 0.112402 0.011876 1.555556 0.076062 0.118318 0.012184 1.633333 0.076062 0.124234 0.012485 1.711111 0.076062 0.130150 0.012779 1.788889 0.076062 0.136066 0.013066 1.866667 0.076062 0.141982 0.013347 1.944444 0.076062 0.147898 0.013623 2.022222 0.076062 0.153814 0.013892 2.100000 0.076062 0.159730 0.014157 2.177778 0.076062 0.165645 0.014417 2.255556 0.076062 0.171561 0.014672 2.333333 0.076062 0.177477 0.014923 2.411111 0.076062 0.183393 0.015169 WWHM Model_Vision House_VAULT 11/7/2025 7:57:24 AM Page 27 2.488889 0.076062 0.189309 0.015412 2.566667 0.076062 0.195225 0.015651 2.644444 0.076062 0.201141 0.015887 2.722222 0.076062 0.207057 0.016118 2.800000 0.076062 0.212973 0.016347 2.877778 0.076062 0.218889 0.016573 2.955556 0.076062 0.224805 0.016795 3.033333 0.076062 0.230721 0.017015 3.111111 0.076062 0.236636 0.017231 3.188889 0.076062 0.242552 0.017445 3.266667 0.076062 0.248468 0.017657 3.344444 0.076062 0.254384 0.017866 3.422222 0.076062 0.260300 0.018072 3.500000 0.076062 0.266216 0.018277 3.577778 0.076062 0.272132 0.018479 3.655556 0.076062 0.278048 0.018678 3.733333 0.076062 0.283964 0.018876 3.811111 0.076062 0.289880 0.019072 3.888889 0.076062 0.295796 0.019265 3.966667 0.076062 0.301711 0.019457 4.044444 0.076062 0.307627 0.019647 4.122222 0.076062 0.313543 0.019835 4.200000 0.076062 0.319459 0.020021 4.277778 0.076062 0.325375 0.020206 4.355556 0.076062 0.331291 0.020388 4.433333 0.076062 0.337207 0.020570 4.511111 0.076062 0.343123 0.021435 4.588889 0.076062 0.349039 0.022933 4.666667 0.076062 0.354955 0.024787 4.744444 0.076062 0.360871 0.026902 4.822222 0.076062 0.366786 0.029217 4.900000 0.076062 0.372702 0.031692 4.977778 0.076062 0.378618 0.034292 5.055556 0.076062 0.384534 0.036992 5.133333 0.076062 0.390450 0.039768 5.211111 0.076062 0.396366 0.042603 5.288889 0.076062 0.402282 0.045477 5.366667 0.076062 0.408198 0.048377 5.444444 0.076062 0.414114 0.051332 5.522222 0.076062 0.420030 0.054866 5.600000 0.076062 0.425946 0.058522 5.677778 0.076062 0.431861 0.062296 5.755556 0.076062 0.437777 0.066184 5.833333 0.076062 0.443693 0.070183 5.911111 0.076062 0.449609 0.090473 5.988889 0.076062 0.455525 0.095982 6.066667 0.076062 0.461441 0.370608 6.144444 0.076062 0.467357 0.966058 6.222222 0.076062 0.473273 1.734165 6.300000 0.076062 0.479189 2.598633 6.377778 0.076062 0.485105 3.483806 6.455556 0.076062 0.491021 4.313764 6.533333 0.076062 0.496936 5.022018 6.611111 0.076062 0.502852 5.566311 6.688889 0.076062 0.508768 5.946911 6.766667 0.076062 0.514684 6.303314 6.844444 0.076062 0.520600 6.610607 6.922222 0.076062 0.526516 6.904051 7.000000 0.076062 0.532432 7.185365 7.077778 0.076062 0.538348 7.455941 END FTABLE 1 END FTABLES EXT SOURCES <-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1 IMPLND 1 999 EXTNL PREC WDM 1 EVAP ENGL 0.76 PERLND 1 999 EXTNL PETINP WDM 1 EVAP ENGL 0.76 IMPLND 1 999 EXTNL PETINP WWHM Model_Vision House_VAULT 11/7/2025 7:57:24 AM Page 28 END EXT SOURCES EXT TARGETS <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg*** RCHRES 1 HYDR RO 1 1 1 WDM 1000 FLOW ENGL REPL RCHRES 1 HYDR STAGE 1 1 1 WDM 1001 STAG ENGL REPL COPY 1 OUTPUT MEAN 1 1 48.4 WDM 701 FLOW ENGL REPL COPY 501 OUTPUT MEAN 1 1 48.4 WDM 801 FLOW ENGL REPL END EXT TARGETS MASS-LINK <Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** <Name> <Name> # #<-factor-> <Name> <Name> # #*** MASS-LINK 2 PERLND PWATER SURO 0.083333 RCHRES INFLOW IVOL END MASS-LINK 2 MASS-LINK 3 PERLND PWATER IFWO 0.083333 RCHRES INFLOW IVOL END MASS-LINK 3 MASS-LINK 5 IMPLND IWATER SURO 0.083333 RCHRES INFLOW IVOL END MASS-LINK 5 MASS-LINK 12 PERLND PWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 12 MASS-LINK 13 PERLND PWATER IFWO 0.083333 COPY INPUT MEAN END MASS-LINK 13 MASS-LINK 15 IMPLND IWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 15 MASS-LINK 16 RCHRES ROFLOW COPY INPUT MEAN END MASS-LINK 16 END MASS-LINK END RUN WWHM Model_Vision House_VAULT 11/7/2025 7:57:24 AM Page 29 Predeveloped HSPF Message File WWHM Model_Vision House_VAULT 11/7/2025 7:57:24 AM Page 30 Mitigated HSPF Message File WWHM Model_Vision House_VAULT 11/7/2025 7:57:24 AM Page 31 Disclaimer Legal Notice This program and accompanying documentation are provided 'as-is' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by End User. Clear Creek Solutions Inc. and the governmental licensee or sublicensees disclaim all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions Inc. be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions Inc. or their authorized representatives have been advised of the possibility of such damages. Software Copyright © by : Clear Creek Solutions, Inc. 2005-2025; All Rights Reserved. Clear Creek Solutions, Inc. 6200 Capitol Blvd. Ste F Olympia, WA. 98501 Toll Free 1(866)943-0304 Local (360)943-0304 www.clearcreeksolutions.com Appendix D Operations and Maintenance APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 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 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 2022 City of Renton Surface Water Design Manual 6/22/2022 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 be 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 6/22/2022 2022 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 2022 City of Renton Surface Water Design Manual 6/22/2022 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. 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 6/22/2022 2022 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 2022 City of Renton Surface Water Design Manual 6/22/2022 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. 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 6/22/2022 2022 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 2022 City of Renton Surface Water Design Manual 6/22/2022 A-17 NO. 11 – GROUNDS (LANDSCAPING) MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Any trash and debris which exceed 1 cubic foot per 1,000 square feet (this is about equal to the amount of trash it would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Trash and debris cleared from site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where City personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Excessive growth of grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Trees and Shrubs Hazard tree identified Any tree or limb of a tree identified as having a potential to fall and cause property damage or threaten human life. A hazard tree identified by a qualified arborist must be removed as soon as possible. No hazard trees in facility. Damaged tree or shrub identified Limbs or parts of trees or shrubs that are split or broken which affect more than 25% of the total foliage of the tree or shrub. Trees and shrubs with less than 5% of total foliage with split or broken limbs. Trees or shrubs that have been blown down or knocked over. No blown down vegetation or knocked over vegetation. Trees or shrubs free of injury. Trees or shrubs which are not adequately supported or are leaning over, causing exposure of the roots. Tree or shrub in place and adequately supported; dead or diseased trees removed. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-31 NO. 21 – PROPRIETARY FACILITY CARTRIDGE FILTER SYSTEMS MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED In addition to the specific maintenance criteria provided below, all manufacturers’ requirements shall be followed. Facility Documentation Update facility inspection record after each inspection. Maintenance records are up to date. Provide certification of replaced filter media. Filter media is certified to meet manufacturer specifications. Site Trash and debris Any trash or debris which impairs the function of the facility. Trash and debris removed from facility. Contaminants and pollution Any evidence of contaminants or pollution such as oils, 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. Life cycle Once per year. Facility is re-inspected and any needed maintenance performed. Vault Treatment Area Sediment on vault floor Varies – Refer to manufacturer’s requirements. Vault is free of sediment. Sediment on top of cartridges Varies – Refer to manufacturer’s requirements. Vault is free of sediment. Multiple scum lines above top of cartridges Thick or multiple scum lines above top of cartridges. Probably due to plugged canisters or underdrain manifold. Cause of plugging corrected, canisters replaced if necessary. Vault Structure Damage to wall, frame, bottom, and/or top slab Cracks wider than ½-inch and any evidence of soil particles entering the structure through the cracks, or qualified inspection personnel determines the vault is not structurally sound. Vault replaced or repaired to design specifications. Baffles damaged Baffles corroding, cracking warping, and/or showing signs of failure as determined by maintenance/inspection person. Repair or replace baffles to specification. Filter Media Standing water in vault Varies – Refer to manufacturer’s requirements. No standing water in vault 24 hours after a rain event. Short circuiting Flows do not properly enter filter cartridges. Flows go through filter media. Underdrains and Clean-Outs Sediment and debris Underdrains or clean-outs partially plugged or filled with sediment and/or debris. Underdrains and clean-outs free of sediment and debris. 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. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-32 NO. 21 – PROPRIETARY FACILITY CARTRIDGE FILTER SYSTEMS MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED 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. 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 be opened as designed. Gaps, doesn't cover completely Large access doors not flat and/or access opening not completely covered. Doors close flat and cover 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 2022 City of Renton Surface Water Design Manual 6/22/2022 A-33 NO. 22 – BAFFLE OIL/WATER SEPARATOR MAINTENANCE COMPONENT DEFECT CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Site Trash and debris Any trash or debris which impairs the function of the facility. Trash and debris removed from facility. Contaminants and pollution Floating oil in excess of 1 inch in first chamber, any oil in other chambers or other contaminants of any type in any chamber. No contaminants present other than a surface oil film. Vault Treatment Area Sediment accumulation Sediment accumulates exceeds 6 inches in the vault. No sediment in the vault. Discharge water not clear Inspection of discharge water shows obvious signs of poor water quality- effluent discharge from vault shows thick visible sheen. Effluent discharge is clear. Trash or debris accumulation Any trash and debris accumulation in vault floatables and non-floatables). Vault is clear of trash and debris. Oil accumulation Oil accumulations that exceed 1 inch, at the surface of the water in the oil/water separator chamber. No visible oil depth on water. Vault Structure Damage to wall, frame, bottom, and/or top slab Cracks wider than ½-inch or evidence of soil particles entering the structure through the cracks, or maintenance/inspection personnel determines that the vault is not structurally sound. Vault replaced or repaired to design specifications. Baffles damaged Baffles corroding, cracking, warping and/or showing signs of failure as determined by maintenance inspection personnel. Repair or replace baffles to specifications. Gravity Drain Inoperable valve Valve will not open and close. Valve opens and closes normally. Valve won’t seal Valve does not seal completely. Valve completely seals closed. 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. 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. 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. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-34 NO. 22 – BAFFLE OIL/WATER SEPARATOR MAINTENANCE COMPONENT DEFECT CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED 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 be opened as designed. Gaps, doesn't cover completely Large access doors not flat and/or access opening not completely covered. Doors close flat and cover access opening completely. Lifting rings missing, rusted Lifting rings not capable of lifting weight of door or cover/lid. Lifting rings sufficient to lift or remove cover/lid. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-37 NO. 24 – CATCH BASIN INSERT (NOT ALLOWED IN THE CITY FOR OIL CONTROL) APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 2022 City of Renton Surface Water Design Manual 6/22/2022 A-47 NO. 38 – SOIL AMENDMENT BMP MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Soil Media Unhealthy vegetation Vegetation not fully covering ground surface or vegetation health is poor. Yellowing: possible Nitrogen (N) deficiency. Poor growth: possible Phosphorous (P) deficiency. Poor flowering, spotting or curled leaves, or weak roots or stems: possible Potassium K) deficiency. Plants are healthy and appropriate for site conditions Inadequate soil nutrients and structure In the fall, return leaf fall and shredded woody materials from the landscape to the site when possible Soil providing plant nutrients and structure Excessive vegetation growth Grass becomes excessively tall (greater than 10 inches); nuisance weeds and other vegetation start to take over. Healthy turf- “grasscycle” (mulch-mow or leave the clippings) to build turf health Weeds Preventive maintenance Avoid use of pesticides (bug and weed killers), like “weed & feed,” which damage the soil Fertilizer needed 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 Integrated Pest Management (IPM) protocols for fertilization followed Bare spots Bare spots on soil No bare spots, area covered with vegetation or mulch mixed into the underlying soil. Compaction Poor infiltration due to soil compaction To remediate compaction, aerate soil, till to at least 8-inch depth, or further amend soil with compost and re-till If areas are turf, aerate compacted areas and top dress them with 1/4 to 1/2 inch of compost to renovate them If drainage is still slow, consider investigating alternative causes (e.g., high wet season groundwater levels, low permeability soils) Also consider site use and protection from compacting activities No soil compaction Poor infiltration Soils become waterlogged, do not appear to be infiltrating. Facility infiltrating properly Erosion/Scouring Erosion Areas of potential erosion are visible Causes of erosion (e.g., concentrate flow entering area, channelization of runoff) identified and damaged area stabilized regrade, rock, vegetation, erosion control matting).For deep channels or cuts (over 3 inches in ponding depth), temporary erosion control measures in place until permanent repairs can be made Grass/Vegetation Unhealthy vegetation Less than 75% of planted vegetation is healthy with a generally good appearance. Healthy vegetation. Unhealthy plants removed/replaced. Appropriate vegetation planted in terms of exposure, soil and soil moisture. Noxious Weeds Noxious weeds Listed noxious vegetation is present (refer to current County noxious weed list). No noxious weeds present. APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS 6/22/2022 2022 City of Renton Surface Water Design Manual A-48 NO. 39 – RETAINED TREES MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED Tree Dead or declining Dead, damaged, or declining Tree replaced per planting plan or acceptable substitute NO. 40 – FILTERRA SYSTEM MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITION WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED In addition to the specific maintenance criteria provided below, all manufacturer’s requirements shall be followed. Facility – General Requirements Life cycle Once per year, except mulch and trash removal twice per year Facility is re-inspected and any needed maintenance performed Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries, or paint Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Inlet Excessive sediment or trash accumulation Accumulated sediments or trash impair free flow of water into system Inlet should be free of obstructions allowing free distributed flow of water into system Mulch Cover Trash and floatable debris accumulation Excessive trash and/or debris accumulation Minimal trash or other debris on mulch cover. Mulch cover raked level. Ponding” of water on mulch cover Ponding” in unit could be indicative of clogging due to excessive fine sediment accumulation or spill of petroleum oils Stormwater should drain freely and evenly through mulch cover Proprietary Filter Media/ Vegetation Substrate Ponding” of water on mulch cover after mulch cover has been maintained Excessive fine sediment passes the mulch cover and clogs the filter media/vegetative substrate Stormwater should drain freely and evenly through mulch cover. Replace substrate and vegetation when needed Vegetation Plants not growing or in poor condition Soil/mulch too wet, evidence of spill, incorrect plant selection, pest infestation, and/or vandalism to plants Plants should be healthy and pest free Media/mulch too dry Irrigation is required Plants absent Plants absent Appropriate plants are present Excessive plant growth Excessive plant growth inhibits facility function or becomes a hazard for pedestrian and vehicular circulation and safety Pruning and/or thinning vegetation maintains proper plant density. Appropriate plants are present. Structure Structure has visible cracks Cracks wider than ½ inch Evidence of soil particles entering the structure through the cracks Structure is sealed and structurally sound