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HomeMy WebLinkAbout25-095 Braunstein.TIRSeptember 11, 2025 25-095 Braunstein.TIR Page 1 DRAINAGE TECHNICAL INFORMATION REPORT Proposed Pavement 600 SW 13th Street Renton, Washington PN: 334040-5025 & 5035 Client: Braunstein Holding Group 600 SW 13th Street #200 Renton, WA 98057 November 20, 2025 Prepared by: DEVELOPMENT ENGINEERING, PLLC 9601 Key Peninsula Hwy. NW Gig Harbor, Washington 98329 (253) 228-0513 www.de-civil.com DEVELOPMENT ENGINEERING HBray 12/19/2025 Surface Water Enginering jfarah 12/22/2025 September 11, 2025 25-095 Braunstein.TIR Page 2 CONTENTS Section 1 – Project Overview 3 Pre-Developed Site Conditions 3 Post-Developed Conditions 3 Site Soils 3 Section 2 - Conditions and Requirements Summary 3 Surface Water Design Manual Minimum Core Requirements 3 King County Surface Water Design Manual Special Requirements 4 Section 3 – Level 1 Offsite Analysis 4 Task 1. Study Area Definition and Maps 4 Task 2. Resource Review 4 Task 3. Field Inspection 5 Section 4 - Flow Control and Water Quality Analysis and Design 5 Section 5 - Conveyance System Analysis and Design 7 Section 6 – Special Reports and Studies 8 Section 7 – Other Permits 8 Section 8 – CSWPPP Analysis and Design 8 Section 9 – Bond Quantities, Facility Summaries, and Declaration of Covenant 8 Section 10 - Operations and Maintenance Manual 8 Table A 9 Figure 1: Technical Information Report (TIR) Worksheet 10 Site Vicinity Map 13 Existing Site Conditions 14 Basin Study Areas 16 Sensitive Areas 17 100 Year 24-Hour Isopluvial 19 Drainage Basin Map 20 Appendix A: Operation and Maintenance Manual 21 Appendix B: Declaration of covenant 23 Appendix C: Geotechnical Report 28 September 11, 2025 25-095 Braunstein.TIR Page 3 SECTION 1 – PROJECT OVERVIEW We are pleased to submit this drainage report for the construction of the proposed pavement on the existing tax parcels located at 600 SW 13th Street in the city of Renton, Washington, as shown on the attached Site Vicinity Map, Figure 2. It is our understanding from the discussions that we have had, our knowledge with the area and our site visit that you intend to construct a paved parking lot the currently vacant parcel. Since the impervious surfacing you’ve planned to install totals to less than 5,000 sqft, the City of Renton will require you to submit a “Full Drainage Review”, requiring you to comply with all nine core requirements from section 1.2 and all five special requirements from section 1.3 of the 2022 Renton Surface Water Design Manual (RSWDM). Pre-Developed Site Conditions The site consists of two existing lots of record that are currently undeveloped which have been cleared of any native vegetation since prior to 2000. The site is triangular in shape and measures approximately 285 feet in height, west to east with a base of 45 feet north to south and encompasses 0.14 acres. The is nearly level with a slight slope to the north. The overall topographic relief across the site is less than 1 foot. The site is bounded by SW 13th Street to the north, SR 405 to the south and unopened Seneca Avenue SW right of way to the east. Post-Developed Conditions Based on our conversations with you and our review of the provided site plan, it is our understanding that the proposed development will include the pavement of the vacant lot to create additional off- street parking for your business. The proposed driveway/parking will measure 4,875sqft for a total added impervious area of 4,980sqft. In addition to the parking lot approximately 3,500sqft of disturbed right of way will be revegetated with grass. No additional clearing is proposed at this time. See the attached site plans and Table A for a complete breakdown of the site areas. For this project, we are proposing to utilize sheet flow dispersion into the SW 13th Street ROW which will then convey the drainage to an existing catchbasin located in 13th Street to the east of the site. Site Soils A geotechnical infiltration report was prepared by our office dated July 28, 2025. Based on the results of that investigation, infiltration is not feasible for this project, see attached. SECTION 2 - CONDITIONS AND REQUIREMENTS SUMMARY Per the FEMA Flood Map no portion of the site is not located within a 100-year flood plain. According to the SWMM the site should be subject to “Directed Drainage Review”. The site will disturb less than 7,000 sqft of area and will add less than 5,000 sqft of new impervious area since 2000. It is assumed that a combination of BMPs will be necessary and will comply with stormwater management as they pertain to the rules and regulations set forth by King County’s SWMM, July 2021 as adopted by the City of Renton. Surface Water Design Manual Minimum Core Requirements Core Requirement 1. Discharge at the natural location: Portions of the site sheet flows to the north where it enters adjacent SW 13th Street row. Currently there is a catch basin that is located in the east central portion of the site that collects some surface water and conveys it to the south. The proposed drainage will be sheet flow dispersed to the north while the grate on the existing catch basin will be replaced with a solid lid. September 11, 2025 25-095 Braunstein.TIR Page 4 Core Requirement 2. Off-Site Analysis: An Off-Site Analysis is included in Section 3 of this report. The analysis includes site inspection and research as required to meet the requirements of a Level 1 off-site analysis. Core Requirement 3. Flow Control: Flow control is not applicable to this project since we proposing less than 5,000sqft of new impervious area. Core Requirement 4. Conveyance System: No conveyance system is proposed at this time. Core Requirement 5. Temporary Erosion & Sediment Control: Basic erosion control measures have been shown on the attached plans with a more detailed explanation given in Section 8 of this report. Core Requirement 6. Maintenance & Operation: An operation and maintenance manual has been included with this report. Core Requirement 7. Financial Guarantees & Liability: It is anticipated that a bond will be required for this development. Core Requirement 8. Water Quality: This project will not be required to meet the basic water quality measures, as the total amount of pollutant generating surfacing is less than 5,000 sqft. Core Requirement 9. Flow Control BMPs: This project will direct the site drainage to the street drainage system see Section 4 of this report for further details. 2022 RSWDM Special Requirements Per the FEMA Flood Map no portion of the site is located within the 100-year flood plain. There are no wetlands mapped on any portion of the site. No development is proposed within any wetland buffer areas. SECTION 3 – LEVEL 1 OFFSITE ANALYSIS Task 1. Study Area Definition and Maps The site is located within the Duwamish-Green River watershed. The site slopes down from south to north at grades of less than 1 percent. Overall topographic relief across the site is less than 1 foot. Stormwater from the proposed pavement will be mitigated through use of a sheet flow dispersion to the existing street drainage system. The proposed development will not negatively impact native drainage patterns. See Section 4 – Flow Control for details. Task 2. Resource Review The following is a summary of the resources reviewed to identify any potential sensitive areas within, adjacent to and downstream of the proposed site. • Wetlands: iMap mapping shows no wetlands on or near the property. • Streams and 100-year Floodplains: No flooding hazard is mapped on or near the property. September 11, 2025 25-095 Braunstein.TIR Page 5 • Erosion Hazard Areas: iMap mapping shows no areas as being mapped as an erosion hazard area. • Landslide Hazard Areas: iMap mapping shows no areas on or near the property as being mapped as a potential landslide hazard area. • Seismic Hazard Areas: iMap shows no seismic hazard on or near the property. • Drainage Complaints: iMap mapping shows no drainage complaints in the project area. See Figures for maps. Task 3. Field Inspection Level 1 Inspection: 1. Investigate any problems reported or observed during the resource review. No problems were identified within the resource review. 2. Locate all existing/potential constrictions or lack of capacity in the existing drainage system. No problems identified. 3. Identify all existing/potential downstream drainage problems as defined in Section 1.2.2.1. The existing road drainage system discharges into a natural ravine through a CMP culvert that is exposed and suspended above the channel. This area appears to have washed out some time ago but is currently in a stable condition. 4. Identify existing/potential overtopping, scouring, bank sloughing, or sedimentation. No evidence was observed of these issues. 5. Identify significant destruction of aquatic habitat or organisms. None noted. 6. Collect qualitative data on features such as land use, impervious surfaces, topography, and soil types. The site and surrounding areas generally consists of urban commercial properties. There was little evidence of concentrated drainage systems other than what was associated with the road systems. 7. Collect information on pipe sizes, channel characteristics, drainage structures, and relevant critical areas (e.g., wetlands, streams, steep slopes). As mentioned, there is a catch basin structure located on the site that is currently accepting water from the site. At the time of our site visit the structure was covered with a metal plate. The SW 13th Street row includes a catch basin that is located to the east of the site at the intersection of SW 13t hand Seneca Street. 8. Verify tributary basins delineated in Task 1. The attached Figure 7 Basin Study Area accurately reflects the basin areas based on our field observations. 9. Contact neighboring property owners or residents in the area about past or existing drainage problems, and describe these in the report (optional). Not done. 10. Note the date and weather conditions at the time of the inspection. The inspection was performed in the afternoon of August 27, 2025. The weather was clear and sunny, no downstream deficiencies were noted during our investigation. SECTION 4 - FLOW CONTROL AND WATER QUALITY ANALYSIS AND DESIGN The proposed drainage will be maintained by directing the impervious surface drainage to the north and sheet flow dispersing into the SW 13th Street right of way and then into the street drainage system. The project is required to implement on-site BMP’s following section 1.2.9.2 Individual Lot BMP September 11, 2025 25-095 Braunstein.TIR Page 6 requirements as identified below for Small Lots. We have included Section 1.2.9.2.1 from the RSWMM with a brief discussion of the viability of each requirement. 1.2.9.2.1 SMALL LOT BMP REQUIREMENTS IF the proposed project is on a site/ lot smaller than 22,000 square feet, THEN on-site BMPs must be applied as specified in the requirements below OR the project must demonstrate compliance with the LID Performance Standard ( described in Section 1.2.9.1.B) using an approved continuous runoff model. Projects on small lots are typically single family residential improvements ( e.g., homes, outbuildings, etc.) but could be a small commercial development.. 1. The feasibility and applicability of full dispersion as detailed in Appendix C, Section C.2.1 must be evaluated for all target impervious surfaces. If feasible and applicable, full dispersion must be implemented as part of the proposed project. Typically, small lot full dispersion will be applicable only in subdivisions where enough forest was preserved by tract, easement, or covenant to meet the minimum requirements for full dispersion in Appendix C, Section C.2.1.1. Full dispersion is not feasible as there is insufficient room for the required 100 foot vegetated flow paths due to the size of the lot. 2. Where full dispersion of target impervious roof areas is not feasible or applicable, or will cause flooding or erosion impacts, the feasibility and applicability of full infiltration as detailed in Appendix C, Section C.2.2 must be evaluated ( note, this will require a soils report for the site/ lot). If feasible and applicable, full infiltration of roof runoff must be implemented as part of the proposed project. Full infiltration is not feasible because of a high groundwater potential and site quality of the site soils. 3. All target impervious surfaces not mitigated by Requirements 1 and 2 above, must be mitigated to the maximum extent feasible using one or more BMPs from the following list. Use of a given BMP is subject to evaluation of its feasibility and applicability as detailed in Appendix C. Feasible BMPs are required to be implemented. The BMPs listed below may be located anywhere on the site/ lot subject to the limitations and design specifications for each BMP. These BMPs must be implemented as part of the proposed project.. a. Full Infiltration per Appendix C, Section C.2.2, or per Section 5.2, whichever is applicable Full infiltration is not feasible because of a high groundwater potential and site quality of the site soils. b. Limited Infiltration per Appendix C, Section C.2.3, Limited infiltration is not feasible due to the quality of soils onsite and potential depth to groundwater and the steep slopes located on site. c. Bioretention per Appendix C, Section C.2.6, sized as follows: i. SeaTac regional scale factor equals 1.0: In till soils, provide bioretention volume based on 0.6 inches of equivalent storage depth; in outwash soils provide bioretention volume based on 0.1 inches of equivalent storage depth, September 11, 2025 25-095 Braunstein.TIR Page 7 ii. SeaTac regional scale factor greater than 1.0: In till soils, provide bioretention volume based on 0.8 inches of equivalent storage depth; in outwash soils, provide bioretention volume based on 0.4 inches of equivalent storage depth, BioRetention is not feasible due to the quality of soils onsite and potential depth to groundwater. d. Permeable Pavement per Appendix C, Section C.2.7, Permeable pavement is not feasible due to the site soils and potential groundwater depth. 4. All target impervious surfaces not mitigated by Requirements 1,2 and 3 above, must be mitigated to the maximum extent feasible using the Basic Dispersion BMP described below. Use of Basic Dispersion is subject to evaluation of its feasibility and applicability as detailed in Appendix C. Feasible BMPs are required to be implemented. Basic Dispersion BMPs may be located anywhere on the site/lot subject to the limitations and design specifications cited in Appendix C. The BMP must be implemented as part of the proposed project. a. Basic Dispersion per Appendix C, Section C.2.4, Basic dispersion is feasible and is proposed for this project. 5. BMPs must be implemented, at minimum, for an impervious area equal to at least 10% of the site/ lot for site/ lot sizes up to 11,000 square feet and at least 20% of the site/ lot for site/ lot sizes between 11,000 and 22,000 square feet. For projects located in Zone 1 of the Aquifer Protection Area, these impervious area amounts must be doubled. Doubling of the minimum impervious area required for BMP implementation in Zone 1 of the Aquifer Protection Area is not required for projects located within 200 feet of a steep slope hazard area, landslide hazard, or erosion hazard area. If these minimum areas are not mitigated using feasible BMPs from Requirements 1, 2, 3, and 4 above, one or more BMPs from the following list are required to be implemented to achieve compliance. These BMPs must be implemented as part of the proposed project. a. Reduced Impervious Surface Credit per Appendix C, Section C.2.9 b. Native Growth Retention Credit per Appendix C, Section C.2.10. c. Tree Retention Credit per Appendix C, Section C.2.14 Not applicable to this project. 6. The soil moisture holding capacity of new pervious surfaces ( target pervious surfaces) must be 7. protected in accordance with the soil amendment BMP as detailed in Appendix C, Section C.2.13. 8. Any proposed connection of roof downspouts to the local drainage system must be via a perforated pipe connection as detailed in Appendix C, Section C.2.11. SECTION 5 - CONVEYANCE SYSTEM ANALYSIS AND DESIGN No conveyance system is proposed at this time. September 11, 2025 25-095 Braunstein.TIR Page 8 SECTION 6 – SPECIAL REPORTS AND STUDIES A geotechnical infiltration report was prepared by our office, dated July 28, 2025. A copy of the report is included for reference. SECTION 7 – OTHER PERMITS No other permits are anticipated at this time. SECTION 8 – CSWPPP ANALYSIS AND DESIGN Typical erosion control measures have been shown on the provided plans. Given the limited amount of area to be worked at any given time and the near surface soils, the chance of erosion from leaving the site is minimal. While we have shown a silt fence along the down slope portions of the clearing limits, it is our opinion that little surface runoff will leave the site uncontrolled and that this will be adequate erosion protection for the site. Surface areas that are cleared are expected to be seeded or landscaped shortly after they have been cleared further minimizing the chance for erosion. In our opinion the plans as prepared are adequate for a project of this nature. SECTION 9 – BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT A Declaration of Covenant is included in this report under Appendix B. SECTION 10 - OPERATIONS AND MAINTENANCE MANUAL An operation and maintenance manual is included with this report. September 11, 2025 25-095 Braunstein.TIR Page 9 TABLE A Proposed Impervious Surface: Fill in all applicable blanks below to list the square footage of all new and existing impervious surface areas proposed on your parcel. When calculating impervious surface areas for buildings do not list living/useable space square-footage, instead list the building roof square-footage, measured to the outside edge of eve or gutter. Impervious New Existing Total Roof Area (House, Attached Garage, Covered Patio, Covered Deck, Covered Porch) - sq. ft. - sq. ft. - sq. ft. Roof Area (Detached Garage) sq. ft. sq. ft. sq. ft. Roof Area (All Out Buildings) sq. ft. sq. ft. sq. ft. On-site Driveway Area 4,175 sq. ft. 0 sq. ft. 4,175 sq. ft. Off-site Driveway Area 700 sq. ft. 0 sq. ft. 700 sq. ft. Walkways / Sidewalks / Stepping Stone Area sq. ft. sq. ft. sq. ft. Uncovered Porch and / or Patio Area sq. ft. sq. ft. sq. ft. Uncovered Decks Area sq. ft. sq. ft. sq. ft. Replaced Impervious Area (Considered New Impervious) sq. ft. sq. ft. sq. ft. All Other Impervious Areas sq. ft. sq. ft. sq. ft. Total New Impervious Surface Area 4,875 sq. ft. Total Existing Impervious Surface Area 0 sq. ft. Total Impervious Areas 4,875 sq. ft. Total Clearing Limits, Site Disturbance / Graded Areas (Include Septic Drain fields Primary and Reserve) 8,375 sq. ft. Total New Pervious Areas [(Total Clearing Limits, Site Disturbance/Graded Areas) – (Total New Impervious Areas)] 3,500 sq. ft. Total Excavation Volume 120 Cubic Yard Total Fill Volume (Exported) Cubic Yard Total Fill Volume (Imported) 120 Cubic Yard For DPER Staff Use ONLY Parcel Number: ____________________ Approved By: _______________________ Application Number: ______________ Date: __________________ 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 Braunstein Holding Group 600 SW 13th Street #200 Renton, WA 98057 Glen Coad, PE Development Engineering, PLLC (253) 228 - 0513 Braunstein Parking 23 5 19 600 SW 13th Street 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 ______________________ Full Drainage review all 9 minimum requirements. 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 Not mapped Flat None X None Noted Site All 9 1 11/20/25 Not Applicable N/A N/A 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: N/A <5,000SQFT PGIS None required 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 Sheet flow along north side 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 September 11, 2025 25-095 Braunstein.TIR Page 13 Not to Scale Approximate Location DE-CIVIL, PLLC P.O. Box 446 Tacoma, WA 98401 Ph (253) 228-0513 www.de-civil.com SITE VICINITY MAP Braunstein Parking 600 SW 13th Street Renton, Washington Job No: 25-095 September 2025 Figure 2 September 11, 2025 25-095 Braunstein.TIR Page 14 DE-CIVIL, PLLC P.O. Box 446 Tacoma, WA 98401 Ph (253) 228-0513 www.de-civil.com EXISTING SITE CONDITIONS Braunstein Parking 600 SW 13th Street Renton, Washington Job No: 25-095 September 2025 Figure 3 September 11, 2025 25-095 Braunstein.TIR Page 15 DE-CIVIL, PLLC P.O. Box 446 Tacoma, WA 98401 Ph (253) 228-0513 www.de-civil.com USDA SOILS MAP Braunstein Parking 600 SW 13th Street Renton, Washington Job No: 25-095 September 2025 Figure 4 September 11, 2025 25-095 Braunstein.TIR Page 16 DE-CIVIL, PLLC P.O. Box 446 Tacoma, WA 98401 Ph (253) 228-0513 www.de-civil.com BASIN STUDY AREAS Braunstein Parking 600 SW 13th Street Renton, Washington Job No: 25-095 September 2025 Figure 4 September 11, 2025 25-095 Braunstein.TIR Page 17 DE-CIVIL, PLLC P.O. Box 446 Tacoma, WA 98401 Ph (253) 228-0513 www.de-civil.com SENSITIVE AREAS Braunstein Parking 600 SW 13th Street Renton, Washington Job No: 25-095 September 2025 Figure 5 September 11, 2025 25-095 Braunstein.TIR Page 18 DE-CIVIL, PLLC P.O. Box 446 Tacoma, WA 98401 Ph (253) 228-0513 www.de-civil.com DRAINAGE COMPLAINTS Braunstein Parking 600 SW 13th Street Renton, Washington Job No: 25-095 September 2025 Figure 7 September 11, 2025 25-095 Braunstein.TIR Page 19 DE-CIVIL, PLLC P.O. Box 446 Tacoma, WA 98401 Ph (253) 228-0513 www.de-civil.com 100 YEAR 24-HOUR ISOPLUVIAL Braunstein Parking 600 SW 13th Street Renton, Washington Job No: 25-095 September 2025 Figure 6 September 11, 2025 25-095 Braunstein.TIR Page 20 DE-CIVIL, PLLC P.O. Box 446 Tacoma, WA 98401 Ph (253) 228-0513 www.de-civil.com DRAINAGE BASIN MAP Braunstein Parking 600 SW 13th Street Renton, Washington Job No: 25-095 September 2025 Figure 7 September 11, 2025 25-095 Braunstein.TIR Page 21 APPENDIX A: OPERATION AND MAINTENANCE MANUAL September 11, 2025 25-095 Braunstein.TIR Page 22 #10 – Maintenance Checklist for Filter Strips (Basic and CAVFS): Drainage System Feature Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed General Sediment Accumulation on Grass Sediment depth exceeds 2 inches. No sediment deposits in treatment areas. General Vegetation When the grass becomes excessively tall (greater than 10 inches); when nuisance weeds and other vegetation starts to take over. Grass is healthy and nuisance vegetation controlled such that flow not impeded. Grass should be mowed to a height between 3-4 inches. General Trash and Debris Accumulation Trash and debris accumulated on the filter strip. No trash or debris present. Any trash and debris removed from filter. General Erosion/Scouring Eroded or scoured areas due to flow channelization, or higher flows. No eroded or scoured areas, cause of erosion or scour addressed. For ruts or bare areas less than 12 inches wide repair the damaged area by filling with crushed gravel (basic filter strip) or a 50/50 mixture of crushed gravel and compost (CAVFS). The grass will creep over the rock in time. If bare areas are large, generally greater that 12 inches wisde, the filter strip should be re-graded and re- seeded. For smaller bare areas, overseed when bare spots are evident. General Flow Spreader Flow spreader uneven or clogged so that flows are not uniformly distributed through entire filter width. Flows are apread even;y over entire filter width/ Spreader is level and clean. September 11, 2025 25-095 Braunstein.TIR Page 23 APPENDIX B: DECLARATION OF COVENANT not applicable - do not use September 11, 2025 25-095 Braunstein.TIR Page 24 September 11, 2025 25-095 Braunstein.TIR Page 25 September 11, 2025 25-095 Braunstein.TIR Page 26 September 11, 2025 25-095 Braunstein.TIR Page 27 September 11, 2025 25-095 Braunstein.TIR Page 28 APPENDIX C: GEOTECHNICAL REPORT