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Ex 11_Preliminary TIR.pdf
PRELIMINARY TECHNICAL INFORMATION REPORT FOR Jones Renton Short Plat – South CITY OF RENTON, KING COUNTY, WASHINGTON Project Manager: Flavio Bainotti Prepared by: Michael R Norton, P.E. Brackon Rawlinson, E.I.T. Approved by: Michael Moody, P.E. Date: October 16, 2024 Core No.: 20081K 10-16-2024 Core Design, Inc. Jones Renton Short Plat – South Phase i Table of Contents SECTION 1: PROJECT OVERVIEW ..................................................................................................... 1 SECTION 2: CONDITIONS AND REQUIREMENTS SUMMARY ........................................................... 3 2.1 Core Requirements ............................................................................................................... 4 2.1.1 Core Requirement #1: Discharge at the Natural Location ............................................ 4 2.1.2 Core Requirement #2: Offsite Analysis .......................................................................... 4 2.1.3 Core Requirement #3: Flow Control Facilities ............................................................... 4 2.1.4 Core Requirement #4: Conveyance System .................................................................. 4 2.1.5 Core Requirements #5: Construction Stormwater Pollution Prevention ...................... 4 2.1.6 Core Requirement #6: Maintenance and Operations ................................................... 4 2.1.7 Core Requirement #7: Financial Guarantees and Liability ............................................ 4 2.1.8 Core Requirement #8: Water Quality ............................................................................ 4 2.1.9 Core Requirement #9: On-Site BMPs............................................................................. 4 2.2 Special Requirements ............................................................................................................ 4 2.2.1 Special Requirement #1: Other adopted Area-Specific requirements .......................... 4 2.2.2 Special Requirement #2: Flood Hazard Area Delineation.............................................. 5 2.2.3 Special Requirement #3: Flood Protection Facilities ..................................................... 5 2.2.4 Special Requirement #4: Source Control ....................................................................... 5 2.2.5 Special Requirement #5: Oil Control ............................................................................. 5 2.2.6 Special Requirement #6: Aquifer Protection Area......................................................... 5 SECTION 3: OFFSITE ANALYSIS ......................................................................................................... 6 TASK 1 Study Area Definition and Maps ..................................................................................... 6 TASK 2 Resource Review ............................................................................................................. 6 TASK 3 Field Investigation ........................................................................................................... 6 TASK 4 Drainage System Description and Problem Description ................................................. 6 SECTION 4: FLOW CONTROL AND WATER QUALITY DESIGN .......................................................... 9 4.1 Performance Standards......................................................................................................... 9 4.2 On-Site BMPs......................................................................................................................... 9 4.2.1 BMP Sizing.................................................................................................................... 11 4.3 Soils: Geotechnical Report Summary .................................................................................. 11 Core Design, Inc. Jones Renton Short Plat – South Phase ii 4.4 Flow Control: Peak Rate Flow Control Standards .............................................................. 12 4.5 Water Quality Design .......................................................................................................... 16 SECTION 5: CONVEYANCE SYSTEM ANALYSIS AND DESIGN .......................................................... 18 SECTION 6: SPECIAL REPORTS AND STUDIES ................................................................................. 19 SECTION 7: OTHER PERMITS.......................................................................................................... 20 SECTION 8: ESC ANALYSIS AND DESIGN ........................................................................................ 21 SECTION 9: BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT ...... 22 9.1 Bond Quantities .................................................................................................................. 22 9.2 Facility Summaries .............................................................................................................. 22 9.3 Declaration of Covenant ..................................................................................................... 22 SECTION 10: OPERATIONS AND MAINTENANCE ........................................................................... 23 Appendix A – Parcel & Basin Information King County Parcel Report Appendix B – Resource Review & Off-site Analysis Documentation City Zoning Map FEMA Map (53033C0664G) City Wellhead Protection Area Map City Drainage Basin Map Flow Control Application Map Groundwater Protection Areas Map City Landslide Hazard Areas Map Appendix C – Stormwater Calculations Appendix D – Soils City Soils Map Geotechnical Evaluation NRCS Soils Map and Map Unit Data Core Design, Inc. Jones Renton Short Plat – South Phase Page 1 SECTION 1: PROJECT OVERVIEW The Jones Renton Short Plat – South Phase project site consists of one parcel with a total area of 0.345 acre (15,024 square feet per survey). A proposed Boundary Line Adjustment (being processed concurrently under separate permit) will result in a parcel size of 18,252 square feet (0.419 acre). Approximately 530 square feet (0.012 acre) will be dedicated to the City of Renton, resulting in a property encompassing 17,722 square feet (0.407 acre). The subject property is located on an unaddressed property on Park Avenue N in King County, City of Renton. The project site is bordered by Park Avenue N and single-family residences to the west, a (future) private road and single-family residences to the north, single family residences to the east and an office building and convenience store to the south. The project site is zoned Residential (R-6) and will be developed in accordance with the applicable City of Renton Code. See Figure 1.1 at the end of this section for a vicinity map. The King County tax parcel ID number for the parcel involved is included in Table 1.1 below. (Refer to the King County parcel report included in Appendix ‘A’). Table 1.1 King County Parcel ID KC Parcel # Parcel Area (SF) 334210-3250 15,024 The project site is currently undeveloped and consists of mostly lawn/grass. Access to the residence is via Park Ave N. See the existing conditions exhibit provided in Section 4. The proposed development of the property will include subdividing the parcel into two lots. The project will also include frontage improvements in Park Avenue N, which includes sidewalk and planter strip. The proposed lots will have approximate areas of 8,933 square feet (Lot 1) and 8,789 square feet (Lot 2). Access to the lots will be provided via a shared roadway on the parcel to the north. The project site slopes downward from the northeast to southwest at magnitudes of 5 to 10 percent and a vertical relief of about 15 feet from approximately 214.7 to approximately 202.7. The site has a single drainage basin that drains to the north. A portion of the site is mapped as being within a Moderate Landslide Hazard Area and the entire site is mapped as being within a Wellhead Protection Area, zone 2. The project will be designed using the guidelines and requirements established in the 2022 Renton Surface Water Design Manual (RSWDM). The project is a single-family residential project that will be adding more than 7,000 square feet of new impervious area, so the project falls under Directed Drainage Review. See Section 2 for the flow chart for determining the drainage review required. The project site falls under Peak Rate Flow Control Standard which necessitates matching the developed conditions to the Pre-Developed conditions peak discharge rates for 2-, 10-, 100-year return periods. However, the developed peak discharge rate for the 100-Year Storm Recurrence Event increases less than 0.15 cfs when compared to the existing conditions, therefore flow control facilities are not required. Water quality is not required since the project will add less than 5,000 square feet of pollution generating impervious surface (PGIS). Core Design, Inc. Jones Renton Short Plat – South Phase Page 2 Figure 1.1 Vicinity Map Core Design, Inc. Jones Renton Short Plat – South Phase Page 3 SECTION 2: CONDITIONS AND REQUIREMENTS SUMMARY The proposed project is classified as requiring “Directed Drainage Review” per Figure 1.1.2.A of the 2022 RSWDM. Therefore, all nine Core Requirements and six Special Requirements will be addressed per Section 1.2 of the 2022 RSWDM. Core Design, Inc. Jones Renton Short Plat – South Phase Page 4 2.1 Core Requirements 2.1.1 Core Requirement #1: Discharge at the Natural Location This project will match the natural discharge location towards Park Avenue N to the west and the two parcels to the south (334210-3251 and 334210-3248) to the maximum extent practicable. The site is within the West Kennydale Drainage Basin. Refer to Appendix ‘B’ of this report for West Kennydale Drainage Basin Map. 2.1.2 Core Requirement #2: Offsite Analysis This core requirement is addressed in Section 3 of this report. See Section 3 for a description of the downstream (offsite) analysis. 2.1.3 Core Requirement #3: Flow Control Facilities Per the City’s Flow Control Application ap, the site falls within the Peak Rate Flow Control area matching Existing Site Conditions (Refer to Appendix ‘B’ for the City of Renton Flow Control Application Map). The site contains one drainage basin. See Section 4 of this report for the analysis of the basin and determination of flow control facilities. 2.1.4 Core Requirement #4: Conveyance System Core Requirement #4 will be addressed during Final Design. 2.1.5 Core Requirements #5: Construction Stormwater Pollution Prevention Core Requirement #5 will be addressed during Final Design. 2.1.6 Core Requirement #6: Maintenance and Operations Core Requirement #6 will be addressed during Final Design. 2.1.7 Core Requirement #7: Financial Guarantees and Liability Core Requirement #7 will be addressed during Final Design. 2.1.8 Core Requirement #8: Water Quality This project is located within a Basic Water Quality Treatment Area. However, the project adds less than 5,000 square feet of PGIS, therefore water quality treatment is not required. 2.1.9 Core Requirement #9: On-Site BMPs The project will implement feasible flow control BMPs to mitigate the impact of storm and surface water runoff from development. Refer to Section 4 of this report for further discussion and design of proposed on-site BMPs. 2.2 Special Requirements 2.2.1 Special Requirement #1: Other adopted Area-Specific requirements Not applicable. No Area-specific requirements were found. Core Design, Inc. Jones Renton Short Plat – South Phase Page 5 2.2.2 Special Requirement #2: Flood Hazard Area Delineation The project is not located adjacent to a flood hazard area. Therefore, the site is not subject to this requirement. 2.2.3 Special Requirement #3: Flood Protection Facilities There are no levees, revetments, or berms within the project boundary. 2.2.4 Special Requirement #4: Source Control The proposed project is single family development. Source control BMPs are not required. 2.2.5 Special Requirement #5: Oil Control The project is not a commercial development nor high use site as defined in the RSDWM. Therefore, oil control BMPs will not be implemented for the project. 2.2.6 Special Requirement #6: Aquifer Protection Area The project is inside the Five-Year Capture Zone for the PW-5A production well. Refer to Appendix ‘B’ of this report for the Groundwater Protection Areas Map Reference 15-B. In Zone 2, a liner may be required for infiltration facilities. Core Design, Inc. Jones Renton Short Plat - South Page 6 SECTION 3: OFFSITE ANALYSIS TASK 1 Study Area Definition and Maps The proposed project contains parcel number 334210-3250, any upstream tributary area and the downstream flow path of 1/4-mile. TASK 2 Resource Review Basin Reconnaissance Summary Reports No Basin Reconnaissance Summary Reports are available for the area within one quarter mile of the project site. FEMA Maps FEMA FIRMette 53033C0664G (effective 8/19/2020) indicates the site is within “Zone X” which is outside of the 500-year floodplain. The FEMA FIRMette is included in Appendix ‘B’ of this report. Sensitive Areas Folio The City of Renton Critical Areas Maps were reviewed to confirm whether the project site is located within a wetland, stream, seismic, landslide, or erosion hazard area (Critical Area Maps are included in Appendix ‘B’). The maps show the site is located within a Moderate landslide hazard area. The site is also within a Zone 2 Wellhead Protection Area. Downstream Drainage Complaints Drainage complaints were researched within a quarter mile of the project site. Based on the King County GIS Drainage Complaints Map. The area downstream of the project site shows no active drainage complaints along the downstream drainage path. TASK 3 Field Investigation Upstream Tributary Analysis Upstream Tributary runon is limited to the area between the internal roadway for the Jones Renton Short Plat to the north and is considered to be negible. TASK 4 Drainage System Description and Problem Description Runoff from the subject property sheet flows west into Park Ave N or south onto Parcels 334210-3251 and 334210-3248 and into the Conveyance system within N 30th Street and flows west. The flow entering Park Ave N flows south and enters the existing conveyance system and flows south. These flows combine at the northeast corner of the intersection of Park Ave N and N 30th St to flow west approximately 577 feet, then flows north across Parcel 334210-1429 for approximately 111 feet, the flows west across Parcel 334210-1434 for approximately 65 feet, then flows north across Parcel 334210-1305 for approximately 120 feet, then Core Design, Inc. Jones Renton Short Plat - South Page 7 flows west within the N 31st St conveyance system for approximately 654 feet to the southeast corner of the intersection of N 31st St and Burnett Ace N, then flows north approximately 30 feet to the northeast corner of the intersection of N 31 st St and Burnett Ave N, then flows west approximately 40 feet to the northwest corner of the intersection of N 31st St and Burnett Ave N, then flows north within the Burnett Ave N conveyance system for approximately 1,072 feet to the southwest corner of the intersection of Burnett Ave N and N 34th St, then is conveyed west underneath City of Renton Property for approximately 178 feet, then flows approximately 178 feet south within the conveyance system on the east side of Lake Washington Blvd N, then flows northwest approximately 98 feet to discharge into Lake Washington. The conveyance system appeared clean from all debris and blockage. No erosion was noticed. The drainage path described above encompasses the ¼ mile distance offsite. 4,514 376 Downstream Flow Path Legend 2560128 Feet Notes 256 WGS_1984_Web_Mercator_Auxiliary_Sphere All data, information, and maps are provided "as is" without warranty or any representation of accuracy, timeliness of completeness. The burden for determining accuracy, completeness, timeliness, merchantability and fitness for or the appropriateness for use rests solely on the user. Streets Points of Interest Parks Waterbodies 2021.sid Red: Band_1 Green: Band_2 Blue: Band_3 Core Design, Inc. Jones Renton Short Plat - South Page 9 SECTION 4: FLOW CONTROL AND WATER QUALITY DESIGN 4.1 Performance Standards All stormwater facilities will be designed using the guidelines and requirements established in the 2022 Renton Surface Water Design Manual (RSWDM). The project is located in a Peak Rate Flow Control Standard area which allows for the existing site conditions to be modeled as the existing conditions of the site immediately prior to the proposed development. Per Section 1.2.3.1 of the RSWDM, the project is not required to provide flow control facilities because the peak flow during the 100-Year Storm Recurrence Event increases less than 0.15 cfs in the Post-Developed condition when compared to the existing condition. Refer to Subsection 4.4 of this report for the basin analysis. 4.2 On-Site BMPs The project is proposing to subdivide the parcel into two (2) lots. The project site is less than five acres in size and is required to meet the Small Subdivision Project BMP Requirements per Section 1.2.9.3.1 of the RSWDM. Individual Lot BMP requirement per Section 1.2.9.2 of the RSWDM will be used to evaluate the BMP for each lot in the following order. Each lot is smaller than 22,000 square feet; thus, the Small Lot BMP Requirements will be evaluated to mitigated target impervious surface onsite to the maximum extent feasible. All sections referenced below are to be found in the RSWDM. Small Lot BMP Requirement 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. Response: Full dispersion BMPs are not feasible as there is insufficient room to provide the required 100-foot flow path through native vegetation. 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 of roof runoff as detailed in Appendix C, Section C.2.2 must be evaluated. Response: Per the Draft Geotechnical Evaluation by Earth Solutions NW (ESNW), dated November 27, 2023, infiltration is feasible where cleaner sand deposits are exposed underlying low permeability layers. Full Infiltration is utilized to the maximum extent practicable for proposed rooftops on both lots. 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. Full Infiltration per Appendix C, Section C.2.2, or per Section 5.2, whichever is applicable. Response: Per the Draft Geotechnical Evaluation by Earth Solutions NW (ESNW), dated November 27, 2023, infiltration is feasible where cleaner sand deposits are exposed underlying low permeability layers. Full Infiltration is utilized to the maximum extent Core Design, Inc. Jones Renton Short Plat - South Page 10 practicable. Driveways are not routed to infiltration drywells due to being pollution generating and feasible onsite soils are not certain to provide soil suitability criteria for treatment. Limited Infiltration per Appendix C, Section C.2.3, Response: Per the Draft Geotechnical Evaluation by Earth Solutions NW (ESNW), dated November 27, 2023, infiltration is feasible where cleaner sand deposits are exposed underlying low permeability layers. Full Infiltration is utilized to the maximum extent practicable. Limited Infiltration BMPs are not proposed for driveways due to being pollution generating and feasible onsite soils are not certain to provide soil suitability criteria for treatment. Rain Gardens per Appendix C, Section C.2.12, sized as follows: Rain gardens have a maximum contributing area of 5,000 square feet. Rain gardens must have a minimum horizontal projected surface area below the overflow that is at least 5% of the area draining to it. Response: Due to onsite slopes and utilization of full infiltration Rain Gardens are infeasible/not applicable. Bioretention per Appendix C, Section C.2.6 Response: Due to onsite slopes and utilization of full infiltration Bioretention BMPs are infeasible/not applicable. Perméable Pavement per Appendix C, Section C.2.7 Response: Per the Draft Geotechnical Evaluation by Earth Solutions NW (ESNW), dated November 27, 2023, infiltration is feasible where cleaner sand deposits are exposed underlying low permeability layers. Full Infiltration is utilized to the maximum extent practicable. Driveways are not proposed to be permeable pavement due to being pollution generating and feasible onsite soils are not certain to provide soil suitability criteria for treatment. 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 per Appendix C, Section C.2.4 Response: Due to site constraints Basic Dispersion BMPs are infeasible as the required flow path cannot be attained. 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. Response: BMPs are implemented for the required impervious area for each lot. 6. The soil moisture holding capacity of new pervious surfaces (target pervious surfaces) must be protected in accordance with the soil amendment BMP as detailed in Appendix C, Section C.2.13 Core Design, Inc. Jones Renton Short Plat - South Page 11 Response: The project will implement soil amendment BMP on all disturbed soils not receiving hard surfacing in the developed condition within the disturbance limits of the project. 7. 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. Response: Not applicable. 4.2.1 BMP Sizing Full Infiltration is proposed for both Lots. The project proposes to construct drywells sized to infiltrate 100% of the stormwater runoff from all proposed impervious surfacing on each lot. The drywells are designed in accordance with Section C2.2.4 of the RSWDM, which states, “When located in medium sands, drywells must contain at least 90 cubic feet of gravel per 1,000 square feet of impervious surface served”. To determine the impervious surface coverage on each Lot, the lesser of the maximum allowed by RMC 4-2-110A (55% for R-6 zoning) or 4,000 square feet was chosen. For both lots, 4,000 was the lesser number. Sizing of the drywells shown here is subject to change as site layouts are developed through the Design/Approval/Permitting process. Drywell sizing is as follows: Each lot has a total maximum impervious surface area of 4,000 square feet. That means drywell storage (V1) of at least 360 cubic feet must be provided on the lot. 4,000 1,000 =𝑉ଵ 90 →𝑉ଵ = 360 𝑐𝑓 Assuming the infiltration drywells for Lots 1 and 2 have a drain rock gravel depth of 5’ (H1) the required radius, (R1), is determined as follows: 𝑉ଵ =𝜋 × (𝑅ଵ )ଶ × 𝐻ଵ 𝑅ଵ =ඨ൬ 𝑉ଵ 𝜋× 𝐻ଵ ൰ =ඨ൬ 360 𝜋× 5 ൰ = 4.8 𝑓𝑒𝑒𝑡= 5 𝑓𝑒𝑒𝑡 (𝑜𝑟 10 𝑓𝑜𝑜𝑡 𝑑𝑖𝑎𝑚𝑒𝑡𝑒𝑟) 4.3 Soils: Geotechnical Report Summary A Draft Geotechnical Evaluation for the proposed Short Plat was prepared by Earth Solutions NW, Inc., on November 27, 2023. Topsoil was observed extending to depths of approximately 6 to 12 inches below the existing ground surface (bgs). The topsoil was characterized by dark brown color and fine organic material. Underlying topsoil, native soil primarily consisted of silty sand and silt with sand (USCS: SM and ML, respectively) overlying sands with varying silt content (USCS: SP and SP-SM). The cleaner sand deposits were encountered beginning at depths of about four and one-half to six and one-half feet bgs. Native soil was generally encountered in a medium dense to dense and moist condition. The maximum exploration depth was approximately 12 feet bgs. The Natural Resources Conservation Service maps site soils as: Core Design, Inc. Jones Renton Short Plat - South Page 12 100% Indianola Loamy Sand, 0 to 15 Percent Slopes (InC) See Appendix ‘D’ for the Geotechnical Evaluation, City of Renton Soil Map and the NRCS Soil Map and Map Unit Data. 4.4 Flow Control: Peak Rate Flow Control Standards Existing Conditions The site has a single Threshold Discharge Area (TDA) that drains to the southwest toward Park Avenue N to the west and over Parcels 3342103251 and 3342103248 to the south. Per Section 1.2.3.1 of the RSWDM, the project could be exempt from flow control facilities if the basin does not cause more than a 0.15 cfs increase to the 100-year peak flow rate in the developed condition compared to the 100-year peak flow rate for the existing condition. Table 4.1 indicates the Pre-Construction Land Use and associated area(s) withing the clearing limits as modeled with WWHM. Note that the areas presented in all storm calculations represent the final condition after the Boundary Line Adjustment and Right-of-Way Dedication are complete. Table 4-1: Pre-Construction Land Use and Areas (WWHM Modeling) Land Cover Area (ac) On-Site: A/B, Pasture, Flat 0.395 Off-Site, Pasture, Flat 0.065 TOTAL 0.460 See Figure 4.1 for a Pre-Developed Basin Map (To be provided further in the Design/Approval/Permitting process). Core Design, Inc. Jones Renton Short Plat - South Page 13 Insert Pre-Developed Basin Map (To be provided further in the Design/Approval/Permitting process). Core Design, Inc. Jones Renton Short Plat - South Page 14 Developed Basin The developed site will consist of 2 single family residences with driveways and associated improvements. Right-of-Way improvements within Park Ave N mainly consist of planter and sidewalk. The stormwater runoff from each of the rooftops will be directed to infiltration drywells, which are designed in accordance with Section C.2.2.4 of the RSWDM. Since these areas are fully infiltrated, they can be subtracted from the final calculations. Table 4-2 presents the Developed Land Use and Areas (Before subtraction of the roofs). See Figure 4.2 for a Developed Basin Map (To be provided further in the Design/Approval/Permitting process). Table 4-2: Developed Areas (Before Subtraction of Infiltrated Areas) Land Cover Area (ac) Modeled As Onsite: Driveway 0.031 Driveways/Moderate Onsite: Roof 0.154 Rooftops/Flat Onsite: Lawn/Landscape 0.210 A/B, Lawn, Flat Offsite: Sidewalk 0.008 Sidewalks/Flat Offsite: Driveway 0.017 Driveway/Moderate Offsite: Road 0.008 Road/Flat Offsite: Lawn/Landscape 0.032 A/B, Lawn, Flat TOTAL: 0.460 - Table 4-3 presents the Developed Land Use and Areas (After subtraction of the roofs). Table 4-3: Developed Areas (After Subtraction of Infiltrated Areas) Land Cover Area (ac) Modeled As Onsite: Driveway 0.031 Driveways/Moderate Onsite: Roof -- -- Onsite: Lawn/Landscape 0.210 A/B, Lawn, Flat Offsite: Sidewalk 0.008 Sidewalks/Flat Offsite: Driveway 0.017 Driveway/Moderate Offsite: Road 0.008 Road/Flat Offsite: Lawn/Landscape 0.032 A/B, Lawn, Flat TOTAL: 0.306 - Core Design, Inc. Jones Renton Short Plat - South Page 15 Insert Developed Basin Map (To be provided further in the Design/Approval/Permitting process). Core Design, Inc. Jones Renton Short Plat - South Page 16 Table 4-3 presents the Pre- and Post-Developed Peak Flows for the 2-, 10-, 25-, 50- and 100-Year Storm Recurrence Events: Table 4-3: Pre- and Post-Developed Peak Flows Recurrence Event Pre-Developed (cfs) Post-Developed (cfs) 2-Year 0.0005 0.0280 10-Year 0.0018 0.0477 25-Year 0.0033 0.0602 50-Year 0.0050 0.0707 100-Year 0.0074 0.0824 The difference between Pre- and Post-Developed flows for the 100-Year Storm Recurrence Event is 0.075 cfs. Therefore, the flow control facility requirement for this project is waived. Stormwater Calculations are Presented in Appendix ‘C’. 4.5 Water Quality Design Since the project is a single-family residential development, it is required to meet Basic water quality requirements per Section 1.2.8.1 and Figure 6.1.A (see below) of the RSWDM. However, the project could be eligible for a water quality exemption if less than 5,000 square feet of new plus replaced PGIS that is not fully dispersed will be created, and less than ¾ acre of new PGPS that is not fully dispersed will be added. Table 4-4 below lists the PGIS areas created by the project. Table 4-4: Pollution Generating Impervious Surfacing Areas Land Cover Area (sf) Lot 1 Driveway 1,058 Lot 2 Driveway 1,057 Road 300 TOTAL: 2,415 The project will create less than 5,000 square feet of new plus replaced PGIS and less than 3/4 acre of new PGPS which is not fully dispersed. Therefore, the project qualifies for a water quality exemption . For the proposed infiltration facilities, a liner may be required as the project lies within Zone 2 of the Aquifer Protection Area (APA). The driveways will convey stormwater toward the future Jones Short Plat, submitted under permit #LUA20-000237, which has a water quality system sized to provide water quality treatment for the driveway areas from this project. Core Design, Inc. Jones Renton Short Plat - South Page 17 Core Design, Inc. Jones Renton Short Plat - South Page 18 SECTION 5: CONVEYANCE SYSTEM ANALYSIS AND DESIGN * This section will be provided in Final Design. Core Design, Inc. Jones Renton Short Plat - South Page 19 SECTION 6: SPECIAL REPORTS AND STUDIES Geotechnical Evaluation – Proposed Short Plat Prepared for: Jones Renton Short Plat - South Prepared by: Earth Solutions NW LLC Dated: November 27, 2023 15365 N.E. 90th Street, Suite 100 Redmond, WA 98052 Core Design, Inc. Jones Renton Short Plat - South Page 20 SECTION 7: OTHER PERMITS The following additional permits are anticipated to be required for this project: Right of Way Use Permit Building Permits Core Design, Inc. Jones Renton Short Plat - South Page 21 SECTION 8: ESC ANALYSIS AND DESIGN * This Section will be provided in Final Design. Core Design, Inc. Jones Renton Short Plat - South Page 22 SECTION 9: BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT 9.1 Bond Quantities To be provided as requested by the City of Renton during Final Design. 9.2 Facility Summaries To be provided as requested by the City of Renton during Final Design. 9.3 Declaration of Covenant To be provided as requested by the City of Renton during Final Design. Core Design, Inc. Jones Renton Short Plat - South Page 23 SECTION 10: OPERATIONS AND MAINTENANCE * To be provided as needed during Final Design. Appendix A Parcel & Basin Information PARCEL Parcel Number 334210-3250 Name JONES CATHERINE+CAROLYN Site Address Legal HILLMANS LK WN GARDEN OF EDEN # 1 S 200 FT LESS E 60 FT LESS W 147 FT OF S 125 FT LESS W 50 FT OF E 110 FT OF S 120 FT BUILDING 1 Year Built Total Square Footage Number Of Bedrooms Number Of Baths Grade Condition Lot Size 15025 Views Yes Waterfront TOTAL LEVY RATE DISTRIBUTION Tax Year: 2024 Levy Code: 2100 Total Levy Rate: $10.50414 Total Senior Rate: $5.39850 55.20% Voter Approved Click here to see levy distribution comparison by year. TAX ROLL HISTORY Valued Year Tax Year Appraised Land Value ($) Appraised Imps Value ($) Appraised Total ($) Appraised Imps Increase ($) Taxable Land Value ($) Taxable Imps Value ($) Taxable Total ($) 2023 2024 675,000 0 675,000 0 675,000 0 675,000 2022 2023 829,000 0 829,000 0 829,000 0 829,000 2021 2022 546,000 0 546,000 0 546,000 0 546,000 2020 2021 537,000 0 537,000 0 537,000 0 537,000 2019 2020 560,000 0 560,000 0 560,000 0 560,000 2018 2019 515,000 0 515,000 0 515,000 0 515,000 2017 2018 469,000 0 469,000 0 469,000 0 469,000 2016 2017 416,000 0 416,000 0 416,000 0 416,000 2015 2016 386,000 0 386,000 0 386,000 0 386,000 2014 2015 345,000 0 345,000 0 345,000 0 345,000 2013 2014 300,000 0 300,000 0 300,000 0 300,000 2012 2013 246,000 0 246,000 0 246,000 0 246,000 2011 2012 239,000 0 239,000 0 239,000 0 239,000 2010 2011 277,000 0 277,000 0 277,000 0 277,000 2009 2010 313,000 0 313,000 0 313,000 0 313,000 2008 2009 369,000 0 369,000 0 369,000 0 369,000 2007 2008 330,000 0 330,000 0 330,000 0 330,000 2006 2007 180,000 0 180,000 0 180,000 0 180,000 2005 2006 170,000 0 170,000 0 170,000 0 170,000 2004 2005 159,000 0 159,000 0 159,000 0 159,000 2003 2004 150,000 0 150,000 0 150,000 0 150,000 2002 2003 144,000 0 144,000 0 144,000 0 144,000 2001 2002 135,000 0 135,000 0 135,000 0 135,000 2000 2001 105,000 0 105,000 0 105,000 0 105,000 1999 2000 93,000 0 93,000 0 93,000 0 93,000 1998 1999 82,000 0 82,000 0 82,000 0 82,000 1997 1998 0 0 0 0 75,000 0 75,000 1996 1997 0 0 0 0 72,100 0 72,100 1994 1995 0 0 0 0 72,100 0 72,100 1992 1993 0 0 0 0 62,200 0 62,200 1990 1991 0 0 0 0 54,100 0 54,100 1988 1989 0 0 0 0 34,000 0 34,000 1986 1987 0 0 0 0 33,800 0 33,800 1984 1985 0 0 0 0 30,000 0 30,000 1982 1983 0 0 0 0 30,000 0 30,000 ADVERTISEMENT Appendix B Resource Review & Off-site Analysis Documentation 9,028 752 City of Renton Zoning Map This map is a user generated static output from an Internet mapping site and is for reference only. Data layers that appear on this map may or may not be accurate, current, or otherwise reliable. None 8/14/2020 Legend 5120256 THIS MAP IS NOT TO BE USED FOR NAVIGATION Feet Notes 512 WGS_1984_Web_Mercator_Auxiliary_Sphere Information Technology - GIS RentonMapSupport@Rentonwa.gov City and County Labels City and County Boundary Parcels Zoning RC-Resource Conservation R1-Residential 1 du/ac R4-Residential 4 du/ac R6-Residential - 6 DU/AC R8-Residential 8 du/ac R10-Residential 10 du/ac R14-Residential 14 du/ac RMF-Residential Multi-Family RMH-Residential Manufactured Homes CN-Commercial Neighborhood CV-Center Village CA-Commercial Arterial UC-Urban Center CD-Center Downtown COR-Commercial Office/Residential CO-Commercial Office IL-Industrial - Light IM-Industrial - Medium IH-Industrial - Heavy Overlay Districts Auto Mall A Auto Mall B 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 FLOOD HAZARD AREAS Without Base Flood Elevation (BFE) Zone A, V, A99 With BFE or DepthZone AE, AO, AH, VE, AR Regulatory Floodway 0.2% Annual Chance Flood Hazard, Areas of 1% annual chance flood with average depth less than one foot or with drainage areas 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 SCREEN Area 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 basemap accuracy standards The flood hazard information is derived directly from the authoritative NFHL web services provided by FEMA. This map was exported on 5/3/2024 at 3:41 PM and does not reflect changes or amendments subsequent to this date and time. The NFHL and effective information may change or become 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 approximate point selected by the user and does not represent an authoritative property location. 1:6,000 122°12'23"W 47°31'23"N 122°11'45"W 47°30'59"N Basemap Imagery Source: USGS National Map 2023 9,028 752 City of Renton Wellhead Protection Area This map is a user generated static output from an Internet mapping site and is for reference only. Data layers that appear on this map may or may not be accurate, current, or otherwise reliable. None 8/14/2020 Legend 5120256 THIS MAP IS NOT TO BE USED FOR NAVIGATION Feet Notes 512 WGS_1984_Web_Mercator_Auxiliary_Sphere Information Technology - GIS RentonMapSupport@Rentonwa.gov City and County Labels City and County Boundary Parcels Wellhead Protection Area Zones Zone 1 Zone 1 Modified Zone 2 Environment Designations Natural Shoreline High Intensity Shoreline Isolated High Intensity Shoreline Residential Urban Conservancy Jurisdictions Streams (Classified) <all other values> Type S Shoreline Type F Fish Type Np Non-Fish Type Ns Non-Fish Seasonal Unclassified Not Visited Wetlands Streets Parks Waterbodies 4,514 376 City of Renton Drainage Basin This map is a user generated static output from an Internet mapping site and is for reference only. Data layers that appear on this map may or may not be accurate, current, or otherwise reliable. None 8/14/2020 Legend 2560128 THIS MAP IS NOT TO BE USED FOR NAVIGATION Feet Notes 256 WGS_1984_Web_Mercator_Auxiliary_Sphere Information Technology - GIS RentonMapSupport@Rentonwa.gov City and County Labels City and County Boundary Addresses Parcels Drainage Sub Basins <all other values> Black River Boren Creek Cabbage Creek Cedar Grove Cedar Main Urban China Creek Country Creek Duamish East Fork May Creek Garrison Creek Ginger Creek Greenes Creek Gypsy Honey Creek Jenkins Creek Main Lake Kathleen Lake Washington - East Lake Washington - West Johns Creek Lake Washington South Lake Desire Shady Lake (Mud Lake) Panther Lake Lake Youngs Lake Washington B l a c k Ri v e r Gre e n Ri v e r C e darRi v er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§- ,§- ,§- q 0LOHV )ORZ&RQWURO$SSOLFDWLRQ0DS 5HIHUHQFH$ 'DWH )ORZ&RQWURO6WDQGDUGV 3HDN5DWH)ORZ&RQWURO6WDQGDUG ([LVWLQJ6LWH&RQGLWLRQV )ORZ&RQWURO'XUDWLRQ6WDQGDUG ([LVWLQJ6LWH&RQGLWLRQV )ORZ&RQWURO'XUDWLRQ6WDQGDUG )RUHVWHG&RQGLWLRQV )ORRG3UREOHP)ORZ 8QLQFRUSRUDWHG.LQJ&RXQW\)ORZ&RQWURO6WDQGDUGV 5HQWRQ&LW\/LPLWV 3RWHQWLDO$QQH[DWLRQ$UHD !!! ! ! !!!!! ! ! !! ! ! !! ! !! 3: 3: 3: 3: 3: 3: 5: 5: (: 3:$ 3: 3: ,§- ,§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edar River Green River Black River May Creek Duwamish Waterway Springbrook Creek Lake Washington Lake Youngs Panther Lake Lake Boren 5HIHUHQFH% :HOOILHOG&DSWXUH=RQHV 2QH<HDU&DSWXUH=RQH )LYH<HDU&DSWXUH=RQH 7HQ<HDU&DSWXUH=RQH &HGDU9DOOH\6ROH6RXUFH $TXLIHU3URMHFW5HYLHZ$UHD 6WUHDPIORZ6RXUFH$UHD &HGDU9DOOH\6ROH6RXUFH$TXLIHU $TXLIHU3URWHFWLRQ$UHD=RQHV =RQH =RQH0RGLILHG =RQH 1HWZRUN6WUXFWXUH !3URGXFWLRQ:HOO !6SULQJEURRN6SULQJV 5HQWRQ&LW\/LPLWV 3RWHQWLDO$QQH[DWLRQ$UHD *URXQGZDWHU3URWHFWLRQ$UHDV 'DWH q 0LOHV 4,514 376 City of Renton Landslide Hazard Area This map is a user generated static output from an Internet mapping site and is for reference only. Data layers that appear on this map may or may not be accurate, current, or otherwise reliable. None 8/14/2020 Legend 2560128 THIS MAP IS NOT TO BE USED FOR NAVIGATION Feet Notes 256 WGS_1984_Web_Mercator_Auxiliary_Sphere Information Technology - GIS RentonMapSupport@Rentonwa.gov City and County Labels City and County Boundary Addresses Parcels Landslide Very High High Moderate Unclassified Environment Designations Natural Shoreline High Intensity Shoreline Isolated High Intensity Shoreline Residential Urban Conservancy Jurisdictions Streams (Classified) <all other values> Type S Shoreline Type F Fish Type Np Non-Fish Type Ns Non-Fish Seasonal Unclassified Not Visited Wetlands Inactive Structures Appendix C Stormwater Calculations WWHM2012 PROJECT REPORT Flow Control South 10/15/2024 4:16:20 PM Page 2 General Model Information WWHM2012 Project Name:Flow Control South Site Name:Jones Short Plat South Site Address: City:Renton Report Date:10/15/2024 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 Flow Control South 10/15/2024 4:16:20 PM Page 3 Landuse Basin Data Predeveloped Land Use Existing Onsite Conditions Bypass:No GroundWater:No Pervious Land Use acre A B, Pasture, Flat 0.395 Pervious Total 0.395 Impervious Land Use acre Impervious Total 0 Basin Total 0.395 Flow Control South 10/15/2024 4:16:20 PM Page 4 Existing Offsite Conditions Bypass:No GroundWater:No Pervious Land Use acre A B, Pasture, Flat 0.065 Pervious Total 0.065 Impervious Land Use acre Impervious Total 0 Basin Total 0.065 Flow Control South 10/15/2024 4:16:20 PM Page 5 Mitigated Land Use Developed Onsite Conditions Bypass:No GroundWater:No Pervious Land Use acre A B, Lawn, Flat 0.21 Pervious Total 0.21 Impervious Land Use acre ROADS MOD 0.031 Impervious Total 0.031 Basin Total 0.241 Flow Control South 10/15/2024 4:16:20 PM Page 6 Developed Offsite Conditions Bypass:No GroundWater:No Pervious Land Use acre A B, Lawn, Flat 0.032 Pervious Total 0.032 Impervious Land Use acre ROADS FLAT 0.008 ROADS FLAT 0.017 SIDEWALKS FLAT 0.008 Impervious Total 0.033 Basin Total 0.065 Flow Control South 10/15/2024 4:16:20 PM Page 7 Routing Elements Predeveloped Routing Flow Control South 10/15/2024 4:16:21 PM Page 8 Mitigated Routing Flow Control South 10/15/2024 4:16:21 PM Page 9 Analysis Results POC 1 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area:0.46 Total Impervious Area:0 Mitigated Landuse Totals for POC #1 Total Pervious Area:0.242 Total Impervious Area:0.064 Flow Frequency Method:Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.000489 5 year 0.001112 10 year 0.001835 25 year 0.003316 50 year 0.005017 100 year 0.007444 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.027978 5 year 0.039034 10 year 0.047658 25 year 0.06016 50 year 0.070726 100 year 0.082441 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 0.000 0.035 1950 0.008 0.049 1951 0.002 0.028 1952 0.000 0.018 1953 0.000 0.021 1954 0.000 0.025 1955 0.000 0.025 1956 0.002 0.027 1957 0.000 0.026 1958 0.000 0.022 Flow Control South 10/15/2024 4:16:47 PM Page 10 1959 0.000 0.023 1960 0.001 0.026 1961 0.001 0.023 1962 0.000 0.020 1963 0.000 0.024 1964 0.001 0.023 1965 0.000 0.028 1966 0.000 0.019 1967 0.001 0.046 1968 0.000 0.039 1969 0.000 0.024 1970 0.000 0.024 1971 0.000 0.029 1972 0.004 0.044 1973 0.000 0.019 1974 0.000 0.027 1975 0.000 0.030 1976 0.000 0.022 1977 0.000 0.022 1978 0.000 0.030 1979 0.000 0.038 1980 0.000 0.037 1981 0.000 0.026 1982 0.000 0.037 1983 0.000 0.031 1984 0.000 0.019 1985 0.000 0.026 1986 0.000 0.023 1987 0.000 0.035 1988 0.000 0.022 1989 0.000 0.032 1990 0.001 0.093 1991 0.001 0.050 1992 0.000 0.019 1993 0.000 0.021 1994 0.000 0.020 1995 0.001 0.024 1996 0.010 0.046 1997 0.001 0.030 1998 0.000 0.025 1999 0.002 0.062 2000 0.000 0.025 2001 0.000 0.030 2002 0.000 0.031 2003 0.000 0.030 2004 0.000 0.050 2005 0.000 0.021 2006 0.000 0.025 2007 0.022 0.098 2008 0.001 0.051 2009 0.000 0.035 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.0216 0.0984 2 0.0100 0.0930 3 0.0083 0.0618 Flow Control South 10/15/2024 4:16:47 PM Page 11 4 0.0040 0.0510 5 0.0022 0.0502 6 0.0019 0.0500 7 0.0016 0.0490 8 0.0015 0.0459 9 0.0011 0.0455 10 0.0011 0.0437 11 0.0009 0.0387 12 0.0009 0.0383 13 0.0008 0.0374 14 0.0008 0.0369 15 0.0006 0.0355 16 0.0006 0.0353 17 0.0004 0.0348 18 0.0004 0.0319 19 0.0004 0.0311 20 0.0004 0.0307 21 0.0004 0.0302 22 0.0004 0.0300 23 0.0004 0.0299 24 0.0004 0.0298 25 0.0004 0.0296 26 0.0004 0.0292 27 0.0004 0.0283 28 0.0004 0.0277 29 0.0004 0.0270 30 0.0004 0.0268 31 0.0004 0.0263 32 0.0004 0.0259 33 0.0004 0.0258 34 0.0004 0.0257 35 0.0004 0.0255 36 0.0004 0.0251 37 0.0004 0.0248 38 0.0004 0.0246 39 0.0004 0.0245 40 0.0004 0.0243 41 0.0004 0.0242 42 0.0004 0.0239 43 0.0004 0.0236 44 0.0004 0.0231 45 0.0004 0.0231 46 0.0004 0.0229 47 0.0004 0.0227 48 0.0004 0.0221 49 0.0004 0.0218 50 0.0004 0.0218 51 0.0004 0.0217 52 0.0004 0.0211 53 0.0004 0.0206 54 0.0004 0.0205 55 0.0003 0.0195 56 0.0003 0.0195 57 0.0003 0.0194 58 0.0003 0.0188 59 0.0003 0.0187 60 0.0003 0.0186 61 0.0003 0.0177 Flow Control South 10/15/2024 4:16:47 PM Page 12 Flow Control South 10/15/2024 4:16:47 PM Page 13 Duration Flows The Duration Matching Failed Flow(cfs)Predev Mit Percentage Pass/Fail 0.0002 3538 233138 6589 Fail 0.0003 1852 219663 11860 Fail 0.0003 721 208327 28894 Fail 0.0004 156 198274 127098 Fail 0.0004 140 189462 135330 Fail 0.0005 126 181783 144272 Fail 0.0005 114 174746 153285 Fail 0.0006 107 168159 157157 Fail 0.0006 92 162170 176271 Fail 0.0007 86 156716 182227 Fail 0.0007 77 151582 196859 Fail 0.0008 70 146877 209824 Fail 0.0008 67 142407 212547 Fail 0.0009 60 138172 230286 Fail 0.0009 58 133979 230998 Fail 0.0010 53 130194 245649 Fail 0.0010 51 126558 248152 Fail 0.0011 50 123050 246100 Fail 0.0011 48 119735 249447 Fail 0.0012 44 116548 264881 Fail 0.0012 41 113510 276853 Fail 0.0013 36 110623 307286 Fail 0.0013 35 107821 308060 Fail 0.0014 33 105212 318824 Fail 0.0014 31 102581 330906 Fail 0.0014 30 100100 333666 Fail 0.0015 28 97747 349096 Fail 0.0015 28 95287 340310 Fail 0.0016 27 93105 344833 Fail 0.0016 26 90924 349707 Fail 0.0017 24 88849 370204 Fail 0.0017 24 86817 361737 Fail 0.0018 22 84721 385095 Fail 0.0018 22 82753 376150 Fail 0.0019 20 80807 404035 Fail 0.0019 19 78967 415615 Fail 0.0020 18 77256 429200 Fail 0.0020 18 75481 419338 Fail 0.0021 16 73856 461600 Fail 0.0021 16 72166 451037 Fail 0.0022 13 70604 543107 Fail 0.0022 13 69000 530769 Fail 0.0023 12 67417 561808 Fail 0.0023 12 65942 549516 Fail 0.0024 12 64487 537391 Fail 0.0024 12 63140 526166 Fail 0.0025 12 61771 514758 Fail 0.0025 12 60338 502816 Fail 0.0026 12 59054 492116 Fail 0.0026 11 57793 525390 Fail 0.0027 10 56616 566160 Fail 0.0027 10 55440 554400 Fail 0.0028 10 54263 542630 Fail 0.0028 10 53066 530660 Fail Flow Control South 10/15/2024 4:16:47 PM Page 14 0.0028 10 51975 519750 Fail 0.0029 10 50798 507979 Fail 0.0029 10 49665 496650 Fail 0.0030 10 48595 485950 Fail 0.0030 10 47611 476110 Fail 0.0031 10 46628 466279 Fail 0.0031 10 45708 457079 Fail 0.0032 10 44703 447029 Fail 0.0032 10 43804 438040 Fail 0.0033 10 42906 429060 Fail 0.0033 10 42029 420290 Fail 0.0034 10 41173 411729 Fail 0.0034 10 40382 403820 Fail 0.0035 10 39569 395690 Fail 0.0035 10 38778 387780 Fail 0.0036 10 38008 380080 Fail 0.0036 10 37238 372380 Fail 0.0037 10 36447 364470 Fail 0.0037 10 35741 357410 Fail 0.0038 10 35035 350350 Fail 0.0038 10 34286 342860 Fail 0.0039 10 33580 335800 Fail 0.0039 10 32917 329170 Fail 0.0040 10 32233 322330 Fail 0.0040 10 31613 316130 Fail 0.0041 9 30992 344355 Fail 0.0041 9 30393 337700 Fail 0.0041 9 29859 331766 Fail 0.0042 9 29281 325344 Fail 0.0042 9 28704 318933 Fail 0.0043 9 28148 312755 Fail 0.0043 9 27613 306811 Fail 0.0044 9 27100 301111 Fail 0.0044 9 26522 294688 Fail 0.0045 9 26009 288988 Fail 0.0045 9 25517 283522 Fail 0.0046 9 25025 278055 Fail 0.0046 9 24576 273066 Fail 0.0047 9 24127 268077 Fail 0.0047 8 23677 295962 Fail 0.0048 8 23207 290087 Fail 0.0048 7 22779 325414 Fail 0.0049 7 22351 319300 Fail 0.0049 7 21902 312885 Fail 0.0050 7 21517 307385 Fail 0.0050 7 21158 302257 Fail The development has an increase in flow durations from 1/2 Predeveloped 2 year flow to the 2 year flow or more than a 10% increase from the 2 year to the 50 year flow. The development has an increase in flow durations for more than 50% of the flows for the range of the duration analysis. Flow Control South 10/15/2024 4:16:47 PM Page 15 Water Quality Water Quality BMP Flow and Volume for POC #1 On-line facility volume:0 acre-feet On-line facility target flow:0 cfs. Adjusted for 15 min:0 cfs. Off-line facility target flow:0 cfs. Adjusted for 15 min:0 cfs. Flow Control South 10/15/2024 4:16:47 PM Page 16 LID Report Flow Control South 10/15/2024 4:17:06 PM Page 17 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. Flow Control South 10/15/2024 4:17:06 PM Page 18 Appendix Predeveloped Schematic Flow Control South 10/15/2024 4:17:09 PM Page 19 Mitigated Schematic Flow Control South 10/15/2024 4:17:14 PM Page 20 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 Flow Control South.wdm MESSU 25 PreFlow Control South.MES 27 PreFlow Control South.L61 28 PreFlow Control South.L62 30 POCFlow Control South1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 4 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Existing Onsite Condition 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 *** 4 A/B, Pasture, Flat 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 4 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 ********* 4 0 0 4 0 0 0 0 0 0 0 0 0 1 9 END PRINT-INFO Flow Control South 10/15/2024 4:17:14 PM Page 21 PWAT-PARM1 <PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 4 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 4 0 5 1.5 400 0.05 0.3 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 4 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 4 0.15 0.5 0.3 0 0.7 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 4 0 0 0 0 3 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 Flow Control South 10/15/2024 4:17:14 PM Page 22 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Existing Onsite Conditions*** PERLND 4 0.395 COPY 501 12 PERLND 4 0.395 COPY 501 13 Existing Offsite Conditions*** PERLND 4 0.065 COPY 501 12 PERLND 4 0.065 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-> *** Flow Control South 10/15/2024 4:17:14 PM Page 23 <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 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 Flow Control South 10/15/2024 4:17:14 PM Page 24 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 Flow Control South.wdm MESSU 25 MitFlow Control South.MES 27 MitFlow Control South.L61 28 MitFlow Control South.L62 30 POCFlow Control South1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 7 IMPLND 2 IMPLND 1 IMPLND 8 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Developed Onsite Conditio 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 *** 7 A/B, Lawn, Flat 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 7 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 ********* Flow Control South 10/15/2024 4:17:14 PM Page 25 7 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 *** 7 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 7 0 5 0.8 400 0.05 0.3 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 7 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 7 0.1 0.5 0.25 0 0.7 0.25 END PWAT-PARM4 PWAT-STATE1 <PLS > *** Initial conditions at start of simulation ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 *** # - # *** CEPS SURS UZS IFWS LZS AGWS GWVS 7 0 0 0 0 3 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 1 ROADS/FLAT 1 1 1 27 0 8 SIDEWALKS/FLAT 1 1 1 27 0 END GEN-INFO *** Section IWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** 2 0 0 1 0 0 0 1 0 0 1 0 0 0 8 0 0 1 0 0 0 END ACTIVITY PRINT-INFO <ILS > ******** Print-flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* 2 0 0 4 0 0 4 1 9 1 0 0 4 0 0 0 1 9 8 0 0 4 0 0 0 1 9 END PRINT-INFO IWAT-PARM1 <PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI *** 2 0 0 0 0 0 1 0 0 0 0 0 8 0 0 0 0 0 END IWAT-PARM1 Flow Control South 10/15/2024 4:17:14 PM Page 26 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC 2 400 0.05 0.1 0.08 1 400 0.01 0.1 0.1 8 400 0.01 0.1 0.1 END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN 2 0 0 1 0 0 8 0 0 END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS 2 0 0 1 0 0 8 0 0 END IWAT-STATE1 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Developed Onsite Conditions*** PERLND 7 0.21 COPY 501 12 PERLND 7 0.21 COPY 501 13 IMPLND 2 0.031 COPY 501 15 Developed Offsite Conditions*** PERLND 7 0.032 COPY 501 12 PERLND 7 0.032 COPY 501 13 IMPLND 1 0.008 COPY 501 15 IMPLND 1 0.017 COPY 501 15 IMPLND 8 0.008 COPY 501 15 ******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 ********* Flow Control South 10/15/2024 4:17:14 PM Page 27 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 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 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 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 END MASS-LINK END RUN Flow Control South 10/15/2024 4:17:14 PM Page 28 Predeveloped HSPF Message File Flow Control South 10/15/2024 4:17:14 PM Page 29 Mitigated HSPF Message File Flow Control South 10/15/2024 4:17:14 PM Page 30 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. 2005-2024; All Rights Reserved. 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We performed our work in general accordance with the scope of services outlined in our proposal PES-9476, which was authorized by you on September 20, 2023. A summary of the subsurface exploration and pertinent geotechnical recommendations for site development are provided in this letter. Based on our evaluation, the proposed project is feasible from a geotechnical standpoint. Project Description We understand the project will include construction of several new single-family residential structures and related infrastructure improvements. We assume the proposed residential structures will be two to three stories in height and constructed utilizing relatively lightly loaded wood framing supported on conventional continuous and spread footing foundations. We anticipate perimeter footing loads of about 1 to 2 kips per linear foot, column loads of up to 20 kips, and slab-on-grade loading of roughly 150 pounds per square foot (psf). We understand infiltration is being evaluated as part of the overall storm design. Our evaluation of site infiltration capacity was completed in general accordance with the requirements of the City of Renton’s 2022 Stormwater Design Manual (2022 SWDM), which locally modifies the 2021 King County Surface Water Design Manual (2021 KCSWDM). Discussion on infiltration feasibility can be found in the Infiltration Feasibility section of this letter. DR A F T Park AVE 5, LLC ES-9476 November 27, 2023 Page 2 Earth Solutions NW, LLC Surface Conditions The subject site is located along the east side of Park Avenue North, directly southeast of the intersection with North 31st Street, in Renton, Washington. The approximate location of the site is illustrated on the attached Vicinity Map (Plate 1). The property is comprised of one tax parcel (King County Parcel No. 3342103250), totaling about 0.34 acres. The site is currently vacant and undeveloped. Vegetation consists of grass and trees along the perimeter. The site topography gently descends from northeast to west-southwest, with about 10 feet of elevation change across the property. Subsurface Conditions An ESNW representative observed, logged, and sampled three test pits, excavated at accessible locations within the property boundaries, on October 11, 2023, using a mini-trackhoe and operator retained by ESNW. The approximate locations of the test pits are depicted on Plate 2 (Test Pit Location Plan). Please refer to the attached test pit logs for a more detailed description of subsurface conditions. Representative soil samples collected at the test pit locations were evaluated in general accordance with Unified Soil Classification System (USCS) and United States Department of Agriculture (USDA) methods and procedures. Topsoil Topsoil was observed extending to depths of approximately 6 to 12 inches below the existing ground surface (bgs). The topsoil was characterized by dark brown color and fine organic material. Native Soil Underlying topsoil, native soil primarily consisted of silty sand and silt with sand (USCS: SM and ML, respectively) overlying sands with varying silt content (USCS: SP and SP-SM). The cleaner sand deposits were encountered beginning at depths of about four and one-half to six and one- half feet bgs. Native soil was generally encountered in a medium dense to dense and moist condition. The maximum exploration depth was approximately 12 feet bgs. Geologic Setting The referenced geologic map identifies Vashon recessional outwash deposits (Qvr) across the subject property and surrounding area. As described on the geologic map resource, recessional outwash deposits consist primarily of moderately sorted to well-sorted, stratified gravel and sand. Recessional outwash deposits were deposited by meltwater flowing from the receding Vashon glacier. The referenced Web Soil Survey (WSS) identifies Indianola loamy sand (Map Unit: InC) as the primary soil unit underlying the subject site. The Indianola series was formed in terraces, kames, and eskers and is derived from sandy glacial outwash. Based on our field observations, native soil likely to be exposed during grading activities will be generally consistent with outwash sand deposits and Indianola series soil. DR A F T Park AVE 5, LLC ES-9476 November 27, 2023 Page 3 Earth Solutions NW, LLC Groundwater Groundwater seepage was not encountered during July 2023 subsurface exploration. Glacial deposits commonly exhibit seasonal, perched seepage zones. Groundwater seepage rates and elevations fluctuate depending on many factors, including precipitation duration and intensity, the time of year, and soil conditions. In general, groundwater flow rates are higher during the winter, spring, and early summer months. Geologically Hazardous Areas As part of this assessment, ESNW reviewed Chapter 4.3.050 of the Renton Municipal Code (RMC) and County-maintained online mapping to evaluate the site for the presence of geologically hazardous areas, as defined by the City. Based on review of the referenced RMC and City maps, the subject site is not mapped within, or adjacent to, any geologic hazard areas. Based on our fieldwork performed at the subject site, it is our opinion the site does not contain geologically hazardous areas. Structural Fill Structural fill is defined as compacted soil placed in foundation, slab-on-grade, roadway, permanent slope, retaining wall, and utility trench backfill areas. Structural fill placed and compacted during site grading activities should meet the following specifications and guidelines: Structural fill material Granular soils* Moisture content At or slightly above optimum** Relative compaction (minimum) 95 percent (Modified Proctor) Loose lift thickness (maximum) 12 inches * The existing soil may not be suitable for use as structural fill unless the soil is at (or slightly above) the optimum moisture content at the time of placement and compaction. ** Soil shall not be placed dry of optimum and should be evaluated by ESNW during construction. Temporary Excavations Based on the soil conditions observed at the test pit locations, the following allowable temporary slope inclinations, as a function of horizontal to vertical (H:V) inclination, may be used. The applicable Federal Occupation Safety and Health Administration and Washington Industrial Safety and Health Act soil classifications are also provided: Areas exposing groundwater seepage 1.5H:1V (Type C) Loose soil 1.5H:1V (Type C) Medium dense soil 1H:1V (Type B) Dense to very dense, cemented native soil 0.75H:1V (Type A) DR A F T Park AVE 5, LLC ES-9476 November 27, 2023 Page 4 Earth Solutions NW, LLC The presence of perched groundwater may cause localized sloughing of temporary slopes. An ESNW representative should observe temporary and permanent slopes to confirm the slope inclinations are suitable for the exposed soil conditions and to provide additional excavation and slope recommendations, as necessary. If the recommended temporary slope inclinations cannot be achieved, temporary shoring may be necessary to support excavations. Permanent slopes should be planted with vegetation to enhance stability and to minimize erosion and should maintain a gradient of 2H:1V or flatter. Foundations The proposed residential structures can be constructed upon a conventional continuous and spread footing foundation system bearing on competent native soil or new structural fill placed directly on competent native soil. Competent native soil suitable for support of foundations will likely be encountered beginning at depths of about two to three feet bgs. We recommend compacting the outwash sand soil in-place where exposed in foundation subgrade areas. ESNW should be retained during construction to perform a foundation subgrade evaluation prior to formwork. Where loose or unsuitable conditions are encountered at foundation subgrade elevations, compaction of the soils to the specifications of structural fill or overexcavation and replacement with structural fill will be necessary. Provided the structures are supported as recommended, the following parameters may be used for foundation design: Allowable soil bearing capacity 2,500 psf Passive earth pressure 300 pcf Coefficient of friction 0.40 The passive earth pressure value provided above assumes the foundation will be backfilled with structural fill. A factor-of-safety of 1.5 has been applied to the passive earth pressure and coefficient of friction values provided in this section. For short-term wind and seismic loading, a one-third increase in the allowable soil bearing capacity may be assumed. With structural loading as expected, total settlement in the range of one inch is anticipated, with differential settlement of about one-half inch. Most of the anticipated settlement should occur during construction as dead loads are applied. Slab-on-Grade Floors Slab-on-grade floors for the proposed structures should be supported on a well-compacted, firm, and unyielding subgrade. Where feasible, native soils exposed at the slab-on-grade subgrade level can likely be compacted in situ to the specifications described in this section. Unstable or yielding areas of subgrade should be recompacted, or overexcavated and replaced with suitable structural fill, prior to slab construction. DR A F T Park AVE 5, LLC ES-9476 November 27, 2023 Page 5 Earth Solutions NW, LLC A capillary break consisting of a minimum of four inches of free-draining crushed rock or gravel should be placed below the slab. The free-draining material should have a fines content of 5 percent or less (where the fines content is defined as the percent passing the Number 200 sieve, based on the minus three-quarter-inch fraction). In areas where slab moisture is undesirable, installation of a vapor barrier below the slab should be considered. If a vapor barrier is utilized, it should be a material specifically designed for use as a vapor barrier and should be installed in accordance with manufacturer specifications. Retaining Walls Retaining walls must be designed to resist earth pressures and applicable surcharge loads. The following parameters may be used for design: Active earth pressure (unrestrained condition) 35 pcf (equivalent fluid) At-rest earth pressure (restrained condition) 55 pcf Traffic surcharge* (passenger vehicles) 70 psf (rectangular distribution) Passive earth pressure 300 pcf (equivalent fluid) Coefficient of friction 0.40 Seismic surcharge 8H psf** * Where applicable. ** Where H equals the retained height (in feet). The passive earth pressure and coefficient of friction values include a safety factor of 1.5. The above design parameters are based on a level backfill condition and level grade at the wall toe. Revised design values will be necessary if sloping grades are to be used above or below retaining walls. Additional surcharge loading from adjacent foundations, sloped backfill, or other relevant loads should be included in the retaining wall design. Retaining walls should be backfilled with free-draining material that extends along the height of the wall and a distance of at least 18 inches behind the wall. In lieu of 18 inches of a free-draining material, a drainage mat can be considered. ESNW should evaluate the suitability of drainage mat application during construction. The upper 12 inches of the wall backfill may consist of a less permeable soil, if desired. A perforated drainpipe should be placed along the base of the wall and connected to an approved discharge location. A typical retaining wall drainage detail is provided on Plate 3. If drainage is not provided, hydrostatic pressures should be included in the wall design. DR A F T Park AVE 5, LLC ES-9476 November 27, 2023 Page 6 Earth Solutions NW, LLC Seismic Design The 2018 International Building Code (2018 IBC) recognizes the most recent edition of the Minimum Design Loads for Buildings and Other Structures manual (ASCE 7-16) for seismic design, specifically with respect to earthquake loads. Based on the soil conditions encountered at the test locations, the parameters and values provided below are recommended for seismic design per the 2018 IBC. Parameter Value Site Class D* Mapped short period spectral response acceleration, SS (g) 1.445 Mapped 1-second period spectral response acceleration, S1 (g) 0.497 Short period site coefficient, Fa 1.0 Long period site coefficient, Fv 1.803** Adjusted short period spectral response acceleration, SMS (g) 1.445 Adjusted 1-second period spectral response acceleration, SM1 (g) 0.896** Design short period spectral response acceleration, SDS (g) 0.963 Design 1-second period spectral response acceleration, SD1 (g) 0.597** * Assumes medium dense to dense soil conditions (at depth), encountered to a maximum depth of 12 feet bgs during the October 2023 field exploration, remain medium dense to dense to at least 100 feet bgs. ** Values assume Fv may be determined using linear interpolation per Table 11.4-2 in ASCE 7-16. Liquefaction Liquefaction is a phenomenon that can occur within a soil profile as a result of an intense ground shaking or loading condition. Most commonly, liquefaction is caused by ground shaking during an earthquake. Sand or silt soil that is loose, cohesionless, and below the groundwater table are most susceptible to liquefaction. During the ground shaking, the soil contracts, and porewater pressure increases. The increased porewater pressure occurs quickly and without sufficient time to dissipate, resulting in water flowing upward to the ground surface and a liquefied soil condition. Soil in a liquefied condition possesses very little shear strength in comparison to the drained condition, which can result in a loss of foundation support for structures. The referenced liquefaction susceptibility map indicates the subject site maintains low to moderate liquefaction susceptibility. In our opinion, site susceptibility to liquefaction may be considered low. The relative density of the native soil and absence of an established shallow groundwater table are the primary bases for this opinion. DR A F T Park AVE 5, LLC ES-9476 November 27, 2023 Page 7 Earth Solutions NW, LLC Drainage Zones of perched groundwater seepage should be anticipated in site excavations depending on the time of year grading operations take place. Temporary measures to control surface water runoff and groundwater during construction would likely involve passive elements such as interceptor trenches and sumps. ESNW should be consulted during preliminary grading to identify areas of seepage and to provide recommendations to reduce the potential for instability related to seepage effects. Finish grades must be designed to direct surface drain water away from the structures. Water must not be allowed to pond adjacent to the structure. Grades adjacent to the building should be sloped away from the building at a gradient of either at least 2 percent for a horizontal distance of 10 feet or the maximum allowed by adjacent structures. In our opinion, footing drains should be installed along building perimeter footings. A typical footing drain detail is provided on Plate 4. Infiltration Feasibility As indicated in the Subsurface Conditions section of this letter, native soils encountered during the fieldwork were characterized primarily as outwash sand and silt deposits. Cleaner sand deposits were encountered beginning at depths of about four and one-half to six and one-half feet bgs at the tested locations. In our opinion, infiltration is feasible where cleaner sand deposits are exposed underlying low permeability layers. For preliminary design purposes, we recommend a preliminary long-term design rate of one inch per hour. Use of this rate requires the infiltration facilities to be sited within relatively clean sand deposits. Adequate separation between the infiltration facility bottom and seasonal high groundwater levels or impermeable layers must be established. In-situ infiltration testing will be required by the City to confirm infiltration rates. ESNW can provide further evaluation and recommendations for site BMPs as plans develop. ESNW should review final stormwater management plans to provide supplementary recommendations, as needed. Additionally, ESNW should observe infiltration system excavations and construction to confirm suitable soil conditions if infiltration is pursued. Limitations & Additional Services This geotechnical evaluation report has been prepared for the exclusive use of Park AVE 5, LLC and its representatives. The recommendations and conclusions provided in this letter are professional opinions consistent with the level of care and skill that is typical of other members in the profession currently practicing under similar conditions in this area. A warranty is not expressed or implied. Variations in the soil and groundwater conditions observed at the test sites may exist and may not become evident until construction. ESNW should reevaluate the conclusions in this letter if variations are encountered. DR A F T Park AVE 5, LLC ES-9476 November 27, 2023 Page 8 Earth Solutions NW, LLC ESNW should have an opportunity to review the final design with respect to the geotechnical recommendations provided in this letter. ESNW should also be retained to provide testing and consultation services during the earthwork phase of construction. We trust this letter meets your current needs. Should you have any questions regarding the content herein, or require additional information, please call. Sincerely, EARTH SOLUTIONS NW, LLC Kyler T. Kelly, L.G. Henry T. Wright, P.E. Project Geologist Associate Principal Engineer Attachments: Plate 1 – Vicinity Map Plate 2 – Test Pit Location Plan Plate 3 – Retaining Wall Drainage Detail Plate 4 – Footing Drain Detail Test Pit Logs Grain Size Distribution References: RMC 2022 SWDM 2021 KCSWDM Liquefaction Susceptibility for King County (Map 11-5), incorporating data from the Washington State Department of Natural Resources, dated May 2010 Geologic Map of King County, Washington, compiled by D.B. Booth et al., dated March 2007 WSS, maintained by the Natural Resources Conservation Service under the USDA DR A F T Drawn CAM Checked KTK Date Nov. 2023 Date 11/06/2023 Proj. No. 9476 Plate 1 Geotechnical Engineering,Construction Observation/Testing and Environmental Services Earth Solutions NWLLCEarthSolutionsNWLLC EarthSolutions NW LLC Vicinity Map Park Avenue Short Plat Renton, Washington Reference: King County, Washington OpenStreetMap.org NORTH NOTE: This plate may contain areas of color. ESNW cannot be responsible for any subsequent misinterpretation of the information resulting from black & white reproductions of this plate. Renton SITE Newcastle Lake Washington DR A F T Drawn CAM Checked KTK Date Nov. 2023 Date 11/06/2023 Proj. No. 9476 Plate 2 Geotechnical Engineering,Construction Observation/Testing and Environmental Services Earth Solutions NWLLCEarthSolutionsNWLLC EarthSolutions NW LLC TP-1 TP-2 TP-3 pa r k a v e n u e n . Test Pit Location Plan Park Avenue Short Plat Renton, Washington NOTE: This plate may contain areas of color. ESNW cannot be responsible for any subsequent misinterpretation of the information resulting from black & white reproductions of this plate. NOTE: The graphics shown on this plate are not intended for design purposes or precise scale measurements, but only to illustrate the approximate test locations relative to the approximate locations of existing and / or proposed site features. The information illustrated is largely based on data provided by the client at the time of our study. ESNW cannot be responsible for subsequent design changes or interpretation of the data by others. LEGEND Approximate Location of ESNW Test Pit, Proj. No. ES-9476, Oct. 2023 Subject Site Existing Building TP-1 NOT - TO - SCALE NORTH DR A F T Geotechnical Engineering,Construction Observation/Testing and Environmental Services Drawn CAM Checked KTK Date Nov. 2023 Date 11/06/2023 Proj. No. 9476 Plate 3 Earth Solutions NWLLCEarthSolutionsNWLLC EarthSolutions NW LLC NOTES: Free-draining Backfill should consist of soil having less than 5 percent fines. Percent passing No. 4 sieve should be 25 to 75 percent. Sheet Drain may be feasible in lieu of Free-draining Backfill, per ESNW recommendations. Drain Pipe should consist of perforated, rigid PVC Pipe surrounded with 1-inch Drain Rock. LEGEND: Free-draining Structural Backfill 1-inch Drain Rock 18" Min. Structural Fill Perforated Rigid Drain Pipe (Surround in Drain Rock) SCHEMATIC ONLY - NOT TO SCALE NOT A CONSTRUCTION DRAWING Retaining Wall Drainage Detail Park Avenue Short Plat Renton, Washington DR A F T Geotechnical Engineering,Construction Observation/Testing and Environmental Services Drawn CAM Checked KTK Date Nov. 2023 Date 11/06/2023 Proj. No. 9476 Plate 4 Earth Solutions NWLLCEarthSolutionsNWLLC EarthSolutions NW LLC Slope Perforated Rigid Drain Pipe (Surround in Drain Rock) 18" Min. NOTES: Do NOT tie roof downspouts to Footing Drain. Surface Seal to consist of 12" of less permeable, suitable soil. Slope away from building. LEGEND: Surface Seal: native soil or other low-permeability material. 1-inch Drain Rock SCHEMATIC ONLY - NOT TO SCALE NOT A CONSTRUCTION DRAWING Footing Drain Detail Park Avenue Short Plat Renton, Washington DR A F T > 1 2 % F i n e s < 5 % F i n e s Hi g h l y Or g a n i c So i l s Si l t s a n d C l a y s Li q u i d L i m i t 5 0 o r M o r e Si l t s a n d C l a y s Li q u i d L i m i t L e s s T h a n 5 0 Fi n e - G r a i n e d S o i l s - 50 % o r M o r e P a s s e s N o . 2 0 0 S i e v e Co a r s e - G r a i n e d S o i l s - Mo r e T h a n 5 0 % R e t a i n e d o n N o . 2 0 0 S i e v e Sa n d s - 5 0 % o r M o r e o f C o a r s e Fr a c t i o n P a s s e s N o . 4 S i e v e Gr a v e l s - M o r e T h a n 5 0 % o f C o a r s e Fr a c t i o n R e t a i n e d o n N o . 4 S i e v e > 1 2 % F i n e s < 5 % F i n e s GW GP GM GC SW SP SM SC ML CL OL MH CH OH PT Well-graded gravel with or without sand, little to no fines Poorly graded gravel with or without sand, little to no fines Silty gravel with or without sand Clayey gravel with or without sand Well-graded sand with or without gravel, little to no fines Poorly graded sand with or without gravel, little to no fines Silty sand with or without gravel Clayey sand with or without gravel Silt with or without sand or gravel; sandy or gravelly silt Clay of low to medium plasticity; lean clay with or without sand or gravel; sandy or gravelly lean clay Organic clay or silt of low plasticity Elastic silt with or without sand or gravel; sandy or gravelly elastic silt Clay of high plasticity; fat clay with or without sand or gravel; sandy or gravelly fat clay Organic clay or silt of medium to high plasticity Peat, muck, and other highly organic soils EEaarrtthh SSoolluuttiioonnss NNWW LLC Geotechnical Engineering,Construction Observation/Testing and Environmental Services EXPLORATION LOG KEY Fi l l FILL Made Ground Classifications of soils in this geotechnical report and as shown on the exploration logs are based on visual field and/or laboratory observations, which include density/consistency, moisture condition, grain size, and plasticity estimates, and should not be construed to imply field or laboratory testing unless presented herein. Visual-manual and/or laboratory classification methods of ASTM D2487 and D2488 were used as an identification guide for the Unified Soil Classification System. Terms Describing Relative Density and Consistency Coarse-Grained Soils: Fine-Grained Soils: SPT blows/foot SPT blows/foot Test Symbols & Units Fines = Fines Content (%) MC = Moisture Content (%) DD = Dry Density (pcf) Str = Shear Strength (tsf) PID = Photoionization Detector (ppm) OC = Organic Content (%) CEC = Cation Exchange Capacity (meq/100 g) LL = Liquid Limit (%) PL = Plastic Limit (%) PI = Plasticity Index (%) Component Definitions Descriptive Term Size Range and Sieve Number Smaller than No. 200 (0.075 mm) Boulders Modifier Definitions Percentage by Weight (Approx.) < 5 5 to 14 15 to 29 > 30 _ Modifier Trace (sand, silt, clay, gravel) Slightly (sandy, silty, clayey, gravelly) Sandy, silty, clayey, gravelly Very (sandy, silty, clayey, gravelly) Moisture Content Dry - Absence of moisture, dusty, dry to the touch Damp - Perceptible moisture, likely below optimum MC Moist - Damp but no visible water, likely at/near optimum MC Wet - Water visible but not free draining, likely above optimum MC Saturated/Water Bearing - Visible free water, typically below groundwater table Symbols Cement grout surface seal Bentonite chips Grout seal Filter pack with blank casing section Screened casing or Hydrotip with filter pack End cap ATD = At time of drilling Static water level (date) _> 50 Density Very Loose Loose Medium Dense Dense Very Dense Consistency Very Soft Soft Medium Stiff Stiff Very Stiff Hard < 4 4 to 9 10 to 29 30 to 49 < 2 2 to 3 4 to 7 8 to 14 15 to 29 _> 30 LLC EarthSolutions NW LLC Cobbles Gravel Coarse Gravel Fine Gravel Sand Coarse Sand Medium Sand Fine Sand Silt and Clay Larger than 12" 3" to 12" 3" to No. 4 (4.75 mm) 3" to 3/4" 3/4" to No. 4 (4.75 mm) No. 4 (4.75 mm) to No. 200 (0.075 mm) No. 4 (4.75 mm) to No. 10 (2.00 mm) No. 10 (2.00 mm) to No. 40 (0.425 mm) No. 40 (0.425 mm) to No. 200 (0.075 mm)DR A F T GB GB GB MC = 15.5 MC = 5.0 Fines = 3.9 MC = 7.1 TPSL SM SP Dark brown TOPSOIL, roots to 8' Brown silty SAND, medium dense, moist -probed 4" -becomes gray, dense, weakly cemented Brown poorly graded SAND, medium dense to dense, moist -probed 2" -weakly cemented [USDA Classification: slightly gravelly SAND] Test pit terminated at 10.0 feet below existing grade. No groundwater encountered during excavation. No caving observed. LIMITATIONS: Ground elevation (if listed) is approximate; the test location was not surveyed. Coordinates are approximate and based on the WGS84 datum. Do not rely on this test log as a standalone document. Refer to the text of the geotechnical report for a complete understanding of subsurface conditions. 0.5 4.5 10.0 SA M P L E T Y P E NU M B E R DE P T H (f t ) 0.0 2.5 5.0 7.5 10.0 PAGE 1 OF 1 TEST PIT NUMBER TP-1 CHECKED BY HTW NOTES SURFACE CONDITIONS Grass AT TIME OF EXCAVATIONAT TIME OF EXCAVATION AFTER EXCAVATION EXCAVATION CONTRACTOR NW Excavating DATE STARTED 10/11/23 COMPLETED 10/11/23 GROUND WATER LEVEL: GROUND ELEVATION LOGGED BY KTK LATITUDE 47.51892 LONGITUDE -122.20100 PROJECT NUMBER ES-9476 PROJECT NAME Park Avenue Short Plat GE N E R A L B H / T P / W E L L - 9 4 7 6 . G P J - G I N T U S . G D T - 1 1 / 2 7 / 2 3 Earth Solutions NW, LLC 15365 N.E. 90th Street, Suite 100 Redmond, Washington 98052 Telephone: 425-449-4704 Fax: 425-449-4711 TESTS U. S . C . S . MATERIAL DESCRIPTION GR A P H I C LO G DR A F T GB GB GB GB MC = 15.6 Fines = 71.9 MC = 11.4 MC = 5.8 MC = 7.3 Fines = 7.8 TPSL ML SP- SM Dark brown TOPSOIL, roots to 8' Brown SILT with sand, medium dense, moist -becomes weakly cemented, increased gravel content [USDA Classification: slightly gravelly LOAM] -probed 4" -becomes gray, dense, light iron oxide staining to 5' -probed 2" Brown poorly graded SAND with silt, medium dense to dense, moist [USDA Classification: slightly gravelly SAND] Test pit terminated at 10.0 feet below existing grade. No groundwater encountered during excavation. No caving observed. LIMITATIONS: Ground elevation (if listed) is approximate; the test location was not surveyed. Coordinates are approximate and based on the WGS84 datum. Do not rely on this test log as a standalone document. Refer to the text of the geotechnical report for a complete understanding of subsurface conditions. 1.0 6.5 10.0 SA M P L E T Y P E NU M B E R DE P T H (f t ) 0.0 2.5 5.0 7.5 10.0 PAGE 1 OF 1 TEST PIT NUMBER TP-2 CHECKED BY HTW NOTES SURFACE CONDITIONS Grass AT TIME OF EXCAVATIONAT TIME OF EXCAVATION AFTER EXCAVATION EXCAVATION CONTRACTOR NW Excavating DATE STARTED 10/11/23 COMPLETED 10/11/23 GROUND WATER LEVEL: GROUND ELEVATION LOGGED BY KTK LATITUDE 47.51902 LONGITUDE -122.20128 PROJECT NUMBER ES-9476 PROJECT NAME Park Avenue Short Plat GE N E R A L B H / T P / W E L L - 9 4 7 6 . G P J - G I N T U S . G D T - 1 1 / 2 7 / 2 3 Earth Solutions NW, LLC 15365 N.E. 90th Street, Suite 100 Redmond, Washington 98052 Telephone: 425-449-4704 Fax: 425-449-4711 TESTS U. S . C . S . MATERIAL DESCRIPTION GR A P H I C LO G DR A F T GB GB GB GB MC = 6.3 MC = 16.0 MC = 5.1 MC = 6.2 Fines = 3.9 TPSL SM SP Dark brown TOPSOIL, roots to 7' Brown silty SAND, medium dense, moist -light iron oxide staining to 3' -becomes dense, probed 6" -becomes gray, weakly cemented -probed 2" Brown poorly graded SAND, medium dense to dense, moist [USDA Classification: SAND] Test pit terminated at 12.0 feet below existing grade. No groundwater encountered during excavation. No caving observed. LIMITATIONS: Ground elevation (if listed) is approximate; the test location was not surveyed. Coordinates are approximate and based on the WGS84 datum. Do not rely on this test log as a standalone document. Refer to the text of the geotechnical report for a complete understanding of subsurface conditions. 0.7 6.0 12.0 SA M P L E T Y P E NU M B E R DE P T H (f t ) 0.0 2.5 5.0 7.5 10.0 PAGE 1 OF 1 TEST PIT NUMBER TP-3 CHECKED BY HTW NOTES SURFACE CONDITIONS Grass AT TIME OF EXCAVATIONAT TIME OF EXCAVATION AFTER EXCAVATION EXCAVATION CONTRACTOR NW Excavating DATE STARTED 10/11/23 COMPLETED 10/11/23 GROUND WATER LEVEL: GROUND ELEVATION LOGGED BY KTK LATITUDE 47.51892 LONGITUDE -122.20160 PROJECT NUMBER ES-9476 PROJECT NAME Park Avenue Short Plat GE N E R A L B H / T P / W E L L - 9 4 7 6 . G P J - G I N T U S . G D T - 1 1 / 2 7 / 2 3 Earth Solutions NW, LLC 15365 N.E. 90th Street, Suite 100 Redmond, Washington 98052 Telephone: 425-449-4704 Fax: 425-449-4711 TESTS U. S . C . S . MATERIAL DESCRIPTION GR A P H I C LO G DR A F T 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100 0.0010.010.1110100 1.86 2.68 2.40 LL TP-01 TP-02 TP-02 TP-03 0.243 0.15 0.165 3/4U.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS GRAVEL SAND 4.75 9.5 4.75 1.18 %Silt 0.91 1.38 1.21 TP-01 TP-02 TP-02 TP-03 2 2003 Cc CuClassification %Clay 16 PID60 D30 coarse SILT OR CLAYfinemedium GRAIN SIZE IN MILLIMETERS 3/8 50 5.0ft. 2.0ft. 10.0ft. 12.0ft. 5.00ft. 2.00ft. 10.00ft. 12.00ft. PL 3 D100 140 Specimen Identification 1 fine 6 HYDROMETER304 3.9 71.9 7.8 3.9 101/2 COBBLES Specimen Identification 4 coarse 20 401.5 8 14 USDA: Brown Slightly Gravelly Sand. USCS: SP. USDA: Brown Slightly Gravelly Loam. USCS: ML with Sand. USDA: Brown Slightly Gravelly Sand. USCS: SP-SM. USDA: Brown Sand. USCS: SP. 6 60 PE R C E N T F I N E R B Y W E I G H T D10 0.316 0.289 0.281 0.451 0.403 0.397 GRAIN SIZE DISTRIBUTION 100 PROJECT NUMBER ES-9476 PROJECT NAME Park Avenue Short Plat GR A I N S I Z E U S D A E S - 9 4 7 6 P A R K A V E N U E S H O R T P L A T . G P J G I N T U S L A B . G D T 1 0 / 2 7 / 2 3 Earth Solutions NW, LLC 15365 N.E. 90th Street, Suite 100 Redmond, Washington 98052 Telephone: 425-449-4704 Fax: 425-449-4711 DR A F T Soil Map—King County Area, Washington (Jones Renton Short Plat - South Phase) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 5/7/2024 Page 1 of 3 52 6 3 1 2 3 52 6 3 1 3 1 52 6 3 1 3 9 52 6 3 1 4 7 52 6 3 1 5 5 52 6 3 1 6 3 52 6 3 1 7 1 52 6 3 1 2 3 52 6 3 1 3 1 52 6 3 1 3 9 52 6 3 1 4 7 52 6 3 1 5 5 52 6 3 1 6 3 52 6 3 1 7 1 560090 560098 560106 560114 560122 560130 560138 560146 560154 560162 560170 560098 560106 560114 560122 560130 560138 560146 560154 560162 560170 47° 31' 9'' N 12 2 ° 1 2 ' 6 ' ' W 47° 31' 9'' N 12 2 ° 1 2 ' 2 ' ' W 47° 31' 7'' N 12 2 ° 1 2 ' 6 ' ' W 47° 31' 7'' N 12 2 ° 1 2 ' 2 ' ' W N Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 10N WGS84 0 15 30 60 90 Feet 0 5 10 20 30 Meters Map Scale: 1:368 if printed on A landscape (11" x 8.5") 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 (Jones Renton Short Plat - South Phase) Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 5/7/2024 Page 2 of 3 Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI InC Indianola loamy sand, 5 to 15 percent slopes 0.5 100.0% Totals for Area of Interest 0.5 100.0% Soil Map—King County Area, Washington Jones Renton Short Plat - South Phase Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 5/7/2024 Page 3 of 3 King County Area, Washington InC—Indianola loamy sand, 5 to 15 percent slopes Map Unit Setting National map unit symbol: 2t635 Elevation: 0 to 980 feet Mean annual precipitation: 30 to 81 inches Mean annual air temperature: 48 to 50 degrees F Frost-free period: 170 to 210 days Farmland classification: Prime farmland if irrigated Map Unit Composition Indianola and similar soils:85 percent Minor components:15 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Indianola Setting Landform:Terraces, kames, eskers Landform position (three-dimensional):Riser Down-slope shape:Linear Across-slope shape:Linear Parent material:Sandy glacial outwash Typical profile Oi - 0 to 1 inches: slightly decomposed plant material A - 1 to 6 inches: loamy sand Bw1 - 6 to 17 inches: loamy sand Bw2 - 17 to 27 inches: sand BC - 27 to 37 inches: sand C - 37 to 60 inches: sand Properties and qualities Slope:5 to 15 percent Depth to restrictive feature:More than 80 inches Drainage class:Somewhat excessively drained Capacity of the most limiting layer to transmit water (Ksat):High to very high (5.95 to 99.90 in/hr) Depth to water table:More than 80 inches Frequency of flooding:None Frequency of ponding:None Available water supply, 0 to 60 inches: Low (about 3.9 inches) Interpretive groups Land capability classification (irrigated): 4e Land capability classification (nonirrigated): 4s Hydrologic Soil Group: A Ecological site: F002XA004WA - Puget Lowlands Forest Map Unit Description: Indianola loamy sand, 5 to 15 percent slopes---King County Area, Washington Jones Renton Short Plat - South Phase Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 5/7/2024 Page 1 of 2 Forage suitability group: Droughty Soils (G002XN402WA), Droughty Soils (G002XS401WA) Other vegetative classification: Droughty Soils (G002XN402WA), Droughty Soils (G002XS401WA) Hydric soil rating: No Minor Components Alderwood Percent of map unit:8 percent Landform:Hills, ridges Landform position (two-dimensional):Shoulder Landform position (three-dimensional):Nose slope, talf Down-slope shape:Convex, linear Across-slope shape:Convex Hydric soil rating: No Everett Percent of map unit:5 percent Landform:Moraines, eskers, kames Landform position (two-dimensional):Shoulder, footslope Landform position (three-dimensional):Base slope, crest Down-slope shape:Convex Across-slope shape:Convex Hydric soil rating: No Norma Percent of map unit:2 percent Landform:Drainageways, depressions Landform position (three-dimensional):Dip Down-slope shape:Linear, concave Across-slope shape:Concave Hydric soil rating: Yes Data Source Information Soil Survey Area: King County Area, Washington Survey Area Data: Version 19, Aug 29, 2023 Map Unit Description: Indianola loamy sand, 5 to 15 percent slopes---King County Area, Washington Jones Renton Short Plat - South Phase Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 5/7/2024 Page 2 of 2