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HomeMy WebLinkAboutTIR-4305 FINAL TECHNICAL INFORMATION REPORT FOR Jones Renton Short Plat CITY OF RENTON IN KING COUNTY, WASHINGTON Project Manager: Flavio Bainotti Prepared by: Brackon Rawlinson, E.I.T. Approved by: Michael Moody, P.E. Date: October 23, 2023 Revised: February 2024, August 2024 Core No.: 20081K 08-22-2024 Surface Water Enginering JFarah 03/03/2025 DEVELOPMENT ENGINEERING HHuynh 04/17/2025 Core Design, Inc. Jones Renton Short Plat 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............................................................................. 5 2.2 Special Requirements ............................................................................................................ 5 2.2.1 Special Requirement #1: Other adopted Area-Specific requirements .............................. 5 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 ................................................. 7 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 .................................................................................. 12 Core Design, Inc. Jones Renton Short Plat ii 4.4 Flow Control: Peak Rate Flow Control Standards .............................................................. 13 4.5 Water Quality Design .......................................................................................................... 15 SECTION 5: CONVEYANCE SYSTEM ANALYSIS AND DESIGN .......................................................... 19 5.1 Results ................................................................................................................................. 19 SECTION 6: SPECIAL REPORTS AND STUDIES ................................................................................. 21 SECTION 7: OTHER PERMITS.......................................................................................................... 22 SECTION 8: ESC ANALYSIS AND DESIGN ........................................................................................ 23 SECTION 9: BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT ...... 26 9.1 Bond Quantities .................................................................................................................. 26 9.2 Facility Summaries .............................................................................................................. 26 9.3 Declaration of Covenant ..................................................................................................... 26 SECTION 10: OPERATIONS AND MAINTENANCE ........................................................................... 27 Appendix A – Parcel & Basin Information King County Parcel Report Appendix B – Resource Review & Off-site Analysis Documentation City Zoning Map FEMA Map (53033C0664 K) City Wellhead Protection Area Map City Drainage Basin Map Groundwater Protection Areas Map City Soils Map City Landslide Hazard Areas Map Downstream Drainage Complaint Map Appendix C – Basin and Water Quality Modeling Documentation WWHM Reports (Flow Control and Water Quality) Appendix D – Geotechnical Report Geotechnical Report Core Design, Inc. Jones Renton Short Plat Page 1 SECTION 1: PROJECT OVERVIEW The Jones Renton Short Plat project site consists of one parcel with a total area of 1.323 acres (57,620 square feet per survey), located at 3102 Park Avenue N in King County, City of Renton, WA. The west property line is shared with Park Avenue N, and the east property line is shared with single family residential homes. 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 of this report). Table 1.1 King County Parcel ID KC Parcel # Parcel Area (SF) 334210-3215 57,620 The project site currently contains one residential building, a greenhouse, and an associated driveway. In addition, a paved driveway which extends to gravel is located near the northern border of the parcel. The remaining site area consists of trees and vegetated cover (grass). The proposed development of the property includes demolishing and removal of the existing structures, and subdividing the parcel into five lots, an open space tract, and an access road. The project also includes frontage improvements along Park Avenue N which consist of pavement replacement and construction of curb and gutter, sidewalk, and a planter strip. The proposed lots have areas ranging from 7,068 square feet to 8,778 square feet. Access to the proposed lots is provided via dedicated right-of-way (ROW) directly east of N 31st Street. Road A provides access for Lot 5 and Road B provides access for Lots 1-4. The site slopes downward from east to west at a magnitude of 5 to 15 percent and relief of about 15 feet. The site contains two drainage basins which drain to the northwest and southwest of the site. Infiltration is feasible on the eastern portion of the property. The site is mapped within a moderate Landslide Hazard Zone and within a Zone 2 Wellhead Protection Area. 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 which will be adding more than 7,000 square feet of new impervious area; thus, the project is required to provide Directed Drainage Review. The project site is located within a Peak Rate Flow Control Standard area; however, the project does not cause more than a 0.15 cubic feet per second (cfs) increase to the developed condition 100-year peak flow rate when compared to the existing condition 100-year peak flow rate; thus, flow control facility requirements are waived for the project per Section 1.2.3.A, Subsection Exceptions, number 1. The South Basin will add more than 5,000 square feet of pollution generating impervious surface (PGIS) which is not fully dispersed; thus, water quality is required. The project is required to provide basic water quality treatment per the City of Renton. A Core Design, Inc. Jones Renton Short Plat Page 2 BayFilterTM System by ADS is proposed to provide Basic Water Quality Treatment for the South Basin. Figure 1.1 Vicinity Map Core Design, Inc. Jones Renton Short Plat 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 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. 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 map, the site falls within the Peak Rate Flow Control area matching Existing Site Conditions (refer to Appendix B of this report for the City’s flow control map). The site contains two drainage basins which each require a separate flow control analysis to be conducted to determine if flow control facilities are required for the basin. Refer to Section 4 of this report for the analysis of each basin and determination of flow control facilities. 2.1.4 Core Requirement #4: Conveyance System See Section 5 of this report for a detailed conveyance system analysis of the 25-year and 100- year storm events. The proposed conveyance system will be designed to convey and contain the 25-year peak flow. The conveyance system may overtop for runoff events exceeding the 25-year design capacity provided overflow from the 100-year runoff event does not create or aggravate a severe flooding or erosion problem. See Section 1.2.4.1 of the 2022 RSWDM for conveyance system requirements. 2.1.5 Core Requirements #5: Construction Stormwater Pollution Prevention A Construction Stormwater Pollution Prevention Plan (CSWPPP) has been prepared for the project and is submitted under separate cover. Refer to Section 8 of this report for the ESC analysis and design. 2.1.6 Core Requirement #6: Maintenance and Operations A maintenance and operations manual has been provided in Section 10 of this report. 2.1.7 Core Requirement #7: Financial Guarantees and Liability A City of Renton Site Improvement Bond Quantity Worksheet has been prepared for the project and provided in Section 9 of this report. 2.1.8 Core Requirement #8: Water Quality This project is located within a Basic Water Quality Treatment Area. Water quality treatment will be provided from the basic treatment menu provided in the 2022 RSWDM. See Section 4 of this report for details. Core Design, Inc. Jones Renton Short Plat Page 5 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. 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 2022 RSDWM. Therefore, oil control BMPs will not be implemented for the project. 2.2.6 Special Requirement #6: Aquifer Protection Area The project lies within Zone 2 of the Aquifer Protection Area (APA). Within this zone, stormwater open conveyance systems, such as ditches and channels, and water quality facilities may require a liner per Section 6.2.4 and 1.2.4.3 of the 2022 RSWDM. Refer to Appendix B of this report for the Groundwater Protection Areas Map Reference 15-B. Core Design, Inc. Jones Renton Short Plat Page 6 SECTION 3: OFFSITE ANALYSIS TASK 1 Study Area Definition and Maps The proposed project contains parcel number 3342103215. 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 A FIRM map dated April 19, 2005 number 53033C0664K F was reviewed. The developable site is within “Zone X” which is outside of the 500-year floodplain. The FEMA Map 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 mild landslide hazard area. The site is also within a Zone 2 Wellhead Protection Area. Downstream Drainage Complaints Drainage complaints were researched within one quarter mile of the project site. Based on King County iMap Drainage Complaints Map, the area downstream of the project site shows three drainage complaints along the drainage path. However, these complaints have been closed with the most recent one being closed on 5/16/2019. See Drainage Complaint Exhibit in Appendix B of this report for the location of nearby drainage complaints. TASK 3 Field Investigation A field investigation was completed on July 14, 2020, and the temperature was 74O F. Tributary Area The parcels to the east of the project site are on higher elevation and thus contribute surface runoff to the entire site. The King County iMap shows three parcels (TPNs 3342103245, 3342103239, 3342103235) make up most of the tributary upstream area. Upstream Tributary Analysis The aforementioned parcels are situated to the east with a solid fence separating them from the project site. It has been determined upon investigation that the upstream tributary area contributes an insignificant amount of runoff to the project site. Core Design, Inc. Jones Renton Short Plat Page 7 TASK 4 Drainage System Description and Problem Description A level one downstream analysis was performed during the field inspection. Stormwater onsite flows from the east of the property to the west towards Park Avenue N. The site topography creates two drainage basins which onsite surface runoff flow into. Refer to the downstream map for a representation of the project proximity. The first basin is situated on the northern portion of the site. Surface runoff sheet flows towards Park Avenue N where it is collected in a ditch along the east side of the roadway and directed north. The City’s conveyance system, located at the southeast corner of where Park Avenue N and N 32nd Street intersect, collects the runoff and directs it northward in Park Avenue N. The conveyance system continues to N 34th Street where it turns 90 degrees to the west and approaches Burnett Avenue N. The underground stormwater system makes its way north within Burnett Avenue N and across Lake Washington Blvd N located to the west where it eventually discharges to Lake Washington. The second basin is located on the southern portion of the property which drains to Park Avenue N. The conveyance system begins at N 31st Street in the northwest corner of the intersection. The conveyance system continues westwards until approaching Burnett Avenue N where it makes 90 degree to the north. The conveyance system turns to the west and crosses Lake Washington Blvd N and also discharges to Lake Washington. The conveyance system was clean from all debris and blockage. The drainage paths described above cover the ¼ mile distance offsite. 6,508 542 City of Renton Print map Template 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 8/13/2020 Legend 3690184 THIS MAP IS NOT TO BE USED FOR NAVIGATION Feet Notes 369 WGS_1984_Web_Mercator_Auxiliary_Sphere Information Technology - GIS RentonMapSupport@Rentonwa.gov City and County Labels City and County Boundary Parcels Network Structures Access Riser Inlet Manhole Utility Vault Clean Out Unknown Pump Stations Discharge Points Stormwater Mains Culverts Open Drain Facility Outlines Private Network Structures Access Riser Inlet Manhole Clean Out Utility Vault Unknown Private Pump Stations Private Discharge Points Private Pipes Core Design, Inc. Jones Renton Short Plat 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 2022 RSWDM, the project is not required to provide flow control facilities because project causes less than a 0.15 cfs increase from the existing condition 100-year peak flow to the developed 100-year peak flow in both the North and South Basins. Refer to Subsection 4.4 of this report for basin analyses. 4.2 On-Site BMPs The project is proposing to subdivide the parcel into five (5) 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 2022 RSWDM. Individual Lot BMP requirement per Section 1.2.9.2 of the 2022 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 2022 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 BPMs are not feasible due to site constraint and the inability 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 as detailed in Appendix C, Section C.2.2 must be evaluated.  Response: Full infiltration devices (infiltration drywells) will be implemented on Lots 1, 4, and 5 which are located on the eastern side of the site to mitigate the roof runoff. Refer to Subsection 4.2.1 of this report for BMP sizing calculations. 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: Full Infiltration is not proposed for pollution generating impervious surfaces but all feasible non-pollution generating impervious surfaces within lots 1, 4, and 5 shall be routed to the infiltration drywell to the maximum extent feasible. Refer to Subsection 4.2.1 of this report for BMP sizing calculations. Application of full infiltration BMPs for Core Design, Inc. Jones Renton Short Plat Page 10 the other target impervious surfaces contained within lots 2 and 3 is infeasible due to the low infiltration capacity of the soils per the project geotechnical engineer. Refer to Geotechnical Report included in Appendix D of this report.  Limited Infiltration per Appendix C, Section C.2.3,  Response: Limited infiltration BMPs are infeasible due to the lack of infiltrative capacity of soils per geotechnical engineer and are not proposed to mitigate any remaining target impervious surfaces.  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: Rain Gardens are infeasible due to the lack of infiltrative capacity of soils per geotechnical engineer and are not proposed to mitigate any remaining target impervious surfaces.  Bioretention per Appendix C, Section C.2.6  Response: Bioretention is infeasible due to the lack of infiltrative capacity of soils per geotechnical engineer and is not proposed to mitigate any remaining target impervious surfaces.  Permeable Pavement per Appendix C, Section C.2.7  Response: Due to the variability of the onsite soil capacity for infiltration, permeable pavement is not proposed for the remaining target impervious surfaces. 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: Lots 2 and 3 will apply Basic Dispersion BMPs to the maximum extent if feasible. 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: Lots 2 and 3 will evaluate and implement BMPs for an impervious area equal to at least 10% of 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 Page 11  Response: The project will implement soil amendment BMP on all disturbed soils 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: Roof downspout connections for Lots 2 and 3 will be via perforated pipe connection to the local drainage system. 4.2.1 BMP Sizing Full Infiltration is proposed for Lots 1, 4, and 5 per Small Lot BMP Requirement discussed in Section 2. The Geotechnical Information report states, “the test pits showed no evidence of high seasonal groundwater table below existing grade.” The Drywell BMP was chosen to provide full infiltration within the building setbacks and property lines. All roof and non-pollution generating impervious surfaces are to be routed to the drywell to the maximum extent practicable. Drywells have been sized to mitigate the maximum impervious allowed per zoning code to remain conservative. Drywell Sizing Per Section C.2.2.4 of the 2022 RSWDM, drywells can be applied onsite in areas where the depth to the maximum wet-season water table is relatively deep. The drywells will be designed using guidance from the 2022 RSWDM. The sizing criteria, per the manual, requires drywells placed within medium sand soils to contain at least 90 cubic feet of gravel per 1,000 square feet of impervious surface being routed to the drywell. Lot 1 Lot 1 has a total maximum impervious surface area allowed per zoning code (55%) of 3,887 square foot. That means drywell storage (V1) of at least 350 cubic feet must be provided on the lot. 3,887 1,000 =𝑉ଵ 90 →𝑉ଵ = 350 𝑐𝑓 Assuming the infiltration drywell for Lot 1 has a drain rock gravel depth of 6’ (H1) the required radius, (R1), is determined as follows: 𝑉ଵ =𝜋 × (𝑅ଵ)ଶ × 𝐻ଵ 𝑅ଵ =ඨ൬ 𝑉ଵ 𝜋× 𝐻ଵ ൰ =ඨ൬ 350 𝜋× 6 ൰ = 4.3 𝑓𝑒𝑒𝑡= 4.5 𝑓𝑒𝑒𝑡 (𝑜𝑟 9 𝑓𝑜𝑜𝑡 𝑑𝑖𝑎𝑚𝑒𝑡𝑒𝑟) Lot 4 Lot 4 has a total maximum impervious surface area allowed per zoning code (55%) of 4,828 square foot which is more than 4,000 square feet; thus, 4,000 square feet will be used for modeling, but the drywell Core Design, Inc. Jones Renton Short Plat Page 12 will be sized for max impervious surface per zoning code. The required drywell storage (V1) of at least 435 cubic feet must be provided on the lot. 4,828 1,000 =𝑉ଵ 90 →𝑉ଵ = 435 𝑐𝑓 Assuming the infiltration drywell for Lot 1 has a drain rock gravel depth of 6’ (H1) the required radius, (R1), is determined as follows: 𝑉ଵ =𝜋 × (𝑅ଵ)ଶ × 𝐻ଵ 𝑅ଵ =ඨ൬ 𝑉ଵ 𝜋× 𝐻ଵ ൰ =ඨ൬ 435 𝜋× 6 ൰ = 4.8 𝑓𝑒𝑒𝑡= 5 𝑓𝑒𝑒𝑡 (𝑜𝑟 10 𝑓𝑜𝑜𝑡 𝑑𝑖𝑎𝑚𝑒𝑡𝑒𝑟) Lot 5 Lot 5 has a total maximum impervious surface area allowed per zoning code (55%) of 3,695 square foot. A required drywell storage (V2) of at least 333 cubic feet must be provided on the lot. 3,695 1,000 =𝑉ଶ 90 →𝑉ଶ = 333 𝑐𝑓 Assuming the infiltration drywell for Lot 1 has a drain rock gravel depth of 6’ (H1) the required radius, (R1), is determined as follows: 𝑉ଵ =𝜋 × (𝑅ଵ)ଶ × 𝐻ଵ 𝑅ଵ =ඨ൬ 𝑉ଵ 𝜋× 𝐻ଵ ൰ =ඨ൬ 333 𝜋× 6 ൰ = 4.2𝑓𝑒𝑒𝑡= 4.5 𝑓𝑒𝑒𝑡 (𝑜𝑟 9 𝑓𝑜𝑜𝑡 𝑑𝑖𝑎𝑚𝑒𝑡𝑒𝑟) 4.3 Soils: Geotechnical Report Summary The site is underlain predominantly by till toils with some outwash soils on the eastern portion of the parcel. Infiltration is suitable in the sandy outwash soil deposits generally located in the eastern half of the property. Very fine-grained soils were encountered in the western portion of the property. Due to variations with recessional outwash, the depth and location of suitable soils is expected to vary with location and depth. Because the recessional deposits have not been overridden by glacial ice, this soil unit is considered normally consolidated. The Washington State Department of Ecology 2015 Stormwater Management Manual for Western Washington allows determination of infiltration rates of this soil unit by Soil Particle Size Distribution testing. This method involves using a logarithmic equation and grain size values along with correction factors for testing type, soil homogeneity, and influent control. The equation in conjunction with sieve analysis results yields a design infiltration rate of 2.2 inches per hour for recessional deposits below the weathered zone, generally 5 to 6 feet below site elevations. Core Design, Inc. Jones Renton Short Plat Page 13 These rates reflect application of correction factors for variability (0.5 used), influent control (0.9), and testing analysis type (0.4). Note: infiltration is not feasible in the very fine-grained native soils. Infiltration systems should have a depth of at least five feet below existing grades and located at least 15 feet apart. Any fine-grained soils or interbeds of fine-grained soils must be removed prior to rock placement. We should be provided with final plans for review to determine if the intent of our recommendations has been incorporated or if additional modifications are needed. Verification testing of infiltration systems should be performed during construction. We can provide location-specific infiltration recommendations once civil plans have been prepared. The geotechnical report has been included in Appendix D of this report for reference. 4.4 Flow Control: Peak Rate Flow Control Standards The site is divided into two separate basins which drain from east to west towards Park Avenue N. WWHM has been used to simulate the difference between the runoff of the existing and developed conditions for both basins. Per Section 1.2.3.1 of the 2022 RSWDM, the project could be exempt from flow control facilities if each 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. A concerted effort was made to match the developed basin areas to the existing basin areas to the maximum extent possible. Basin North: The existing project site areas were taken from survey data collected by Core Design, Inc. and are tabulated in Table 4-1 below. The developed project site areas were established as the maximum impervious area allowed by zoning code (55% of lot) or 4,000 square feet, whichever is less, for lots 2 and 3, minus a portion of the proposed driveways which are included in the south drainage basin per City of Renton comment. The proposed frontage improvement areas are calculated per the site plan for the project. For lots 2 and 3 the maximum impervious is above 4,000 square feet; thus, 4,000 square feet (0.09 acres) is assumed for each lots impervious coverage. The developed project site areas are tabulated in Table 4-1 below. Refer to the Existing and Developed Condition Exhibits at the end of this Section. Table 4-1 Existing Project Site Coverage Developed Project Site Coverage Land Cover Type Area (Acres) Land Cover Type Area (Acres) - - Roof Area (40% of lot) 0.15 Driveway 0.08 Driveway 0.03 Till Grass 0.33 Till Grass 0.20 Frontage (Imp.) 0.02 Sidewalk (Frontage) 0.01 - - Road (Frontage) 0.04 Total 0.43 Total 0.43 The areas in Table 4-1 were input into the latest version of WWHM and a model run was created using 15-minute timesteps to determine the peak flow rates for the existing and developed conditions. See Table 4-2: North Basin Flow Frequency Analysis below. Core Design, Inc. Jones Renton Short Plat Page 14 Table 4-2: North Basin Flow Frequency Analysis The difference between the 100-year return period of both the predeveloped and mitigated (developed) site coverage is approximately 0.034 cfs which is less than 0.15 cfs. Therefore, a flow control facility is not required for the North Basin. Refer to the full WWHM report in Appendix C of this report. Basin South: The existing project site areas were taken from survey data collected by Core Design, Inc. and are tabulated in Table 4-3 below. The developed project site areas were established as the maximum impervious area allowed by zoning code (55% of lot), or 4,000 square feet, whichever is less for lots 1, 4, and 5. For lots 1 and 5, 55 percent of the lot is less than 4,000 square feet. The areas used for lots 1 and 5 are 3,887 and 3,695 square feet, respectively. For lot 4, 55% of the lot is more than 4,000 square feet; thus, 4,000 square feet has been assumed for the impervious site coverage. The total impervious area for lots 1, 4, and 5 is approximately 11,582 square feet (0.27 acres). The proposed frontage improvement areas are measured from the proposed site plan. Tract A is for tree retention and is modeled as fully forested (0.07 acres). Tract B1 and B2 are modeled as grass cover (0.08 acres). Fully infiltrated areas are deducted from the total area of the model and are discussed in Subsection 4.2.1 of this report. The developed project site areas are tabulated in Table 4-3 below. Refer to the Existing and Developed Condition Exhibits at the end of Section 4. Table 4-3 Existing Project Site Coverage Developed Project Site Coverage Land Cover Type Area (Acres) Land Cover Type Area (Acres) Roof Area 0.03 Roof/Non PGIS (Fully Infiltrated) -0.23 Driveway 0.04 Driveways (within Lots) 0.05 Walkway 0.01 - - Till Grass 0.26 Till Grass (Onsite and Frontage) 0.40 Till Forest 0.62 Till Forest 0.07 Frontage (Imp.) 0.02 Sidewalk (Frontage) 0.05 - - Road (Frontage) 0.18 Total 0.98 Total 0.75 Core Design, Inc. Jones Renton Short Plat Page 15 The areas in Table 4-3 were input into the latest version of WWHM and a model run was created using 15-minute timesteps to determine the peak flow rates for the existing and developed conditions. See Table 4-4: South Basin Flow Frequency Analysis below. Table 4-4: South Basin Flow Frequency Analysis The difference between the 100-year return period of both the predeveloped and mitigated (developed) site coverage is approximately 0.145 cfs which is no more than the allowed difference. Therefore, a flow control facility is not required for the North Basin. Refer to the full WWHM report in Appendix C of this report. 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 2022 City of Renton Surface water Design Manual (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. North Basin The development within the North Basin will create approximately 1,454 square feet of new plus replaced PGIS and less than 3/4 acre of new PGPS which is not fully dispersed. Hence, the North Basin qualifies for a water quality exemption. South Basin The development within the South Basin will create more than 5,000 square feet of new plus replaced PGIS, but less than 3/4 acre of new PGPS which is not fully dispersed. Therefore, the South Basin is required to provide a water quality facility as determined by the 2022 RSWDM. Core Design, Inc. Jones Renton Short Plat Page 16 Core Design, Inc. Jones Renton Short Plat Page 17 The Basic Water Quality Menu includes the following pollutant removal target:  Treatment Goal: The Basic WQ menu is designed to achieve 80% TSS removal for flows up to and including the WQ design flow or volume. The project proposes to use Basic Option 8 – Proprietary Facility. A BayFilterTM System Water Quality Filter by ADS is proposed. This type of facility has GULD Approval from Washington State DOE. Developed project site areas for the South Basin are shown in Table 4-3 above. A Developed Conditions Exhibit is also provided at the end of this section. BayFilterTM System Design A BayFilterTM System will be used to provide water quality treatment for the pollution generating impervious surfaces within the South Basin of the project. A copy of the GULD Approval of the BayFilterTM System from the Washington State DOE is also provided on the following pages. WWHM was used to generate the 15-minute, on-line, water quality flow rate for BayFilterTM System treating the South Basin areas. Refer to Appendix C of this report for the full WWHM report. The BayFilterTM system was designed using the ADS BayFilterTM design tool and the table below. Refer to the ADS BayFilterTM design sheets on the following pages. MANHOLE BayFilter™ Model Precast Size Number of Cartridges Treatment Capacity - 522 (cfs) Treatment Capacity - 530 (cfs) Treatment Capacity - 545 (cfs) BF-48-1 48” 1 0.05 0.067 0.10 BF-60-2 60” 2 0.10 0.13 0.20 BF-72-3 72” 3 0.15 0.20 0.30 BF-84-4 84” 4 0.20 0.27 0.40 BF-96-5 96” 5 0.25 0.33 0.50 BF-96-6 96” 6 0.30 0.40 0.60 BF-96-7 96” 7 0.35 0.47 0.70 Treatment Area: Approximately 0.24 acres impervious area which consists of the frontage road (0.14 acres), sidewalk (0.04 acres), and lot driveway areas (0.06 acres) as well as 0.07 acres of pervious which are tributary to the BayFilterTM System. On-line 15-minute Water Quality Flow Rate from WWHM Model: 0.0415 cfs Proposed BayFilterTM Model: BF-48-1 (48”) Manhole with Model 522 Filter Jones Short Plat -Rev 07-19-24 Renton- WA BAYSAVER BAYFILTER SPECIFICATIONS PRODUCTS A.INTERNAL COMPONENTS: ALL COMPONENTS INCLUDING CONCRETE STRUCTURE(S), PVC MANIFOLD PIPING AND FILTER CARTRIDGES, SHALL BE PROVIDED BY BAYSAVER TECHNOLOGIES LLC, 1030 DEER HOLLOW DRIVE, MOUNT AIRY, MD (800.229.7283). B.PVC MANIFOLD PIPING: ALL INTERNAL PVC PIPE AND FITTINGS SHALL MEET ASTM D1785. MANIFOLD PIPING SHALL BE PROVIDED TO THE CONTRACTOR PARTIALLY PRE-CUT AND PRE-ASSEMBLED. C.FILTER CARTRIDGES: EXTERNAL SHELL OF THE FILTER CARTRIDGES SHALL BE SUBSTANTIALLY CONSTRUCTED OF POLYETHYLENE OR EQUIVALENT MATERIAL ACCEPTABLE TO THE MANUFACTURER. FILTRATION MEDIA SHALL BE ARRANGED IN A SPIRAL LAYERED FASHION TO MAXIMIZE AVAILABLE FILTRATION AREA. AN ORIFICE PLATE SHALL BE SUPPLIED WITH EACH CARTRIDGE TO RESTRICT THE FLOW RATE TO A MAXIMUM OF 45 GPM. D.FILTER MEDIA: FILTER MEDIA SHALL BE BY BAYSAVER TECHNOLOGIES LLC AND SHALL CONSIST OF THE FOLLOWING MIX: A BLEND OF ZEOLITE, PERLITE AND ACTIVATED ALUMINA. E.PRECAST CONCRETE VAULT: CONCRETE STRUCTURES SHALL BE PROVIDED ACCORDING TO ASTM C. THE MATERIALS AND STRUCTURAL DESIGN OF THE DEVICES SHALL BE PER ASTM C478, C857 AND C858. PRECAST CONCRETE SHALL BE PROVIDED BY BAYSAVER TECHNOLOGIES, LLC. PERFORMANCE A.THE STORMWATER FILTER SYSTEM SHALL BE AN OFFLINE DESIGN CAPABLE OF TREATING 100% OF THE REQUIRED TREATMENT FLOW AT FULL SEDIMENT LOAD CONDITIONS.B.THE STORMWATER FILTER SYSTEM'S CARTRIDGES SHALL HAVE NO MOVING PARTS. C.THE STORMWATER TREATMENT UNIT SHALL BE DESIGNED TO REMOVE AT LEAST 85% OF SUSPENDED SOLIDS, 65% OF TOTAL PHOSPHORUS, 65% OF TURBIDITY, 40% OF TOTAL COPPER, AND 40% OF TOTAL ZINC BASED ON FIELD DATA COLLECTED IN COMPLIANCE WITH THE TECHNOLOGY ACCEPTANCE RECIPROCITY PARTNERSHIP TIER II TEST PROTOCOL. D.THE STORMWATER FILTRATION SYSTEM SHALL REDUCE INCOMING TURBIDITY (MEASURED AS NTUs) BY 50% OR MORE AND SHALL NOT HAVE ANY COMPONENTS THAT LEACH NITRATES OR PHOSPHATES. E.THE STORMWATER FILTRATION CARTRIDGE SHALL BE EQUIPPED WITH A HYDRODYNAMIC BACKWASH MECHANISM TO EXTEND THE FILTER'S LIFE AND OPTIMIZE ITS PERFORMANCE. F.THE STORMWATER FILTRATION SYSTEM SHALL BE DESIGNED TO REMOVE A MINIMUM OF 65% OF THE INCOMING TOTAL PHOSPHORUS (TP) LOAD. G.THE STORMWATER FILTRATION SYSTEM'S CARTRIDGES SHALL HAVE A TREATED SEDIMENT CAPACITY FOR 80% TSS REMOVAL BETWEEN 150-350 LBS. 2021 ADS, INC. BAYFILTER MAINTENANCE THE BAYFILTER SYSTEM REQUIRES PERIODIC MAINTENANCE TO CONTINUE OPERATING AT ITS PEAK EFFICIENCY DESIGN. THE MAINTENANCE PROCESS COMPRISES THE REMOVAL AND REPLACEMENT OF EACH BAYFILTER CARTRIDGE AND THE CLEANING OF THE VAULT OR MANHOLE WITH A VACUUM TRUCK. FOR BEST RESULTS, BAYFILTER MAINTENANCE SHOULD BE PERFORMED BY A CERTIFIED MAINTENANCE CONTRACTOR. A QUICK CALL TO AN ADS ENGINEER OR CUSTOMER SERVICE REPRESENTATIVE WILL PROVIDE YOU WITH A LIST OF RELIABLE CONTRACTORS IN YOUR AREA. WHEN BAYFILTER IS INITIALLY INSTALLED, WE RECOMMEND THAT AN INSPECTION BE PERFORMED ON THE SYSTEM IN THE FIRST SIX (6) MONTHS. AFTER THAT, THE INSPECTION CYCLE TYPICALLY FALLS INTO A BIANNUAL PATTERN GIVEN NORMAL STORM OCCURRENCE AND ACTUAL SOLIDS LOADS. WHEN BAYFILTER EXHIBITS FLOWS BELOW DESIGN LEVELS, THE SYSTEM SHOULD BE INSPECTED AND MAINTAINED AS SOON AS PRACTICAL. REPLACING A BAYFILTER CARTRIDGE SHOULD BE CONSIDERED AT OR ABOVE THE LEVEL OF THE MANIFOLD. MAINTENANCE PROCEDURES 1.REMOVE THE MANHOLE COVERS AND OPEN ALL ACCESS HATCHES. 2.BEFORE ENTERING THE SYSTEM MAKE SURE THE AIR IS SAFE PER OSHA STANDARDS OR USE A BREATHING APPARATUS. USE LOW O2, HIGH CO, OR OTHER APPLICABLE WARNING DEVICES PER REGULATORY REQUIREMENTS. 3.USING A VACUUM TRUCK, REMOVE ANY LIQUID AND SEDIMENTS THAT CAN BE REMOVED PRIOR TO ENTRY. 4.USING A SMALL LIFT OR THE BOOM OF THE VACUUM TRUCK, REMOVE THE USED CARTRIDGES BY LIFTING THEM OUT. 5.ANY CARTRIDGES THAT CANNOT BE READILY LIFTED CAN BE EASILY SLID ALONG THE FLOOR TO A LOCATION THEY CAN BE LIFTED VIA A BOOM LIFT.6.WHEN ALL THE CARTRIDGES HAVE BEEN REMOVED, IT IS NOW PRACTICAL TO REMOVE THE BALANCE OF THE SOLIDS AND WATER. LOOSEN THE STAINLESS CLAMPS ON THE FERNCO COUPLINGS FOR THE MANIFOLD AND REMOVE THE DRAINPIPES AS WELL. CAREFULLY CAP THE MANIFOLD AND THE FERNCO'S AND RINSE THE FLOOR, WASHING AWAY THE BALANCE OF ANY REMAINING COLLECTED SOLIDS.7.CLEAN THE MANIFOLD PIPES, INSPECT, AND REINSTALL.8.INSTALL THE EXCHANGE CARTRIDGES AND CLOSE ALL COVERS. 9.THE USED CARTRIDGES MUST BE SENT BACK TO ADS FOR EXCHANGE/RECYCLING AND CREDIT ON UNDAMAGED UNITS. BAYFILTER INSTALLATION NOTES 1.CONTACT UTILITY LOCATOR TO MARK ANY NEARBY UNDERGROUND UTILITIES AND MAKE SURE IT IS SAFE TO EXCAVATE.2.REFERENCE THE SITE PLAN AND STAKE OUT THE LOCATION OF THE BAYFILTER VAULT. 3.EXCAVATE THE HOLE, PROVIDING ANY SHEETING AND SHORING NECESSARY TO COMPLY WITH ALL FEDERAL, STATE AND LOCAL SAFETY REGULATIONS. 4.LEVEL THE SUB—GRADE TO THE PROPER ELEVATION. VERIFY THE ELEVATION AGAINST THE MANHOLE DIMENSIONS, THE INVERT ELEVATIONS, AND THE SITE PLANS. ADJUST THE BASE AGGREGATE, IF NECESSARY. 5.HAVE THE SOIL BEARING CAPACITY VERIFIED BY A LICENSED/ENGINEER FOR THE REQUIRED LOAD BEARING CAPACITY. ON SOLID SUB—GRADE, SET THE FIRST SECTION OF THE BAYFILTER PRE--CAST VAULT. 6.CHECK THE LEVEL AND ELEVATION OF THE FIRST SECTION TO ENSURE IT IS CORRECT BEFORE ADDING ANY RISER SECTIONS. 7.IF ADDITIONAL SECTION(S) ARE REQUIRED, ADD A WATERTIGHT SEAL TO THE FIRST SECTION OF THE BAYFILTER VAULT. SET ADDITIONAL SECTION(S) OF THE VAULT, ADDING A WATERTIGHT SEAL TO EACH JOINT.8.INSTALL THE PVC OUTLET MANIFOLD.9.INSTALL THE PVC OUTLET PIPE IN BAYFILTER VAULT.10.INSTALL THE INLET PIPE TO THE BAYFILTER VAULT. 11.AFTER THE SITE IS STABILIZED, REMOVE ANY ACCUMULATED SEDIMENT OR DEBRIS FROM THE VAULT AND INSTALL THE FLOW DISKS, DRAINDOWN MODULES (IF APPLICABLE), AND THE BAYFILTER CARTRIDGES. 12.PLACE FULL SET OF HOLD DOWN BARS AND BRACKETS INTO PLACE. 522 BAYFILTER WQU-1 WATER QUALITY FLOW RATE 0.04 cfs DRAINAGE AREA CARTRIDGE DESIGN FLOW RATE 22.5 GPM # BAYFILTER CARTRIDGES 1 TREATED SEDIMENT CAPACITY 175 lbs THE BAYFILTER STORMWATER MANAGEMENT SYSTEM IS A STORMWATER FILTRATION DEVICE DESIGNED TO REMOVE FINE SEDIMENTS, HEAVY METALS, AND PHOSPORUS. THE BAYFILTER SYSTEM RELIES ON A SPIRAL WOUND MEDIA FILTER CARTRIDGE WITH APPROXIMATELY 45 SQUARE FEET OF FILTRATION AREA. THE FILTER CARTRIDGES ARE HOUSED IN A CONCRETE STRUCTURE THAT EVENLY DISTRIBUTES THE FLOW BETWEEN CARTRIDGES. THE SYSTEM IS OFFLINE WITH AN EXTERNAL BYPASS THAT ROUTES HIGH INTENSITY STORMS AROUND THE SYSTEM. THE FILTER CARTRIDGES REMOVE POLLUTANTS FROM RUNOFF BY FILTRATION (INTERCEPTION/ATTACHMENT) AND ADSORPTION. SECTION A-A SCALE: N.T.S. NOTE: THIS DETAIL SHOWS A FUNCTIONAL FILTER DESIGN PER SITE SPECIFIC INFORMATION PROVIDED. THE FINAL APPROVED PRECAST DRAWINGS WILL DETERMINE THE FINAL SIZE, INCLUDING BUT NOT LIMITED TO; OVERALL DIMENSIONS, RISER SIZE, RISER TYPE & HEIGHT AND FRAMES & COVERS BEING PROVIDED. PLAN VIEW SCALE: N.T.S. SHEET OFAAJones Short Plat -Rev 07-19-244640 TRUEMAN BLVDHILLIARD, OH 43026Bayfilter ®Stormwater Media FiltersRenton - WA7/19/24 DRAWN: XXXDATE:NOT TO SCALE1-800-229-7283 | WWW.BAYSAVER.COMPROJECT #: S######CHECKED: XXXDATE DRWN CHKDDESCRIPTIONTHIS DRAWING HAS BEEN PREPARED BASED ON INFORMATION PROVIDED TO ADS UNDER THE DIRECTION OF THE SITE DESIGN ENGINEER OR OTHER PROJECT REPRESENTATIVE. THE SITE DESIGN ENGINEER SHALL REVIEW THIS DRAWING PRIOR TO CONSTRUCTION. IT IS THE ULTIMATE RESPONSIBILITY OF THE SITE DESIGN ENGINEER TO ENSURE THAT THE PRODUCT(S) DEPICTED AND ALL ASSOCIATED DETAILS MEET ALL APPLICABLE LAWS, REGULATIONS, AND PROJECT REQUIREMENTS.2 2 Jones Short Plat -Rev 07-19-24 BAYFILTER 522 – 48" BILL OF MATERIALS PART NUMBER QUANTITY DESCRIPTION 1 1 3-IN PVC ELBOW 2 1 3-IN PVC TEE WITH 1.5- IN FLOWDISK 3 1 522 CARTRIDGES 4 1 DRAINDOWN 5 1 12" STANDPIPE 6 2 INLET PIPE 7 1 3-IN FLEXIBLE COUPLER 8 1 3-IN PVC PLUG 9 1 HOLD DOWN BAR 10 2 3-IN PVC 12" LONG The MosT AdvAnced NaMe iN waTer MaNageMeNT soluTioNsTM The BayFilter system requires periodic maintenance to continue operating at the design efficiency. The maintenance process is comprised of the removal and replacement of each BayFilter cartridge, vertical drain down module; and the cleaning of the vault or manhole with a vacuum truck. The maintenance cycle of the BayFilter system will be driven mostly by the actual solids load on the filter. The system should be periodically monitored to be certain it is operating correctly. Since stormwater solids loads can be variable, it is possible that the maintenance cycle could be more or less than the projected duration. BayFilter systems in volume-based applications are designed to treat the WQv in 24 to 48 hours initially. Late in the operational cycle of the BayFilter, the flow rate will diminish as a result of occlusion. When the drain down exceeds the regulated standard, maintenance should be performed. When a BayFilter system is first installed, it is recommended that it be inspected every six (6) months. When the filter system exhibits flows below design levels the system should be maintained. Filter cartridge replacement should also be considered when sediment levels are at or above the level of the manifold system. Please contact the BaySaver Technologies Engineering Department for maintenance cycle estimations or assistance at 1.800.229.7283. BayFilter System Cleanout Vactor Truck Maintenance Jet Vactoring Through Access Hatch Bayfilter™ inspection and Maintenance Manual The ADS logo and the Green Stripe are registered trademarks of Advanced Drainage Systems, Inc. BaySaver® and BayFilterTM are registered trademarks of BaySaver Technologies, LLC© 2018 Advanced Drainage Systems, Inc. #XXXXX 02/18 MH Advanced Drainage Systems, Inc. 4640 Trueman Blvd., Hilliard, OH 43026 1-800-821-6710 www.ads-pipe.com The MosT AdvAnced NaMe iN waTer MaNageMeNT soluTioNsTM Maintenance Procedures 1. Contact BaySaver Technologies for replacement filter cartridge pricing and availability at 1-800-229-7283. 2. Remove the manhole covers and open all access hatches. 3. Before entering the system make sure the air is safe per OSHA Standards or use a breathing apparatus. Use low O2, high CO, or other applicable warning devices per regulatory requirements. 4. Using a vacuum truck remove any liquid and sediments that can be removed prior to entry. 5. Using a small lift or the boom of the vacuum truck, remove the used cartridges by lifting them out. 6. Any cartridges that cannot be readily lifted can be easily slid along the floor to a location they can be lifted via a boom lift. 7. When all the cartridges have been removed, it is not practical to remove the balance of the solids and water. Loosen the stainless clamps on the Fernco couplings for the manifold and remove the drain pipes as well. Carefully cap the manifold and the Ferncos and rinse the floor, washing away the balance of any remaining collected solids. 8. Clean the manifold pipes, inspect, and reinstall. 9. Install the exchange cartridgess and close all covers. 10. The used cartridges may be sent back to BaySaver Technologies for recycling. Manifold Tee View of a Cleaned System Cartridge Hoist Point For more information please see the BaySaver website at www.baysaver.com or contact 1-800-229-7283. July 2019 GENERAL USE LEVEL DESIGNATON FOR BASIC (TSS) AND PHOSPHORUS TREATMENT For BaySaver Technologies, LLC BayFilter™ System using Enhanced Media Cartridges (EMC) Ecology’s Decision: 1. Based on BaySaver Technologies’ application submissions, Ecology hereby issues a General Use Level Designation (GULD) for Basic and Phosphorus Treatment for the BayFilter™ System using Enhanced Media Cartridges (EMC).  Sized at a hydraulic loading rate of no greater than 0.50 gallons per minute (gpm) per square foot (sq ft.) of filter area. o 45 gpm (0.10 cfs) per cartridge (example dimensions 28-inch diameter, 30- inches tall (90 sq ft filter area)) o 75 gpm (0.167 cfs) per cartridge (example dimensions 39-inch diameter, 30- inches tall (150 sq ft filter area))  Canisters that provide 0.50 gpm per sq ft filter area, regardless of dimensions meet this requirement  Using BaySaver’s EMC Media Blend of Zeolite, Perlite, and Activated Alumina. Specifications of media shall match the specifications provided by the manufacturer and approved by Ecology. 2. Ecology approves use of BayFilter™ Enhanced Media Cartridges for treatment at the above flow rates per cartridge. Designers shall calculate the water quality design flow rates using the following procedures:  Western Washington: For treatment installed upstream of detention or retention, the water quality design flow rate is the peak 15-minute flow rate as calculated using the latest version of the Western Washington Hydrology Model or other Ecology- approved continuous runoff model.  Eastern Washington: For treatment installed upstream of detention or retention, the water quality design flow rate is the peak 15-minute flow rate as calculated using one of the three methods described in Chapter 2.2.5 of the Stormwater Management Manual for Eastern Washington (SWMMEW) or local manual.  Entire State: For treatment installed downstream of detention, the water quality design flow rate is the full 2-year release rate of the detention facility. 3. The GULD has no expiration date, but it may be amended or revoked by Ecology, and is subject to the conditions specified below. Ecology’s Conditions of Use: BayFilter™ units shall comply with these conditions: 1. Design, assemble, install, operate, and maintain BayFilter™ units in accordance with BaySaver Technologies’ applicable manuals and documents and the Ecology Decision. 2. Maintenance: The required inspection/maintenance interval for stormwater treatment devices is often dependent upon the efficiency of the device and the degree of pollutant loading from a particular drainage basin. Therefore, Ecology does not endorse or recommend a “one size fits all” maintenance cycle for a particular model/size of manufactured filter treatment device.  BaySaver recommends that the following be considered during the design application of the BayFilter Cartridge systems: o Water Quality Flow Rate o Anticipated Pollutant Load o Maintenance Frequency  A BayFilter System tested adjacent to construction activity required maintenance after 4-months of operation. Monitoring personnel observed construction washout in the device during the testing period; the construction activity may have resulted in a shorter maintenance interval.  Ecology has found that pre-treatment device prior to the BayFilter system can provide a reduction in pollutant loads on these systems, thereby extending the maintenance interval.  Test results provided to Ecology from other BayFilter Systems, including the above mentioned system that was evaluated again after construction activities had been completed, have indicated the BayFilter System typically has longer maintenance intervals, sometimes exceeding 12-months.  The BayFilter system contains filter fabric that is highly oleophilic (oil absorptive). When sufficient quantities of oils are present in the runoff, the oil and subsequent sediment particles may become attached to the fabric. As a result, it may compromise the maintenance interval of the BayFilter system. Oil control BMP’s should be installed upstream of BayFilter installations if warranted, and/or the BayFilter system should be inspected after any known oil spill or release.  Owners/operators must inspect BayFilter systems for a minimum of twelve months from the start of post-construction operation to determine site-specific inspection/maintenance schedules and requirements. Owners/operators must conduct inspections monthly during the wet season, and every other month during the dry season. (According to the SWMMWW, the wet season in western Washington is October 1 to April 30. According to SWMMEW, the wet season in eastern Washington is October 1 to June 30.) After the first year of operation, owners/operators must conduct inspections based on the findings during the first year of inspections or the manufacturer’s anticipated maintenance interval, whichever is more frequent.  Conduct inspections by qualified personnel, follow manufacturer’s guidelines, and must use methods capable of determining either a decrease in treated effluent flowrate and/or a decrease in pollutant removal ability. 3. When inspections are performed, the following findings typically serve as maintenance triggers:  Accumulated vault sediment depths exceed an average of 2 inches, or  Accumulated sediment depths on the tops of the cartridges exceed an average of 0.5 inches, or  Standing water remains in the vault between rain events.  Bypass during storms smaller than the design storm.  Note: If excessive floatables (trash and debris) are present, perform minor maintenance consisting of gross solids removal, not cartridge replacement. 4. Discharges from the BayFilter™ units shall not cause or contribute to water quality standards violations in receiving waters. Applicant: Advanced Drainage Systems - BaySaver Applicant’s Address: 4640 Trueman Blvd Hilliard, Ohio 43065 Application Documents:  Technical Evaluation Report BayFilter™ System Woodinville Sammamish River Outfall, Woodinville, Washington and Appendices A through M (March 2, 2017)  Technical Evaluation Report BayFilter System, Grandview Place Apartments, Vancouver, Washington and Appendices A through O (May 18, 2011)  Washington State Department of Ecology Technology Assessment Protocol – Environmental BayFilter™ Conditional Use Designation Application (March 2007)  BaySaver Technologies, Inc. BayFilter™ System Washington State Technical and Design Manual, Version 1.1 (December 2006)  Efficiency Assessment of BaySeparator and Bay filter Systems in the Richard Montgomery High School January 6.2009.  Evaluation of MASWRC Sample Collection, Sample Analysis, and Data Analysis, December 27, 2008  Letter from Mid-Atlantic Stormwater Research Center to BaySaver Technologies, In. dated October 22, 2009.  Letter from Mid-Atlantic Stormwater Research Center to BaySaver Technologies, In. dated November 5, 2009.  Maryland Department of the Environment letter to BaySaver Technologies dated Jan. 13, 2008 regarding approval of BayFilter as a standalone BMP for Stormwater treatment.  NJCAT letter to BaySaver Technologies dated June 18, 2009 regarding Interim Certification. Applicant’s Use Level Request:  General use level designation as a basic, enhanced, and phosphorus treatment device in accordance with Ecology’s Stormwater Management Manual for Western Washington. Applicant’s Performance Claims:  Removes and retains 80% of TSS based on laboratory testing using Sil-Co-Sil 106 as a laboratory stimulant.  Removes 42% of dissolved Copper and 38% of dissolved Zinc.  Expected to remove 50% of the influent phosphorus load. Ecology’s Recommendations:  BaySaver Technologies, Inc. has shown Ecology, through laboratory and field testing, that the BayFilter™ System using Enhanced Media Cartridges (EMC) (as a single treatment facility) is capable of attaining Ecology’s Basic and Phosphorus Treatment goals.  Ecology should provide BaySaver Technologies, Inc. with the opportunity to demonstrate, through additional laboratory and field-testing, whether the BayFilter™ System using Enhanced Media Cartridges (EMC) (as a single treatment facility) can attain Ecology’s Enhanced Treatment goals. Findings of Fact:  BaySaver conducted field monitoring of a BayFilter™ using EMC at a site in Woodinville, WA between November 2013 and March 2015. BaySaver sized the system at a hydraulic loading rate of 0.50 gpm/sq. ft. The manufacturer collected flow-weighted influent and effluent composite samples during 12 storm events. o Influent TSS concentrations from sampled storm events ranged from 17 to 140 mg/L. For all samples, the upper 95 percent confidence limit (UCL) of the mean effluent concentration was less than 10 mg/L. For influent concentrations greater than 100 mg/L (n=2) the removal efficiency was greater than 80%. o Influent total phosphorus concentrations from sampled storm events ranged from 0.073 to 0.320 mg/L. A bootstrap estimate of the lower 95 percent confidence limit (LCL95) of the mean total phosphorus reduction was 64 percent. o BaySaver inspected the system regularly, however they did not need maintenance during the 18 month evaluation period.  Based on field testing in Vancouver, WA, at a flow rate less than or equal to 30 gpm per canister, the BayFilter™ system demonstrated a total suspended solids removal efficiency of greater than 80% for influent concentrations between 100 and 200 mg/l and an effluent concentration < 20 mg/l for influent concentration < 100 mg/l.  Based on laboratory testing, at a flowrate of 30 GPM per filter, the BayFilter™ system demonstrated a total suspended solids removal efficiency of 81.5% using Sil-Co-Sil 106 with an average influent concentration of 268 mg/L and zero initial sediment loading.  Based on laboratory testing, at a flowrate of 30 GPM per filter, the BayFilter™ system demonstrated a dissolved phosphorus removal efficiency of 55% using data from the Richard Montgomery High School field-testing. The average influent concentration was 0.31 mg/L phosphorus and zero initial sediment loading.  Based on data from field-testing at Richard Montgomery High School in Rockville, MD the BayFilter system demonstrated a Cu removal efficiency of 51% and 41% for total and dissolved Cu respectively. Average influent concentrations are 41.6 µg/l total and 17.5 µg/l dissolved.  Based on data from field-testing at Richard Montgomery High School in Rockville, MD the BayFilter system demonstrated a Zn removal efficiency of 45% and 38% for total and dissolved Cu, respectively. Average influent concentrations are 354 µg/l total and 251 µg/l dissolved, respectively. Other BayFilter™ Related Issues to be Addressed By the Company: 1. The Washington State field test results submitted in the TER do not yet show whether the BayFilter™ system can reliably attain 30% removal of dissolved Cu or 60% removal of dissolved Zn found on local highways, parking lots, and other high-use areas at the design operating rate. 2. BaySaver Technologies, Inc. should test a variety of operating rates to establish conservative design flow rates. 3. The manufacturer should continue to monitor the system to measure bypass and to calculate if the system treats 91% of the volume of the total annual runoff volume. 4. The manufacturer should test the system under normal operating conditions, with a partially pollutant filled settling basin. Results obtained for “clean” systems may not be representative of typical performance. 5. Conduct field-testing at sites that are indicative of the treatment goals. 6. BaySaver should continue monitoring the system for a longer period to help establish a maintenance period and to obtain data from additional qualified storms. Conduct testing to obtain information about maintenance requirements in order to come up with a maintenance cycle. 7. Conduct loading tests on the filter to determine maximum treatment life of the system. 8. Conduct testing to determine if oils and grease affect the treatment ability of the filter. This should include a determination of how oil and grease may affect the ion-exchange capacity of the system if BaySaver wishes to make claims for phosphorus removal. 9. BaySaver should develop easy-to-implement methods of determining when a BayFilter system requires maintenance (cleaning and filter replacement). 10. BaySaver must update their O&M documents to include information and instructions on the “24-hour draw-down” method to determine if cartridges need replacing. Technology Description: Download at www.BaySaver.com Contact Information: Applicant: Brian Rustia Advanced Drainage Systems - BaySaver 4640 Trueman Blvd Hilliard, Ohio 43065 (866) 405-9292 brian.rustia@ads-pipe.com Applicant website: www.BaySaver.com Ecology web link: http://www.ecy.wa.gov/programs/wq/stormwater/newtech/index.html Ecology: Douglas C. Howie, P.E. Department of Ecology Water Quality Program (360) 407-6444 douglas.howie@ecy.wa.gov Revision History Date Revision April 2008 Original use-level-designation document February 2010 Revision August 2011 GULD awarded for Basic Treatment April 2012 Maintenance requirements updated. August 2012 Revised design storm criteria December 2012 Revised contact information and document formatting December 2013 Revised expiration and submittal dates December 2014 Revised Inspection/maintenance discussion, Updated cartridge descriptions January 2015 Revised discussion for flow rate controls December 2015 Revised Expiration date January 2016 Revised Manufacturer Contact Information and expiration date January 2017 Revised Expiration, QAPP and TER due dates April 2017 Approved GULD designation for Basic and Phosphorus Treatment December 2017 Removed CULD for Enhanced Treatment at request of Manufacturer July 2019 Revised Applicant Contact Information N 31ST STREETPARK AVENUE NPARK AVENUE N ALLEYDESIGN12100 NE 195th St, Suite 300 Bothell, Washington 98011 425.885.7877CIVIL ENGINEERINGLANDSCAPE ARCHITECTUREPLANNINGSURVEYING120081K1 N 31ST STREETPARK AVENUE NPARK AVENUE N ALLEYDESIGN12100 NE 195th St, Suite 300 Bothell, Washington 98011 425.885.7877CIVIL ENGINEERINGLANDSCAPE ARCHITECTUREPLANNINGSURVEYING120081K1 Core Design, Inc. Jones Renton Short Plat Page 19 SECTION 5: CONVEYANCE SYSTEM ANALYSIS AND DESIGN The conveyance system was designed for the 100-year, 24-hour storm event. Conveyance spreadsheets were generated using the rational method to calculate flows for each area collected by each catch basin. The 100-year, 24-hour precipitation value for the project location is 3.9 inches and the 25-year, 24-hour precipitation value is 3.4 inches. See isopluvial maps from the 2021 KCSWDM provided on the following pages. The flows generated from the conveyance system spreadsheets were then input into backwater analysis spreadsheets to confirm adequate conveyance sizing for the project. See conveyance and backwater spreadsheets provided on the following pages. 5.1 Results During the 25- and 100-year storm all the headwater elevations remained below the rim elevations of catch basins. The designed stormwater system has sufficient conveyance capacity to safely convey the 25- and 100-year storm flows. See Rational and Backwater Calculation Sheets on the following pages of this report. RATIONAL METHOD CONVEYANCE SYSTEM DESIGN LOCATION: KING COUNTY PR (24-HR RAINFALL):3.4 INCHES PROJECT NAME: JONES SHORT PLAT PROJECT NUMBER: 20081K PREPARED BY: BCR DESIGN STORM: 25 YEAR SUBBASIN PIPE PIPE PIPE ACTUAL TRAVEL PIPE CAPACITY SUMMARY LOCATION AREA SUM OF Tc IR QR MANNING'S SIZE SLOPE LENGTH VELOCITY (VR)TIME Q(FULL) V(FULL)QR/Q(FULL) FROM TO (AC) "C" (A * C) (A * C) (MIN) (IN/HR) (CFS) "n" (IN) (%) (FT) (FT/SEC) (MIN) (CFS) (FT/SEC) (%) CB 10 CB 9 0.122 0.88 0.107 0.107 6.30 2.73 0.368 0.012 12 0.033 36 0.90 0.66 0.702 0.89 52.4% CB 9 CB 8 0.027 0.85 0.023 0.130 6.96 2.56 0.334 0.012 12 0.127 71 1.44 0.82 1.377 1.75 24.2% CB 7 CB 8 0.107 0.74 0.079 0.079 6.30 2.73 0.216 0.012 12 0.028 21 0.73 0.48 0.647 0.82 33.5% CB 8 WQ 0.053 0.77 0.041 0.250 7.79 2.38 0.596 0.012 12 0.023 13 0.85 0.25 0.587 0.75 101.6% WQ CB 3 0.027 0.82 0.022 0.272 8.04 2.33 0.636 0.012 12 0.064 12 1.33 0.15 0.978 1.25 65.0% CB 4 CB 3 0.011 0.88 0.010 0.010 6.30 2.73 0.026 0.012 12 0.194 34 0.66 0.86 1.698 2.16 1.6% CB 5 CB 3 0.069 0.60 0.041 0.041 6.30 2.73 0.113 0.012 12 0.059 56 0.79 1.18 0.937 1.19 12.1% CB 3 CB 2 0.000 0.90 0.000 0.324 8.19 2.30 0.746 0.012 12 0.016 57 0.61 1.55 0.482 0.61 154.7% CB 2 CB 1 0.030 0.90 0.027 0.351 9.74 2.06 0.722 0.012 12 0.134 114 1.80 1.06 1.411 1.80 51.2% RATIONAL METHOD CONVEYANCE SYSTEM DESIGN LOCATION: KING COUNTY PR (24-HR RAINFALL):3.9 INCHES PROJECT NAME: JONES SHORT PLAT PROJECT NUMBER: 20081K PREPARED BY: BCR DESIGN STORM: 100 YEAR SUBBASIN PIPE PIPE PIPE ACTUAL TRAVEL PIPE CAPACITY SUMMARY LOCATION AREA SUM OF Tc IR QR MANNING'S SIZE SLOPE LENGTH VELOCITY (VR)TIME Q(FULL) V(FULL)QR/Q(FULL) FROM TO (AC) "C" (A * C) (A * C) (MIN) (IN/HR) (CFS) "n" (IN) (%) (FT) (FT/SEC) (MIN) (CFS) (FT/SEC) (%) CB 10 CB 9 0.122 0.88 0.107 0.107 6.30 3.19 0.368 0.012 12 0.033 36 0.90 0.66 0.702 0.89 52.4% CB 9 CB 8 0.027 0.85 0.023 0.130 6.96 3.00 0.391 0.012 12 0.127 71 1.50 0.79 1.377 1.75 28.4% CB 7 CB 8 0.107 0.74 0.079 0.079 6.30 3.19 0.253 0.012 12 0.028 21 0.77 0.46 0.647 0.82 39.1% CB 8 WQ 0.053 0.77 0.041 0.250 7.75 2.80 0.701 0.012 12 0.023 13 0.75 0.29 0.587 0.75 119.5% WQ CB 3 0.027 0.82 0.022 0.272 8.04 2.74 0.746 0.012 12 0.064 12 1.37 0.15 0.978 1.25 76.2% CB 4 CB 3 0.011 0.88 0.010 0.010 6.30 3.19 0.031 0.012 12 0.194 34 0.66 0.86 1.698 2.16 1.8% CB 5 CB 3 0.069 0.60 0.041 0.041 6.30 3.19 0.132 0.012 12 0.059 56 0.83 1.13 0.937 1.19 14.1% CB 3 CB 2 0.000 0.90 0.000 0.324 8.19 2.71 0.875 0.012 12 0.016 57 0.61 1.55 0.482 0.61 181.6% CB 2 CB 1 0.030 0.90 0.027 0.351 9.74 2.43 0.851 0.012 12 0.134 114 1.89 1.00 1.411 1.80 60.3% BACKWATER CALCULATIONS PROJECT NAME: JONES SHORT PLAT PREPARED BY: BCR PROJECT NUMBER: 20081K DESIGN STORM: 25 YEAR ENTRANCE ENTRANCE EXIT OUTLET INLET APPROACH BEND JUNCTION PIPE PIPE MANNING'S OUTLET INLET PIPE FULL VELOCITY TAILWATER FRICTION HGL HEAD HEAD CONTROL CONTROL VELOCITY HEAD HEAD HEADWATER RIM FROM TO Q LENGTH SIZE "n" ELEVATION ELEVATION AREA VELOCITY HEAD ELEVATION LOSS ELEVATION LOSS LOSS ELEVATION ELEVATION HEAD LOSS LOSS ELEVATION ELEVATION FREEBOARD CB CB (CFS) (FT) (IN) VALUE (FT) (FT) (SQ FT) (FT/SEC) (FT) (FT) (FT) (FT) (FT) (FT) (FT) (FT) (FT) (FT) (FT) (FT) (FT) (FT) CB 1 CB 2 0.72 114 12 0.012 179.57 194.81 0.79 0.92 0.01 180.57 0.04 180.61 0.01 0.01 180.63 195.81 0.01 0.00 0.00 180.62 182.06 1.44 CB 2 CB 3 0.75 57 12 0.012 194.81 195.70 0.79 0.95 0.01 180.62 0.02 180.64 0.01 0.01 180.66 196.70 0.01 0.00 0.00 180.65 205.36 24.71 CB 3 CB 5 0.11 56 12 0.012 195.70 199.00 0.79 0.14 0.00 180.65 0.00 195.70 0.00 0.00 195.70 200.00 0.00 0.00 0.00 195.70 203.96 8.26 CB 3 CB 4 0.03 34 12 0.012 195.70 202.28 0.79 0.03 0.00 180.65 0.00 195.70 0.00 0.00 195.70 203.28 0.00 0.00 0.00 195.70 206.28 10.58 CB 3 WQ 0.64 12 12 0.012 195.70 196.47 0.79 0.81 0.01 180.65 0.00 195.71 0.01 0.01 195.73 197.47 0.01 0.00 0.00 195.72 204.90 9.18 WQ CB 8 0.60 13 12 0.012 196.97 197.27 0.79 0.76 0.01 196.97 0.00 196.97 0.00 0.01 196.99 198.27 0.00 0.00 0.00 196.99 204.52 7.53 CB 8 CB 7 0.22 21 12 0.012 197.27 197.86 0.79 0.28 0.00 196.99 0.00 198.86 0.00 0.00 198.86 198.86 0.00 0.00 0.00 198.86 204.64 5.78 CB 8 CB 9 0.33 71 12 0.012 197.27 206.31 0.79 0.42 0.00 196.99 0.01 197.28 0.00 0.00 197.28 207.31 0.00 0.00 0.00 197.28 211.21 13.93 CB 9 CB 10 0.37 36 12 0.012 206.31 207.50 0.79 0.47 0.00 197.28 0.00 197.28 0.00 0.00 197.29 208.50 0.00 0.00 0.00 197.29 213.80 16.51 PIPE SEGMENT BACKWATER CALCULATIONS PROJECT NAME: JONES SHORT PLAT PREPARED BY: BCR PROJECT NUMBER: 20081K DESIGN STORM: 100 YEAR ENTRANCE ENTRANCE EXIT OUTLET INLET APPROACH BEND JUNCTION PIPE PIPE MANNING'S OUTLET INLET PIPE FULL VELOCITY TAILWATER FRICTION HGL HEAD HEAD CONTROL CONTROL VELOCITY HEAD HEAD HEADWATER RIM FROM TO Q LENGTH SIZE "n" ELEVATION ELEVATION AREA VELOCITY HEAD ELEVATION LOSS ELEVATION LOSS LOSS ELEVATION ELEVATION HEAD LOSS LOSS ELEVATION ELEVATION FREEBOARD CB CB (CFS) (FT) (IN) VALUE (FT) (FT) (SQ FT) (FT/SEC) (FT) (FT) (FT) (FT) (FT) (FT) (FT) (FT) (FT) (FT) (FT) (FT) (FT) (FT) CB 1 CB 2 0.85 114 12 0.012 179.57 194.81 0.79 1.08 0.02 180.57 0.05 180.62 0.01 0.02 180.65 195.81 0.02 0.00 0.00 180.63 182.06 1.43 CB 2 CB 3 0.88 57 12 0.012 194.81 195.70 0.79 1.11 0.02 180.63 0.03 180.66 0.01 0.02 180.69 196.70 0.01 0.01 0.00 180.68 205.36 24.68 CB 3 CB 5 0.13 56 12 0.012 195.70 199.00 0.79 0.17 0.00 180.68 0.00 195.70 0.00 0.00 195.70 200.00 0.00 0.00 0.00 195.70 203.96 8.26 CB 3 CB 4 0.03 34 12 0.012 195.70 202.28 0.79 0.04 0.00 180.68 0.00 195.70 0.00 0.00 195.70 203.28 0.00 0.00 0.00 195.70 206.28 10.58 CB 3 WQ 0.75 12 12 0.012 195.70 196.47 0.79 0.95 0.01 180.68 0.00 195.72 0.01 0.01 195.74 197.47 0.01 0.00 0.00 195.73 204.90 9.17 WQ CB 8 0.70 13 12 0.012 196.97 197.27 0.79 0.89 0.01 196.97 0.00 196.97 0.01 0.01 196.99 198.27 0.00 0.00 0.00 196.99 204.52 7.53 CB 8 CB 7 0.25 21 12 0.012 197.27 197.86 0.79 0.32 0.00 196.99 0.00 198.86 0.00 0.00 198.86 198.86 0.00 0.00 0.00 198.86 204.64 5.78 CB 8 CB 9 0.39 71 12 0.012 197.27 206.31 0.79 0.50 0.00 196.99 0.01 197.28 0.00 0.00 197.29 207.31 0.00 0.00 0.00 197.28 211.21 13.93 CB 9 CB 10 0.37 36 12 0.012 206.31 207.50 0.79 0.47 0.00 197.28 0.00 197.29 0.00 0.00 197.29 208.50 0.00 0.00 0.00 197.29 213.80 16.51 PIPE SEGMENT N 31ST STREETPARK AVENUE N ALLEYDESIGN12100 NE 195th St, Suite 300 Bothell, Washington 98011 425.885.7877CIVIL ENGINEERINGLANDSCAPE ARCHITECTUREPLANNINGSURVEYING120081K1 Core Design, Inc. Jones Renton Short Plat Page 21 SECTION 6: SPECIAL REPORTS AND STUDIES  Geotechnical Investigation (Provided under separate cover) Prepared for: Jones Renton Short Plat Prepared by: Cobalt Geosciences Dated: April 3, 2020 Cobalt Geosciences PO Box 82243 Kenmore, Washington 98028  Arborist Report (provided under separate cover) Prepared for: Jones Renton Short Plat Prepared by: American Forest Management Dated: May 28th, 2020 Cobalt Geosciences 11415 NE 128th St, Suite 110 Kirkland, Washington 98034 Core Design, Inc. Jones Renton Short Plat Page 22 SECTION 7: OTHER PERMITS  Right of Way Use Permit  Building Permits  NPDES Permit Core Design, Inc. Jones Renton Short Plat Page 23 SECTION 8: ESC ANALYSIS AND DESIGN A CSWPPP has been created for the project and is submitted under separate cover. The site will utilize Appendix D of the 2022 RSWDM and the DOE SWMMWW for the erosion and sedimentation control design to reduce the discharge of sediment-laden runoff from the site. Clearing limits will be established prior to any earthwork on the project site. Perimeter protection will be provided by silt fencing along the downstream perimeter of the disturbed areas to limit the downstream transport of sediment to streams, wetlands and neighboring properties. Dust control, if required, will be provided by a water truck. A Certified Erosion and Sediment Control Lead inspector will be present onsite during earthwork activities. The inspector shall determine frequency of watering of the project site and will authorize and direct any additional erosion and sediment control measures as needed during all construction activities. The project proposes to use separate temporary sediment traps for the North and South Basins to provide sediment and flow control during construction. The sediment trap for the North Basin will be constructed at the northwest corner of the site, within the buildable area of the site. The sediment trap for the North Basin will be constructed at the southwest edge of the site, within the buildable area of the site. Runoff from the site will sheet flow across cleared areas into temporary interceptor swales which discharge the runoff into the sediment traps for erosion and sediment control. The sediment traps have been sized to receive flows from approximately 0.37 acres of the site within the North Basin and approximately 0.89 acres of the site within the South Basin. Areas near the boundary of the site which cannot be picked up by interceptor swales will be mitigated using silt fencing, which can receive 100 linear feet of sheet flow. Refer to the TESC plan at the end of this section. The minimum sediment trap surface area is calculated below using the 10-year, 15-minute peak storm event assuming developed site conditions with the potential of work during the wet season (October 1 to April 30). Engineering Calculations Runoff from the site will sheet flow across cleared areas into temporary interceptor swales and into a temporary sediment trap. WWHM, an approved continuous simulation hydrology model, was used to calculate the 10-year, 15-minute storm event for the North and South Basins under full buildout conditions. The model does not account for BMP credits to provide a conservative design. Core Design, Inc. Jones Renton Short Plat Page 24 North Basin ONSITE NORTH BASIN Total Area = 0.37 acres GROUND COVER AREA (acres) Till Grass 0.14 Impervious 0.23 The following equations from the 2022 RSWDM, Appendix D, show the calculated required surface area for the sediment pond and sizing for the required risers. TESC Pond Surface Area Calculation The following equation shows the calculation for the temporary surface area. 𝑆𝐴=𝑄ଵ଴ × 2080 Where: 𝑄ଵ଴= Design inflow (10yr 15min) = 0.1503 cfs SA= Surface Area Sediment Pond Summary: The 10-year, 15-minute return period developed flow rate is 0.1503 cfs. The minimum required surface area for the sediment pond is 2,080 * 0.1503 = 313 SF. Interior Slope: 3H:1V Exterior slope: 2H:1V Storage depth: 3.5 ft The project proposes to use a temporary sediment trap per D.2.1.5.1 to provide temporary sediment storage for the site. The provided surface area will be 494 square feet, which exceeds the minimum and therefore, is adequately sized. Core Design, Inc. Jones Renton Short Plat Page 25 South Basin ONSITE SOUTH BASIN Total Area = 0.89 acres GROUND COVER AREA (acres) Till Grass 0.37 Impervious 0.52 The following equations from the 2022 RSWDM, Appendix D, show the calculated required surface area for the sediment pond and sizing for the required risers. TESC Pond Surface Area Calculation The following equation shows the calculation for the temporary surface area. 𝑆𝐴=𝑄ଵ଴ × 2080 Where: 𝑄ଵ଴= Design inflow (10yr 15min) = 0.5556 cfs SA= Surface Area Sediment Pond Summary: The 10-year, 15-minute return period developed flow rate is 0.3948 cfs. The minimum required surface area for the sediment pond is 2,080 * 0.3948 = 821 SF. Interior Slope: 3H:1V Exterior slope: 2H:1V Storage depth: 3.5 ft The project proposes to use a temporary sediment pond per D.2.1.5.1 to provide temporary sediment storage for the site. The provided surface area will be 1,172 square feet which exceeds the minimum and therefore, is adequately sized. Core Design, Inc. Jones Renton Short Plat Page 26 SECTION 9: BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT 9.1 Bond Quantities To be provided prior to final engineering approval. 9.2 Facility Summaries To be provided prior to final engineering approval. 9.3 Declaration of Covenant To be provided prior to final engineering approval. Core Design, Inc. Jones Renton Short Plat Page 27 SECTION 10: OPERATIONS AND MAINTENANCE To be provided prior to final engineering approval. Appendix A Parcel & Basin Information Fair, Equitable, and Understandable Property Valuations You're in: Assessor >> Look up Property Info >> eReal Property Department ofAssessments 500 FourthAvenue,Suite ADM- AS-0708,Seattle, WA98104 Office Hours:Mon - Fri 8:30 a.m. to4:30 p.m. TEL: 206-296-7300 FAX: 206-296-5107TTY: 206-296-7888 Send us mail ADVERTISEMENT New SearchProperty Tax BillMap This PropertyGlossary of TermsArea ReportProperty Detail PARCEL ParcelNumber 334210-3215 Name JONES F ALAN SiteAddress 3102 PARK AVE N 98056 Legal HILLMANS LK WN GARDEN OF EDEN # 1 LESS N 200 FT OF 34 & 39 LESS S 200 FT EXC E 60 FT &LESS S 120 FT OF E 60 FT THOF BUILDING 1 Year Built 1946 Total Square Footage 2180 Number Of Bedrooms 3 Number Of Baths 1.00 Grade 7 Average Condition Good Lot Size 57614 Views Yes Waterfront TOTAL LEVY RATE DISTRIBUTION Tax Year: 2020      Levy Code: 2100      Total Levy Rate: $11.11810      Total Senior Rate: $6.23509  48.57% Voter Approved Click here to see levy distribution comparison by year.  TAX ROLL HISTORY ValuedYear TaxYear Appraised LandValue ($)Appraised ImpsValue ($)AppraisedTotal ($)Appraised ImpsIncrease ($)Taxable LandValue ($)Taxable ImpsValue ($)TaxableTotal ($) 2019 2020 1,155,000 20,000 1,175,000 0 1,155,000 20,000 1,175,000 2018 2019 1,316,000 73,000 1,389,000 0 1,316,000 73,000 1,389,000 2017 2018 1,197,000 74,000 1,271,000 0 1,197,000 74,000 1,271,000 2016 2017 1,062,000 65,000 1,127,000 0 1,062,000 65,000 1,127,000 2015 2016 984,000 60,000 1,044,000 0 984,000 60,000 1,044,000 2014 2015 879,000 50,000 929,000 0 879,000 50,000 929,000 2013 2014 765,000 43,000 808,000 0 765,000 43,000 808,000 2012 2013 620,000 43,000 663,000 0 620,000 43,000 663,000 2011 2012 602,000 39,000 641,000 0 602,000 39,000 641,000 2010 2011 697,000 46,000 743,000 0 697,000 46,000 743,000 2009 2010 785,000 54,000 839,000 0 785,000 54,000 839,000 2008 2009 924,000 68,000 992,000 0 924,000 68,000 992,000 2007 2008 825,000 61,000 886,000 0 825,000 61,000 886,000 2006 2007 462,000 124,000 586,000 0 462,000 124,000 586,000 2005 2006 436,000 92,000 528,000 0 436,000 92,000 528,000 2004 2005 408,000 90,000 498,000 0 408,000 90,000 498,000 2003 2004 385,000 86,000 471,000 0 385,000 86,000 471,000 ADVERTISEMENT ReferenceLinks: King County TaxingDistricts Codes andLevies (.PDF) King County TaxLinks Property Tax Advisor Washington StateDepartment ofRevenue (Externallink) Washington StateBoard of TaxAppeals (Externallink) Board of Appeals/Equalization Districts Report iMap Recorder's Office  Scanned images of surveys and other map documents Scanned images of plats   Search Kingcounty.gov Home How do I... Services About King County Departments  King County Department of Assessments Information for... Residents Businesses Job seekers Volunteers King County employees Do more online Trip Planner Property tax information & payment Jail inmate look up Parcel viewer or iMap Public records More online tools... Get help Contact us  Customer service Phone list Employee directory Subscribe to alerts  Stay connected! View King County social media    © King County, WA 2020 Privacy Accessibility Terms of use 2002 2003 369,000 74,000 443,000 0 369,000 74,000 443,000 2001 2002 345,000 100,000 445,000 0 345,000 100,000 445,000 2000 2001 353,000 1,000 354,000 0 353,000 1,000 354,000 1999 2000 313,000 1,000 314,000 0 313,000 1,000 314,000 1998 1999 275,000 1,000 276,000 0 275,000 1,000 276,000 1997 1998 0 0 0 0 250,000 1,000 251,000 1996 1997 0 0 0 0 246,500 1,000 247,500 1994 1995 0 0 0 0 246,500 1,000 247,500 1992 1993 0 0 0 0 132,900 62,000 194,900 1990 1991 0 0 0 0 115,600 53,900 169,500 1988 1989 0 0 0 0 93,500 31,100 124,600 1986 1987 0 0 0 0 93,200 22,900 116,100 1985 1986 0 0 0 0 85,000 26,600 111,600 1984 1985 0 0 0 0 85,000 26,600 111,600 1982 1983 0 0 0 0 63,700 26,600 90,300 ADVERTISEMENT Updated: Jan. 29, 2019  Share   Tweet   Email Information for...Do more online Get help 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 Project Site ))))!!!!!!!!!!!!!!!!! !!!!!!!!! ! ! ! !! !! !! !! !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!ÑÑÑLINCOLNZONE XAVENUE 20 STREET 36TH SE 87TH H AVENUESTREET 405 14434 PLACEAVENUE NCAMASNEMEADOW11 3 TH PARKSTREET MONTEREYSTREET COURT76 AVENUE NERAILROAD19 STREET R AIL R OA D 28TH STREET NEAVENUEAVENUEMay Creek PARK NE 40TH STREET STREET F AVENUENE43RD N E K BURNETT10TH N 1M ZONE X 30TH X PARKNE 35TH ZONE XN PARK N PL A C E KING COUNTY 40TH AVENUE82ND N RAILROAD 1N NEWCASTLE 32ND NE30 ZONE X PLACEAVENUE NEZONE AE61DETAILED STUDY 28TH N NE NE 18TH STREET 9 8 TNEBOULEVARD AVENUE NENED R IV E 16TH STREET 28TH NEBLAINEJONES1H STREET STREET ABERDEEN1 1 2 TH2728TH 71 PLACE 12TH KING COUNTY34TH North Boeing Bridge N E 29 SUNSET68NE 19TH 32ND NCITY OF RENTONZONE X STREET 42I AVENUE NCREEK 530071 NE AVENUE LAKE WASHINGTON 81 AVENUE117STREET 36TH 33RD 2 4 T H P L A C E NMONTEREYPLACECITY OF RENTONN ZONE X NEZONE X 29TH LINCOLN6 6 BEACH NS E STREET CAMASKENNEWICK AVENUE NES T REET NEMONTE R EY MUNICIPAL AVENUEZONE AE NNEBNCITY OF SY0159 A 27TH 530083 1E S T R EET 96LINCOLNN116WI LLI AMS MAY CREEK PARK N RIVERSIDE DRIVE ACCESSZONE PROFILE BASELINE NE 33RD 31ST STREET UNINCORPORATED AREAS N CAMASXPLACE 30TH 37TH 27TH N 1F S T R E ETSTREET ¥k405 STREET LIMIT OF DETAILED STUDY PARKPLACE NE AVENUE AVENUE NEN 8 T. 23 N.GPLACE ZONE X J NRAILROADSY0157 MAY CREEK PARK RAI L ROADROAD PARKN NE AVENUE2514THAVENUE N¥k405 1L PLACE33RD ZONE AE BOEING26TH AVENUE NE23 AVENUE NEN E NE110TH 114THNEVIEW56 H O U SER N GARDEN46 KING COUNTYNE KENNEWICKMAY 32 ABE R D E E N D R IV E 99 ZONE X STREET STREET STREETPLACEAVENUEAVENUE NEM O NT EREY34TH N STREET 20TH 111ZONE P L AC E NOTE: MAP AREA SHOWN ON THIS PANEL IS LOCATEDWITHIN TOWNSHIP 23 NORTH, RANGE 5 EASTAND TOWNSHIP 24 NORTH, RANGE 5 EAST.PARK 35TH A COULONWASHINGTON26 RENTON 24 NE11838 NAVENUE NESTREET AVENUE530088 HIGHPCITY OF MERCER ISLAND NLIMIT OF AVENUERAILROADP L A C E SE 110TH CITY OF RENTON CAMASWASHI NGT ONMEADOWC SESTREET AVENUEW A Y 24TH NEAIRPORT NE QBLAINEAVENUE1I SEN 2 0 T H 1G KEN N E WI C K 31 34TH AE N ACCESS 1T91J Cedar River P L A C E NE AE ZONE X NE1VMONTEREYSTREET 89NE 25TH 21 N NNELAKEAVENUENEBOULEVARD33JONESNLAKE MONTEREYAVALON PLACE SE NEM S T R E E T BLAINEShoreline NE NE ZONE 101 Shoreline SE 28TH SE 13TH PLACE 38THA STREET UN BNE SL A NE 100 K N STREET ZONE X ZONE X 530134 LINCOLNSTREET KENNEWICK86TH PLACE ZONE X 1UN PLACE RAILROADAVENUEAVENUEPLACEONENE STREET86NR 5 T. 24 N.EMEADOWZONEN 36TH 33RD 22 ¥k405 MEADOWROADPLACE COURTCAMAS1 0 61D A V E N UEBOULEVARDN E STREET 1N N E 2 9 T H SY0161 N NE 23RD STREET N NE MOUNTAINAVENUESTREET RNCITY OF SEATTLE530089 530071UNINCORPORATED AREASKING COUNTY CITY OF NEWCASTLECITY OF RENTONShoreline 6 31 STREET 7 6 559000m E 560000m E 561000m E 5262000m N 5263000m N 5264000m N 122°13'07.5"47°31'52.5" 122°13'07.5" 47°30'00.0"122°11'15.0"47°30'00.0" 122°11'15.0"47°31'52.5"JOINS PANEL 0668JOINS PANEL 0663JOINS PANEL 0977 JOINS PANEL 0675 Floodplain boundary Floodway boundary Zone D boundary LEGENDSPECIAL FLOOD HAZARD AREAS (SFHAs) SUBJECT TOINUNDATION BY THE 1% ANNUAL CHANCE FLOOD The 1% annual chance flood (100-year flood), also known as the base flood, is the floodthat has a 1% chance of being equaled or exceeded in any given year. The SpecialFlood Hazard Area is the area subject to flooding by the 1% annual chance flood.Areasof Special Flood Hazard include Zones A, AE, AH, AO, AR, A99, V and VE. The BaseFlood Elevation is the water-surface elevation of the 1% annual chance flood. ZONE A No Base Flood Elevations determined.ZONE AE Base Flood Elevations determined.ZONE AH Flood depths of 1 to 3 feet (usually areas of ponding); Base FloodElevations determined.ZONE AO Flood depths of 1 to 3 feet (usually sheet flow on sloping terrain);average depths determined. For areas of alluvial fan flooding,velocitiesalso determined.ZONE AR Special Flood Hazard Area formerly protected from the 1%annualchance flood by a flood control system that was subsequentlydecertified. Zone AR indicates that the former flood control system isbeing restored to provide protection from the 1% annual chance orgreater flood.ZONE A99 Area to be protected from 1% annual chance flood by a Federalflood protection system under construction; no Base Flood Elevationsdetermined.ZONE V Coastal flood zone with velocity hazard (wave action); no Base FloodElevations determined.ZONE VE Coastal flood zone with velocity hazard (wave action); Base FloodElevations determined. FLOODWAY AREAS IN ZONE AE The floodway is the channel of a stream plus any adjacent floodplain areas that must bekept free of encroachment so that the 1% annual chance flood can be carried withoutsubstantial increases in flood heights. OTHER FLOOD AREAS ZONE X Areas of 0.2% annual chance flood; areas of 1% annual chance floodwith average depths of less than 1 foot or with drainage areas less than1 square mile; and areas protected by levees from 1% annual chanceflood. OTHER AREAS ZONE X Areas determined to be outside the 0.2% annual chance floodplain.ZONE D Areas in which flood hazards are undetermined, but possible. COASTAL BARRIER RESOURCES SYSTEM (CBRS) AREAS OTHERWISE PROTECTED AREAS (OPAs) CBRS areas and OPAs are normally located within or adjacent to Special Flood Hazard Areas. CBRS and OPA boundary Boundary dividing Special Flood Hazard Areas of differentBase Flood Elevations, flood depths or flood velocities. Base Flood Elevation line and value; elevation in feet*~~~~~~~~~~513 (EL 987)Base Flood Elevation value where uniform within zone;elevation in feet** Referenced to the North American Vertical Datum of 1988 (NAVD 88) A A Cross section line ---------Transect line2323 97°07'30", 32°22'30"Geographic coordinates referenced to the North AmericanDatum of 1983 (NAD 83) 4275000mN 1000-meter Universal Transverse Mercator grid ticks, zone 10 6000000 M 5000-foot grid ticks: Washington State Plane coordinatesystem, north zone (FIPSZONE 4601),Lambert Conformal Conic DX5510 Bench mark (see explanation in Notes to Users section ofthis FIRM panel) M1.5 River Mile MAP REPOSITORIES To determine if flood insurance is available in this community, contact your insuranceagent or call the National Flood Insurance Program at 1- 800- 638- 6620. Refer to Map Repositories list on Map Index EFFECTIVE DATE OF COUNTYWIDEFLOOD INSURANCE RATE MAPSeptember 29, 1989EFFECTIVE DATE(S) OF REVISION(S) TO THIS PANELMay 16, 1995 May 20, 1996 March 30, 1998 November 8, 1999 December 6, 2001 April 19, 2005_____________ - to update corporate limits, to change Base Flood Elevations, to add roads androad names, to incorporate previously issued Letters of Map Revision, to change Special FloodHazard Areas, and to change zone designations. For community map revision history prior to countywide mapping, refer to the CommunityMap History table located in the Flood Insurance Study report for this jurisdiction. MAP SCALE 1" = 500'250 0 500 1000FEET 150 0 150 300METERS PANEL 0664KFIRMFLOOD INSURANCE RATE MAP Notice to User: The shown below should beused when placing map orders; the Community Number shownabove should be used on insurance applications for the subjectcommunity. Map Number CONTAINS:COMMUNITY NUMBER PANEL SUFFIX MAP NUMBER53033C0664KMAP REVISED Federal Emergency Management Agency KING COUNTY, WASHINGTON AND INCORPORATED AREAS KING COUNTY 530071 0664 KMERCER ISLAND, CITY OF 530083 0664 KNEWCASTLE, CITY OF 530134 0664 KRENTON, CITY OF 530088 0664 KSEATTLE, CITY OF 530089 0664 K PANEL 664 OF 1700(SEE MAP INDEX FOR FIRM PANEL LAYOUT) The profile baselines depicted on this map represent the hydraulic modelingbaselines that match the flood profiles in the FIS report. As a result of improvedtopographic data, the profile baseline, in some cases, may deviate significantly from thechannel centerline or appear outside the SFHA. NOTES TO USERSThis map is for use in administering the National Flood Insurance Program.Itdoes not necessarily identify all areas subject to flooding, particularly from localcommunity map repositorydrainage sources of small size. The should beconsulted for possible updated or additional flood hazard information. Base Flood ElevationsTo obtain more detailed information in areas where floodways(BFEs) and/or have been determined, users are encouraged to consultthe Flood Profiles and Floodway Data and/or Summary of Stillwater Elevationstables contained within the Flood Insurance Study (FIS) report that accompaniesthis FIRM. Users should be aware that BFEs shown on the FIRM representrounded whole- foot elevations. These BFEs are intended for flood insurancerating purposes only and should not be used as the sole source of floodelevation information. Accordingly, flood elevation data presented in the FISreport should be utilized in conjunction with the FIRM for purposes ofconstruction and/or floodplain management. Coastal Base Flood Elevations shown on this map apply only landwardNorth American Vertical Datum of 1988 (NAVD 88).of 0.0'Users of thisFIRM should be aware that coastal flood elevations are also provided in theSummary of Stillwater Elevations table in the Flood Insurance Study reportfor this jurisdiction. Elevations shown in the Summary of Stillwater Elevationstable should be used for construction and/or floodplain management purposeswhen they are higher than the elevations shown on this FIRM. floodwaysBoundaries of the were computed at cross sections and interpolatedbetween cross sections. The floodways were based on hydraulic considerationswith regard to requirements of the National Flood Insurance Program.Floodwaywidths and other pertinent floodway data are provided in the Flood InsuranceStudy report for this jurisdiction. Certain areas not in Special Flood Hazard Areas may be protected by floodcontrol structures. Refer to Section 2.4 "Flood Protection Measures"ofthe Flood Insurance Study report for information on flood control structuresfor this jurisdiction. projectionThe used in the preparation of this map was Universal Transversehorizontal datumMercator (UTM) zone The was 10.NAD83, GRS1980spheroid. Differences in datum, spheroid, projection or UTM zones used inthe production of FIRMs for adjacent jurisdictions may result in slight positionaldifferences in map features across jurisdiction boundaries. These differencesdo not affect the accuracy of this FIRM. Flood elevations on this map are referenced to the North American VerticalDatum of 1988.These flood elevations must be compared to structure andvertical datum.ground elevations referenced to the same For informationregarding conversion between the National Geodetic Vertical Datum of 1929and the North American Vertical Datum of 1988, visit the National Geodetichttp://www.ngs.noaa.gov/Survey website at or contact the National GeodeticSurvey at the following address: NGS Information ServicesNOAA, N/NGS12National Geodetic SurveySSMC- 3, #92021315 East- West HighwaySilver Spring, MD 20910- 3282 To obtain current elevation, description, and/or location information for bench marksshown on this map, please contact the Information Services Branch of the(301) 713- 3242,National Geodetic Survey at or visit its website athttp://www.ngs.noaa.gov/. Base map information shown on this FIRM was derived from multiple sources. Basemap files were provided in digital format by King County GIS, WA DNR, WSDOT,and Pierce County GIS. This information was compiled at scales of 1:1200 to1:24,000 during the time period 1994-2006. This map reflects more detailed and up- to- date stream channel configurationsthan those shown on the previous FIRM for this jurisdiction. The floodplainsand floodways that were transferred from the previous FIRM may have beenadjusted to conform to these new stream channel configurations. As aresult, the Flood Profiles and Floodway Data tables in the Flood InsuranceStudy report (which contains authoritative hydraulic data) may reflect streamchannel distances that differ from what is shown on this map. Corporate limits shown on this map are based on the best data availableat the time of publication. Because changes due to annexations or de- annexationsmay have occurred after this map was published, map users should contactappropriate community officials to verify current corporate limit locations. Map IndexPlease refer to the separately printed for an overview map of thecounty showing the layout of map panels; community map repository addresses;and a Listing of Communities table containing National Flood Insurance Programdates for each community as well as a listing of the panels on which eachcommunity is located. Contact the FEMA Map Service Center at 1- 800- 358- 9616 for information onavailable products associated with this FIRM. Available products may includepreviously issued Letters of Map Change, a Flood Insurance Study report,and/or digital versions of this map. The FEMA Map Service Center may also bereached by Fax at 1- 800- 358- 9620 and its website at http://www.msc.fema.gov/. If you have questions about this map or questions concerning the NationalFlood Insurance Program in general, please call1- 877- FEMA MAP(1- 877- 336- 2627)or visit the FEMA website at http://www.fema.gov/. Project Site 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 Project Site 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. 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%H' %K %U (Y% (Y& (Y' (Z& ,Q$ ,Q& ,Q' .S% .S& .S' 0D 1J 1N 1R 2U 2V 2Y& 2Y' 3,76 3F 3N 3X 3\ 5G& 5G( 5H 5K 6K 6N 6P 6R 7X 8U : :R 'DWH 0LOHVq6RLO6XUYH\ Site 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 Project Site Appendix C WWHM Reports North Basin Flow Control Model South Basin Flow Control Model South Basin Water Quality Model WWHM2012 PROJECT REPORT 20081K North Basin Flow Control Model 7/18/2024 2:39:02 PM Page 2 General Model Information WWHM2012 Project Name:20081K North Basin Flow Control Model Site Name:Jones Short Plat Site Address: City:Renton Report Date:7/18/2024 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 20081K North Basin Flow Control Model 7/18/2024 2:39:02 PM Page 3 Landuse Basin Data Predeveloped Land Use Predev Conditions North Basin Bypass:No GroundWater:No Pervious Land Use acre C, Lawn, Mod 0.33 Pervious Total 0.33 Impervious Land Use acre ROADS FLAT 0.02 ROADS FLAT 0.08 Impervious Total 0.1 Basin Total 0.43 20081K North Basin Flow Control Model 7/18/2024 2:39:02 PM Page 4 Mitigated Land Use Dev Conditions North Basin Bypass:No GroundWater:No Pervious Land Use acre C, Lawn, Mod 0.2 Pervious Total 0.2 Impervious Land Use acre ROADS FLAT 0.04 ROOF TOPS FLAT 0.15 ROADS FLAT 0.03 SIDEWALKS FLAT 0.01 Impervious Total 0.23 Basin Total 0.43 20081K North Basin Flow Control Model 7/18/2024 2:39:02 PM Page 5 Routing Elements Predeveloped Routing 20081K North Basin Flow Control Model 7/18/2024 2:39:02 PM Page 6 Mitigated Routing 20081K North Basin Flow Control Model 7/18/2024 2:39:02 PM Page 7 Analysis Results POC 1 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area:0.33 Total Impervious Area:0.1 Mitigated Landuse Totals for POC #1 Total Pervious Area:0.2 Total Impervious Area:0.23 Flow Frequency Method:Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.066292 5 year 0.098267 10 year 0.122297 25 year 0.155989 50 year 0.183564 100 year 0.213314 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.103525 5 year 0.137807 10 year 0.162058 25 year 0.194528 50 year 0.220081 100 year 0.246832 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 0.110 0.151 1950 0.110 0.136 1951 0.064 0.091 1952 0.038 0.066 1953 0.034 0.071 1954 0.053 0.085 1955 0.055 0.093 1956 0.055 0.091 1957 0.077 0.113 1958 0.046 0.082 20081K North Basin Flow Control Model 7/18/2024 2:39:48 PM Page 8 1959 0.037 0.074 1960 0.068 0.095 1961 0.059 0.093 1962 0.038 0.072 1963 0.061 0.092 1964 0.051 0.082 1965 0.082 0.118 1966 0.041 0.070 1967 0.108 0.135 1968 0.091 0.145 1969 0.074 0.107 1970 0.061 0.097 1971 0.075 0.117 1972 0.102 0.136 1973 0.035 0.062 1974 0.077 0.112 1975 0.081 0.116 1976 0.057 0.085 1977 0.052 0.080 1978 0.063 0.099 1979 0.062 0.130 1980 0.128 0.157 1981 0.063 0.106 1982 0.121 0.164 1983 0.065 0.114 1984 0.047 0.077 1985 0.064 0.106 1986 0.063 0.092 1987 0.066 0.130 1988 0.032 0.074 1989 0.040 0.093 1990 0.205 0.239 1991 0.143 0.179 1992 0.049 0.077 1993 0.033 0.062 1994 0.027 0.062 1995 0.054 0.093 1996 0.098 0.117 1997 0.075 0.107 1998 0.058 0.093 1999 0.160 0.225 2000 0.068 0.105 2001 0.050 0.100 2002 0.104 0.145 2003 0.087 0.117 2004 0.143 0.206 2005 0.062 0.093 2006 0.061 0.085 2007 0.188 0.215 2008 0.138 0.174 2009 0.082 0.114 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.2046 0.2391 2 0.1878 0.2253 3 0.1601 0.2155 20081K North Basin Flow Control Model 7/18/2024 2:39:48 PM Page 9 4 0.1434 0.2065 5 0.1427 0.1789 6 0.1385 0.1743 7 0.1278 0.1636 8 0.1205 0.1566 9 0.1104 0.1506 10 0.1097 0.1448 11 0.1080 0.1446 12 0.1036 0.1362 13 0.1024 0.1360 14 0.0976 0.1354 15 0.0909 0.1300 16 0.0874 0.1297 17 0.0822 0.1180 18 0.0818 0.1170 19 0.0810 0.1166 20 0.0774 0.1166 21 0.0771 0.1155 22 0.0747 0.1140 23 0.0747 0.1140 24 0.0735 0.1134 25 0.0683 0.1122 26 0.0679 0.1071 27 0.0659 0.1069 28 0.0650 0.1060 29 0.0645 0.1057 30 0.0637 0.1052 31 0.0631 0.1003 32 0.0631 0.0989 33 0.0628 0.0973 34 0.0625 0.0948 35 0.0622 0.0930 36 0.0613 0.0930 37 0.0608 0.0928 38 0.0607 0.0927 39 0.0592 0.0927 40 0.0585 0.0927 41 0.0571 0.0918 42 0.0553 0.0917 43 0.0546 0.0913 44 0.0542 0.0911 45 0.0532 0.0853 46 0.0518 0.0853 47 0.0509 0.0848 48 0.0498 0.0825 49 0.0488 0.0817 50 0.0465 0.0805 51 0.0463 0.0770 52 0.0413 0.0765 53 0.0404 0.0744 54 0.0377 0.0742 55 0.0376 0.0723 56 0.0372 0.0710 57 0.0347 0.0701 58 0.0344 0.0655 59 0.0332 0.0621 60 0.0323 0.0619 61 0.0274 0.0616 20081K North Basin Flow Control Model 7/18/2024 2:39:48 PM Page 10 20081K North Basin Flow Control Model 7/18/2024 2:39:49 PM Page 11 Duration Flows The Duration Matching Failed Flow(cfs)Predev Mit Percentage Pass/Fail 0.0331 1168 6034 516 Fail 0.0347 1009 5283 523 Fail 0.0362 867 4652 536 Fail 0.0377 757 4124 544 Fail 0.0392 646 3630 561 Fail 0.0407 584 3247 555 Fail 0.0423 527 2894 549 Fail 0.0438 478 2575 538 Fail 0.0453 434 2308 531 Fail 0.0468 385 2068 537 Fail 0.0483 354 1866 527 Fail 0.0499 317 1667 525 Fail 0.0514 292 1524 521 Fail 0.0529 273 1369 501 Fail 0.0544 249 1239 497 Fail 0.0559 227 1131 498 Fail 0.0575 210 1027 489 Fail 0.0590 197 926 470 Fail 0.0605 179 856 478 Fail 0.0620 163 773 474 Fail 0.0635 146 713 488 Fail 0.0651 136 655 481 Fail 0.0666 125 605 484 Fail 0.0681 114 553 485 Fail 0.0696 106 519 489 Fail 0.0711 105 483 460 Fail 0.0726 101 441 436 Fail 0.0742 95 414 435 Fail 0.0757 90 381 423 Fail 0.0772 85 359 422 Fail 0.0787 82 341 415 Fail 0.0802 79 324 410 Fail 0.0818 76 304 400 Fail 0.0833 72 286 397 Fail 0.0848 66 267 404 Fail 0.0863 61 245 401 Fail 0.0878 56 226 403 Fail 0.0894 52 216 415 Fail 0.0909 48 204 425 Fail 0.0924 47 191 406 Fail 0.0939 45 171 380 Fail 0.0954 44 160 363 Fail 0.0970 42 152 361 Fail 0.0985 41 139 339 Fail 0.1000 39 133 341 Fail 0.1015 38 125 328 Fail 0.1030 36 119 330 Fail 0.1046 35 114 325 Fail 0.1061 32 108 337 Fail 0.1076 30 105 350 Fail 0.1091 28 104 371 Fail 0.1106 26 99 380 Fail 0.1122 24 93 387 Fail 0.1137 23 87 378 Fail 20081K North Basin Flow Control Model 7/18/2024 2:39:49 PM Page 12 0.1152 22 83 377 Fail 0.1167 22 76 345 Fail 0.1182 20 72 360 Fail 0.1198 19 71 373 Fail 0.1213 17 70 411 Fail 0.1228 17 68 400 Fail 0.1243 17 64 376 Fail 0.1258 17 58 341 Fail 0.1273 17 58 341 Fail 0.1289 14 56 400 Fail 0.1304 13 50 384 Fail 0.1319 13 47 361 Fail 0.1334 13 45 346 Fail 0.1349 13 44 338 Fail 0.1365 11 39 354 Fail 0.1380 11 37 336 Fail 0.1395 10 36 360 Fail 0.1410 8 34 425 Fail 0.1425 8 31 387 Fail 0.1441 6 31 516 Fail 0.1456 5 29 580 Fail 0.1471 5 29 580 Fail 0.1486 5 28 560 Fail 0.1501 5 24 480 Fail 0.1517 5 23 460 Fail 0.1532 4 23 575 Fail 0.1547 4 22 550 Fail 0.1562 4 21 525 Fail 0.1577 3 19 633 Fail 0.1593 3 19 633 Fail 0.1608 2 18 900 Fail 0.1623 2 18 900 Fail 0.1638 2 16 800 Fail 0.1653 2 16 800 Fail 0.1669 2 15 750 Fail 0.1684 2 14 700 Fail 0.1699 2 14 700 Fail 0.1714 2 13 650 Fail 0.1729 2 13 650 Fail 0.1744 2 12 600 Fail 0.1760 2 12 600 Fail 0.1775 2 10 500 Fail 0.1790 2 8 400 Fail 0.1805 2 8 400 Fail 0.1820 2 8 400 Fail 0.1836 2 7 350 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. 20081K North Basin Flow Control Model 7/18/2024 2:39:49 PM Page 13 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. 20081K North Basin Flow Control Model 7/18/2024 2:39:49 PM Page 14 LID Report 20081K North Basin Flow Control Model 7/18/2024 2:40:18 PM Page 15 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. 20081K North Basin Flow Control Model 7/18/2024 2:40:18 PM Page 16 Appendix Predeveloped Schematic 20081K North Basin Flow Control Model 7/18/2024 2:40:23 PM Page 17 Mitigated Schematic 20081K North Basin Flow Control Model 7/18/2024 2:40:27 PM Page 18 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 20081K North Basin Flow Control Model.wdm MESSU 25 Pre20081K North Basin Flow Control Model.MES 27 Pre20081K North Basin Flow Control Model.L61 28 Pre20081K North Basin Flow Control Model.L62 30 POC20081K North Basin Flow Control Model1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 17 IMPLND 1 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Predev Conditions North B 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 *** 17 C, Lawn, Mod 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 17 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 ********* 17 0 0 4 0 0 0 0 0 0 0 0 0 1 9 END PRINT-INFO 20081K North Basin Flow Control Model 7/18/2024 2:40:27 PM Page 19 PWAT-PARM1 <PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 17 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 17 0 4.5 0.03 400 0.1 0.5 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 17 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 17 0.1 0.25 0.25 6 0.5 0.25 END PWAT-PARM4 PWAT-STATE1 <PLS > *** Initial conditions at start of simulation ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 *** # - # *** CEPS SURS UZS IFWS LZS AGWS GWVS 17 0 0 0 0 2.5 1 0 END PWAT-STATE1 END PERLND IMPLND GEN-INFO <PLS ><-------Name-------> Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 1 ROADS/FLAT 1 1 1 27 0 END GEN-INFO *** Section IWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** 1 0 0 1 0 0 0 END ACTIVITY PRINT-INFO <ILS > ******** Print-flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* 1 0 0 4 0 0 4 1 9 END PRINT-INFO IWAT-PARM1 <PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI *** 1 0 0 0 0 0 END IWAT-PARM1 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC 1 400 0.01 0.1 0.1 END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN 1 0 0 20081K North Basin Flow Control Model 7/18/2024 2:40:27 PM Page 20 END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS 1 0 0 END IWAT-STATE1 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Predev Conditions North Basin*** PERLND 17 0.33 COPY 501 12 PERLND 17 0.33 COPY 501 13 IMPLND 1 0.02 COPY 501 15 IMPLND 1 0.08 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 ********* 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 20081K North Basin Flow Control Model 7/18/2024 2:40:27 PM Page 21 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 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 MASS-LINK 15 IMPLND IWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 15 END MASS-LINK END RUN 20081K North Basin Flow Control Model 7/18/2024 2:40:27 PM Page 22 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 20081K North Basin Flow Control Model.wdm MESSU 25 Mit20081K North Basin Flow Control Model.MES 27 Mit20081K North Basin Flow Control Model.L61 28 Mit20081K North Basin Flow Control Model.L62 30 POC20081K North Basin Flow Control Model1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 17 IMPLND 1 IMPLND 4 IMPLND 8 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Dev Conditions North Basi 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 *** 17 C, Lawn, Mod 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 17 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 ********* 20081K North Basin Flow Control Model 7/18/2024 2:40:27 PM Page 23 17 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 *** 17 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 17 0 4.5 0.03 400 0.1 0.5 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 17 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 17 0.1 0.25 0.25 6 0.5 0.25 END PWAT-PARM4 PWAT-STATE1 <PLS > *** Initial conditions at start of simulation ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 *** # - # *** CEPS SURS UZS IFWS LZS AGWS GWVS 17 0 0 0 0 2.5 1 0 END PWAT-STATE1 END PERLND IMPLND GEN-INFO <PLS ><-------Name-------> Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 1 ROADS/FLAT 1 1 1 27 0 4 ROOF TOPS/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 *** 1 0 0 1 0 0 0 4 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 ********* 1 0 0 4 0 0 4 1 9 4 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 *** 1 0 0 0 0 0 4 0 0 0 0 0 8 0 0 0 0 0 END IWAT-PARM1 20081K North Basin Flow Control Model 7/18/2024 2:40:27 PM Page 24 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC 1 400 0.01 0.1 0.1 4 400 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 1 0 0 4 0 0 8 0 0 END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS 1 0 0 4 0 0 8 0 0 END IWAT-STATE1 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Dev Conditions North Basin*** PERLND 17 0.2 COPY 501 12 PERLND 17 0.2 COPY 501 13 IMPLND 1 0.04 COPY 501 15 IMPLND 4 0.15 COPY 501 15 IMPLND 1 0.03 COPY 501 15 IMPLND 8 0.01 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 ********* END PRINT-INFO HYDR-PARM1 20081K North Basin Flow Control Model 7/18/2024 2:40:27 PM Page 25 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 20081K North Basin Flow Control Model 7/18/2024 2:40:27 PM Page 26 Predeveloped HSPF Message File 20081K North Basin Flow Control Model 7/18/2024 2:40:28 PM Page 27 Mitigated HSPF Message File 20081K North Basin Flow Control Model 7/18/2024 2:40:28 PM Page 28 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. Clear Creek Solutions, Inc. 6200 Capitol Blvd. Ste F Olympia, WA. 98501 Toll Free 1(866)943-0304 Local (360)943-0304 www.clearcreeksolutions.com WWHM2012 PROJECT REPORT 20081K South Basin Flow Control Model 8/21/2024 2:00:37 PM Page 2 General Model Information WWHM2012 Project Name:20081K South Basin Flow Control Model Site Name:Jones Short Plat Site Address: City:Renton Report Date:8/21/2024 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 20081K South Basin Flow Control Model 8/21/2024 2:00:37 PM Page 3 Landuse Basin Data Predeveloped Land Use Predev Conditions South Basin Bypass:No GroundWater:No Pervious Land Use acre C, Forest, Mod 0.62 C, Lawn, Mod 0.26 Pervious Total 0.88 Impervious Land Use acre ROADS FLAT 0.06 ROOF TOPS FLAT 0.03 SIDEWALKS FLAT 0.01 Impervious Total 0.1 Basin Total 0.98 20081K South Basin Flow Control Model 8/21/2024 2:00:38 PM Page 4 Mitigated Land Use Dev Condition South Basin Bypass:No GroundWater:No Pervious Land Use acre C, Lawn, Mod 0.4 C, Forest, Mod 0.07 Pervious Total 0.47 Impervious Land Use acre ROADS FLAT 0.04 ROADS MOD 0.14 DRIVEWAYS FLAT 0.05 SIDEWALKS FLAT 0.05 Impervious Total 0.28 Basin Total 0.75 20081K South Basin Flow Control Model 8/21/2024 2:00:38 PM Page 5 Routing Elements Predeveloped Routing 20081K South Basin Flow Control Model 8/21/2024 2:00:38 PM Page 6 Mitigated Routing 20081K South Basin Flow Control Model 8/21/2024 2:00:38 PM Page 7 Analysis Results POC 1 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area:0.88 Total Impervious Area:0.1 Mitigated Landuse Totals for POC #1 Total Pervious Area:0.47 Total Impervious Area:0.28 Flow Frequency Method:Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.072392 5 year 0.108293 10 year 0.135461 25 year 0.173759 50 year 0.205249 100 year 0.239346 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.148781 5 year 0.203251 10 year 0.242556 25 year 0.296014 50 year 0.338664 100 year 0.383797 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 0.119 0.224 1950 0.118 0.207 1951 0.081 0.133 1952 0.047 0.089 1953 0.038 0.096 1954 0.059 0.120 1955 0.065 0.133 1956 0.066 0.123 1957 0.086 0.161 1958 0.049 0.113 20081K South Basin Flow Control Model 8/21/2024 2:01:29 PM Page 8 1959 0.045 0.102 1960 0.088 0.145 1961 0.065 0.126 1962 0.036 0.096 1963 0.065 0.134 1964 0.063 0.113 1965 0.083 0.167 1966 0.048 0.100 1967 0.119 0.208 1968 0.083 0.216 1969 0.068 0.151 1970 0.067 0.139 1971 0.079 0.168 1972 0.105 0.197 1973 0.043 0.083 1974 0.077 0.166 1975 0.093 0.166 1976 0.066 0.128 1977 0.049 0.120 1978 0.061 0.150 1979 0.061 0.177 1980 0.147 0.263 1981 0.063 0.144 1982 0.130 0.236 1983 0.060 0.152 1984 0.049 0.104 1985 0.059 0.141 1986 0.084 0.135 1987 0.080 0.170 1988 0.033 0.095 1989 0.040 0.141 1990 0.242 0.367 1991 0.160 0.275 1992 0.058 0.111 1993 0.039 0.095 1994 0.027 0.086 1995 0.057 0.127 1996 0.131 0.194 1997 0.089 0.154 1998 0.061 0.134 1999 0.169 0.333 2000 0.072 0.148 2001 0.048 0.140 2002 0.098 0.204 2003 0.101 0.190 2004 0.130 0.307 2005 0.075 0.130 2006 0.073 0.125 2007 0.211 0.336 2008 0.164 0.262 2009 0.101 0.169 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.2425 0.3667 2 0.2113 0.3357 3 0.1695 0.3325 20081K South Basin Flow Control Model 8/21/2024 2:01:29 PM Page 9 4 0.1640 0.3072 5 0.1597 0.2753 6 0.1466 0.2628 7 0.1308 0.2620 8 0.1298 0.2363 9 0.1297 0.2242 10 0.1193 0.2157 11 0.1187 0.2077 12 0.1181 0.2070 13 0.1051 0.2039 14 0.1013 0.1970 15 0.1012 0.1940 16 0.0978 0.1896 17 0.0931 0.1775 18 0.0894 0.1701 19 0.0881 0.1689 20 0.0856 0.1681 21 0.0836 0.1670 22 0.0830 0.1659 23 0.0830 0.1658 24 0.0812 0.1612 25 0.0802 0.1544 26 0.0790 0.1524 27 0.0769 0.1508 28 0.0746 0.1497 29 0.0733 0.1483 30 0.0722 0.1448 31 0.0683 0.1439 32 0.0670 0.1414 33 0.0663 0.1406 34 0.0657 0.1399 35 0.0654 0.1388 36 0.0653 0.1346 37 0.0653 0.1344 38 0.0633 0.1342 39 0.0625 0.1333 40 0.0612 0.1331 41 0.0607 0.1301 42 0.0606 0.1281 43 0.0595 0.1268 44 0.0591 0.1261 45 0.0589 0.1251 46 0.0583 0.1227 47 0.0574 0.1205 48 0.0493 0.1196 49 0.0486 0.1133 50 0.0486 0.1131 51 0.0484 0.1113 52 0.0476 0.1039 53 0.0466 0.1016 54 0.0446 0.1001 55 0.0428 0.0959 56 0.0404 0.0958 57 0.0391 0.0949 58 0.0375 0.0947 59 0.0361 0.0892 60 0.0325 0.0859 61 0.0269 0.0834 20081K South Basin Flow Control Model 8/21/2024 2:01:30 PM Page 10 20081K South Basin Flow Control Model 8/21/2024 2:01:30 PM Page 11 Duration Flows The Duration Matching Failed Flow(cfs)Predev Mit Percentage Pass/Fail 0.0362 3181 10701 336 Fail 0.0379 2729 9475 347 Fail 0.0396 2359 8479 359 Fail 0.0413 2069 7597 367 Fail 0.0430 1802 6776 376 Fail 0.0447 1564 6074 388 Fail 0.0464 1367 5491 401 Fail 0.0481 1209 4947 409 Fail 0.0499 1057 4438 419 Fail 0.0516 936 4008 428 Fail 0.0533 844 3630 430 Fail 0.0550 729 3296 452 Fail 0.0567 629 2988 475 Fail 0.0584 547 2714 496 Fail 0.0601 490 2443 498 Fail 0.0618 432 2231 516 Fail 0.0635 383 2064 538 Fail 0.0652 338 1893 560 Fail 0.0669 303 1745 575 Fail 0.0686 272 1624 597 Fail 0.0703 238 1516 636 Fail 0.0721 216 1382 639 Fail 0.0738 199 1288 647 Fail 0.0755 179 1201 670 Fail 0.0772 160 1113 695 Fail 0.0789 146 1040 712 Fail 0.0806 132 953 721 Fail 0.0823 123 891 724 Fail 0.0840 107 830 775 Fail 0.0857 98 771 786 Fail 0.0874 93 718 772 Fail 0.0891 88 671 762 Fail 0.0908 80 632 790 Fail 0.0925 74 597 806 Fail 0.0943 70 553 790 Fail 0.0960 66 519 786 Fail 0.0977 63 501 795 Fail 0.0994 56 472 842 Fail 0.1011 56 443 791 Fail 0.1028 53 420 792 Fail 0.1045 49 397 810 Fail 0.1062 48 374 779 Fail 0.1079 46 363 789 Fail 0.1096 42 345 821 Fail 0.1113 40 326 814 Fail 0.1130 37 310 837 Fail 0.1147 35 294 839 Fail 0.1165 32 283 884 Fail 0.1182 29 268 924 Fail 0.1199 26 256 984 Fail 0.1216 24 245 1020 Fail 0.1233 22 230 1045 Fail 0.1250 22 219 995 Fail 0.1267 21 206 980 Fail 20081K South Basin Flow Control Model 8/21/2024 2:01:30 PM Page 12 0.1284 21 194 923 Fail 0.1301 18 189 1050 Fail 0.1318 15 182 1213 Fail 0.1335 14 173 1235 Fail 0.1352 13 165 1269 Fail 0.1369 13 156 1200 Fail 0.1387 13 149 1146 Fail 0.1404 13 140 1076 Fail 0.1421 13 135 1038 Fail 0.1438 12 131 1091 Fail 0.1455 12 126 1050 Fail 0.1472 11 118 1072 Fail 0.1489 11 114 1036 Fail 0.1506 10 111 1110 Fail 0.1523 10 104 1040 Fail 0.1540 9 101 1122 Fail 0.1557 8 99 1237 Fail 0.1574 7 97 1385 Fail 0.1591 7 95 1357 Fail 0.1609 6 94 1566 Fail 0.1626 6 92 1533 Fail 0.1643 5 90 1800 Fail 0.1660 5 88 1760 Fail 0.1677 5 85 1700 Fail 0.1694 5 80 1600 Fail 0.1711 4 75 1875 Fail 0.1728 4 72 1800 Fail 0.1745 4 67 1675 Fail 0.1762 4 65 1625 Fail 0.1779 4 61 1525 Fail 0.1796 4 57 1425 Fail 0.1813 4 56 1400 Fail 0.1831 4 54 1350 Fail 0.1848 2 54 2700 Fail 0.1865 2 51 2550 Fail 0.1882 2 50 2500 Fail 0.1899 2 49 2450 Fail 0.1916 2 46 2300 Fail 0.1933 2 44 2200 Fail 0.1950 2 41 2050 Fail 0.1967 2 41 2050 Fail 0.1984 2 40 2000 Fail 0.2001 2 39 1950 Fail 0.2018 2 38 1900 Fail 0.2035 2 36 1800 Fail 0.2052 2 33 1650 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. 20081K South Basin Flow Control Model 8/21/2024 2:01:30 PM Page 13 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. 20081K South Basin Flow Control Model 8/21/2024 2:01:30 PM Page 14 LID Report 20081K South Basin Flow Control Model 8/21/2024 2:02:02 PM Page 15 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. 20081K South Basin Flow Control Model 8/21/2024 2:02:02 PM Page 16 Appendix Predeveloped Schematic 20081K South Basin Flow Control Model 8/21/2024 2:02:06 PM Page 17 Mitigated Schematic 20081K South Basin Flow Control Model 8/21/2024 2:02:11 PM Page 18 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 20081K South Basin Flow Control Model.wdm MESSU 25 Pre20081K South Basin Flow Control Model.MES 27 Pre20081K South Basin Flow Control Model.L61 28 Pre20081K South Basin Flow Control Model.L62 30 POC20081K South Basin Flow Control Model1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 11 PERLND 17 IMPLND 1 IMPLND 4 IMPLND 8 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Predev Conditions South B MAX 1 2 30 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 501 1 1 END TIMESERIES END COPY GENER OPCODE # # OPCD *** END OPCODE PARM # # K *** END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 11 C, Forest, Mod 1 1 1 1 27 0 17 C, Lawn, Mod 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 11 0 0 1 0 0 0 0 0 0 0 0 0 17 0 0 1 0 0 0 0 0 0 0 0 0 END ACTIVITY 20081K South Basin Flow Control Model 8/21/2024 2:02:11 PM Page 19 PRINT-INFO <PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* 11 0 0 4 0 0 0 0 0 0 0 0 0 1 9 17 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 *** 11 0 0 0 0 0 0 0 0 0 0 0 17 0 0 0 0 0 0 0 0 0 0 0 END PWAT-PARM1 PWAT-PARM2 <PLS > PWATER input info: Part 2 *** # - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC 11 0 4.5 0.08 400 0.1 0.5 0.996 17 0 4.5 0.03 400 0.1 0.5 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 11 0 0 2 2 0 0 0 17 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 11 0.2 0.5 0.35 6 0.5 0.7 17 0.1 0.25 0.25 6 0.5 0.25 END PWAT-PARM4 PWAT-STATE1 <PLS > *** Initial conditions at start of simulation ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 *** # - # *** CEPS SURS UZS IFWS LZS AGWS GWVS 11 0 0 0 0 2.5 1 0 17 0 0 0 0 2.5 1 0 END PWAT-STATE1 END PERLND IMPLND GEN-INFO <PLS ><-------Name-------> Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 1 ROADS/FLAT 1 1 1 27 0 4 ROOF TOPS/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 *** 1 0 0 1 0 0 0 4 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 ********* 1 0 0 4 0 0 4 1 9 4 0 0 4 0 0 0 1 9 8 0 0 4 0 0 0 1 9 END PRINT-INFO 20081K South Basin Flow Control Model 8/21/2024 2:02:11 PM Page 20 IWAT-PARM1 <PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI *** 1 0 0 0 0 0 4 0 0 0 0 0 8 0 0 0 0 0 END IWAT-PARM1 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC 1 400 0.01 0.1 0.1 4 400 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 1 0 0 4 0 0 8 0 0 END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS 1 0 0 4 0 0 8 0 0 END IWAT-STATE1 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Predev Conditions South Basin*** PERLND 11 0.62 COPY 501 12 PERLND 11 0.62 COPY 501 13 PERLND 17 0.26 COPY 501 12 PERLND 17 0.26 COPY 501 13 IMPLND 1 0.06 COPY 501 15 IMPLND 4 0.03 COPY 501 15 IMPLND 8 0.01 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 20081K South Basin Flow Control Model 8/21/2024 2:02:11 PM Page 21 <PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR ********* END PRINT-INFO HYDR-PARM1 RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** END HYDR-PARM1 HYDR-PARM2 # - # FTABNO LEN DELTH STCOR KS DB50 *** <------><--------><--------><--------><--------><--------><--------> *** END HYDR-PARM2 HYDR-INIT RCHRES Initial conditions for each HYDR section *** # - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> END HYDR-INIT END RCHRES SPEC-ACTIONS END SPEC-ACTIONS FTABLES END FTABLES EXT SOURCES <-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1 IMPLND 1 999 EXTNL PREC 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 MASS-LINK 15 IMPLND IWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 15 END MASS-LINK END RUN 20081K South Basin Flow Control Model 8/21/2024 2:02:11 PM Page 22 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 20081K South Basin Flow Control Model.wdm MESSU 25 Mit20081K South Basin Flow Control Model.MES 27 Mit20081K South Basin Flow Control Model.L61 28 Mit20081K South Basin Flow Control Model.L62 30 POC20081K South Basin Flow Control Model1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 17 PERLND 11 IMPLND 1 IMPLND 2 IMPLND 5 IMPLND 8 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Dev Condition South Basin 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 *** 17 C, Lawn, Mod 1 1 1 1 27 0 11 C, Forest, Mod 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 17 0 0 1 0 0 0 0 0 0 0 0 0 11 0 0 1 0 0 0 0 0 0 0 0 0 END ACTIVITY 20081K South Basin Flow Control Model 8/21/2024 2:02:11 PM Page 23 PRINT-INFO <PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* 17 0 0 4 0 0 0 0 0 0 0 0 0 1 9 11 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 *** 17 0 0 0 0 0 0 0 0 0 0 0 11 0 0 0 0 0 0 0 0 0 0 0 END PWAT-PARM1 PWAT-PARM2 <PLS > PWATER input info: Part 2 *** # - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC 17 0 4.5 0.03 400 0.1 0.5 0.996 11 0 4.5 0.08 400 0.1 0.5 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 17 0 0 2 2 0 0 0 11 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 17 0.1 0.25 0.25 6 0.5 0.25 11 0.2 0.5 0.35 6 0.5 0.7 END PWAT-PARM4 PWAT-STATE1 <PLS > *** Initial conditions at start of simulation ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 *** # - # *** CEPS SURS UZS IFWS LZS AGWS GWVS 17 0 0 0 0 2.5 1 0 11 0 0 0 0 2.5 1 0 END PWAT-STATE1 END PERLND IMPLND GEN-INFO <PLS ><-------Name-------> Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 1 ROADS/FLAT 1 1 1 27 0 2 ROADS/MOD 1 1 1 27 0 5 DRIVEWAYS/FLAT 1 1 1 27 0 8 SIDEWALKS/FLAT 1 1 1 27 0 END GEN-INFO *** Section IWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** 1 0 0 1 0 0 0 2 0 0 1 0 0 0 5 0 0 1 0 0 0 8 0 0 1 0 0 0 END ACTIVITY PRINT-INFO <ILS > ******** Print-flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* 1 0 0 4 0 0 4 1 9 20081K South Basin Flow Control Model 8/21/2024 2:02:11 PM Page 24 2 0 0 4 0 0 0 1 9 5 0 0 4 0 0 0 1 9 8 0 0 4 0 0 0 1 9 END PRINT-INFO IWAT-PARM1 <PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI *** 1 0 0 0 0 0 2 0 0 0 0 0 5 0 0 0 0 0 8 0 0 0 0 0 END IWAT-PARM1 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC 1 400 0.01 0.1 0.1 2 400 0.05 0.1 0.08 5 400 0.01 0.1 0.1 8 400 0.01 0.1 0.1 END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN 1 0 0 2 0 0 5 0 0 8 0 0 END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS 1 0 0 2 0 0 5 0 0 8 0 0 END IWAT-STATE1 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Dev Condition South Basin *** PERLND 17 0.4 COPY 501 12 PERLND 17 0.4 COPY 501 13 PERLND 11 0.07 COPY 501 12 PERLND 11 0.07 COPY 501 13 IMPLND 1 0.04 COPY 501 15 IMPLND 2 0.14 COPY 501 15 IMPLND 5 0.05 COPY 501 15 IMPLND 8 0.05 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 20081K South Basin Flow Control Model 8/21/2024 2:02:11 PM Page 25 RCHRES GEN-INFO RCHRES Name Nexits Unit Systems Printer *** # - #<------------------><---> User T-series Engl Metr LKFG *** in out *** END GEN-INFO *** Section RCHRES*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR ********* END PRINT-INFO HYDR-PARM1 RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** END HYDR-PARM1 HYDR-PARM2 # - # FTABNO LEN DELTH STCOR KS DB50 *** <------><--------><--------><--------><--------><--------><--------> *** END HYDR-PARM2 HYDR-INIT RCHRES Initial conditions for each HYDR section *** # - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> END HYDR-INIT END RCHRES SPEC-ACTIONS END SPEC-ACTIONS FTABLES END FTABLES EXT SOURCES <-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1 IMPLND 1 999 EXTNL PREC 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 20081K South Basin Flow Control Model 8/21/2024 2:02:11 PM Page 26 MASS-LINK 15 IMPLND IWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 15 END MASS-LINK END RUN 20081K South Basin Flow Control Model 8/21/2024 2:02:11 PM Page 27 Predeveloped HSPF Message File 20081K South Basin Flow Control Model 8/21/2024 2:02:11 PM Page 28 Mitigated HSPF Message File 20081K South Basin Flow Control Model 8/21/2024 2:02:11 PM Page 29 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. Clear Creek Solutions, Inc. 6200 Capitol Blvd. Ste F Olympia, WA. 98501 Toll Free 1(866)943-0304 Local (360)943-0304 www.clearcreeksolutions.com WWHM2012 PROJECT REPORT 20081K Water Quality Model 8/21/2024 2:11:12 PM Page 2 General Model Information WWHM2012 Project Name:20081K Water Quality Model Site Name:Jones Short Plat Site Address: City:Renton Report Date:8/21/2024 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 20081K Water Quality Model 8/21/2024 2:11:12 PM Page 3 Landuse Basin Data Predeveloped Land Use Predev South Basin Bypass:No GroundWater:No Pervious Land Use acre C, Forest, Mod 0.27 Pervious Total 0.27 Impervious Land Use acre Impervious Total 0 Basin Total 0.27 20081K Water Quality Model 8/21/2024 2:11:13 PM Page 4 Mitigated Land Use Dev South Basin Bypass:No GroundWater:No Pervious Land Use acre C, Lawn, Mod 0.07 Pervious Total 0.07 Impervious Land Use acre ROADS MOD 0.14 DRIVEWAYS FLAT 0.06 SIDEWALKS MOD 0.04 Impervious Total 0.24 Basin Total 0.31 20081K Water Quality Model 8/21/2024 2:11:13 PM Page 5 Routing Elements Predeveloped Routing 20081K Water Quality Model 8/21/2024 2:11:13 PM Page 6 Mitigated Routing 20081K Water Quality Model 8/21/2024 2:11:13 PM Page 7 Analysis Results POC 1 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area:0.27 Total Impervious Area:0 Mitigated Landuse Totals for POC #1 Total Pervious Area:0.07 Total Impervious Area:0.24 Flow Frequency Method:Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.008039 5 year 0.013173 10 year 0.016474 25 year 0.020401 50 year 0.02312 100 year 0.025661 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.107002 5 year 0.137869 10 year 0.159605 25 year 0.188607 50 year 0.211365 100 year 0.235143 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 0.009 0.144 1950 0.011 0.140 1951 0.018 0.086 1952 0.006 0.067 1953 0.004 0.081 1954 0.007 0.086 1955 0.011 0.102 1956 0.009 0.090 1957 0.007 0.107 1958 0.008 0.087 20081K Water Quality Model 8/21/2024 2:11:58 PM Page 8 1959 0.007 0.091 1960 0.012 0.095 1961 0.007 0.090 1962 0.004 0.077 1963 0.006 0.094 1964 0.008 0.089 1965 0.005 0.109 1966 0.005 0.075 1967 0.012 0.128 1968 0.007 0.163 1969 0.007 0.100 1970 0.005 0.100 1971 0.006 0.121 1972 0.013 0.122 1973 0.006 0.074 1974 0.007 0.114 1975 0.009 0.115 1976 0.007 0.090 1977 0.001 0.088 1978 0.006 0.123 1979 0.003 0.152 1980 0.016 0.167 1981 0.005 0.105 1982 0.010 0.154 1983 0.009 0.121 1984 0.005 0.077 1985 0.003 0.102 1986 0.014 0.089 1987 0.012 0.138 1988 0.005 0.083 1989 0.003 0.132 1990 0.029 0.196 1991 0.015 0.164 1992 0.006 0.079 1993 0.006 0.089 1994 0.002 0.080 1995 0.009 0.095 1996 0.020 0.122 1997 0.016 0.100 1998 0.004 0.100 1999 0.017 0.223 2000 0.006 0.103 2001 0.001 0.119 2002 0.007 0.129 2003 0.011 0.128 2004 0.011 0.213 2005 0.008 0.085 2006 0.009 0.080 2007 0.022 0.201 2008 0.027 0.154 2009 0.013 0.143 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.0291 0.2230 2 0.0268 0.2129 3 0.0220 0.2014 20081K Water Quality Model 8/21/2024 2:11:58 PM Page 9 4 0.0204 0.1963 5 0.0176 0.1674 6 0.0173 0.1636 7 0.0157 0.1626 8 0.0157 0.1539 9 0.0154 0.1535 10 0.0138 0.1524 11 0.0133 0.1437 12 0.0125 0.1428 13 0.0123 0.1397 14 0.0122 0.1377 15 0.0121 0.1322 16 0.0113 0.1288 17 0.0110 0.1281 18 0.0109 0.1280 19 0.0106 0.1226 20 0.0102 0.1223 21 0.0095 0.1219 22 0.0093 0.1214 23 0.0091 0.1208 24 0.0088 0.1189 25 0.0088 0.1147 26 0.0087 0.1139 27 0.0084 0.1091 28 0.0081 0.1065 29 0.0079 0.1053 30 0.0071 0.1028 31 0.0071 0.1019 32 0.0069 0.1017 33 0.0068 0.1000 34 0.0068 0.0999 35 0.0068 0.0996 36 0.0067 0.0996 37 0.0066 0.0953 38 0.0065 0.0946 39 0.0063 0.0943 40 0.0062 0.0915 41 0.0061 0.0902 42 0.0061 0.0901 43 0.0059 0.0898 44 0.0057 0.0894 45 0.0055 0.0892 46 0.0055 0.0888 47 0.0054 0.0880 48 0.0054 0.0872 49 0.0052 0.0862 50 0.0052 0.0857 51 0.0049 0.0853 52 0.0048 0.0829 53 0.0045 0.0813 54 0.0041 0.0804 55 0.0039 0.0802 56 0.0033 0.0791 57 0.0032 0.0773 58 0.0031 0.0767 59 0.0021 0.0754 60 0.0011 0.0738 61 0.0010 0.0667 20081K Water Quality Model 8/21/2024 2:11:58 PM Page 10 20081K Water Quality Model 8/21/2024 2:11:58 PM Page 11 Duration Flows The Duration Matching Failed Flow(cfs)Predev Mit Percentage Pass/Fail 0.0040 17079 130087 761 Fail 0.0042 15488 126258 815 Fail 0.0044 14070 122665 871 Fail 0.0046 12797 119328 932 Fail 0.0048 11567 115991 1002 Fail 0.0050 10515 112783 1072 Fail 0.0052 9561 109831 1148 Fail 0.0054 8750 106987 1222 Fail 0.0056 8036 104206 1296 Fail 0.0058 7347 101554 1382 Fail 0.0059 6733 99030 1470 Fail 0.0061 6192 96592 1559 Fail 0.0063 5730 94175 1643 Fail 0.0065 5309 91886 1730 Fail 0.0067 4924 89619 1820 Fail 0.0069 4569 87330 1911 Fail 0.0071 4235 85256 2013 Fail 0.0073 3951 83267 2107 Fail 0.0075 3643 81256 2230 Fail 0.0077 3388 79374 2342 Fail 0.0079 3133 77556 2475 Fail 0.0081 2915 75738 2598 Fail 0.0083 2704 74005 2736 Fail 0.0085 2490 72273 2902 Fail 0.0086 2314 70626 3052 Fail 0.0088 2136 68979 3229 Fail 0.0090 1972 67439 3419 Fail 0.0092 1824 65878 3611 Fail 0.0094 1702 64380 3782 Fail 0.0096 1577 62947 3991 Fail 0.0098 1442 61536 4267 Fail 0.0100 1325 60124 4537 Fail 0.0102 1233 58755 4765 Fail 0.0104 1150 57514 5001 Fail 0.0106 1087 56253 5175 Fail 0.0108 1020 54969 5389 Fail 0.0110 949 53771 5666 Fail 0.0112 888 52616 5925 Fail 0.0114 824 51376 6234 Fail 0.0115 761 50221 6599 Fail 0.0117 725 49151 6779 Fail 0.0119 676 48082 7112 Fail 0.0121 623 47034 7549 Fail 0.0123 590 46071 7808 Fail 0.0125 553 45130 8160 Fail 0.0127 506 44146 8724 Fail 0.0129 469 43270 9226 Fail 0.0131 428 42350 9894 Fail 0.0133 388 41366 10661 Fail 0.0135 356 40532 11385 Fail 0.0137 328 39719 12109 Fail 0.0139 298 38863 13041 Fail 0.0141 270 38008 14077 Fail 0.0142 242 37259 15396 Fail 20081K Water Quality Model 8/21/2024 2:11:58 PM Page 12 0.0144 219 36532 16681 Fail 0.0146 198 35719 18039 Fail 0.0148 174 34971 20098 Fail 0.0150 152 34243 22528 Fail 0.0152 130 33559 25814 Fail 0.0154 119 32875 27626 Fail 0.0156 104 32233 30993 Fail 0.0158 95 31570 33231 Fail 0.0160 83 30950 37289 Fail 0.0162 74 30351 41014 Fail 0.0164 69 29752 43118 Fail 0.0166 61 29110 47721 Fail 0.0168 53 28511 53794 Fail 0.0169 46 27955 60771 Fail 0.0171 39 27399 70253 Fail 0.0173 29 26822 92489 Fail 0.0175 25 26330 105319 Fail 0.0177 22 25816 117345 Fail 0.0179 20 25303 126515 Fail 0.0181 17 24832 146070 Fail 0.0183 14 24340 173857 Fail 0.0185 12 23913 199275 Fail 0.0187 8 23421 292762 Fail 0.0189 7 23014 328771 Fail 0.0191 7 22565 322357 Fail 0.0193 7 22137 316242 Fail 0.0195 6 21710 361833 Fail 0.0196 6 21310 355166 Fail 0.0198 6 20895 348250 Fail 0.0200 6 20531 342183 Fail 0.0202 6 20129 335483 Fail 0.0204 5 19750 395000 Fail 0.0206 5 19333 386660 Fail 0.0208 5 18955 379100 Fail 0.0210 5 18632 372640 Fail 0.0212 5 18302 366040 Fail 0.0214 5 17967 359340 Fail 0.0216 5 17635 352700 Fail 0.0218 4 17301 432525 Fail 0.0220 4 16968 424200 Fail 0.0222 3 16643 554766 Fail 0.0223 3 16341 544700 Fail 0.0225 3 16061 535366 Fail 0.0227 3 15802 526733 Fail 0.0229 3 15524 517466 Fail 0.0231 3 15218 507266 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. 20081K Water Quality Model 8/21/2024 2:11:58 PM Page 13 Water Quality Water Quality BMP Flow and Volume for POC #1 On-line facility volume:0.0315 acre-feet On-line facility target flow:0.0415 cfs. Adjusted for 15 min:0.0415 cfs. Off-line facility target flow:0.0232 cfs. Adjusted for 15 min:0.0232 cfs. 20081K Water Quality Model 8/21/2024 2:11:58 PM Page 14 LID Report 20081K Water Quality Model 8/21/2024 2:12:28 PM Page 15 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. 20081K Water Quality Model 8/21/2024 2:12:28 PM Page 16 Appendix Predeveloped Schematic 20081K Water Quality Model 8/21/2024 2:12:31 PM Page 17 Mitigated Schematic 20081K Water Quality Model 8/21/2024 2:12:36 PM Page 18 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 20081K Water Quality Model.wdm MESSU 25 Pre20081K Water Quality Model.MES 27 Pre20081K Water Quality Model.L61 28 Pre20081K Water Quality Model.L62 30 POC20081K Water Quality Model1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 11 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Predev South Basin MAX 1 2 30 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 501 1 1 END TIMESERIES END COPY GENER OPCODE # # OPCD *** END OPCODE PARM # # K *** END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 11 C, Forest, Mod 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 11 0 0 1 0 0 0 0 0 0 0 0 0 END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* 11 0 0 4 0 0 0 0 0 0 0 0 0 1 9 END PRINT-INFO 20081K Water Quality Model 8/21/2024 2:12:36 PM Page 19 PWAT-PARM1 <PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 11 0 0 0 0 0 0 0 0 0 0 0 END PWAT-PARM1 PWAT-PARM2 <PLS > PWATER input info: Part 2 *** # - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC 11 0 4.5 0.08 400 0.1 0.5 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 11 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 11 0.2 0.5 0.35 6 0.5 0.7 END PWAT-PARM4 PWAT-STATE1 <PLS > *** Initial conditions at start of simulation ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 *** # - # *** CEPS SURS UZS IFWS LZS AGWS GWVS 11 0 0 0 0 2.5 1 0 END PWAT-STATE1 END PERLND IMPLND GEN-INFO <PLS ><-------Name-------> Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** END GEN-INFO *** Section IWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** END ACTIVITY PRINT-INFO <ILS > ******** Print-flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* END PRINT-INFO IWAT-PARM1 <PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI *** END IWAT-PARM1 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS END IWAT-STATE1 20081K Water Quality Model 8/21/2024 2:12:36 PM Page 20 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Predev South Basin*** PERLND 11 0.27 COPY 501 12 PERLND 11 0.27 COPY 501 13 ******Routing****** END SCHEMATIC NETWORK <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 501 OUTPUT MEAN 1 1 48.4 DISPLY 1 INPUT TIMSER 1 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** END NETWORK RCHRES GEN-INFO RCHRES Name Nexits Unit Systems Printer *** # - #<------------------><---> User T-series Engl Metr LKFG *** in out *** END GEN-INFO *** Section RCHRES*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR ********* END PRINT-INFO HYDR-PARM1 RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** END HYDR-PARM1 HYDR-PARM2 # - # FTABNO LEN DELTH STCOR KS DB50 *** <------><--------><--------><--------><--------><--------><--------> *** END HYDR-PARM2 HYDR-INIT RCHRES Initial conditions for each HYDR section *** # - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> END HYDR-INIT END RCHRES SPEC-ACTIONS END SPEC-ACTIONS FTABLES END FTABLES EXT SOURCES <-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1 IMPLND 1 999 EXTNL PREC 20081K Water Quality Model 8/21/2024 2:12:37 PM Page 21 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 20081K Water Quality Model 8/21/2024 2:12:37 PM Page 22 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 20081K Water Quality Model.wdm MESSU 25 Mit20081K Water Quality Model.MES 27 Mit20081K Water Quality Model.L61 28 Mit20081K Water Quality Model.L62 30 POC20081K Water Quality Model1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 17 IMPLND 2 IMPLND 5 IMPLND 9 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Dev South Basin 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 *** 17 C, Lawn, Mod 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 17 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 ********* 20081K Water Quality Model 8/21/2024 2:12:37 PM Page 23 17 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 *** 17 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 17 0 4.5 0.03 400 0.1 0.5 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 17 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 17 0.1 0.25 0.25 6 0.5 0.25 END PWAT-PARM4 PWAT-STATE1 <PLS > *** Initial conditions at start of simulation ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 *** # - # *** CEPS SURS UZS IFWS LZS AGWS GWVS 17 0 0 0 0 2.5 1 0 END PWAT-STATE1 END PERLND IMPLND GEN-INFO <PLS ><-------Name-------> Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 2 ROADS/MOD 1 1 1 27 0 5 DRIVEWAYS/FLAT 1 1 1 27 0 9 SIDEWALKS/MOD 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 5 0 0 1 0 0 0 9 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 5 0 0 4 0 0 0 1 9 9 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 5 0 0 0 0 0 9 0 0 0 0 0 END IWAT-PARM1 20081K Water Quality Model 8/21/2024 2:12:37 PM Page 24 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC 2 400 0.05 0.1 0.08 5 400 0.01 0.1 0.1 9 400 0.05 0.1 0.08 END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN 2 0 0 5 0 0 9 0 0 END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS 2 0 0 5 0 0 9 0 0 END IWAT-STATE1 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Dev South Basin*** PERLND 17 0.07 COPY 501 12 PERLND 17 0.07 COPY 501 13 IMPLND 2 0.14 COPY 501 15 IMPLND 5 0.06 COPY 501 15 IMPLND 9 0.04 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 ********* END PRINT-INFO HYDR-PARM1 RCHRES Flags for each HYDR Section *** 20081K Water Quality Model 8/21/2024 2:12:37 PM Page 25 # - # 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 20081K Water Quality Model 8/21/2024 2:12:37 PM Page 26 Predeveloped HSPF Message File 20081K Water Quality Model 8/21/2024 2:12:37 PM Page 27 Mitigated HSPF Message File 20081K Water Quality Model 8/21/2024 2:12:37 PM Page 28 Disclaimer Legal Notice This program and accompanying documentation are provided 'as-is' without warranty of any kind. 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Clear Creek Solutions, Inc. 6200 Capitol Blvd. Ste F Olympia, WA. 98501 Toll Free 1(866)943-0304 Local (360)943-0304 www.clearcreeksolutions.com Appendix D Geotechnical Report Geotechnical Investigation Proposed Residential Development 3102 Park Avenue North Renton, Washington April 3, 2020 GEOTECHNICAL INVESTIGATION RENTON, WASHINGTON i Table of Contents 1.0 INTRODUCTION ............................................................................................................. 1 2.0 PROJECT DESCRIPTION .............................................................................................. 1 3.0 SITE DESCRIPTION ....................................................................................................... 1 4.0 FIELD INVESTIGATION ............................................................................................... 1 4.1.1 Site Investigation Program ................................................................................... 1 5.0 SOIL AND GROUNDWATER CONDITIONS .............................................................. 2 5.1.1 Area Geology ........................................................................................................ 2 5.1.2 Groundwater ........................................................................................................ 2 6.0 GEOLOGIC HAZARDS ................................................................................................... 3 6.2 Erosion Hazard .................................................................................................... 3 6.3 Seismic Hazard .................................................................................................... 3 7.0 DISCUSSION ................................................................................................................... 4 7.1.1 General................................................................................................................. 4 8.0 RECOMMENDATIONS .................................................................................................. 4 8.1.1 Site Preparation ................................................................................................... 4 8.1.2 Temporary Excavations ........................................................................................ 4 8.1.3 Erosion and Sediment Control.............................................................................. 5 8.1.4 Foundation Design ............................................................................................... 6 8.1.5 Stormwater Management ..................................................................................... 7 8.1.6 Slab-on-Grade ...................................................................................................... 7 8.1.7 Groundwater Influence on Construction .............................................................. 8 8.1.8 Utilities ................................................................................................................ 8 8.1.9 Pavements ............................................................................................................ 9 9.0 CONSTRUCTION FIELD REVIEWS ...........................................................................10 10.0 CLOSURE ...................................................................................................................10 LIST OF APPENDICES Appendix A — Statement of General Conditions Appendix B — Figures Appendix C — Exploration Logs GEOTECHNICAL INVESTIGATION RENTON, WASHINGTON April 3, 2020 1 PO Box 82243 Kenmore, WA 98028 cobaltgeo@gmail.com 206-331-1097 1.0 Introduction In accordance with your authorization, Cobalt Geosciences, LLC (Cobalt) has completed a geotechnical investigation for the proposed residential development located at 3102 Park Avenue North in Renton, Washington (Figure 1). The purpose of the geotechnical investigation was to identify subsurface conditions and to provide geotechnical recommendations for foundation design, stormwater management, earthwork, soil compaction, and suitability of the on-site soils for use as fill. The scope of work for the geotechnical evaluation consisted of a site investigation followed by engineering analyses to prepare this report. Recommendations presented herein pertain to various geotechnical aspects of the proposed development, including foundation support of the new buildings and new pavements. 2.0 Project Description The project includes construction of up to eight new residential buildings, utilities, and access roadways. We have not received a site plan showing the planned lot layout or roadway locations. Anticipated building loads are expected to be light to moderate and site grading will include cuts and fills on the order of 4 feet or less. Stormwater management will include infiltration devices, if feasible. We should be provided with the final plans when they become available. 3.0 Site Description The site is located at 3102 Park Avenue North in Renton, Washington (Figure 1). The property consists of one irregularly shaped parcel (No. 3342103215) with a total area of about 57,614 square feet. The central portion of the property is developed with a single family residence and accessory structure. A driveway extends onto the property from the west. The site is vegetated with grasses, bushes, and sparse trees. The site slopes downward from east to west at magnitudes of 5 to 15 percent and relief of about 15 feet. There is a slightly steeper cut slopes along the west property line, adjacent to Park Avenue North. The slope is less than 5 feet tall. The site is bordered to the north and south by residential properties, to the east by a reservoir and residential properties, and to the west by Park Avenue North. 4.0 Field Investigation 4.1.1 Site Investigation Program The geotechnical field investigation program was completed on March 24, 2020 and included excavating and sampling three test pits within the property for subsurface analysis. GEOTECHNICAL INVESTIGATION RENTON, WASHINGTON April 3, 2020 2 PO Box 82243 Kenmore, WA 98028 cobaltgeo@gmail.com 206-331-1097 The soils encountered were logged in the field and are described in accordance with the Unified Soil Classification System (USCS). A Cobalt Geosciences field representative conducted the explorations, collected disturbed soil samples, classified the encountered soils, kept a detailed log of the explorations, and observed and recorded pertinent site features. The results of the sampling are presented on the exploration logs enclosed in Appendix C. 5.0 Soil and Groundwater Conditions 5.1.1 Area Geology The site lies within the Puget Lowland. The lowland is part of a regional north-south trending trough that extends from southwestern British Columbia to near Eugene, Oregon. North of Olympia, Washington, this lowland is glacially carved, with a depositional and erosional history including at least four separate glacial advances/retreats. The Puget Lowland is bounded to the west by the Olympic Mountains and to the east by the Cascade Range. The lowland is filled with glacial and non-glacial sediments consisting of interbedded gravel, sand, silt, till, and peat lenses. The Geologic Map of King County, indicates that the site is underlain by Vashon Recessional Outwash. Vashon Recessional Outwash consists of sand with gravel along with layers and interbeds of silt and clay. These materials vary widely in composition with location and depth. These materials are normally consolidated (not glacially overconsolidated). Explorations Test Pits TP-1 and TP-3 encountered approximately 12 inches of topsoil and vegetation underlain by about 4.5 to 5 feet of loose to medium dense, silty-fine to medium grained sand trace gravel (Weathered Recessional Outwash). This layer was underlain by medium dense, fine to medium grained sand trace gravel (Recessional Outwash), which continued to the termination depth of the test pits. Test Pit TP-2 encountered approximately 6 inches of topsoil and grass underlain by approximately 1.5 feet of loose, silty-fine to medium grained sand with organics (Weathered Recessional Outwash). This layer was underlain by medium dense/stiff, silty-fine to fine grained sand trace gravel (Recessional Outwash – Lacustrine Deposits), which continued to the termination depth of the test pit. 5.1.2 Groundwater Groundwater was not encountered in any of the explorations. We anticipate that very light amounts of perched groundwater could be encountered in fine grained soils below the site. Water table elevations often fluctuate over time. The groundwater level will depend on a variety of factors that may include seasonal precipitation, irrigation, land use, climatic conditions and soil permeability. Water levels at the time of the field investigation may be different from those encountered during the construction phase of the project. GEOTECHNICAL INVESTIGATION RENTON, WASHINGTON April 3, 2020 3 PO Box 82243 Kenmore, WA 98028 cobaltgeo@gmail.com 206-331-1097 6.0 Geologic Hazards 6.1 Erosion Hazard The Natural Resources Conservation Services (NRCS) maps for King County indicate that the site is underlain by Indianola loamy sand (5 to 15 percent slopes). These soils would have a slight to moderate erosion potential in a disturbed state, depending on the slope magnitude. It is our opinion that soil erosion potential at this project site can be reduced through landscaping and surface water runoff control. Typically erosion of exposed soils will be most noticeable during periods of rainfall and may be controlled by the use of normal temporary erosion control measures, such as silt fences, hay bales, mulching, control ditches and diversion trenches. The typical wet weather season, with regard to site grading, is from October 31st to April 1st. Erosion control measures should be in place before the onset of wet weather. 6.2 Seismic Hazard The overall subsurface profile corresponds to a Site Class D as defined by Table 1613.5.2 of the 2015 International Building Code (2015 IBC). A Site Class D applies to an overall profile consisting of dense to very dense soils within the upper 100 feet. We referenced the U.S. Geological Survey (USGS) Earthquake Hazards Program Website to obtain values for SS, S1, Fa, and Fv. The USGS website includes the most updated published data on seismic conditions. The site specific seismic design parameters and adjusted maximum spectral response acceleration parameters are as follows: PGA (Peak Ground Acceleration, in percent of g) SS 144.50% of g S1 49.70% of g FA 1.00 FV Null Additional seismic considerations include liquefaction potential and amplification of ground motions by soft/loose soil deposits. The liquefaction potential is highest for loose sand with a high groundwater table. The relatively dense soil deposits that underlie the site have a low liquefaction potential. GEOTECHNICAL INVESTIGATION RENTON, WASHINGTON April 3, 2020 4 PO Box 82243 Kenmore, WA 98028 cobaltgeo@gmail.com 206-331-1097 7.0 DISCUSSION 7.1.1 General The site is underlain by weathered to unweathered recessional outwash. The proposed residential buildings may be supported on shallow foundation systems bearing on medium dense or firmer native soils and/or structural fill placed on suitable native soils. Local overexcavation of fill and/or loose soils may be necessary below proposed foundation elements. Localized infiltration may be feasible depending on the lot layout and location of the proposed developments. Infiltration is only feasible in the sandy recessional outwash materials which appear to be prevalent in the eastern half of the property. Field determination of infiltration system locations, depths, and suitability is required. 8.0 Recommendations 8.1.1 Site Preparation Trees, shrubs and other vegetation should be removed prior to stripping of surficial organic-rich soil and fill. Based on observations from the site investigation program, it is anticipated that the stripping depth will be 6 to 18 inches. Deeper excavations will be necessary below large trees and in any areas underlain by undocumented fill materials. The native soils consist of silty-sand with gravel and poorly graded sand with gravel and silt. These soils may be used as structural fill provided they achieve compaction requirements and are within 3 percent of the optimum moisture. Some of these soils may only be suitable for use as fill during the summer months, as they will be above the optimum moisture levels in their current state. These soils are variably moisture sensitive and may degrade during periods of wet weather and under equipment traffic. Imported structural fill should consist of a sand and gravel mixture with a maximum grain size of 3 inches and less than 5 percent fines (material passing the U.S. Standard No. 200 Sieve). Structural fill should be placed in maximum lift thicknesses of 12 inches and should be compacted to a minimum of 95 percent of the modified proctor maximum dry density, as determined by the ASTM D 1557 test method. 8.1.2 Temporary Excavations Based on our understanding of the project, we anticipate that the grading could include local cuts on the order of approximately 4 feet or less for foundation and utility placement. Excavations should be sloped no steeper than 1H:1V in medium dense native soils. If an excavation is subject to heavy vibration or surcharge loads, we recommend that the excavations be sloped no steeper than 1.5H:1V, where room permits. Temporary cuts should be in accordance with the Washington Administrative Code (WAC) Part N, Excavation, Trenching, and Shoring. Temporary slopes should be visually inspected daily by a qualified person during construction activities and the inspections should be documented in daily reports. The GEOTECHNICAL INVESTIGATION RENTON, WASHINGTON April 3, 2020 5 PO Box 82243 Kenmore, WA 98028 cobaltgeo@gmail.com 206-331-1097 contractor is responsible for maintaining the stability of the temporary cut slopes and reducing slope erosion during construction. Temporary cut slopes should be covered with visqueen to help reduce erosion during wet weather, and the slopes should be closely monitored until the permanent retaining systems or slope configurations are complete. Materials should not be stored or equipment operated within 10 feet of the top of any temporary cut slope. Soil conditions may not be completely known from the geotechnical investigation. In the case of temporary cuts, the existing soil conditions may not be completely revealed until the excavation work exposes the soil. Typically, as excavation work progresses the maximum inclination of temporary slopes will need to be re-evaluated by the geotechnical engineer so that supplemental recommendations can be made. Soil and groundwater conditions can be highly variable. Scheduling for soil work will need to be adjustable, to deal with unanticipated conditions, so that the project can proceed and required deadlines can be met. If any variations or undesirable conditions are encountered during construction, we should be notified so that supplemental recommendations can be made. If room constraints or groundwater conditions do not permit temporary slopes to be cut to the maximum angles allowed by the WAC, temporary shoring systems may be required. The contractor should be responsible for developing temporary shoring systems, if needed. We recommend that Cobalt Geosciences and the project structural engineer review temporary shoring designs prior to installation, to verify the suitability of the proposed systems. 8.1.3 Erosion and Sediment Control Erosion and sediment control (ESC) is used to reduce the transportation of eroded sediment to wetlands, streams, lakes, drainage systems, and adjacent properties. Erosion and sediment control measures should be implemented and these measures should be in general accordance with local regulations. At a minimum, the following basic recommendations should be incorporated into the design of the erosion and sediment control features for the site: Schedule the soil, foundation, utility, and other work requiring excavation or the disturbance of the site soils, to take place during the dry season (generally May through September). However, provided precautions are taken using Best Management Practices (BMP’s), grading activities can be completed during the wet season (generally October through April). All site work should be completed and stabilized as quickly as possible. Additional perimeter erosion and sediment control features may be required to reduce the possibility of sediment entering the surface water. This may include additional silt fences, silt fences with a higher Apparent Opening Size (AOS), construction of a berm, or other filtration systems. Any runoff generated by dewatering discharge should be treated through construction of a sediment trap if there is sufficient space. If space is limited other filtration methods will need to be incorporated. GEOTECHNICAL INVESTIGATION RENTON, WASHINGTON April 3, 2020 6 PO Box 82243 Kenmore, WA 98028 cobaltgeo@gmail.com 206-331-1097 8.1.4 Foundation Design The proposed residential buildings may be supported on shallow spread footing foundation systems bearing on undisturbed medium dense or firmer native soils or on properly compacted structural fill placed on the suitable native soils. If structural fill is used to support foundations, then the zone of structural fill should extend beyond the faces of the footing a lateral distance at least equal to the thickness of the structural fill. Depending on the location and finish floor elevations of new residences, some overexcavation may be required. Any fill will need to be removed below new footings and replaced with compacted structural fill as discussed above. For shallow foundation support, we recommend widths of at least 16 and 24 inches, respectively, for continuous wall and isolated column footings supporting the proposed structure. Provided that the footings are supported as recommended above, a net allowable bearing pressure of 2,000 pounds per square foot (psf) may be used for design. A 1/3 increase in the above value may be used for short duration loads, such as those imposed by wind and seismic events. Structural fill placed on bearing, native subgrade should be compacted to at least 95 percent of the maximum dry density based on ASTM Test Method D1557. Footing excavations should be inspected to verify that the foundations will bear on suitable material. Exterior footings should have a minimum depth of 18 inches below pad subgrade (soil grade) or adjacent exterior grade, whichever is lower. Interior footings should have a minimum depth of 12 inches below pad subgrade (soil grade) or adjacent exterior grade, whichever is lower. If constructed as recommended, the total foundation settlement is not expected to exceed 1 inch. Differential settlement, along a 25-foot exterior wall footing, or between adjoining column footings, should be less than ½ inch. This translates to an angular distortion of 0.002. Most settlement is expected to occur during construction, as the loads are applied. However, additional post-construction settlement may occur if the foundation soils are flooded or saturated. All footing excavations should be observed by a qualified geotechnical consultant. Resistance to lateral footing displacement can be determined using an allowable friction factor of 0.40 acting between the base of foundations and the supporting subgrades. Lateral resistance for footings can also be developed using an allowable equivalent fluid passive pressure of 225 pounds per cubic foot (pcf) acting against the appropriate vertical footing faces (neglect the upper 12 inches below grade in exterior areas). The allowable friction factor and allowable equivalent fluid passive pressure values include a factor of safety of 1.5. The frictional and passive resistance of the soil may be combined without reduction in determining the total lateral resistance. A 1/3 increase in the above values may be used for short duration transient loads. Care should be taken to prevent wetting or drying of the bearing materials during construction. Any extremely wet or dry materials, or any loose or disturbed materials at the bottom of the footing excavations, should be removed prior to placing concrete. The potential for wetting or drying of the bearing materials can be reduced by pouring concrete as soon as possible after completing the footing excavation and evaluating the bearing surface by the geotechnical engineer or his representative. GEOTECHNICAL INVESTIGATION RENTON, WASHINGTON April 3, 2020 7 PO Box 82243 Kenmore, WA 98028 cobaltgeo@gmail.com 206-331-1097 8.1.5 Stormwater Management The site is underlain by Vashon Recessional Outwash. Infiltration is suitable in the sandy outwash soil deposits, generally located in the eastern half of the property. Very fine grained soils were encountered in the western portion of the property. Due to variations with recessional outwash, the depth and location of suitable soils is expected to vary with location and depth. Because the recessional deposits have not been overridden by glacial ice, this soil unit is considered normally-consolidated. The Washington State Department of Ecology 2015 Stormwater Management Manual for Western Washington allows determination of infiltration rates of this soil unit by Soil Particle Size Distribution testing. This method involves using a logarithmic equation and grain size values along with correction factors for testing type, soil homogeneity, and influent control. The equation in conjunction with sieve analysis results yields a design infiltration rate of 2.2 inches per hour for recessional deposits below the weathered zone, generally 5 to 6 feet below site elevations. These rates reflect application of correction factors for variability (0.5 used), influent control (0.9), and testing analysis type (0.4). Note: infiltration is not feasible in the very fine grained native soils. Infiltration systems should have a depth of at least 5 feet below existing grades and located at least 15 feet apart. Any fine grained soils or interbeds of fine grained soils must be removed prior to rock placement. We should be provided with final plans for review to determine if the intent of our recommendations has been incorporated or if additional modifications are needed. Verification testing of infiltration systems should be performed during construction. We can provide location-specific infiltration recommendations once civil plans have been prepared. 8.1.6 Slab-on-Grade We recommend that the upper 12 inches of the existing fill and/or native soils within slab areas be re- compacted to at least 95 percent of the modified proctor (ASTM D1557 Test Method). Often, a vapor barrier is considered below concrete slab areas. However, the usage of a vapor barrier could result in curling of the concrete slab at joints. Floor covers sensitive to moisture typically requires the usage of a vapor barrier. A materials or structural engineer should be consulted regarding the detailing of the vapor barrier below concrete slabs. Exterior slabs typically do not utilize vapor barriers. The American Concrete Institutes ACI 360R-06 Design of Slabs on Grade and ACI 302.1R-04 Guide for Concrete Floor and Slab Construction are recommended references for vapor barrier selection and floor slab detailing. Slabs on grade may be designed using a coefficient of subgrade reaction of 180 pounds per cubic inch (pci) assuming the slab-on-grade base course is underlain by structural fill placed and compacted as outlined in Section 8.1. A 6 inch thick capillary break should be placed over the subgrade. This material should consist of pea gravel or 5/8 inch clean angular rock. A perimeter drainage system is recommended unless interior slab areas are elevated a minimum of 12 inches above adjacent exterior grades. If installed, a perimeter drainage system should consist of a 4 inch diameter perforated drain pipe surrounded by a minimum 6 inches of drain rock wrapped in a non-woven GEOTECHNICAL INVESTIGATION RENTON, WASHINGTON April 3, 2020 8 PO Box 82243 Kenmore, WA 98028 cobaltgeo@gmail.com 206-331-1097 geosynthetic filter fabric to reduce migration of soil particles into the drainage system. The perimeter drainage system should discharge by gravity flow to a suitable stormwater system. Exterior grades surrounding buildings should be sloped at a minimum of one percent to facilitate surface water flow away from the building and preferably with a relatively impermeable surface cover immediately adjacent to the building. 8.1.7 Groundwater Influence on Construction Groundwater was not encountered in any of the explorations. We anticipate that perched groundwater could be encountered during construction if the work takes place during late winter to early spring. Any groundwater would be light in volume and likely within 10 feet of the ground surface in the areas underlain by fine-grained soils. If groundwater is encountered, we anticipate that sump excavations and small diameter pumps systems will adequately de-water short-term excavations, if required. Any system should be designed by the contractor. We can provide additional recommendations upon request. 8.1.8 Utilities Utility trenches should be excavated according to accepted engineering practices following OSHA (Occupational Safety and Health Administration) standards, by a contractor experienced in such work. The contractor is responsible for the safety of open trenches. Traffic and vibration adjacent to trench walls should be reduced; cyclic wetting and drying of excavation side slopes should be avoided. Depending upon the location and depth of some utility trenches, groundwater flow into open excavations could be experienced, especially during or shortly following periods of precipitation. In general, silty and sandy soils were encountered at shallow depths in the explorations at this site. These soils have low cohesion and density and will have a tendency to cave or slough in excavations. Shoring or sloping back trench sidewalls is required within these soils in excavations greater than 4 feet deep. All utility trench backfill should consist of imported structural fill or suitable on site soils. Utility trench backfill placed in or adjacent to buildings and exterior slabs should be compacted to at least 95 percent of the maximum dry density based on ASTM Test Method D1557. The upper 5 feet of utility trench backfill placed in pavement areas should be compacted to at least 95 percent of the maximum dry density based on ASTM Test Method D1557. Below 5 feet, utility trench backfill in pavement areas should be compacted to at least 90 percent of the maximum dry density based on ASTM Test Method D1557. Pipe bedding should be in accordance with the pipe manufacturer's recommendations. The contractor is responsible for removing all water-sensitive soils from the trenches regardless of the backfill location and compaction requirements. Depending on the depth and location of the proposed utilities, we anticipate the need to re-compact existing fill soils below the utility structures and pipes. The contractor should use appropriate equipment and methods to avoid damage to the utilities and/or structures during fill placement and compaction procedures. GEOTECHNICAL INVESTIGATION RENTON, WASHINGTON April 3, 2020 9 PO Box 82243 Kenmore, WA 98028 cobaltgeo@gmail.com 206-331-1097 8.1.9 Pavement Recommendations The near surface subgrade soils generally consist of silty sand with gravel. These soils are rated as good for pavement subgrade material (depending on silt content and moisture conditions). We estimate that the subgrade will have a California Bearing Ratio (CBR) value of 10 and a modulus of subgrade reaction value of k = 200 pci, provided the subgrade is prepared in general accordance with our recommendations. We recommend that at a minimum, 12 inches of the existing subgrade material be moisture conditioned (as necessary) and re-compacted to prepare for the construction of pavement sections. Deeper levels of recompaction or overexcavation and replacement may be necessary in areas where fill and/or very poor (soft/loose) soils are present. Any soils that cannot be compacted to required levels and soils that have more than 40 percent fines by weight should be removed and replaced with imported structural fill. The subgrade should be compacted to at least 95 percent of the maximum dry density as determined by ASTM Test Method D1557. In place density tests should be performed to verify proper moisture content and adequate compaction. The recommended flexible and rigid pavement sections are based on design CBR and modulus of subgrade reaction (k) values that are achieved, only following proper subgrade preparation. It should be noted that subgrade soils that have relatively high silt contents will likely be highly sensitive to moisture conditions. The subgrade strength and performance characteristics of a silty subgrade material may be dramatically reduced if this material becomes wet. Based on our knowledge of the proposed project, we expect the traffic to range from light duty (passenger automobiles) to heavy duty (delivery trucks). The following tables show the recommended pavement sections for light duty and heavy duty use. ASPHALTIC CONCRETE (FLEXIBLE) PAVEMENT LIGHT DUTY Asphaltic Concrete Aggregate Base* Compacted Subgrade* ** 2.5 in. 6.0 in. 12.0 in. HEAVY DUTY Asphaltic Concrete Aggregate Base* Compacted Subgrade* ** 3.5 in. 6.0 in. 12.0 in. GEOTECHNICAL INVESTIGATION RENTON, WASHINGTON April 3, 2020 10 PO Box 82243 Kenmore, WA 98028 cobaltgeo@gmail.com 206-331-1097 PORTLAND CEMENT CONCRETE (RIGID) PAVEMENT Min. PCC Depth Aggregate Base* Compacted Subgrade* ** 6.0 in. 6.0 in. 12.0 in. * 95% compaction based on ASTM Test Method D1557 ** A proof roll may be performed in lieu of in place density tests The asphaltic concrete depth in the flexible pavement tables should be a surface course type asphalt, such as Washington Department of Transportation (WSDOT) ½ inch HMA. The rigid pavement design is based on a Portland Cement Concrete (PCC) mix that has a 28 day compressive strength of 4,000 pounds per square inch (psi). The design is also based on a concrete flexural strength or modulus of rupture of 550 psi. 9.0 Construction Field Reviews Cobalt Geosciences should be retained to provide part time field review during construction in order to verify that the soil conditions encountered are consistent with our design assumptions and that the intent of our recommendations is being met. This will require field and engineering review to: Monitor and test structural fill placement and soil compaction Observe bearing capacity at foundation locations Observe slab-on-grade preparation Verify soil conditions at infiltration system locations Monitor subgrade preparation of roadways Observe excavation stability Geotechnical design services should also be anticipated during the subsequent final design phase to support the structural design and address specific issues arising during this phase. Field and engineering review services will also be required during the construction phase in order to provide a Final Letter for the project. 10.0 Closure This report was prepared for the exclusive use of Alan Jones and his appointed consultants. Any use of this report or the material contained herein by third parties, or for other than the intended purpose, should first be approved in writing by Cobalt Geosciences, LLC. The recommendations contained in this report are based on assumed continuity of soils with those of our test holes, and assumed structural loads. Cobalt Geosciences should be provided with final architectural and civil drawings when they become available in order that we may review our design recommendations and advise of any revisions, if necessary. GEOTECHNICAL INVESTIGATION RENTON, WASHINGTON April 3, 2020 11 PO Box 82243 Kenmore, WA 98028 cobaltgeo@gmail.com 206-331-1097 Use of this report is subject to the Statement of General Conditions provided in Appendix A. It is the responsibility of Alan Jones who is identified as “the Client” within the Statement of General Conditions, and its agents to review the conditions and to notify Cobalt Geosciences should any of these not be satisfied. Respectfully submitted, Cobalt Geosciences, LLC Original signed by: Exp. 6/26/2020 Phil Haberman, PE, LG, LEG Principal PH/sc APPENDIX A Statement of General Conditions Statement of General Conditions USE OF THIS REPORT: This report has been prepared for the sole benefit of the Client or its agent and may not be used by any third party without the express written consent of Cobalt Geosciences and the Client. Any use which a third party makes of this report is the responsibility of such third party. BASIS OF THE REPORT: The information, opinions, and/or recommendations made in this report are in accordance with Cobalt Geosciences present understanding of the site specific project as described by the Client. The applicability of these is restricted to the site conditions encountered at the time of the investigation or study. If the proposed site specific project differs or is modified from what is described in this report or if the site conditions are altered, this report is no longer valid unless Cobalt Geosciences is requested by the Client to review and revise the report to reflect the differing or modified project specifics and/or the altered site conditions. STANDARD OF CARE: Preparation of this report, and all associated work, was carried out in accordance with the normally accepted standard of care in the state of execution for the specific professional service provided to the Client. No other warranty is made. INTERPRETATION OF SITE CONDITIONS: Soil, rock, or other material descriptions, and statements regarding their condition, made in this report are based on site conditions encountered by Cobalt Geosciences at the time of the work and at the specific testing and/or sampling locations. Classifications and statements of condition have been made in accordance with normally accepted practices which are judgmental in nature; no specific description should be considered exact, but rather reflective of the anticipated material behavior. Extrapolation of in situ conditions can only be made to some limited extent beyond the sampling or test points. The extent depends on variability of the soil, rock and groundwater conditions as influenced by geological processes, construction activity, and site use. VARYING OR UNEXPECTED CONDITIONS: Should any site or subsurface conditions be encountered that are different from those described in this report or encountered at the test locations, Cobalt Geosciences must be notified immediately to assess if the varying or unexpected conditions are substantial and if reassessments of the report conclusions or recommendations are required. Cobalt Geosciences will not be responsible to any party for damages incurred as a result of failing to notify Cobalt Geosciences that differing site or sub-surface conditions are present upon becoming aware of such conditions. PLANNING, DESIGN, OR CONSTRUCTION: Development or design plans and specifications should be reviewed by Cobalt Geosciences, sufficiently ahead of initiating the next project stage (property acquisition, tender, construction, etc), to confirm that this report completely addresses the elaborated project specifics and that the contents of this report have been properly interpreted. Specialty quality assurance services (field observations and testing) during construction are a necessary part of the evaluation of sub-subsurface conditions and site preparation works. Site work relating to the recommendations included in this report should only be carried out in the presence of a qualified geotechnical engineer; Cobalt Geosciences cannot be responsible for site work carried out without being present. 10.2 PO Box 82243 Kenmore, WA 98028 cobaltgeo@gmail.com 206-331-1097 APPENDIX B Figures: Vicinity Map, Site Plan SITE N Project Location Renton WASHINGTON VICINITY MAP FIGURE 1 Cobalt Geosciences, LLCP.O. Box 82243 Kenmore, WA 98028 (206) 331-1097 www.cobaltgeo.com cobaltgeo@gmail.com Proposed Residential Development 3102 Park Avenue North Renton, Washington Cobalt Geosciences, LLCP.O. Box 82243 Kenmore, WA 98028 (206) 331-1097 www.cobaltgeo.com cobaltgeo@gmail.com SITE PLAN FIGURE 2 N TP-1 TP-2 TP-1 Proposed Residential Development 3102 Park Avenue North Renton, Washington TP-3 Subject Property APPENDIX C Exploration Logs PT Well-graded gravels, gravels, gravel-sand mixtures, little or no fines Poorly graded gravels, gravel-sand mixtures, little or no fines Silty gravels, gravel-sand-silt mixtures Clayey gravels, gravel-sand-clay mixtures Well-graded sands, gravelly sands, little or no fines COARSE GRAINED SOILS (more than 50% retained on No. 200 sieve) Primarily organic matter, dark in color, and organic odor Peat, humus, swamp soils with high organic content (ASTM D4427)HIGHLY ORGANIC SOILS FINE GRAINED SOILS (50% or more passes the No. 200 sieve) MAJOR DIVISIONS SYMBOL TYPICAL DESCRIPTION Gravels (more than 50% of coarse fraction retained on No. 4 sieve) Sands (50% or more of coarse fraction passes the No. 4 sieve) Silts and Clays(liquid limit lessthan 50) Silts and Clays (liquid limit 50 or more) Organic Inorganic Organic Inorganic Sands with Fines (more than 12% fines) Clean Sands (less than 5%fines) Gravels with Fines (more than 12% fines) Clean Gravels (less than 5% fines) Unified Soil Classification System (USCS) Poorly graded sand, gravelly sands, little or no fines Silty sands, sand-silt mixtures Clayey sands, sand-clay mixtures Inorganic silts of low to medium plasticity, sandy silts, gravelly silts, or clayey silts with slight plasticity Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, silty clays, lean clays Organic silts and organic silty clays of low plasticity Inorganic silts, micaceous or diatomaceous fine sands or silty soils, elastic silt Inorganic clays of medium to high plasticity, sandy fat clay, or gravelly fat clay Organic clays of medium to high plasticity, organic silts Moisture Content Definitions Grain Size Definitions Dry Absence of moisture, dusty, dry to the touch Moist Damp but no visible water Wet Visible free water, from below water table Grain Size Definitions Description Sieve Number and/or Size Fines <#200 (0.08 mm) Sand -Fine -Medium -Coarse Gravel -Fine -Coarse Cobbles Boulders #200 to #40 (0.08 to 0.4 mm) #40 to #10 (0.4 to 2 mm) #10 to #4 (2 to 5 mm) #4 to 3/4 inch (5 to 19 mm) 3/4 to 3 inches (19 to 76 mm) 3 to 12 inches (75 to 305 mm) >12 inches (305 mm) Classification of Soil Constituents MAJOR constituents compose more than 50 percent, by weight, of the soil. Major constituents are capitalized (i.e., SAND). Minor constituents compose 12 to 50 percent of the soil and precede the major constituents (i.e., silty SAND). Minor constituents preceded by “slightly” compose 5 to 12 percent of the soil (i.e., slightly silty SAND). Trace constituents compose 0 to 5 percent of the soil(i.e., slightly silty SAND, trace gravel). Relative Density Consistency (Coarse Grained Soils) (Fine Grained Soils) N, SPT, Relative Blows/FT Density 0 - 4 Very loose 4 - 10 Loose 10 - 30 Medium dense 30 - 50 Dense Over 50 Very dense N, SPT, Relative Blows/FT Consistency Under 2 Very soft 2 - 4 Soft4 - 8 Medium stiff8 - 15 Stiff15 - 30 Very stiff Over 30 Hard Cobalt Geosciences, LLCP.O. Box 82243 Kenmore, WA 98028(206) 331-1097 www.cobaltgeo.com cobaltgeo@gmail.com Soil Classification Chart Figure C1 Proposed Plat 3102 Park Avenue North Renton, Washington Test Pit Logs Cobalt Geosciences, LLCP.O. Box 82243 Kenmore, WA 98028 (206) 331-1097 www.cobaltgeo.com cobaltgeo@gmail.com Test Pit TP-1 Date: March 24, 2020 Contractor: Jim Depth: 10’ Elevation: Logged By: PH Checked By: SC Groundwater: None Material Description Moisture Content (%)PlasticLimit Liquid Limit 10 20 30 400 50 1 2 3 4 5 6 DCP Equivalent N-Value 7 8 9 10 Loose to medium dense, silty-fine to medium grained sand trace gravel, reddish brown to yellowish brown, moist. (Weathered Recessional Outwash) SM/ SP End of Test Pit 10’ Test Pit TP-2 Date: March 24, 2020 Contractor: Jim Depth: 10’ Elevation: Logged By: PH Checked By: SC Groundwater: None Material Description Moisture Content (%)Plastic Limit Liquid Limit 10 20 30 400 50 1 2 3 4 5 6 DCP Equivalent N-Value 7 8 9 10 Medium dense, fine to medium grained sand trace gravel, grayish brown, moist. (Recessional Outwash)SP Topsoil/Grass Loose to medium dense, silty-fine to medium grained sand with gravel,yellowish brown to grayish brown, moist. (Weathered Recessional Outwash) SM Medium dense/stiff, silty-fine to fine grained sand trace gravel, mottled yellowish brown to grayish brown, moist. (Recessional Outwash - Lacustrine) SM/ ML End of Test Pit 10’ Topsoil/Grass -Roots to 6’ Proposed Plat 3102 Park Avenue North Renton, Washington Test Pit Logs Cobalt Geosciences, LLCP.O. Box 82243 Kenmore, WA 98028 (206) 331-1097 www.cobaltgeo.com cobaltgeo@gmail.com Test Pit TP-3 Date: March 24, 2020 Contractor: Jim Depth: 10’ Elevation: Logged By: PH Checked By: SC Groundwater: None Material Description Moisture Content (%)PlasticLimit Liquid Limit 10 20 30 400 50 1 2 3 4 5 6 DCP Equivalent N-Value 7 8 9 10 Loose to medium dense, silty-fine to medium grained sand trace gravel, reddish brown to yellowish brown, moist. (Weathered Recessional Outwash) SM/ SP End of Test Pit 10’ Medium dense, fine to medium grained sand trace gravel, grayish brown, moist. (Recessional Outwash) SP Topsoil/Grass -Roots to 5’