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HomeMy WebLinkAboutRS_Preliminary_Drainage_Report_251209_v1 SITE ADDRESS PROJECT NO. DATE JURISDICTION Renton, Washington 23382 7/23/2025 City of Renton Preliminary Technical Information Report PREPARED BY Talbot Hills Barghausen Consulting Engineers, LLC PREPARED FOR CLIENT ADDRESS Schneider Family Homes, LLC 6510 Southcenter Blvd, Suite 1 Tukwila, WA 98188 7/23/202512/08/25 12/08/25 23382-TIR-PREL.doc TABLE OF CONTENTS 1.0 PROJECT OVERVIEW Figure 1 – Technical Information Report (TIR) Worksheet Figure 2 – Site Location Map Figure 3 – Drainage Basins, Subbasins, and Site Characteristics Figure 4 – Soils Figure 5 – Assessor's Map Figure 6 – FEMA Map Figure 7 – Sensitive Area Map 2.0 CONDITIONS AND REQUIREMENTS SUMMARY 2.1 Analysis of the Core Requirements and Special Requirements 3.0 OFFSITE ANALYSIS 4.0 FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN 4.1 Existing Site Hydrology 4.2 Developed Site Hydrology 4.3 Performance Standards 4.4 Flow Control System 4.5 Water Quality System 5.0 CONVEYANCE SYSTEM ANALYSIS AND DESIGN 5.1 Conveyance Basin Maps and Calculations 5.2 Backwater Calculations 6.0 SPECIAL REPORTS AND STUDIES 7.0 OTHER PERMITS 8.0 CSWPP PLAN ANALYSIS AND DESIGN 9.0 BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT 10.0 OPERATIONS AND MAINTENANCE MANUAL Tab 1.0 23382-TIR-PREL.doc 1.0 PROJECT OVERVIEW This section contains the following information: Figure 1 – Technical Information Report (TIR) Worksheet Figure 2 – Vicinity Map Figure 3 – Predeveloped Drainage Basin Map Figure 4 – Soils Figure 5 – Assessor's Map Figure 6 – FEMA Map Figure 7 – Sensitive Area Map Figure 1 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 Schneider Family Homes, LLC 206-450-8330 6510 Southcenter BLVD. STE 1 Mark Sumrok Barghausen Consulting Engineers 425-251-6222 Tukwila, WA 98188 Talbott Hills PRE 24-000146 23N 05 E 31 TBD Renton, WA x x x x x x 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 ______________________ Renton Black River 2022 Renton Surface Water Design Manual x x 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 AgC Alderwood Gravelly Sandy Loam 8-15%Low x Level 1 Talbott Hills Site Outfall 1 Control Structure within Catch basin TBD Level 2 TBD TBD 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 x x x x x x x x x x x x x x x x Detention Chambers x x x Feasability to be determined for individual lot permitting x Biofilter vault 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 x x x x Figure 2 Horizontal: Scale: Vertical: For: Title: V I C I N I T Y M A P Job Number N.T.S.N/A 23382 DATE: 7/03/25 Talbot Hills Renton, Washington P:\23000s\23382\exhibit\graphics\23382 vmap.cdr RE FER ENC E: Geomap (2025) SITE Figure 3 OF PREDEVELOPED BASIN MAP SCALE 1"=30" TALBOT HILLS A PORTION OF SECTION 31, TOWNSHIP 23 N., RANGE 05 E., W.M. CITY OF RENTON, KING COUNTY, WASHINGTON PR E D E V E L O P E D B A S I N M A P 6 SC H N E I D E R F A M I L Y H O M E S 65 1 0 S O U T H C E N T E R B L V D , S U I T E 1 TU K W I L A , W A 9 8 1 8 8 23 3 8 2 1 OF TA L B O T H I L L S PREDEVELOPED BASIN 1 PREDEVELOPED BASIN 98 T H A V E S S 55TH ST UPSTREAM BASIN Figure 4 Horizontal: Scale: Vertical: For: Title: S O I L S U RV E Y M A P Job Number N.T.S.N/A 23382 DATE: 7/03/25 Talbot Hills Renton, Washington P:\23000s\23382\exhibit\graphics\23382 soil.cdr HS G B RE FER ENCE: US DA, Natural Resources Conservation Service L EGE ND: SITE AgC = Alderwood gravelly sandy loam, 8-15% slopes Figure 5 Horizontal: Scale: Vertical: For: Title: A S S E S S O R M A P Job Number N.T.S.N/A 23382 DATE: 7/03/25 Talbot Hills Renton, Washington P:\23000s\23382\exhibit\graphics\23382 amap.cdr SITE RE FER ENC E: King County Department of Assessments (Aug. 2021) Figure 6 Horizontal: Scale: Vertical: For: Title: F E M A M A P Job Number N.T.S.N/A 23382 DATE: 7/03/25 Talbot Hills Renton, Washington P:\23000s\23382\exhibit\graphics\23382 fema.cdr REF ERE NC E: Federal Emergency Management Agency (Portion of Map 53033CIND1B, Aug. 2020) L EG E N D Areas determined to be outside the 0.2% annual chance floodplain. ZONE X OTHER AREAS SITE IN THIS PANEL * PANEL NOT PRINTED - AREA IN ZONE X Figure 7 Horizontal: Scale: Vertical: For: Title: S E N S I T I V E A R E A S M A P Job Number N.T.S.N/A 23382 DATE: 7/03/25 Talbot Hills Renton, Washington P:\23000s\23382\exhibit\graphics\23382 sens.cdr Chinook distribution SITE RE FER ENC E: King County iM AP (2025) Environmentally Sensitive Areas Stream type S - Shoreline of the state F - Fish habitat, Biological F - Fish habitat, Physical F - Fish habitat, Presumed N - Non-fish bearing Unclassified Erosion hazard (1990 SAO) Wetlands (National Wetland Inventory 2024) Estuarine and Marine Wetland Freshwater Emergent Wetland Freshwater Forested/Shrub Wetland Freshwater Pond Riverine Environmentally Sensitive Areas Stream type S - Shoreline of the state F - Fish habitat, Biological F - Fish habitat, Physical F - Fish habitat, Presumed N - Non-fish bearing Unclassified Potential landslide hazard areas (2016) Potential landslide hazard areas 50-foot buffer Potential steep slope hazard areas (2016) Erosion hazard (1990 SAO) Seismic hazard (1990 SAO) Coal mine hazard (1990 SAO) Stream (1990 SAO) class 1 class 2 perennial class 2 salmonid class 3 unclassified Wetlands (National Wetland Inventory 2024) Estuarine and Marine Wetland Freshwater Emergent Wetland Freshwater Forested/Shrub Wetland Freshwater Pond Riverine Wildlife habitat network Channel migration hazard areas severe moderate Shoreline management designations aquatic shoreline natural shoreline forestry shoreline resource shoreline conservancy shoreline rural shoreline residential shoreline high intensity shoreline Fans and Debris Flows Lowland fans Alpine fans less likely subject to debris flows Alpine fans less likely subject to debris flows L E G E N D Wetland (1990 SAO) L EG E N D Horizontal: Scale: Vertical: For: Title: E R O S I O N A N D L A N D S L I D E H A Z A R D M A P Job Number N.T.S.N/A 23382 DATE: 7/03/25 Talbot Hills Renton, Washington P:\23000s\23382\exhibit\graphics\23382 sens - renton.cdr Chinook distribution SITE RE FER ENC E: COR Maps (rentonwa.gov 2025) Environmentally Sensitive Areas Stream type S - Shoreline of the state F - Fish habitat, Biological F - Fish habitat, Physical F - Fish habitat, Presumed N - Non-fish bearing Unclassified Erosion hazard (1990 SAO) Wetlands (National Wetland Inventory 2024) Estuarine and Marine Wetland Freshwater Emergent Wetland Freshwater Forested/Shrub Wetland Freshwater Pond Riverine Environmentally Sensitive Areas Stream type S - Shoreline of the state F - Fish habitat, Biological F - Fish habitat, Physical F - Fish habitat, Presumed N - Non-fish bearing Unclassified Potential landslide hazard areas (2016) Potential landslide hazard areas 50-foot buffer Potential steep slope hazard areas (2016) Erosion hazard (1990 SAO) Seismic hazard (1990 SAO) Coal mine hazard (1990 SAO) Stream (1990 SAO) class 1 class 2 perennial class 2 salmonid class 3 unclassified Wetlands (National Wetland Inventory 2024) Estuarine and Marine Wetland Freshwater Emergent Wetland Freshwater Forested/Shrub Wetland Freshwater Pond Riverine Wildlife habitat network Channel migration hazard areas severe moderate Shoreline management designations aquatic shoreline natural shoreline forestry shoreline resource shoreline conservancy shoreline rural shoreline residential shoreline high intensity shoreline Fans and Debris Flows Lowland fans Alpine fans less likely subject to debris flows Alpine fans less likely subject to debris flows L E G E N D Wetland (1990 SAO) L E G E ND L E G E N D 23382-TIR-PREL.doc 1.0 PROJECT OVERVIEW The project is in Renton, Washington within a portion of Section 31, Township 23 North, Range 05 East, Willamette Meridian, King County, Washington. The project area is approximately 2.25(±) acres in size and is generally located northwest of the intersection of S 55th Street and 98th Avenue S Avenue SE. Please refer to the vicinity map in Figure 2. The project has approximately 154 feet of frontage along S 55th street. The project currently consists of one existing tax parcel. The existing tax parcel number is 312305-9119. The existing parcel is currently undeveloped. 138th Avenue SE is classified as an Residential Access street. The topography of the site slopes from east to west. The soils are classified as glacial till soils according to the Soils map in Figure 4 and the geotechnical report in Section 7. The proposed project is to construct 4 single-family lots, with associated roads, utilities, and stormwater facilities. The Talbot Hills project is a proposed single-family residential housing short plat consisting of 4 lots with a Native Growth Protection Area and a stormwater facility. The project will be constructing new roadways, utilities, and a stormwater facility. The project will gain access from S 55th Street. The project is zoned R-4 and R-1/Urban Separator. The R-4 zone allows 50% Max Impervious Coverage per lot and the R-1 zone allows 25% Max Impervious Coverage per lot. The site slopes east to west. Steep slopes are located along the easterly portion of the site with slopes grater that 40% with the proposed development being located below the steep slope areas. The King County Soils Conservation Service Soils Map for this area shown in Figure 4 of this section indicates the on-site soils are considered Alderwood gravelly sandy loam with 8-15% slopes. Due to the zero infiltration capacity of the dense, unweathered and weakly cemented glacial till soils on this site, infiltration on the site is not recommended by Earth Solutions Northwest, LLC. Please refer to Section 7 for the Geotechnical report. On-site construction will include constructing a private access driveway, a landscape tract, and a stormwater facility that will provide detention and water quality treatment. Stormwater from this site will drain from the roads, driveways, and rooftops to catch basins and will be conveyed through storm pipes to the drainage facility. Please refer to Sections 3 and 4 for a detailed description of the storm drainage system. Water mains, sanitary sewers, power, gas, and phone facilities will be constructed on site to serve each individual lot. Soos Creek Water and Sewer District will provide the water service and City of Renton will provide sanitary sewer for the project. The project will be mass graded to build the infrastructure to serve the proposed lots. All lots will be graded for tuck-under pads ready for home building. The project is required meet the drainage requirements of the 2022 City of Renton Surface Water Design Manual. Tab 2.0 23382-TIR-PREL.doc 2.0 CONDITIONS AND REQUIREMENTS SUMMARY This section contains the following information: 2.1 Analysis of the Core Requirements and Special Requirements 23382-TIR-PREL.doc 2.1 Analysis of the Core Requirements and Special Requirements CORE REQUIREMENTS HOW PROJECT HAS ADDRESSED REQUIREMENT No. 1: Discharge at Natural Location The project is proposing to discharge the sites developed drainage to the natural downstream drainage course. The pre-development drainage currently drains from east to west through private property and the roadside ditch of S 55th Street. Eventually drainage connects to Springbrook Creek and continues to flow west along S 55th Street before turning north to a point approximately 1 mile downstream of the site. Please refer sections 3.0 and 4.0 of this Technical Information Report (TIR) for a detailed description of the downstream drainage course. This requirement should be satisfied with the review and approval of this TIR. No. 2: Off-Site Analysis The Off-Site Analysis is included in Section 3.0 of this TIR. This requirement will be satisfied with the review and approval of this TIR. No. 3: Flow Control Facilities The project is mapped in the Conservation Flow Control and Basic Water Quality Treatment. Please refer to Section 4.0 of this TIR for narrative, maps, and calculations on how the project will be satisfying this requirement. The project is proposing to utilize a detention chamber system for flow control with a water quality vault after detention. No. 4: Conveyance System The projects proposed stormwater conveyance system will be sized to accommodate the developed flows to the proposed drainage facility. Please refer to section 5.0 of this TIR that should satisfy this condition. No. 5: Construction Stormwater Pollution Prevention Temporary erosion control measures for this project will include: stabilized construction entrances, perimeter runoff control, cover practices, sedimentation facilities, and construction sequencing per the 2022 Renton Surface Water Design Manual. The project will be preparing a SWPPP and seeking a General Construction Permit from the department of Ecology. This requirement will be addressed at final engineering. No. 6: Maintenance and Operations King County will own and maintain the public drainage facilities, roads and conveyance system for this project. Road A is a public road and Tract C will be owned by the HOA with an easement to the City of Renton. An Operations and Maintenance Manual, if required, will be provided in Section 10.0 of this Technical Information Report. No. 7: Financial Guarantees and Liability Bonding for site improvements and landscape will be required by King County using the county’s Bond Quantity Worksheet that will be included in section 9.0 of this TIR with the review and approval of the final engineering plans. No. 8: Water Quality Facilities The site is mapped in the Basic Water Quality treatment area. The project is proposing a basic sized wetvault to provide water quality treatment. Please refer to Section 4.0 of this TIR that should satisfy this requirement. 23382-TIR-PREL.doc No. 9: On-Site BMPs As described in the geotechnical report in section 6.0 of this TIR, the site is underlain by very dense and weakly cemented silty sand soils, which normally are not favorable for infiltration capacity. The LID Performance Standard for Flow Control (matching 8% of the 2yr flow) is not practical for this site. As a result, this project will be utilizing the individual lot BMPs where practical and feasible. All soil in the lawn and landscaped areas for the site will be amended to meet the post-Construction Soil Quality and Depth requirement. Each individual lot will be evaluated at the time of home construction permitting for feasibility of BMPs. At this time, it is assumed that each lot will have a perforated stub-out connection for rooftops and will implement a reduced impervious surface credit. No flow control credits have been taken for the design of the drainage facility at this time. Refer to Section 4.3 of this TIR for additional information. SPECIAL REQUIREMENTS HOW PROJECT HAS ADDRESSED REQUIREMENT No. 1: Other Adopted Area Specific Requirements The project does not contain any other Adopted Area Specific requirements. Please see Section 3.0 for further analysis. No. 2: Flood Hazard Area Delineation The project is not within a Floodplain/Floodway. Please refer to Section 3.0 and the FEMA map in Section 1.0, Figure 6. No. 3: Flood Protection Facilities This project does not rely on an existing flood protection facility, nor propose to modify or construct a new flood protection facility; therefore, this special requirement does not apply. No. 4: Source Controls The project is not seeking a commercial building permit or commercial site development permit, so this requirement does not apply to the project. The project is a proposed residential subdivision No. 5: Oil Control This site is not classified as a high-use site given the criteria found in the 2022 RSWDM, therefore no special oil control treatment is necessary. No. 6: Aquifer Protection Area This site is shown to not be within an aquifer protection area based on an analysis of both KC iMap and City of Renton COR Maps. Tab 3.0 23382-TIR-PREL.doc 3.0 OFF-SITE ANALYSIS This section contains the following information: Task 1 – Study Area Definitions and Maps Task 2 – Resource Review Task 3 – Field Inspection Task 4 – Drainage System Description and Problem Descriptions 23382-TIR-PREL.doc TASK 1 – STUDY AREA DEFINITION AND MAPS The Proposed Short Plat of Talbot Hills is a single-family residential project consisting of 4 lots. The project site is 2.25 (+/-) acres, parcel number 312305-9119. The site address is not assigned within City of Renton, King County, WA within a portion Section 31, Township 23 North, Range 5 East Willamette Meridian. The existing site is undeveloped. The parcel is mostly forested. The property is bordered by single family residences to the North, South, East and West. Onsite soils are mapped as Alderwood gravelly sandy loam. Please refer to the soils map in section 1. The topography of the site is moderately sloped from the East to West. A drainage swale enters the site near the Southeast corner and flows westerly to a culvert within S 55th Street. Elevations on the site range from 297 to 215 feet. The project will be mass graded with cuts and fills balanced onsite. The proposed drainage facilities are required to meet the requirements of the 2022 Renton Surface Water Design Manual (RSWDM). The drainage design shall meet at a minimum Conservation Flow control and Basic Water Quality Treatment. One detention facility is proposed to address the stormwater needs of the threshold discharge area on site. Following detention, the controlled stormwater will be conveyed to a water quality system before being discharged to existing roadside ditch and downstream conveyance systems. UPSTREAM DRAINAGE ANALYSIS The site’s high point is along the Eastern boundary. Upstream drainage from S 55th St. is discharged from a culvert near the Southeast corner of the site along the right-of -way to a drainage swale that crosses the southeast portion of the site and is collected by a culvert within S 55th St. to continue being conveyed west. This existing drainage course will remain and a new culvert will be installed to direct drainage through the proposed frontage improvements. The project is proposing to provide an interceptor trench to collect any upstream flows from the existing slopes in a bypass pipe to the project’s discharge pipe. 23382-TIR-PREL.doc TASK 2 – RESOURCE REVIEW Resources were reviewed within 1 mile downstream of the discharge basins. The following were reviewed: · Adopted Basin Plans: The site is within the Black River drainage basin. · Basin Reconnaissance Summary Report: A Basin Reconnaissance Summary Report was not found for the downstream drainage course. This is not applicable. · Floodplain and Floodway FEMA Maps: Please see the attached FEMA Map (Section 1.0) utilized for this analysis. As indicated on the map, the site is located in Zone X and is outside of the 500- year flood plain. · Other Off-Site Analysis Reports: No addition off-site analysis reports were reviewed at this time. · Sensitive Areas Folios: Based on a review of the King County Sensitive Areas Map Folios and City of Renton COR Maps, there is a wetland along the north side of S 55th St. approximately 0.4 miles downstream of the site. Please see Figure 7 in Section 1.0 of the TIR for more information. · United States Department of Agriculture King County Soils Survey: Based on the Soils Map for this area (see figure 3 – Soils Map Section 1.0), the site is located in the soils configuration known as Alderwood gravelly sandy loam. · Wetland Inventory Map: Based on the King County iMap there are no wetlands identified on or near the project site. · Water Quality: The Water Quality Atlas from the Department of Ecology was reviewed and the map is included in this section. The Water Quality Atlas does identify Sprinbrook Creek as a Category 5 water listed for Benthic Macroinvertebrates Bioassessments within the 1-mile downstream reach. The project will be providing basic water treatment per King County requirements to treat the stormwater prior to discharging downstream. Therefore, the project should not contribute or create any quality concerns. · City of Renton Erosion Maps and Landslide Maps: Based on the City of Renton COR Maps there are no erosion hazard areas identified on or near the project site. The site is within the Landslide Hazard designated areas. Refer to the Landslide Hazard Map within this section. The project will utilize appropriate erosion control measures to prevent erosion issues and will implement measures recommended by the project’s geotechnical engineer to avoid potential landslide hazards for the site. 23382-TIR-PREL.doc TASK 3 – FIELD INSPECTION Level 1 Off-site Drainage Analysis: The field reconnaissance for a Level 1 Off-site Drainage Analysis was conducted on February 18, 2025. The site flows through a single threshold discharge area. For the majority of the site, flow travels over land from the East of the site in a westerly direction until leaving at the western site boundary. A small portion of the Southeast corner of the site drains to an existing swale that conveys flows from the right of way of S 55th St at the east of the project to an existing culvert S 55th St along the southern portion of the site. Drainage within the right of way travels west within the roadside ditches and then to the closed pipe system at the intersection of Talbot Rd S and S 55th St. The overland drainage that leaves the western boundary of the site is either collected by the private drainage systems within the parcels to the west of the site or collected within Talbot Rd S and conveyed to the intersection of Talbot Rd S and S 55th St. Drainage continues west within the closed pipe system in S 55th St right of way to a point approximately 0.18 miles from the site where it is discharged to an open channel. Drainage reaches the ¼ mile point downstream within this open channel. Stormwater is then conveyed to a point approximately 0.3 miles west of the site where it is discharged to Sprinbrook Creek and continues west, traveling under Hwy 167 within a 36” culvert. Any runoff continues from this point within Springbrook Creek where it eventually reaches the point 1 mile downstream of the site along S 192nd St. No downstream drainage complaints were identified within this corridor at the time of this report. 23382-TIR-PREL.doc TASK 4 – DRAINAGE SYSTEM DESCRIPTION AND PROBLEM DESCRIPTIONS DOWNSTREAM DRAINAGE DESCRIPTION For the majority of the site, flow travels over land from the East of the site in a westerly direction until leaving at the western site boundary. A small portion of the Southeast corner of the site drains to an existing swale that conveys flows from the right of way of S 55th St at the east of the project to an existing culvert S 55th St along the southern portion of the site. Drainage within the right of way travels west within the roadside ditches and then to the closed pipe system at the intersection of Talbot Rd S and S 55th St. The overland drainage that leaves the western boundary of the site is either collected by the private drainage systems within the parcels to the west of the site or collected within Talbot Rd S and conveyed to the intersection of Talbot Rd S and S 55th St. The existing roadside ditch in this section of S 55th St. may be required to be modified to improve it’s ability to convey the existing drainage. This will be analyzed during final engineering to determine if any improvements are needed. Drainage continues west within the closed pipe system in S 55th St right of way to a point approximately 0.18 miles from the site where it is discharged to an open channel. Drainage reaches the ¼ mile point downstream within this open channel. Stormwater is then conveyed to a point approximately 0.3 miles west of the site where it is discharged to Sprinbrook Creek and continues west, traveling under Hwy 167 within a 36” culvert. Any runoff continues from this point within Springbrook Creek where it eventually reaches the point 1 mile downstream of the site along S 192nd St. No downstream drainage complaints were identified within this corridor at the time of this report. PROBLEM DESCRIPTIONS Through an onsite visit the downstream drainage course will not be of concern as a result of this proposed development. The project will provide Flow Control and Water Quality control to the applicable level for the site. 23382-Off-Site Analysis Drainage System Table.doc OFF-SITE ANALYSIS DRAINAGE SYSTEM TABLE Surface Water Design Manual, Core Requirement #2 Basin: Black River Subbasin Name: Springbrook Creek Subbasin Number: P1/D1 Location ID Drainage Component Type, Name, and Size Drainage Component Description Slope Distance from Site Discharge Existing Problems Potential Problems Observations of Field Inspector, Resource Reviewer, or Resident See Map Type: sheet flow, swale, stream, channel, pipe, pond; size, diameter, surface area Drainage basin, vegetation, cover, depth, type of sensitive area, volume % Ft. Constrictions, under capacity, ponding, overtopping, flooding, habitat or organism destruction, scouring, bank sloughing, sedimentation, incision, other erosion Tributary area, likelihood of problem, overflow pathways, potential impacts 1 54 LF 12” CONC. CULVERT Accepts drainage from drainage swale crossing south portion of project and roadside ditch from upstream area +/- 10% 0 Some sediment buildup noted at discharge end None observed Free flowing pipe with no apparent obstructions. 2 210 LF GRASS LINED DITCH Shallow grass lined ditch flowing west on the north side of 55th +/-15% 0’ None observed None observed Free flowing ditch with no apparent obstructions. 3 60 LF 12” CONC CULVERT Crossing under driveway +/-15% 120’ None observed None observed Free flowing pipe with no apparent obstructions. 4 100 LF GRASS LINED DITCH Shallow grass lined ditch conveying flows west on the north side of 55th +/- 15% 180’ None observed None observed Free flowing ditch with no apparent obstructions. 5 27 LF 12” CONC PIPE Crossing under driveway +/- 15% 280’ None observed None observed Free flowing pipe with no apparent obstructions 6 315 LF GRASS LINED DTICH Drains west along north side of 55th +/- 15% 307’ None observed None observed Free flowing with no apparent obstructions 7 73 LF 18” LINED CPEP Drains west to CB in intersection of 55th and Talbott Rd +/- 20% 622’ None observed None observed Closed Pipe system, no sign of any issues 8 40 LF 18” LINED CPEP Drains west to CB behind sidewalk north side of 55th/192nd +/- 13% 880’ None Observed None Observed Closed Pipe system, no sign of any issues 9 175 LF 18” ADS PIPE Drains west to CB behind sidewalk north side of 55th/192nd +/- 12% 662’ None observed None observed Closed Pipe system, no sign of any issues 10 15 LF 18” ADS PIPE Outlets to roadside ditch flowing west along 55th +/- 1% 837’ None observed None observed Closed Pipe system, no sign of any issues 23382-Off-Site Analysis Drainage System Table.doc 11 +/-625 LF grass lined ditch Drains westerly to the connection with Sprongbrook Creek along North side of 55th +/-10% 852’ None observed None Observed SD 1/4 MILE DOWNSTREAM FROM SITE OF DOWNSTREAM ANALYSIS MAP SCALE 1"=60 TALBOT HILLS A PORTION OF SECTION 31, TOWNSHIP 23 N., RANGE 05 E., W.M. CITY OF RENTON, KING COUNTY, WASHINGTON DO W N S T R E A M A N A L Y S I S M A P 4 SC H N E I D E R F A M I L Y H O M E S 65 1 0 S O U T H C E N T E R B L V D , S U I T E 1 TU K W I L A , W A 9 8 1 8 8 23 3 8 2 1 FLOWPATH LEGEND SD SPECIAL NOTES OF TA L B O T H I L L S TA L B O T R D S 9 8 T H A V E S 97 T H A V E S PROJECT SITE S 55TH ST S 192ND ST #5 #6 #4 #1#2#3#7 #8#9#10 #11 #12 Photo 1, Concrete pipe outlet to ditch(looking upstream) Photo 2, ditch draining downhill to driveway culvert. Photo 3, Inlet to concrete pipe under driveway. Photo 4, Pipe outlet to ditch. Photo 5, Inlet to concrete pipe under driveway. Photo 6, Pipe outlet to roadside ditch Photo 7, Pipe inlet to closed pipe system Photo 8, CB in intersection of Talbott Rd. and S 55th St. Photo 9, CB along 192nd St/55th St Photo 10, CB along 192nd St/55th St near outlet to roadside ditch. Photo 11, Roadside ditch along 192nd St/55th St Photo 12, Springbrook Creek near inlet of roadside ditch Tab 4.0 23382-TIR-PREL.doc 4.0 FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN This section contains the following information: 4.1 Existing Site Hydrology 4.2 Developed Site Hydrology 4.3 Performance Standards 4.4 Flow Control System 4.5 Water Quality System 23382-TIR-PREL.doc 4.1 Existing Site Hydrology The project site area is approximately 2.25 acres consisting of one existing tax parcel. The existing tax parcel number is 312305-9119. The existing parcel is currently undeveloped. The project site drains in an East to West direction with moderate slopes ranging from 8% to 40% slopes. The native on-site soils consist of 6-12” of topsoil. Underlaying the topsoil is medium dense to dense silty sand with varying amounts of gravel, consistent with the typical makeup of glacial till approximately 9’ below the existing grades. Please refer to the geotechnical report in section 6.0. The drainage leaves the site as sheet flow to the west on private property. Drainage leaving the site is collected in the existing roadside ditch along S 55th St and conveyance system that convey the flows to Springbrook Creek. Upstream drainage sheet flows onto the site from the east from the adjacent parcel. Upstream drainage within S 55th St. is discharged to a drainage swale near the southeast corner of the site and flows west to a culvert along the S 55th St. right of way along the site’s southwestern frontage. In the pre-developed state, the site’s area can be broken down as follows: Impervious area = 0.0 ac Till Grass area =0.0 ac Forested area =2.25 ac Total pre-developed area = 2.25 ac Total proposed developed area = 1.15 ac For the WWHM sizing calculations the proposed developed area of 1.15 acres was modeled. The entire proposed developed area was modeled as Till Forest as required by the 2022 RSWD manual for the WWHM drainage facility sizing calculations. Please refer to the pre-developed drainage area map and the WWHM detention sizing calculations in this section. OF PREDEVELOPED BASIN MAP SCALE 1"=30" TALBOT HILLS A PORTION OF SECTION 31, TOWNSHIP 23 N., RANGE 05 E., W.M. CITY OF RENTON, KING COUNTY, WASHINGTON PR E D E V E L O P E D B A S I N M A P 6 SC H N E I D E R F A M I L Y H O M E S 65 1 0 S O U T H C E N T E R B L V D , S U I T E 1 TU K W I L A , W A 9 8 1 8 8 23 3 8 2 1 OF TA L B O T H I L L S PREDEVELOPED BASIN 1 PREDEVELOPED BASIN 98 T H A V E S S 55TH ST UPSTREAM BASIN 4.2 Developed Site Hydrology 23382-TIR-PREL.doc 4.2 Developed Site Hydrology The project will be constructing a private access tract with a reverse crown and a stormwater conveyance system for the new single-family residences. A storm stub for each lot will be provided for roof and footing drains. A driveway connection will be constructed to S 55th St. at the project frontage. The stormwater will be conveyed to a proposed stormwater drainage facility located in Tract A. The stormwater drainage facility will consist of a detention chamber system to provide conservation flow control followed by a water quality vault to provide basic water quality treatment. The detention facility is located at the southwest corner of the project within the private access tract. The water quality facility will outlet to the existing roadside ditch in S 55th St. where the drainage will be conveyed to the existing drainage outfall to Springbrook Creek, which is the natural downstream drainage course. The existing conveyance system contains roadside ditches and 12-inch and 18-inch pipes. The project is proposing to install 12” drainage pipes and catch basins to convey the upstream flows within the S 55th St. frontage. Please refer to the Post Developed Drainage Area Map for a graphical depiction of the proposed stormwater system. The proposed detention vault will receive flows from approximately 1.15 acres of developed area. Please refer to the Post-Developed Drainage Area map that depicts the developed area draining to the new drainage facility. The impervious calculations were computed using CAD to measure the area for the road and sidewalk areas. It was assumed that 50% of the proposed developed lot area allowed by zoning in the R-4 zone, is impervious, which is more than 4,000 sq ft per lot required in the 2022 RSWDM section 3.2 on page 3-24. Below is a summary of the basin area breakdown: The project will contain a bypass basin area that will be 0.07 acres of pasture landscape. The drainage from the bypass area will continue to drain where it does in the pre-developed condition. Basin D1 Total basin area = 1.15 ac. Impervious area = 0.77 ac Roads and Sidewalks = 0.12 ac Lot Impervious area (50% of lot area) = 1.10 ac x 50% = 0.55 ac Lot Driveway/Uncovered Porch/Walkway area = 0.10 ac Lawn (Moderate Pasture) area = 0.38 ac OF DEVELOPED BASIN MAP SCALE 1"=30" TALBOT HILLS A PORTION OF SECTION 31, TOWNSHIP 23 N., RANGE 05 E., W.M. CITY OF RENTON, KING COUNTY, WASHINGTON DE V E L O P E D B A S I N M A P 5 SC H N E I D E R F A M I L Y H O M E S 65 1 0 S O U T H C E N T E R B L V D , S U I T E 1 TU K W I L A , W A 9 8 1 8 8 23 3 8 2 1 OF TA L B O T H I L L S DEVELOPED BASIN 1 DEVELOPED BASIN 3 4 2 1 98 T H A V E S S 55TH ST UPSTREAM BASIN BYPASS BASIN 4.3 Performance Standard 23382-TIR-PREL.doc 4.3 Performance Standards The project is required to meet the requirements of the 2021 RSWD manual. Please refer to section 2.1 for responses to each of the Core Requirements. The area specific flow control requirement is Conservation Flow, Level 2 flow control and assumed historic site conditions for the pre-developed condition. Level 2 flow control must match developed discharge durations to the pre-developed durations for the range of pre-developed discharges rates for 50% of the 2-year peak flow up to the full 50-yeaer peak flow. Also match developed peak discharge rate to the pre-developed peak discharges rates of the 2- and 10-year return periods. The WWHM program was used to compute the drainage calculations and are included in this section of the TIR. The project will be utilizing a Detention chamber system to meet these requirements. The project is required to provide Basic water quality treatment for the developed PGIS areas of the project. WWHM was used to calculate the required 24-hour volume from the unmitigated developed flow to the drainage facility. The project is using a combined wet/detention vault to provide Basic Water Quality Treatment. The proposed conveyance system will be designed with sufficient capacity to convey and contain the 25-year peak flow at developed conditions. The site is underlain by medium dense to dense silty sand with varying gravel, typical of glacial till, which normally are non-favorable for infiltration capacity. Due to native soil condition as described in the geotechnical report in section 6.0 of this TIR, the Low Impact Development (LID) requirements are impractical for the site. Therefore, the developer has opted to not meet the LID Performance Standard for Flow Control. As a result, this project will be providing the individual lot BMPs. All soil in the lawn and landscaped areas for the site will be amended to meet the post- Construction Soil Quality and Depth requirement. Each individual lot will have a perforated stub- out connection for rooftops. The project is not proposing to take any credits for individual lot LID BMP’s. The Project Site is subject to implement BMP’s based on fesability per KCSWDM Section 1.2.9.3. Below is an evaluation for the list of the BMP’s. Lawn and Landscape Areas: Post-Construction Soil Quality and Depth (BMP T5.13) This BMP is feasible and will be used onsite in landscape areas. Roof Areas: Full Dispersion This site is not proposing to protect at least 65% of the site in native condition or forest to allow full dispersion onsite. Downspout Infiltration systems: The site does not have 12 inches of permeable soil. infiltration is not recommended by the geotechnical engineer. Limited infiltration may be feasible at shallow depths and will be assessed for each lot during final engineering and individual home building permitting. No infiltration credit has been taken for the drainage facility sizing at this time. Downspout Dispersion A vegetated flow path of 50 feet from the downspout to a slope over 20% is not feasible due to the proposed lot sizes. 23382-TIR-PREL.doc Basic Dispersion: Basin Dispersion of a portion of the roof areas may be feasible dependent on the individual lot characteristics. Individual lots will be analyzed for feasibility at time of home construction permitting for applicability of basic dispersion dependent on home size and location on lot. Bioretention or Rain Gardens: The geotechnical report recommends infiltration not be used to control stormwater. Limited infiltration may be feasible at shallow depths and will be assessed for each lot during final engineering and individual home building permitting. No infiltration credit has been taken for the drainage facility sizing at this time. Perforated Stub-Out Connections Perforated stub-out connections are feasible and will be used for each individual lot to allow as much stormwater as possible to infiltrate prior to discharging to the drainage facility. Other Hard Surfaces: Full Dispersion This site is not proposing to protect at least 65% of the site in native condition or forest to allow full dispersion onsite. Permeable Pavement Full infiltration is not recommended for this site. Limited infiltration may be feasible at shallow depths and will be analyzed at time of final engineering design and/or individual home building permitting. No infiltration credit has been taken for the drainage facility sizing at this time. Bio Retention The geotechnical report recommends infiltration not be used to control stormwater. Sheet flow dispersion Infeasible due to small lot sized and flow path length constraints. Areas adjacent to the roadways do not provide the required flow path length necessary for this BMP to be appropriate. 4.4 Flow Control System 23382-TIR-PREL.doc 4.4 Flow Control System This section includes an illustrative sketch of the detention facility along with the WWHM drainage computations. Detention vault volume required is 18,379 c.f. Detention vault volume provided is 20,867 c.f. (13.5% factor of safety) TRACT A TRACT B CB#1 CB#3 CB#4 CB#5 TALBOT HILLS IN COMPLIANCE WITH CITY OF RENTON STANDARDS AA A N N N N N N N TALBOT HILLS SCHNEIDER FAMILY HOMES 6510 SOUTHCENTER BLVD, SUITE 1 TUKWILA, WA 98188 TA L B O T H I L L S HA R M O N Y R I D G E A-NNNNNNN B. C . E . J O B N O . 2 3 3 8 2 7 NO T F O R CO N S T R U C T I O N OF PRELIMINARY DRAINAGE FACILITY PLAN SCALE: 1"=10' 6 Datasheet Wavin AquaCell Stormwater Management System Wavin AquaCell 100% recycled module polypropylene system for rainwater management. Technical Specifications Product Datasheet General Raw material 100% recycled polypropylene Color Black Vertical inspection access 10in Base Unit Dimensions (Length x Width x Height)48x24x17 (LxWxH) Without Baseplate Attached 76 gal / 10.25 cf With Baseplate Attached 73 gal / 9.74 cf Void Rate (Varies by layer/side plates added)94% - 96% Weight 24lbs Pipe Connections 6in, 8in, 10in, 12in Bottom Plate Dimensions (Length x Width x Height)48x24x1.5 in (LxWxH) Weight 8 lb Side Plate Dimensions (Length x Width x Height)45.5x15x2 in (LxWxH) Weight 5 lb Top Adaptor (Inspection and Maintenance) Dimensions 10/12in. Weight 3lbs Dimensions 10/16 in. Weight 11lbs Connection Adaptor 8in - 12in Dimensions (Length x Width x Height)14x14x12in Weight 3lbs Minimum (d) / Maximum (H) cover depth * See diagram Type of load Regular Version Extra Strong Version H-10 Traffic Loading [in/ft]d=12in. / H= 14.4ft d=12in. / H=26.2 ft HS-20 Traffic Loading [in/ft]d=24 in. / H=14.4ft d=18 in. / H=26.2ft HS-25 Traffic Loading [in/ft]d=32in. / H=14.1 ft d=22in. / H=26.1 ft. Wavin’s AquaCell is a high-tech modular system designed for the temporary storage of rainwater with a volumetric ratio equal to 96%, equivalent to 10 cubic feet of storage for each base unit. The system allows for the construction of underground rainwater retention tanks to retain and detain surface runoff and efficiently mitigate the effect of potential floods through the infiltration and reuse of stored water with pumping systems. The modular system is easy and quick to install and allows for inspection and maintenance, making it the ideal solution for the construction of sustainable projects, with a wide range of applications including residential, commercial, industrial, and infrastructure projects. Note: Each project requires a stress analysis to ensure the stability of the system based on the acting loads, soil type, and water table involved. Wavin recommends a minimum cover over the top of the tank of 12 inches. For use in the regular or extra strong versions, or if you need further information, contact the technical marketing team in your country. Cover min. (d) Depth max. (H) Urban Climate Resilience © 2024 Wavin Wavin reserves the right to modify product specifications without prior notice. Due to its program of continuous product development, technical specifications may change. Installation must comply with the installation instructions. Product Datasheet AqueCell requires no additional accessories. It is manually assembled through components that allow the cisterns or below-ground tanks to be configured per the technical specifications of each proposed design. Regular Configuration Plan View Base Unit Pipe Connector 8 - 12 in Top Adaptor • 10/12 in • 10/16 in Bottom Plate Side Plate Transverse DirectionElevation View: Longitudinal Direction Extra Strong Configuration Wavin AquaCell Module Dimensions System Versions 47.2” 23.6"10"16.7" 1"1.4" 1.4"2.4" 7.9"5.9" 7.5"6.3"8.3"5.5" 7.3"6.5" Storage capacity Regular Configuration Gross Volume / (without bottom plate) 10.25 cf Net volume / (without bottom plate) 9.74 cf Void Ratio / (varies by layer/side plates added) 94% - 96% Extra strong Configuration Gross Volume 11.70 ft³ Net Volume 10.84 ft³ Void Ratio / (without bottom plate)92.7% WavinTechSupport@orbia.com WWHM2012 PROJECT REPORT 23382-Talbot 7/18/2025 4:40:23 PM Page 2 General Model Information WWHM2012 Project Name:23382-Talbot Site Name:Talbot Hills Site Address:TBD City:Renton, WA Report Date:7/18/2025 Gage:Seatac Data Start:1948/10/01 Data End:2009/09/30 Timestep:15 Minute Precip Scale:1.000 Version Date:2023/01/27 Version:4.2.19 POC Thresholds Low Flow Threshold for POC1:50 Percent of the 2 Year High Flow Threshold for POC1:50 Year 23382-Talbot 7/18/2025 4:40:23 PM Page 3 Landuse Basin Data Predeveloped Land Use Predev Basin P1 Bypass:No GroundWater:No Pervious Land Use acre C, Forest, Mod 1.15 Pervious Total 1.15 Impervious Land Use acre Impervious Total 0 Basin Total 1.15 23382-Talbot 7/18/2025 4:40:23 PM Page 4 Mitigated Land Use PostDev Basin D1 Bypass:No GroundWater:No Pervious Land Use acre C, Pasture, Mod 0.38 Pervious Total 0.38 Impervious Land Use acre ROADS MOD 0.12 ROOF TOPS FLAT 0.55 ROADS FLAT 0.1 Impervious Total 0.77 Basin Total 1.15 23382-Talbot 7/18/2025 4:40:23 PM Page 5 Routing Elements Predeveloped Routing 23382-Talbot 7/18/2025 4:40:23 PM Page 6 Mitigated Routing Vault 1 Width:24 ft. Length:108.164549424198 ft. Depth:7.08 ft. Discharge Structure Riser Height:6.08 ft. Riser Diameter:18 in. Notch Type:Rectangular Notch Width:0.011 ft. Notch Height:1.575 ft. Orifice 1 Diameter:0.592 in.Elevation:0 ft. Element Flows To: Outlet 1 Outlet 2 Vault Hydraulic Table Stage(feet)Area(ac.)Volume(ac-ft.)Discharge(cfs)Infilt(cfs) 0.0000 0.059 0.000 0.000 0.000 0.0787 0.059 0.004 0.002 0.000 0.1573 0.059 0.009 0.003 0.000 0.2360 0.059 0.014 0.004 0.000 0.3147 0.059 0.018 0.005 0.000 0.3933 0.059 0.023 0.006 0.000 0.4720 0.059 0.028 0.006 0.000 0.5507 0.059 0.032 0.007 0.000 0.6293 0.059 0.037 0.007 0.000 0.7080 0.059 0.042 0.008 0.000 0.7867 0.059 0.046 0.008 0.000 0.8653 0.059 0.051 0.008 0.000 0.9440 0.059 0.056 0.009 0.000 1.0227 0.059 0.060 0.009 0.000 1.1013 0.059 0.065 0.010 0.000 1.1800 0.059 0.070 0.010 0.000 1.2587 0.059 0.075 0.010 0.000 1.3373 0.059 0.079 0.011 0.000 1.4160 0.059 0.084 0.011 0.000 1.4947 0.059 0.089 0.011 0.000 1.5733 0.059 0.093 0.011 0.000 1.6520 0.059 0.098 0.012 0.000 1.7307 0.059 0.103 0.012 0.000 1.8093 0.059 0.107 0.012 0.000 1.8880 0.059 0.112 0.013 0.000 1.9667 0.059 0.117 0.013 0.000 2.0453 0.059 0.121 0.013 0.000 2.1240 0.059 0.126 0.013 0.000 2.2027 0.059 0.131 0.014 0.000 2.2813 0.059 0.136 0.014 0.000 2.3600 0.059 0.140 0.014 0.000 2.4387 0.059 0.145 0.014 0.000 2.5173 0.059 0.150 0.015 0.000 2.5960 0.059 0.154 0.015 0.000 2.6747 0.059 0.159 0.015 0.000 2.7533 0.059 0.164 0.015 0.000 2.8320 0.059 0.168 0.016 0.000 DETENTION VOLUME REQUIRED = 18,379 CF DETENTION VOLUME PROVIDED = 20,867 CF 13.5% SAFETY FACTOR 23382-Talbot 7/18/2025 4:40:24 PM Page 7 2.9107 0.059 0.173 0.016 0.000 2.9893 0.059 0.178 0.016 0.000 3.0680 0.059 0.182 0.016 0.000 3.1467 0.059 0.187 0.016 0.000 3.2253 0.059 0.192 0.017 0.000 3.3040 0.059 0.196 0.017 0.000 3.3827 0.059 0.201 0.017 0.000 3.4613 0.059 0.206 0.017 0.000 3.5400 0.059 0.211 0.017 0.000 3.6187 0.059 0.215 0.018 0.000 3.6973 0.059 0.220 0.018 0.000 3.7760 0.059 0.225 0.018 0.000 3.8547 0.059 0.229 0.018 0.000 3.9333 0.059 0.234 0.018 0.000 4.0120 0.059 0.239 0.019 0.000 4.0907 0.059 0.243 0.019 0.000 4.1693 0.059 0.248 0.019 0.000 4.2480 0.059 0.253 0.019 0.000 4.3267 0.059 0.257 0.019 0.000 4.4053 0.059 0.262 0.020 0.000 4.4840 0.059 0.267 0.020 0.000 4.5627 0.059 0.271 0.020 0.000 4.6413 0.059 0.276 0.022 0.000 4.7200 0.059 0.281 0.024 0.000 4.7987 0.059 0.286 0.026 0.000 4.8773 0.059 0.290 0.028 0.000 4.9560 0.059 0.295 0.031 0.000 5.0347 0.059 0.300 0.034 0.000 5.1133 0.059 0.304 0.036 0.000 5.1920 0.059 0.309 0.039 0.000 5.2707 0.059 0.314 0.042 0.000 5.3493 0.059 0.318 0.045 0.000 5.4280 0.059 0.323 0.048 0.000 5.5067 0.059 0.328 0.051 0.000 5.5853 0.059 0.332 0.055 0.000 5.6640 0.059 0.337 0.059 0.000 5.7427 0.059 0.342 0.063 0.000 5.8213 0.059 0.346 0.067 0.000 5.9000 0.059 0.351 0.071 0.000 5.9787 0.059 0.356 0.092 0.000 6.0573 0.059 0.361 0.098 0.000 6.1360 0.059 0.365 0.311 0.000 6.2147 0.059 0.370 0.883 0.000 6.2933 0.059 0.375 1.643 0.000 6.3720 0.059 0.379 2.510 0.000 6.4507 0.059 0.384 3.407 0.000 6.5293 0.059 0.389 4.254 0.000 6.6080 0.059 0.393 4.981 0.000 6.6867 0.059 0.398 5.543 0.000 6.7653 0.059 0.403 5.935 0.000 6.8440 0.059 0.407 6.295 0.000 6.9227 0.059 0.412 6.607 0.000 7.0013 0.059 0.417 6.904 0.000 7.0800 0.059 0.421 7.188 0.000 7.1587 0.075 0.536 7.462 0.000 23382-Talbot 7/18/2025 4:40:24 PM Page 8 Analysis Results POC 1 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area:1.15 Total Impervious Area:0 Mitigated Landuse Totals for POC #1 Total Pervious Area:0.38 Total Impervious Area:0.77 Flow Frequency Method:Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.034241 5 year 0.056108 10 year 0.070167 25 year 0.086892 50 year 0.098476 100 year 0.109297 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.018959 5 year 0.028805 10 year 0.037012 25 year 0.049592 50 year 0.060767 100 year 0.073666 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 0.039 0.015 1950 0.047 0.018 1951 0.075 0.058 1952 0.023 0.013 1953 0.019 0.016 1954 0.029 0.016 1955 0.047 0.016 1956 0.037 0.020 1957 0.030 0.016 1958 0.034 0.017 WATER QUALITY FLOW RATE MINIMUM OVERFLOW BYPASS FLOW RATE 23382-Talbot 7/18/2025 4:40:47 PM Page 9 1959 0.029 0.015 1960 0.052 0.036 1961 0.028 0.018 1962 0.018 0.013 1963 0.024 0.017 1964 0.034 0.017 1965 0.023 0.019 1966 0.022 0.016 1967 0.053 0.017 1968 0.030 0.016 1969 0.029 0.016 1970 0.023 0.017 1971 0.026 0.017 1972 0.057 0.041 1973 0.025 0.019 1974 0.028 0.017 1975 0.039 0.016 1976 0.028 0.017 1977 0.004 0.014 1978 0.023 0.018 1979 0.014 0.012 1980 0.067 0.050 1981 0.021 0.016 1982 0.043 0.020 1983 0.037 0.017 1984 0.022 0.014 1985 0.013 0.014 1986 0.059 0.019 1987 0.052 0.025 1988 0.020 0.014 1989 0.014 0.014 1990 0.124 0.035 1991 0.066 0.029 1992 0.027 0.018 1993 0.026 0.014 1994 0.009 0.012 1995 0.038 0.018 1996 0.087 0.056 1997 0.067 0.067 1998 0.016 0.014 1999 0.073 0.036 2000 0.026 0.017 2001 0.005 0.012 2002 0.030 0.019 2003 0.045 0.015 2004 0.048 0.047 2005 0.036 0.017 2006 0.040 0.020 2007 0.094 0.081 2008 0.114 0.047 2009 0.053 0.019 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.1240 0.0815 2 0.1142 0.0672 3 0.0937 0.0583 23382-Talbot 7/18/2025 4:40:47 PM Page 10 4 0.0868 0.0565 5 0.0748 0.0500 6 0.0735 0.0471 7 0.0670 0.0471 8 0.0669 0.0410 9 0.0658 0.0359 10 0.0587 0.0356 11 0.0568 0.0353 12 0.0533 0.0292 13 0.0526 0.0246 14 0.0518 0.0198 15 0.0516 0.0197 16 0.0483 0.0197 17 0.0468 0.0193 18 0.0465 0.0193 19 0.0452 0.0192 20 0.0434 0.0190 21 0.0403 0.0187 22 0.0394 0.0183 23 0.0388 0.0181 24 0.0376 0.0181 25 0.0375 0.0179 26 0.0371 0.0177 27 0.0358 0.0175 28 0.0344 0.0174 29 0.0336 0.0173 30 0.0303 0.0172 31 0.0303 0.0171 32 0.0296 0.0170 33 0.0291 0.0169 34 0.0288 0.0166 35 0.0288 0.0166 36 0.0284 0.0166 37 0.0279 0.0166 38 0.0278 0.0164 39 0.0269 0.0164 40 0.0262 0.0163 41 0.0261 0.0162 42 0.0261 0.0162 43 0.0252 0.0161 44 0.0242 0.0157 45 0.0235 0.0156 46 0.0235 0.0155 47 0.0231 0.0151 48 0.0229 0.0148 49 0.0223 0.0148 50 0.0220 0.0142 51 0.0210 0.0140 52 0.0204 0.0139 53 0.0190 0.0139 54 0.0177 0.0138 55 0.0164 0.0137 56 0.0142 0.0137 57 0.0135 0.0133 58 0.0133 0.0128 59 0.0088 0.0125 60 0.0047 0.0120 61 0.0041 0.0118 23382-Talbot 7/18/2025 4:40:47 PM Page 11 23382-Talbot 7/18/2025 4:40:47 PM Page 12 Duration Flows The Facility PASSED Flow(cfs)Predev Mit Percentage Pass/Fail 0.0171 17075 16110 94 Pass 0.0179 15488 11655 75 Pass 0.0188 14072 7940 56 Pass 0.0196 12805 4823 37 Pass 0.0204 11569 3302 28 Pass 0.0212 10525 2982 28 Pass 0.0221 9561 2766 28 Pass 0.0229 8750 2565 29 Pass 0.0237 8036 2406 29 Pass 0.0245 7349 2263 30 Pass 0.0253 6740 2121 31 Pass 0.0262 6188 1998 32 Pass 0.0270 5726 1891 33 Pass 0.0278 5309 1784 33 Pass 0.0286 4924 1666 33 Pass 0.0294 4569 1549 33 Pass 0.0303 4239 1449 34 Pass 0.0311 3951 1341 33 Pass 0.0319 3643 1241 34 Pass 0.0327 3388 1163 34 Pass 0.0336 3133 1092 34 Pass 0.0344 2915 1031 35 Pass 0.0352 2706 960 35 Pass 0.0360 2488 895 35 Pass 0.0368 2314 858 37 Pass 0.0377 2136 808 37 Pass 0.0385 1973 771 39 Pass 0.0393 1825 732 40 Pass 0.0401 1702 696 40 Pass 0.0410 1577 654 41 Pass 0.0418 1442 611 42 Pass 0.0426 1325 565 42 Pass 0.0434 1232 514 41 Pass 0.0442 1147 469 40 Pass 0.0451 1083 424 39 Pass 0.0459 1020 391 38 Pass 0.0467 947 350 36 Pass 0.0475 886 308 34 Pass 0.0483 824 282 34 Pass 0.0492 760 248 32 Pass 0.0500 725 227 31 Pass 0.0508 674 208 30 Pass 0.0516 623 189 30 Pass 0.0525 589 176 29 Pass 0.0533 549 155 28 Pass 0.0541 506 142 28 Pass 0.0549 469 127 27 Pass 0.0557 427 112 26 Pass 0.0566 388 98 25 Pass 0.0574 356 89 25 Pass 0.0582 328 81 24 Pass 0.0590 297 73 24 Pass 0.0599 270 69 25 Pass 23382-Talbot 7/18/2025 4:40:47 PM Page 13 0.0607 241 65 26 Pass 0.0615 218 62 28 Pass 0.0623 198 59 29 Pass 0.0631 173 55 31 Pass 0.0640 152 53 34 Pass 0.0648 130 49 37 Pass 0.0656 119 43 36 Pass 0.0664 104 39 37 Pass 0.0672 95 32 33 Pass 0.0681 83 28 33 Pass 0.0689 74 21 28 Pass 0.0697 69 19 27 Pass 0.0705 61 18 29 Pass 0.0714 53 16 30 Pass 0.0722 46 15 32 Pass 0.0730 39 14 35 Pass 0.0738 29 14 48 Pass 0.0746 25 13 52 Pass 0.0755 22 13 59 Pass 0.0763 20 11 55 Pass 0.0771 17 11 64 Pass 0.0779 14 10 71 Pass 0.0788 12 9 75 Pass 0.0796 8 8 100 Pass 0.0804 7 6 85 Pass 0.0812 7 3 42 Pass 0.0820 7 0 0 Pass 0.0829 6 0 0 Pass 0.0837 6 0 0 Pass 0.0845 6 0 0 Pass 0.0853 6 0 0 Pass 0.0861 6 0 0 Pass 0.0870 5 0 0 Pass 0.0878 5 0 0 Pass 0.0886 5 0 0 Pass 0.0894 5 0 0 Pass 0.0903 5 0 0 Pass 0.0911 5 0 0 Pass 0.0919 5 0 0 Pass 0.0927 4 0 0 Pass 0.0935 4 0 0 Pass 0.0944 3 0 0 Pass 0.0952 3 0 0 Pass 0.0960 3 0 0 Pass 0.0968 3 0 0 Pass 0.0977 3 0 0 Pass 0.0985 3 0 0 Pass 23382-Talbot 7/18/2025 4:40:47 PM Page 14 Water Quality Water Quality BMP Flow and Volume for POC #1 On-line facility volume:0.0305 acre-feet On-line facility target flow:0.0154 cfs. Adjusted for 15 min:0.0154 cfs. Off-line facility target flow:0.0101 cfs. Adjusted for 15 min:0.0101 cfs. 23382-Talbot 7/18/2025 4:40:47 PM Page 15 LID Report 23382-Talbot 7/18/2025 4:40:55 PM 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. 23382-Talbot 7/18/2025 4:40:55 PM Page 17 Appendix Predeveloped Schematic 23382-Talbot 7/18/2025 4:40:55 PM Page 18 Mitigated Schematic 23382-Talbot 7/18/2025 4:40:55 PM 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 23382-Talbot.wdm MESSU 25 Pre23382-Talbot.MES 27 Pre23382-Talbot.L61 28 Pre23382-Talbot.L62 30 POC23382-Talbot1.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 Predev Basin P1 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 23382-Talbot 7/18/2025 4:40:55 PM 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 23382-Talbot 7/18/2025 4:40:55 PM Page 21 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Predev Basin P1*** PERLND 11 1.15 COPY 501 12 PERLND 11 1.15 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 23382-Talbot 7/18/2025 4:40:55 PM 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 23382-Talbot 7/18/2025 4:40:55 PM 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 23382-Talbot.wdm MESSU 25 Mit23382-Talbot.MES 27 Mit23382-Talbot.L61 28 Mit23382-Talbot.L62 30 POC23382-Talbot1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 14 IMPLND 2 IMPLND 4 IMPLND 1 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 *** 14 C, Pasture, 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 *** 14 0 0 1 0 0 0 0 0 0 0 0 0 END ACTIVITY PRINT-INFO 23382-Talbot 7/18/2025 4:40:55 PM Page 24 <PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* 14 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 *** 14 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 14 0 4.5 0.06 400 0.1 0.5 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 14 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 14 0.15 0.4 0.3 6 0.5 0.4 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 14 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 *** 2 ROADS/MOD 1 1 1 27 0 4 ROOF TOPS/FLAT 1 1 1 27 0 1 ROADS/FLAT 1 1 1 27 0 END GEN-INFO *** Section IWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** 2 0 0 1 0 0 0 4 0 0 1 0 0 0 1 0 0 1 0 0 0 END ACTIVITY PRINT-INFO <ILS > ******** Print-flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* 2 0 0 4 0 0 4 1 9 4 0 0 4 0 0 0 1 9 1 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 *** 2 0 0 0 0 0 4 0 0 0 0 0 1 0 0 0 0 0 23382-Talbot 7/18/2025 4:40:55 PM Page 25 END IWAT-PARM1 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC 2 400 0.05 0.1 0.08 4 400 0.01 0.1 0.1 1 400 0.01 0.1 0.1 END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN 2 0 0 4 0 0 1 0 0 END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS 2 0 0 4 0 0 1 0 0 END IWAT-STATE1 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** PostDev Basin D1*** PERLND 14 0.38 RCHRES 1 2 PERLND 14 0.38 RCHRES 1 3 IMPLND 2 0.12 RCHRES 1 5 IMPLND 4 0.55 RCHRES 1 5 IMPLND 1 0.1 RCHRES 1 5 ******Routing****** PERLND 14 0.38 COPY 1 12 IMPLND 2 0.12 COPY 1 15 IMPLND 4 0.55 COPY 1 15 IMPLND 1 0.1 COPY 1 15 PERLND 14 0.38 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 *** 23382-Talbot 7/18/2025 4:40:55 PM 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 0.02 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 91 4 Depth Area Volume Outflow1 Velocity Travel Time*** (ft) (acres) (acre-ft) (cfs) (ft/sec) (Minutes)*** 0.000000 0.059595 0.000000 0.000000 0.078667 0.059595 0.004688 0.002670 0.157333 0.059595 0.009376 0.003776 0.236000 0.059595 0.014064 0.004624 0.314667 0.059595 0.018752 0.005340 0.393333 0.059595 0.023441 0.005970 0.472000 0.059595 0.028129 0.006540 0.550667 0.059595 0.032817 0.007064 0.629333 0.059595 0.037505 0.007551 0.708000 0.059595 0.042193 0.008009 0.786667 0.059595 0.046881 0.008443 0.865333 0.059595 0.051569 0.008855 0.944000 0.059595 0.056257 0.009248 1.022667 0.059595 0.060946 0.009626 1.101333 0.059595 0.065634 0.009989 1.180000 0.059595 0.070322 0.010340 1.258667 0.059595 0.075010 0.010679 1.337333 0.059595 0.079698 0.011008 1.416000 0.059595 0.084386 0.011327 1.494667 0.059595 0.089074 0.011637 1.573333 0.059595 0.093762 0.011940 1.652000 0.059595 0.098451 0.012235 1.730667 0.059595 0.103139 0.012522 1.809333 0.059595 0.107827 0.012804 1.888000 0.059595 0.112515 0.013079 1.966667 0.059595 0.117203 0.013349 2.045333 0.059595 0.121891 0.013613 2.124000 0.059595 0.126579 0.013873 2.202667 0.059595 0.131267 0.014127 2.281333 0.059595 0.135956 0.014377 2.360000 0.059595 0.140644 0.014623 2.438667 0.059595 0.145332 0.014865 23382-Talbot 7/18/2025 4:40:55 PM Page 27 2.517333 0.059595 0.150020 0.015103 2.596000 0.059595 0.154708 0.015337 2.674667 0.059595 0.159396 0.015567 2.753333 0.059595 0.164084 0.015795 2.832000 0.059595 0.168772 0.016019 2.910667 0.059595 0.173461 0.016240 2.989333 0.059595 0.178149 0.016458 3.068000 0.059595 0.182837 0.016673 3.146667 0.059595 0.187525 0.016885 3.225333 0.059595 0.192213 0.017095 3.304000 0.059595 0.196901 0.017302 3.382667 0.059595 0.201589 0.017507 3.461333 0.059595 0.206277 0.017709 3.540000 0.059595 0.210966 0.017910 3.618667 0.059595 0.215654 0.018107 3.697333 0.059595 0.220342 0.018303 3.776000 0.059595 0.225030 0.018497 3.854667 0.059595 0.229718 0.018689 3.933333 0.059595 0.234406 0.018878 4.012000 0.059595 0.239094 0.019066 4.090667 0.059595 0.243782 0.019252 4.169333 0.059595 0.248471 0.019436 4.248000 0.059595 0.253159 0.019619 4.326667 0.059595 0.257847 0.019800 4.405333 0.059595 0.262535 0.019979 4.484000 0.059595 0.267223 0.020157 4.562667 0.059595 0.271911 0.020839 4.641333 0.059595 0.276599 0.022312 4.720000 0.059595 0.281287 0.024194 4.798667 0.059595 0.285976 0.026366 4.877333 0.059595 0.290664 0.028760 4.956000 0.059595 0.295352 0.031330 5.034667 0.059595 0.300040 0.034038 5.113333 0.059595 0.304728 0.036855 5.192000 0.059595 0.309416 0.039757 5.270667 0.059595 0.314104 0.042723 5.349333 0.059595 0.318792 0.045732 5.428000 0.059595 0.323481 0.048770 5.506667 0.059595 0.328169 0.051835 5.585333 0.059595 0.332857 0.055535 5.664000 0.059595 0.337545 0.059365 5.742667 0.059595 0.342233 0.063322 5.821333 0.059595 0.346921 0.067400 5.900000 0.059595 0.351609 0.071596 5.978667 0.059595 0.356297 0.092761 6.057333 0.059595 0.360986 0.098550 6.136000 0.059595 0.365674 0.311126 6.214667 0.059595 0.370362 0.883480 6.293333 0.059595 0.375050 1.643563 6.372000 0.059595 0.379738 2.510900 6.450667 0.059595 0.384426 3.407492 6.529333 0.059595 0.389114 4.254511 6.608000 0.059595 0.393802 4.981828 6.686667 0.059595 0.398491 5.543299 6.765333 0.059595 0.403179 5.935883 6.844000 0.059595 0.407867 6.295926 6.922667 0.059595 0.412555 6.607158 7.001333 0.059595 0.417243 6.904177 7.080000 0.059595 0.421931 7.188769 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 23382-Talbot 7/18/2025 4:40:55 PM 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 23382-Talbot 7/18/2025 4:40:55 PM Page 29 Predeveloped HSPF Message File 23382-Talbot 7/18/2025 4:40:55 PM Page 30 Mitigated HSPF Message File 23382-Talbot 7/18/2025 4:40:55 PM 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 4.5 Water Quality System 23382-TIR-PREL.doc 4.5 Water Quality System This section includes an illustrative sketch of the proposed water quality facility and the WWHM computations for sizing the facility. A BioPod or approved equal water quality unit is proposed in accordance with Basic WQ Option 8. The required treatment flow rate calculated is based on the 2-year mitigated flow rate as required by the 2022 RSWDM requirements. The 100-year mitigated flow rate is used to determine the minimum overflow bypass flow rate. Wetvault Water Quality Flow Rate required = 0.019 cfs Wetvault Minumum Overflow Bypass Flow Rate Volume provided = 0.074 cfs Tab 5.0 23382-TIR-PREL.doc 5.0 CONVEYANCE SYSTEM ANALYSIS AND DESIGN The on-site conveyance system will be designed in accordance with the 2022 RSWDM. The proposed conveyance system for this project is curb, gutter, catch basins, and storm drainage pipe. The storm drainage pipe used will consist of smooth-walled lined corrugated polyethylene pipe with steel rib reinforcement with a Manning’s roughness coefficient of 0.014. 100-year conveyance calculations for the pipe with be completed using the rational method. The design intent of the conveyance system is to fully accommodate the 100-year storm event flowing at full condition. Conveyance calculations will be provided during final engineering. Tab 6.0 23382-TIR-PREL.doc 6.0 SPECIAL REPORTS AND STUDIES 6.1 Geotechnical Engineering Study prepared by Earth Solutions NW, LLC, dated August 8, 2023 6.2 Grading Analysis prepared by Earth Solutions NW, LLC, dated July ##, 2025 6.3 Critical Areas Report prepared by Sewall Wetland Consulting, Inc. dated September 11, 2024 6.1 Geotechnical Engineering Study 6.2 Grading Analysis 6.3 Critical Areas Report Tab 7.0 23382-TIR-PREL.doc 7.0 OTHER PERMITS City of Renton will be the governing body for the storm drainage permitting. A building permit and grading permit will be required from City of Renton for the development of the on-site drainage and roadway facilities. Soos Creek Water and Sewer District will be the governing body for the water and City of Renton will be the governing body for the sanitary sewer system. The project will also be seeking coverage for a Construction Stormwater General Permit (NPDES) from the Department of Ecology. Other permits will include: Postmaster approval of the mailbox locations. Fire Marshal Hydrant Location These permits and all other permit applications required will be obtained during final engineering design. Tab 8.0 23382-TIR-PREL.doc 8.0 ESC ANALYSIS AND DESIGN A. Erosion and Sediment Control (ESC) Plan Analysis and Design The ESC plans will consist of erosion and sediment control plans, prepared in accordance with the 2022 City of Renton Surface Water Design Manual, and standard industry practices throughout the construction process to limit the amount of sediment traveling into the downstream systems. BMPs that are will likely be provided include a rocked construction entrance, silt fence where needed, straw mulch for the areas that reach final grade in the lot areas, V-ditches with rock check dams, sediment traps, and hydroseeding. The project involves less than 3 acres of ground disturbance, a temporary sediment trap is an appropriate BMP for sediment removal from this construction project. The temporary sediment trap will be used in combination with v-ditches for surface water control, silt fence for perimeter protection, and a stabilized construction entrance to reduce the amount of sediment transported onto paved roads by vehicles or equipment. The following outline summarizes the sediment pond sizing. The 2-year peak 15 min. peak flow will be used for calculating the required surface area. The total disturbance area is approximately 1.22 acre. The temporary sediment trap will be sized using the following equation from the 2022 RSWD manual: S.A. = 2 x Q2/0.00096 = 2080 square feet per cfs of inflow Q2 = 0.0461 cfs S.A.=96 sf 23382-TIR-PREL.doc B. Stormwater Pollution Prevention and Spill (SWPPS) Plan Design A Stormwater Pollution Prevention and Spill Site Plan will be prepared for Talbot Hills as part of the final engineering design. This is a site-specific plan that outlines the project scope of work and presents a comprehensive plan to prevent, respond to, and report spills or releases to the environment. It also provides suggested locations for: · equipment parking/maintenance areas · chemical storage areas with secondary containment · construction materials and construction waste storage areas · truck wheel washout areas This plan also provides general locations of erosion control measures such as silt fencing, sediment pond, construction entrance, and clearing limits. The site is generally underlain by glacial till soils. perched groundwater will be present during the wet winter and early spring months. Potential Spill Sources or Releases Potential spill sources during construction will include materials and equipment brought on-site. Potential spill sources include fueling, lubricating oil, hydraulic oil, backhoes, bulldozers, water trucks, support trucks, lighting units, pumps, and generators. Equipment staging and maintenance areas for fueling, hazardous materials, and hazardous waste materials have been designated on the SWPPS. Construction debris will be present during demolition of the existing on-site buildings. No fuel tanks, gasoline, oils, and hydraulic fuels will be stored on-site. Control Pollutants Pollutants other than sediment will be controlled as part of the implemented SWPPS plan. Maintenance and repair of heavy equipment and vehicles that may result in discharge or spillage of pollutants to the ground or surface water runoff will be conducted using spill prevention measures. Contaminated surfaces will be cleaned immediately following any discharge or spill incident. Spills will be reported within 24 hours. Emergency repairs may be performed on-site using temporary plastic placed beneath and, if raining, over the vehicle. Concrete truck chutes and pumps shall be washed out only into formed areas awaiting installation of concrete or asphalt. Unused concrete remaining in the truck and pump shall be returned to the originating batch plant for recycling. Hand tools including, but not limited to, screeds, shovels, rakes, and trowels shall be washed off only into formed areas awaiting installation of concrete or asphalt. When no formed areas are available, wash water and leftover product shall be contained in a lined container or in a sump designed to receive the materials. Contained concrete shall be disposed of in a manner that does not violate groundwater or surface water quality standards. Recommended BMP’s include Concrete Handling (BMP C151) Spill Prevention and Containment The following is a list of BMP’s that will be used for the project. 23382-TIR-PREL.doc · Store and maintain equipment in a designated area. · Reduce the amount of hazardous materials and waste by substituting non-hazardous or less hazardous materials. · Use secondary containment (drain pan) to catch spills when removing or changing fluids. · Use proper equipment (pumps, funnels) to transfer fluids · Keep spill kits readily accessible. · Check incoming vehicles for leaking oil and fluids. · Transfer used fluids and oil filters to waste or recycling drums. · Inspect equipment immediately, if necessary. · Implement a preventative maintenance schedule for equipment and vehicles. · Perform fueling in designated fueling area. · Do not “top-off” tanks · Use secondary containment (drain pan) to catch spills. · Keep spill kits readily accessible. · Inspect fueling areas routinely for leaks and spills. · Monitor pollution prevention BMP’s and maintain records/reports of all inspections using the worksheets at the end of this section. Spill Response Response in the first 15 minutes is critical to minimize the impacts to human health and the environment and to minimize property damage and cleanup costs. The contractor will respond immediately to spills and regulated materials. Spill response equipment shall be stored in spill response kits located in a clearly marked and accessible area. The standard approach toward spill response will be as follows: · Stop operations. · Stop the source of the spill. · Use appropriate materials to absorb, berm, or cover the area to prevent further contamination. · Notify the construction manager. · Determine the method of clean up required. All methods shall comply with the state or local requirements to spill response. · Contact a cleanup response firm if necessary. Contact Personnel The designated personnel responsible for managing, implementing, and maintaining this SWPPS plan include: Schneider Family Homes, LLC CECL – TBD The contractor – TBD A SWPPP report has also been prepared following the Department of Ecology (Ecology) format and will be kept on-site during all construction activities. The SWPPP report 23382-TIR-PREL.doc includes a narrative discussion of construction BMP’s that will be implemented during construction, based on the 13 required elements as defined by Ecology. The SWPPP report also outlines inspection, monitoring, and reporting requirements to meet the requirements of the NPDES permit. Tab 9.0 23382-TIR-PREL.doc 9.0 BOND QUANTITIES AND FACILITY SUMMARIES This section will be completed during final engineering prior to permitting. The bonds that will be required Site Improvement and Landscape. The Facilities Summaries will also be included during final engineering. Tab 10.0 23382-TIR-PREL.doc 10.0 OPERATIONS AND MAINTENANCE MANUAL The drainage facilities on this project will be public facilities owned and maintained by City of Renton. Storm drainage is collected in catch basins in the roadways and conveyed first to a combined wet/detention vault for flow control and basic water quality treatment, before discharging to an existing conveyance system. An Operations and Maintenance Manual will be provided during final engineering if needed. www.wavin.usOverview of Maintenance1 Overview of Maintenance Wavin AquaCell www.wavin.usOverview of Maintenance2 for AquaCell SystemOverview of Maintenance The Wavin AquaCell is an innovative stormwater management system designed for the efficient collection, retention, and infiltration of rainwater. It consists of modular cells that can be configured to meet various project requirements, providing a flexible and sustainable solution for managing stormwater runoff. Maintenance of the Wavin AquaCell is essential to ensure its efficient and reliable operation. Regular maintenance involves cleaning the system to remove debris, sediment, and other obstructions that can cause blockages and reduce the system’s capacity. This process helps prevent flooding, minimizes environmental impact, and extends the lifespan of the infrastructure. By conducting routine inspections and cleaning, potential issues can be identified and addressed before they escalate into major problems, ensuring the Wavin AquaCell system continues to protect communities and properties from stormwater-related damage. A. Preparation & Planning 1. Inspect the AQUACELL system a. Conduct a preliminary inspection to identify areas that require cleaning and assess the condition of the system. 2. Gather Necessary Equipment a. Ensure you have all the necessary equipment, including a high-pressure water jet, vacuum truck, personal protective equipment (PPE), gas detector, and communication devices. 3. Safety Protocols a. Establish safety protocols, including confined space entry procedures, traffic control measures, and emergency response plans. B. Safety Measures 1. PPE a. Equip all workers with appropriate PPE, including hard hats, gloves, safety goggles, respirators, and protective clothing. 2. Gas Detection a. Use gas detectors to check for hazardous gases like methane, hydrogen sulfide, and carbon monoxide in the system before entry. 3. Ventilation a. Ensure proper ventilation to prevent the accumulation of hazardous gases. 4. Confined Space Entry a. Follow confined space entry procedures, including having a trained attendant and using a harness and lifeline for the worker entering the space. C. System Isolation 1. Isolate the Area 2. Block off the section of the stormwater system being cleaned to prevent water from entering during the cleaning process. 3. Notify Relevant Parties a. Inform local authorities, businesses, and residents about the cleaning operation and potential disruptions. www.wavin.usOverview of Maintenance3 D. Debris Removal 1. Access the AQUACELL through 10” Ø ventilation / inspection ports located directly above the system. 2. Initial Debris Removal a. Use manual tools or mechanical equipment to remove large debris and objects that may obstruct the cleaning process. 3. High-Pressure Water Jetting a. Use a high-pressure water jet to dislodge sediment, silt, and smaller debris from the walls and floor of the system. E. Vacuum Extraction 1. Vacuum Truck a. Use a vacuum truck to suck out the dislodged debris and water from the system. Ensure the vacuum hose reaches all areas of the section being cleaned. 2. Repeat Process a. Repeat the jetting and vacuuming process until the section is thoroughly cleaned. F. Inspection and Verification 1. Inspect Cleaned Sections a. Conduct a post-cleaning inspection to verify that all debris has been removed and the system is functioning properly. 2. CCTV Inspection a. Use a CCTV camera to inspect the interior of the system for any remaining debris, blockages, or structural issues. G. Final Steps 1. Dispose of Waste a. Properly dispose of the collected debris and wastewater according to local regulations and environmental guidelines. 2. Document the Process a. Record the cleaning process, including areas cleaned, equipment used, and any issues encountered. 3. Reopen System a. Remove isolation measures and restore the AQUACELL system to normal operation. H. Regular Maintenance 1. Schedule Regular Cleanings a. Establish a regular maintenance schedule based on the system’s usage and local conditions to prevent future blockages and ensure efficient operation. 2. Monitor System Performance a. Continuously monitor the system’s performance and address any issues promptly to maintain its effectiveness. www.wavin.usOverview of Maintenance4 D1 E1 4.4 in 4.4 in 4.4 in 4.4 in 4.4 in4.4 in 4.4 in 4.4 in 4.4 in 0.7 in 0.7 in 0.7 in 0.7 in 0.7 in 0.7 in 0.7 in 0.7 in9.4 in 5.8 in 9.4" open entry through top adapter and 5.8" width of inner channels between columns allow for clear access into interior of AQUACELL tank 16.7 in 12.1 in Wavin 950 Winter Street, South Entrance 1st Floor, Waltham, MA 02451 (US) | 5700 Côte de Liesse, Montréal, QC H4T 1B1 (CAN) © 2024 Wavin Wavin reserves the right to make alterations without prior notice. Due to continuous product development, changes in technical specifications may change. Installation & maintenance must comply with the installation. Wavin operates a program of continuous product development, and therefore reserves the right to modify or amend the specification of their products without notice. All information in this publication is given in good faith and believed to be correct at the time of going to press. However, no responsibility can be accepted for any errors, omissions, or incorrect assumptions.