Loading...
HomeMy WebLinkAboutRS_Stormwater_TIR_240401_v2 Civil Engineers ● Structural Engineers ● Landscape Architects ● Community Planners ● Land Surveyors ● Neighbors Technical Information Report PREPARED FOR: Renton School District 300 SW 7th Street Renton, WA 98057 PROJECT: Maplewood Heights E.S. 130 Jericho Avenue NE Renton, WA 98059 2230871.10 PREPARED BY: Jason Hein Project Engineer REVIEWED BY: David Nason, PE Principal DATE: April 2024 Revised June 2024 DEVELOPMENT ENGINEERING SAMorman 07/05/2024 Surface Water Enginering JFarah 07/10/2024 Technical Information Report PREPARED FOR: Renton School District 300 SW 7th Street Renton, WA 98057 PROJECT: Maplewood Heights E.S. 130 Jericho Avenue NE Renton, WA 98059 2191083.10 PREPARED BY: Jason Hein Project Engineer REVIEWED BY: David Nason, PE Principal DATE: April 2024 Revised June 2024 I hereby state that this Technical Information Report for the Maplewood Heights E.S. project has been prepared by me or under my supervision, and meets the standard of care and expertise that is usual and customary in this community for professional engineers. I understand that City of Renton does not and will not assume liability for the sufficiency, suitability, or performance of drainage facilities prepared by me. 06/20/2024 0 Technical Information Report Maplewood Heights E.S. 2191083.10 Table of Contents Section Page 1.0 Project Overview ....................................................................................................................... 1 1.1 Purpose and Scope ........................................................................................................ 1 1.2 Existing Conditions ......................................................................................................... 1 1.3 Post-Development Conditions ......................................................................................... 1 1.4 Drainage Basins ............................................................................................................. 1 1.5 Sensitive Areas .............................................................................................................. 2 2.0 Conditions and Requirements Summary ................................................................................. 2 2.1 CR 1 – Discharge at the Natural Location ....................................................................... 2 2.2 CR 2 – Offsite Analysis ................................................................................................... 2 2.3 CR 3 – Flow Control ....................................................................................................... 2 2.4 CR 4 – Conveyance System ........................................................................................... 2 2.5 CR 5 – Erosion and Sediment Control ............................................................................ 2 2.6 CR 6 – Maintenance and Operations .............................................................................. 3 2.7 CR 7 – Financial Guarantees and Liability ...................................................................... 3 2.8 CR 8 – Water Quality ...................................................................................................... 3 2.9 CR 9 – Onsite BMPs....................................................................................................... 3 2.10 SR 1 – Other Adopted Requirements .............................................................................. 4 2.11 SR 2 – Flood Hazard Delineation .................................................................................... 4 2.12 SR 3 – Flood Protection Facilities ................................................................................... 4 2.13 SR 4 – Source Control .................................................................................................... 4 2.14 SR 5 – Oil Control........................................................................................................... 4 2.15 SR 6 – Aquifer Protection Area ....................................................................................... 4 3.0 Off-Site Analysis ....................................................................................................................... 4 4.0 Flow Control, Low Impact Development (LID), and Water Quality Facility Analysis and Design ....................................................................................................................................... 4 5.0 Conveyance System Analysis and Design .............................................................................. 5 6.0 Special Reports and Studies .................................................................................................... 5 7.0 Other Permits ............................................................................................................................ 5 8.0 CSWPPP Analysis and Design ................................................................................................. 5 8.1 ESC Plan Analysis and Design ....................................................................................... 5 Technical Information Report Maplewood Heights E.S. 2191083.10 8.2 SWPPS Plan Design ...................................................................................................... 6 9.0 Bond Qualities, Facility Summaries, and Declaration of Covenant ........................................ 6 10.0 Operations and Maintenance Manual ....................................................................................... 6 Conclusion ............................................................................................................................................. 7 Appendices Appendix A Figures 1-1............. TIR Worksheet 1-2............. Vicinity Map 1-3............. Soil Map 3-1............. Erosion Hazards Map 3-2............. Steep Slopes Map 3-3............. Slide Hazard Map 3-4............. Flood Hazard Map 3-5............. Coal Mine Hazard Map 3-6............. Aquifer Protection Map 3-7............. Wetland and Water Classifications Map 3-8............. FEMA Flood Hazard Map Technical Information Report Maplewood Heights E.S. 1 2191083.10 1.0 Project Overview 1.1 Purpose and Scope This report accompanies the civil engineering plans and documents for the Maplewood Heights Elementary School located at 130 Jericho Avenue NE in Renton, Washington. The project site encompasses Tax Parcel 0847100090 in the City of Renton, King County, Washington. The parcel is located within the Southeast Quarter of the Northeast Quarter of Section 15, Township 23 North, Range 5 East, of the Willamette Meridian. See Figure 1-2 for a Site Vicinity Map. The Renton School District is proposing improvements to the Maplewood Heights Elementary School. The project proposes to update multiple ADA ramps within the park lot, re-grading the existing ADA parking stalls to meet current standards, install two separate French Drains to address on-site erosion, provide an asphalt path from the playground to an existing man gate on the east side of the site, replace damaged fence at several different location around the site and resurface the existing ball field in the southeast corner of the site. In additional multiple existing man gates are proposed to be replaced and provide a locking mechanism for school security. The project site is bounded by 144th Avenue SE to the west of the school, SE 136th Street to the south and 146th Avenue SE to the east with private residences to the north. There are no proposed revisions to any portion of the frontage and no proposed changes to the wet or dry utilities apart from the French Drain connection to the existing onsite stormwater system. The 2022 City of Renton Surface Water Design Manual (CORSWDM) establishes the methodology and design criteria used for the project. 1.2 Existing Conditions The site is the current location for the Maplewood Height Elementary School. The school was constructed in 1969 with a total building area of 53,303 square feet. Since the construction of the school the Renton School District has added an additional six classroom portables with a total area of 5,376 square feet of space for staff and students. The site which the school resides on has a total area of 377,665 square feet (8.67 Acres). 1.3 Post-Development Conditions The Renton School District is proposing several improvements to the Maplewood Heights Elementary School. Upon completion of this project the site will have updated all existing ramps to meet current ADA standards, revised grading at the existing ADA parking stalls to meet current ADA standards, a new 6-foot-wide asphalt path from the playground to an existing gate on the east side of the property, repaired fencing around the site along with a new 6-foot-tall chain-link fence along the southern property boundary. In addition, the existing ball field will be resurfaced, and the existing batting cage will also have new chain-link fabric installed. The proposed improvements will replace 4,998 square feet (0.11 ac) of hard surfaces to the site. 1.4 Drainage Basins The site is located within the Lake Washington/Cedar River Watershed basin, as delineated by the King County Department of Natural Resources and Parks Water and Land Resources Division. There are no new proposed impervious surfaces within the scope of this project and no proposed changes to the existing onsite stormwater drainage system. Technical Information Report Maplewood Heights E.S. 2 2191083.10 1.5 Sensitive Areas Upon reviewing the Sensitive Area maps provided by the City of Renton it was determined that a small portion of the site in the northeast corner of the site has a Steep Slope. There is no work proposed in this area will not be impacted by this project. 2.0 Conditions and Requirements Summary The project triggers Full Drainage Review because it results in more than 2,000 square feet of new and/or replaced impervious surface. Below is a summary of how the proposed project will meet the Core Requirements (CR) and how it will meet applicable Special Requirements (SR). 2.1 CR 1 – Discharge at the Natural Location Maplewood Heights E.S. has a single discharge point from a catch basin located in one of the site entrances on the west property line. There is a second discharge point from a surface water ditch into a catch basin at the southwest corner of the site. Both points of discharge combine in a public catch basin in a catch basin located on the east side of Jericho Avenue SE. Both discharge points will be maintained by this project. There are no proposed changes to the existing storm system. 2.2 CR 2 – Offsite Analysis The project is exempt from providing an offsite analysis. The project does not change the rate, volume, duration, or location of discharge to and from the project site. 2.3 CR 3 – Flow Control This project is exempt from providing flow control. The proposed work for this project is adding less than 5,000 square feet of new plus replaced impervious surface and is not adding any new pervious surface. The existing storm facilities are in good working order to the best of our understanding. 2.4 CR 4 – Conveyance System The conveyance system is not required to be analyzed for conveyance capacity. The existing onsite conveyance system will not experience a change in flow characteristics as a result of the proposed project. 2.5 CR 5 – Erosion and Sediment Control Onsite land disturbance will consist of clearing the work site, demolished damaged fencing and resurfacing an existing ball field. Erosion and sediment control will be provided with the use of catch basin inlet protection. See Section 8.0 for Construction Stormwater Pollution Prevention Plan (CSWPPP) analysis and design. Technical Information Report Maplewood Heights E.S. 3 2191083.10 2.6 CR 6 – Maintenance and Operations Maintenance and operations of all drainage facilities will be maintained by the Renton School District. The project does not propose any changes to the existing storm system. The existing Operation and Maintenance Manual will apply to the system. 2.7 CR 7 – Financial Guarantees and Liability This project will provide financial guarantees and liability per City of Renton requirements. See the City of Renton Bond Quantities Worksheet in Figure 9-1. 2.8 CR 8 – Water Quality This project is exempt from providing water quality. The proposed work for this project is adding less than 5,000 square feet of new plus replaced pollution generating impervious surfaces. 2.9 CR 9 – Onsite BMPs This project proposes work on an Individual Lot that is classified as a Large Lot as the site is larger than 22,000 square feet. Therefore, for CR 9 it must meet the requirements for Large Lot BMPs, as described in Section 1.2.9.2.2 in the CORSWDM. Due to the existing developed site conditions, meeting the LID performance requirement is not feasible. The onsite BMPs required by the City are listed below: • Full Infiltration: - Existing developed area is designed to drain into the onsite stormwater system. It is not feasible to meet this BMP. • Limited Infiltration: Existing developed area is designed to drain into the onsite stormwater system. It is not feasible to meet this BMP. • Bioretention: Existing developed area is designed to drain into the onsite stormwater system. It is not feasible to meet this BMP. • Permeable Pavement: Existing developed area is designed to drain into the onsite stormwater system. It is not feasible to meet this BMP. • Basic Dispersion: Existing developed area is designed to drain into the onsite stormwater system. It is not feasible to meet this BMP. • Reduced Impervious Surface Credit: Existing developed area is designed to drain into the onsite stormwater system. It is not feasible to meet this BMP. • Native Growth Retention Credit: There is no new impervious surface that could be mitigated by the native vegetated surface. It is not feasible to meet this BMP. • Tree Retention Credit: There is no new impervious surface proposed. It is not feasible to meet this BMP. Technical Information Report Maplewood Heights E.S. 4 2191083.10 2.10 SR 1 – Other Adopted Requirements The project is included in The Lake Washington/Cedar River Watershed Basin. City and County basin requirements will be followed where applicable. 2.11 SR 2 – Flood Hazard Delineation The proposed project is not in or adjacent to the 100-year floodplain. See Figure 3-8 for the FEMA National Flood Hazard map. 2.12 SR 3 – Flood Protection Facilities This project does not rely on existing flood protection facilities, nor will it modify or construct new flood protection facilities. 2.13 SR 4 – Source Control The project proposes the replacement of existing ramps to meet ADA requirements and a new asphalt path that will not be exposed to any vehicles. Therefore, it does not meet the requirements for source control purposes. 2.14 SR 5 – Oil Control The site does not meet high use criteria and is not subject to oil control measures. 2.15 SR 6 – Aquifer Protection Area The site is not located within any of the Groundwater Protection Areas. 3.0 Off-Site Analysis The project is exempt from providing an Off-Site Analysis. Per Section 1.2.2 Core Requirement #2: Offsite Analysis under the Exemption From Core Requirement #2 this project does not change the rate, volume, duration, or location of discharges to and from the project site (e.g., where existing impervious surface is replaced with other impervious surface having similar runoff-generating characteristics, or where pipe/ditch modification do not change existing discharge characteristics). 4.0 Flow Control, Low Impact Development (LID), and Water Quality Facility Analysis and Design The project is not proposing any changes to the existing storm system. Per Section 1.2.3 Core Requirements #3: Flow Control Facilities under Exemption From Core Requirement #3 this project has less than 5,000 square feet of new plus replaced impervious surfaces proposed and less than ¾ acres of new pervious surfaces added. Therefore, we are exempt from providing any Flow Control Facilities Per Section 1.2.8 Core Requirements #8: Water Quality Facilities under Exemption From Core Requirement #8 this project has less than 5,000 square feet of new plus replaced impervious surfaces proposed and less than ¾ acres of new pervious surfaces added. Therefore, we are exempt from providing a Water Quality Facility. Technical Information Report Maplewood Heights E.S. 5 2191083.10 There are no Low Impact Developments (LID) proposed for this project. 5.0 Conveyance System Analysis and Design There are no proposed changes to the existing storm system. The existing conveyance system will be protected and maintained throughout this project. 6.0 Special Reports and Studies The project is not proposed any changes to the existing storm system. A Geotechnical Report was not necessary for the scope of the site improvements. The nearest wetland to the site is more than 300 feet to the northeast. The site stormwater is collected on site and discharges on the west side of the site and does not drain towards the wetland. A Wetland Report was not necessary for the scope of the improvements. No other reports and/or studies were needed for the proposed site improvements. 7.0 Other Permits No other permits are required for the proposed site improvements. 8.0 CSWPPP Analysis and Design 8.1 ESC Plan Analysis and Design The proposed development shall comply with guidelines set forth in City of Renton drainage requirements. The plan will include erosion/sedimentation control features designed to prevent sediment-laden runoff from leaving the site or adversely affecting critical water resources during construction. A construction Stormwater Pollution Prevention Plan (CSWPPP) is provided in a separate document. The following measures will be shown on the ESC plans and will be used to control sedimentation/erosion processes: 1. Clearing Limits – All areas to remain undisturbed during the construction of the project will be delineated prior to any site clearing or grading. 2. Cover Measures – Cover measures will be implemented for the disturbed areas. 3. Perimeter Protection – Filter fabric fences for site runoff protection will be provided at the downstream site perimeter. 4. Traffic Area Stabilization – Traffic area stabilization is not applicable for this project. 5. Sediment Retention – Inlet sediment protection will be utilized as part of this project. 6. Surface Water Collection – Catch basins and conveyance pipes will provide surface water collection. 7. Dewatering Control – Water from dewatering operations should be discharged to a well- vegetated area or to a temporary sediment control facility. Technical Information Report Maplewood Heights E.S. 6 2191083.10 8. Dust Control – Dust control measures, including sweeping and water truck, will be implemented when exposed soils are dry to the point that wind transport is possible; and roadways, drainage ways, or surface waters are likely to be impacted. 9. Flow Control – Flow control is not required for this project. 10. Control Pollutants – Stormwater pollution prevention measures will be implemented to prevent, reduce or eliminate the discharge of pollutants to onsite or adjacent stormwater systems. 11. Protect Existing and Proposed Stormwater Facilities and On-site BMPs – Contractor shall inspect and maintained protective measures at all times until the completion of the project. 12. Maintain Protective BMPs – All protective BMPs used during construction will be properly monitored and maintained until the completion of the project. 13. Manage the Project – Contractor shall coordinate in a timely manner all inspection. 8.2 SWPPS Plan Design The project is proposing the replacement and/or installation of pedestrian ramps to meet current ADA requirements. In addition, there will be some minor work in existing grassy areas that will have the potential for dirt and debris to collect in paved areas. Below is a list BMPs from the King County Stormwater Pollution Prevention Manual dated July 2021, that will be applied throughout the extent of the project. • A-20: Concrete and Asphalt Application • A-26: Landscaping Activities, Vegetation Management, and Irrigation • A-27: Clearing and Grading of Land for Small Construction Projects • A-32: Sidewalk Maintenance 9.0 Bond Qualities, Facility Summaries, and Declaration of Covenant Bond Quantities – A Site Improvement Bond Quantities Worksheet has been completed and submitted along with Site Plans and this TIR. Facility Summaries – This project is exempt from Flow Control and Water Quality. A flow Control and Water Quality Facility Summary Sheet and Sketch is not needed for this project. Declaration of Covenant – There are no proposed changes to the existing stormwater system. A Declaration of Covenant is not required for this project. 10.0 Operations and Maintenance Manual Maintenance and operations of all drainage facilities will be maintained by the owner. There are no proposed changes to the existing storm water system. The existing Operations and Maintenance Manual shall be referred to for the existing system. Technical Information Report Maplewood Heights E.S. 7 2191083.10 Conclusion This site has been designed to meet or exceed the requirements of the 2022 City of Renton Surface Water Design Manual (CORSWDM). This analysis is based on data and records either supplied to or obtained by AHBL. These documents are referenced within the text of the analysis. The analysis has been prepared using procedures and practices within the standard accepted practices of the industry. AHBL, Inc. Jason Hein Project Engineer April 2024 Revised June 2024 Q:\2023\2230871\10_CIV\NON_CAD\REPORTS\TIR\20240326 Rpt (TIR) 2230871.docx Technical Information Report Maplewood Heights E.S. 2191083.10 Appendix A Figures 1-1....................TIR Worksheet 1-2....................Vicinity Map 1-3....................Soil Map 3-1....................Erosion Hazards Map 3-2....................Steep Slopes Map 3-3....................Slide Hazard Map 3-4....................Flood Hazard Map 3-5....................Coal Mine Hazard Map 3-6....................Aquifer Protection Map 3-7....................Wetland and Water Classifications Map 3-8....................FEMA Flood Hazard Map 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 __________________ __________________ __________________ Renton School District 425-204-2300 300 SW 7th Street Renton, WA 98057 Jason Hein AHBL Inc. 253-383-2422 Maplewood Heights E.S. 23 5 E 15 130 Jericho Avenue NE Renton, WA 98059 X X April 2024 X April 2024 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 ______________________  _____________________________________ Cedar River - Lake Washington X NE Corner of Site 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 Alderwood gravelly sandy loam 8 - 15 %None 1 Not Required Not Required 1 & 2 N/A To be determined 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: 1 Catch Basin Inlet Protection None Required Commercial None None Required None 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 _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ _____________ XX X X X X X None Required None Required 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 XNone None 2215 North 30th Street Suite 300 Tacoma, WA 98403 253.383.2422 TEL 253.383.2572 FAX Maplewood Heights Elementary School Vicinity Map Figure 1-2 Soil Map—King County Area, Washington Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 3/26/2024 Page 1 of 35258950525898052590105259040525907052591005259130525916052591905259220525925052589505258980525901052590405259070525910052591305259160525919052592205259250564170564200564230564260564290564320564350564380 564170 564200 564230 564260 564290 564320 564350 564380 47° 29' 0'' N 122° 8' 54'' W47° 29' 0'' N122° 8' 43'' W47° 28' 50'' N 122° 8' 54'' W47° 28' 50'' N 122° 8' 43'' WN Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 10N WGS84 0 50 100 200 300 Feet 0 20 40 80 120 Meters Map Scale: 1:1,490 if printed on A portrait (8.5" x 11") sheet. Soil Map may not be valid at this scale. MAP LEGEND MAP INFORMATION Area of Interest (AOI) Area of Interest (AOI) Soils Soil Map Unit Polygons Soil Map Unit Lines Soil Map Unit Points Special Point Features Blowout Borrow Pit Clay Spot Closed Depression Gravel Pit Gravelly Spot Landfill Lava Flow Marsh or swamp Mine or Quarry Miscellaneous Water Perennial Water Rock Outcrop Saline Spot Sandy Spot Severely Eroded Spot Sinkhole Slide or Slip Sodic Spot Spoil Area Stony Spot Very Stony Spot Wet Spot Other Special Line Features Water Features Streams and Canals Transportation Rails Interstate Highways US Routes Major Roads Local Roads Background Aerial Photography The soil surveys that comprise your AOI were mapped at 1:24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: King County Area, Washington Survey Area Data: Version 19, Aug 29, 2023 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jul 31, 2022—Aug 8, 2022 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Soil Map—King County Area, Washington Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 3/26/2024 Page 2 of 3 Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI AgC Alderwood gravelly sandy loam, 8 to 15 percent slopes 9.5 100.0% Totals for Area of Interest 9.5 100.0% Soil Map—King County Area, Washington Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 3/26/2024 Page 3 of 3 Maplewood Heights Elementary School Maplewood Heights Elementary School Maplewood Heights Elementary School Maplewood Heights Elementary School Maplewood Heights Elementary School Maplewood Heights Elementary School Maplewood Heights Elementary School National Flood Hazard Layer FIRMette 0 500 1,000 1,500 2,000250 Feet Ü SEE FIS REPORT FOR DETAILED LEGEND AND INDEX MAP FOR FIRM PANEL LAYOUT SPECIAL FLOODHAZARD AREAS Without Base Flood Elevation (BFE)Zone A, V, A99With BFE or DepthZone AE, AO, AH, VE, AR Regulatory Floodway 0.2% Annual Chance Flood Hazard, Areasof 1% annual chance flood with averagedepth less than one foot or with drainageareas of less than one square mileZone X Future Conditions 1% Annual Chance Flood HazardZone X Area with Reduced Flood Risk due to Levee. See Notes.Zone X Area with Flood Risk due to LeveeZone D NO SCREENArea of Minimal Flood Hazard Zone X Area of Undetermined Flood HazardZone D Channel, Culvert, or Storm Sewer Levee, Dike, or Floodwall Cross Sections with 1% Annual Chance 17.5 Water Surface Elevation Coastal Transect Coastal Transect Baseline Profile Baseline Hydrographic Feature Base Flood Elevation Line (BFE) Effective LOMRs Limit of Study Jurisdiction Boundary Digital Data Available No Digital Data Available Unmapped This map complies with FEMA's standards for the use of digital flood maps if it is not void as described below.The basemap shown complies with FEMA's basemapaccuracy standards The flood hazard information is derived directly from theauthoritative NFHL web services provided by FEMA. This mapwas exported on 3/26/2024 at 8:04 PM and does notreflect changes or amendments subsequent to this date andtime. The NFHL and effective information may change orbecome superseded by new data over time. This map image is void if the one or more of the following map elements do not appear: basemap imagery, flood zone labels, legend, scale bar, map creation date, community identifiers, FIRM panel number, and FIRM effective date. Map images for unmapped and unmodernized areas cannot be used for regulatory purposes. Legend OTHER AREAS OF FLOOD HAZARD OTHER AREAS GENERAL STRUCTURES OTHER FEATURES MAP PANELS 8 B 20.2 The pin displayed on the map is an approximatepoint selected by the user and does not representan authoritative property location. 1:6,000 122°9'12"W 47°29'13"N 122°8'35"W 47°28'49"N Basemap Imagery Source: USGS National Map 2023