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Home My WebLink AboutTIR-4082 Western Washington Division Eastern Washington Division 165 NE Juniper St., Ste 201, Issaquah, WA 98027 407 Swiftwater Blvd., Cle Elum, WA 98922 Phone: (425) 392-0250 Fax: (425) 391-3055 Phone: (509) 674-7433 Fax: (509) 674-7419 www.EncompassES.net TECHNICAL INFORMATION REPORT CITY OF RENTON For 28 Hundred Unit Lot Subdivision 2800 NE 12th Street & 2801 NE 13th Street Renton WA, 98056 November 15, 2019 11/15/19 Prepared by: Noah Anderson Encompass Engineering Job No. 16663 IN COMPLIANCE WITH CITY OF RENTON STANDARDS Prepared For: Yves Tang Greystoke LLC 720 North 10th Street #A282 Renton, WA 98057 DEVELOPMENT ENGINEERING jchavez 12/06/2019 SURFACE WATER UTILITY jfarah 12/06/2019 28 Hundred Unit Lot Subdivision Technical Information Report 11/15/19 Page i TABLE OF CONTENTS I. PROJECT OVERVIEW ................................................................................................................. 1 II. CONDITIONS AND REQUIREMENTS SUMMARY ....................................................................... 3 III. OFF-SITE ANALYSIS ................................................................................................................... 6 IV. FLOW CONTROL, LOW IMPACT DESIGN AND WATER QUALITY FACILITY ANALYSIS AND DESIGN ................................................................................................................................... 11 V. CONVEYANCE SYSTEM ANALYSIS AND DESIGN ..................................................................... 18 VI. SPECIAL REPORTS AND STUDIES ............................................................................................ 18 VII. OTHER PERMITS ..................................................................................................................... 18 VIII. CSWPPP ANALYSIS AND DESIGN ............................................................................................ 19 IX. BOND QUANTITIES, FACILITY SUMMARIES, & DECLARATION OF COVENANT ...................... 21 X. OPERATIONS AND MAINTENANCE MANUAL ......................................................................... 21 LIST OF FIGURES 1. TIR Worksheet 2. Soils Map 3. Vicinity Map 4. Flow Control Application Area 5. Downstream Map 6. Basin Map 7. Flow Frequencies 8. Water Quality Outputs 9. Biopod Detail 10. Existing Conditions Map 11. Developed Conditions Map LIST OF APPENDICIES A. WWHM2012 Output B. Infiltration Evaluation by Earth Solutions NW, LLC dated August 26, 2014 C. Site Improvement Bond Quantity Worksheet D. Operations and Maintenance Manual E. Biopod Submittal Package F. Declaration of Covenant Yves Tang (206) 396-0958 720 North 10th Street #A282 Renton, WA 98057 Nicole Mecum Encompass Engineering & Surveying (425)392-0250 23 5 4 4 8/1/19 11/15/19 4 8/1/19 11/15/19 4 10/21/19 10/21/19 SW 4 28 Hundred Unit Lot Subdivision 2800 NE 12th Street & 2801 NE 13th Street 4 4 None No Flow Control Duration Newcastle N/A East Lake Washington NONE4 - Exemption Alderwood 6-15%Low East Lake Washington 1 1 1/19/17 Peak Rate Flow Control Standard Infiltration Trenches T.B.D. T.B.D. 4 NONE Private No Yes Enhanced Basic None None None N/A No 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 Bio-Pod 4 4 Infiltration Trenches 4 Infiltration Trences 11/15/19Nicole Mecum 28 Hundred Unit Lot Subdivision Technical Information Report 11/15/19 Page 1 I. PROJECT OVERVIEW Project: 28 Hundred Unit Lot Subdivision Tax Parcel #: 722780-1690 & 722780-1695 Site Addresses: 2800 NE 12th St & 2801 NE 13th ST, Renton WA, 98056 Zoning: R-14 Site Area: The total project area is 0.69 Acres Site Location: The site is on the east side of Harrington Avenue NE between NE 12th Street and NE 13th Street. (See attached Figure 1: Site Plan) Project Description: This project involves developing a 0.66-acre parcel into an 11-unit, Unit Lot Subdivision. Existing Adjacent Development: Existing development adjacent to the subject site includes the following: North – Single Family Residences and NE 13th Street East – Single Family Residences South – Single Family/Multifamily Residences & NE 12th Street West – McKnight Middle School & Harrington Avenue NE Pre-developed Site Conditions: The project site presently consists of two parcels totaling 0.66 acres with existing houses/garages with sidewalks and driveways. The remaining site area is covered with lawn and a few trees. The site generally slopes down from the north to south at approximately 1%. See Figure 10 for a map of the pre-developed site conditions. Critical Areas: There are no mapped onsite critical areas. Soils: Per the SCS soil maps, the site is underlain with Arents, Alderwood, gravelly sandy loam (AmC) soil. Per Geotech report prepared for this project, “Infiltration Evaluation Proposed Harrington Glade Townhomes 2800 Northeast 12th Street Renton, Washington”, dated August 26, 2014, and prepared by Earth Solutions NW (see Appendix B), the site is underlain with at least 8’ – 14’ of silty sand, infiltration capable soil. The soil is suitable for infiltration BMPs at a design infiltration rate of 1.0 in/hr. 28 Hundred Unit Lot Subdivision Technical Information Report 11/15/19 Page 2 Figure 2: Soils Map Post-developed Site Conditions: The proposal incorporates the construction of frontage improvements along NE 13th and NE 12th Streets together with associated utilities for an 11-unit Unit Lot Subdivision. The existing single-family residences will be removed. See Figure 11 for a map of the developed site conditions. 28 Hundred Unit Lot Subdivision Technical Information Report 11/15/19 Page 3 Figure 3: Vicinity Map II. CONDITIONS AND REQUIREMENTS SUMMARY The 2017 City of Renton Surface Water Design Manual (RSWDM) along with the 2016 King County Surface Water Design Manual (KCSWDM) were utilized for stormwater design per the City of Renton requirements. This project is subject to a Full Drainage Review per Section 1.1.2.4 of the 2017 CRSWDM. Core Requirements: Core Requirement #1: Discharge at the Natural Location The proposed on-site drainage patterns emulate those of the existing site conditions: infiltrating into the onsite soil, and running off to the south into the existing City storm system. Core Requirement #2: Off-site Analysis See the Downstream Analysis in Section III of this report for a complete description of the existing drainage basin and flow paths. Core Requirement #3: Flow Control Facilities After applying the BMP credits for full infiltration per Table 1.2.9.A of the 2017 RSWDM, the WWHM output displayed an increase in peak flow runoff of less than 0.15 CFS using 15- minute timesteps. Therefore, the project meets the exemption for Conservation Flow Control Areas per Section 1.2.3.1 of the 2017 RSWDM and no further flow control facilities are required. See Section IV for full discussion of flow control facilities and Appendix A for full WWHM2012 Output. 28 Hundred Unit Lot Subdivision Technical Information Report 11/15/19 Page 4 Core Requirement #4: Conveyance System See Section V of this report for conveyance capacity analysis. Core Requirement #5: Construction Stormwater Pollution Prevention See temporary erosion and sediment control (TESC) plan and Construction Stormwater Pollution Prevention (CSWPPP) plan have been prepared for this project, which will serve to minimize soil erosion/sedimentation during the proposed site construction. These are submitted with the submittal. Core Requirement #6: Maintenance & Operations See Section X of this report for maintenance & operations documentation. Core Requirement #7: Financial Guarantees & Liability The owner will arrange for any financial guarantees and liabilities required by the permit. Core Requirement #8: Water Quality Because there will be greater than 5,000 SF of new pollution-generating impervious surfaces (PGIS), water quality requirements are proposed to be met using an Oldcastle Biopod. This biofiltration device has been sized to provide enhanced water quality treatment for the site. This proprietary facility has been approved per an email from Jonathan Chavez, P.E. for the City of Renton. See Section IV of this TIR for full discussion of water quality facilities and Figure 9 for Biopod details. Core Requirement #9: Flow Control BMPs Per the Flow Control Application Map in the 2017 RSWDM, this project site is within the “Peak Rate Flow Control Standard (Existing Site Conditions)” area. In this area, flow control facilities are required to be designed to match the existing conditions 2-, 10-, and 100-year peak-rate runoff from the site. This site is greater than 22,000 square feet and is therefore designed to comply with the Small Subdivision Project BMP Requirements detailed in Section 1.2.9.3.1 of the RSWDM. Flow Control BMPs have been considered in order of preference as prescribed by the Small Subdivision Project BMP Requirements. See Section IV of this TIR for complete Flow Control details. Full Dispersion: Infeasible; site design does not allow for minimum native vegetated flowpath lengths required for full dispersion BMPs. Full Infiltration: Feasible; per the attached “Infiltration Evaluation” by Earth Solution NW, LLC · Full infiltration of the plat infrastructure improvements (rooftops, road, sidewalks, walkways, etc) areas is proposed for the site in the form of Gravel Filled Trenches per Appendix C.2.2.3. Soil Amendment: Feasible; soil quality and depth shall be retained and reestablished as necessary for the developed site. · Soil Amendment for all of the non-native pervious surfaces is proposed for the site per Appendix C.2.13. 28 Hundred Unit Lot Subdivision Technical Information Report 11/15/19 Page 5 Figure 4: Flow Control Application Map Special Requirements: Special Requirement #1: Other Adopted Area-Specific Requirements Master Drainage Plan – N/A Basin Plan – N/A Salmon Conservation Plans – N/A Lake Management Plans – N/A Hazard Mitigation Plan – N/A Shared Facility Drainage Plan – N/A Special Requirement #2: Flood Hazard Area Delineation The limits of this project do not lie within the FEMA 100-year floodplain. Special Requirement #3: Flood Protection Facilities This project does not rely on or propose to modify or construct a new flood protection facility. Special Requirement #4: Source Control Source control is not required for this project. Special Requirement #5: Oil Control This project is not considered high-use in need of oil control. Special Requirement #6: Aquifer Protection Area Per the City of Renton review comments, the project is not located within an aquifer protection area and Special Requirement #6 is not applicable. 28 Hundred Unit Lot Subdivision Technical Information Report 11/15/19 Page 6 III. OFF-SITE ANALYSIS The field inspection portion of the Level 1 Downstream Analysis was performed by Encompass Engineering & Surveying on January 19, 2017. The site is contained within a single drainage basin within the East Lake Washington - Renton Drainage Basin which discharges to the Cedar River / Lake Washington Watershed per King County iMap. Encompass’ resource review shows no wetlands, sensitive areas, floodplains/floodways, or erosion and landslide areas located on the project site. Existing Upstream Drainage: Surface water runoff from adjacent properties to the west likely drain onto the site. This runoff is directed into open space vegetated areas and will likely cause little to no impact to the site. Existing Downstream Drainage: Any runoff from the site sheet flows southwest and enters into street gutter which drains into public storm drainage system—a CB at point (A) which is located in the intersection of NE 12th St and Harrington Ave NE. This system is part of the approved “Sunset Community – Green Connection Site Plan” improvements, project number CD: D-363508. From there flow drains southwest through an 8-inch Conc. pipe (B) into a CB type II-MH per survey field and per city of Renton (GIS) records at point (C). From point (C) flow also drains southwest through a 24-inch CMP pipe (D) into another CB type II-MH at point (E). From there flow drains west along the NE 12th St through a 36-inch pipe (F) to another CB type II-MH at point (G) for a total of 120-feet downstream from the site. From point (G) flow continues west through a 36-inch pipe (H) to another CB at point (I) per city of Renton records. Form there flow drains through a 36-inch pipe (J) to another CB type II-MH at point (K) for a total of approximately 470-feet down stream. From there flow drains through a 36-inch pipe (L) to another CB type II-MH at point (M). From there flow drains through a pipe (N) to another CB type II-MH at point (O) located on intersection of NE 12th St and Edmonds Ave NE for a total of approximately 800-feet from the site. From point (O) flow continues south along Edmonds Ave NE through an 18-inch pipe (P) to another CB type II-MH at point (Q). From there flow continues south through an 18-inch pipe (R) to another CB at point (S). From Point (S) flow drains through another 18-inch (T) pipe to another CB at point (U) for a total of approximately 1150-feet downstream from the site. From there pipe (V) continues south to ¼ mile downstream from the site and enters into public storm drainage system along the NE Sunset Blvd. Eventually the runoff discharges into Lake Washington. King County iMap and City of Renton GIS map show no downstream drainage complaints that relate to this development. No major existing drainage system problems were observed during Encompass’ field inspection or resource review. Potential drainage system problems include increased sedimentation and erosion of site soils. These possible problems will be addressed via flow control and water quality BMPs as well as the preparation of a site-specific temporary erosion and sediment control (TESC) plan. 28 Hundred Unit Lot Subdivision Technical Information Report 11/15/19 Page 7 OFF-SITE ANALYSIS DRAINAGE SYSTEM TABLE SURFACE WATER DESIGN MANUAL, CORE REQUIREMENT #2 Basin: East Lake Washington Subbasin Name: Subbasin Number: Sym bol Drainage Component Type, Name, and Size Drainage Component Description Slope Distance from site discharge Existing Problems Potential Problems Observations of field inspector, resource reviewer, or resident see map Type: sheet flow, swale, stream, channel, pipe, pond; Size: diameter, surface area drainage basin, vegetation, cover, depth, type of sensitive area, volume % ¼ ml = 1,320 ft. constrictions, under capacity, ponding, overtopping, flooding, habitat or organism destruction, scouring, bank sloughing, sedimentation, incision, other erosion tributary area, likelihood of problem, overflow pathways, potential impacts A CATCH BASIN TYPE 1 N/A 0’-5’ NO SEDIMENTATION SITE BASIN COLLECTION B PIPE 8” CONCRETE 2% 5’-50’ NO SEDIMENTATION CONVEYANCE UNDER NE 12TH ST C CATCH BASIN TYPE 2 N/A 50’ NO SEDIMENTATION CITY OF RENTON MANHOLE D PIPE 24” CMP 2% 50’-75’ NO SEDIMENTATION CONVEYANCE ALONG NE 12TH ST E CATCH BASIN TYPE 2 N/A 75’ NO SEDIMENTATION CITY OF RENTON MANHOLE F PIPE 36” 2% 75’-120’ NO SEDIMENTATION CONVEYANCE ALONG NE 12TH ST G CATCH BASIN TYPE 2 N/A 120’ NO SEDIMENTATION CITY OF RENTON MANHOLE H PIPE 36” 2% 120’-320’ NO SEDIMENTATION CONVEYANCE ALONG NE 12TH ST I CATCH BASIN TYPE 2 N/A 320’ NO SEDIMENTATION CITY OF RENTON MANHOLE J PIPE 36” 2% 320’-470’ NO SEDIMENTATION CONVEYANCE ALONG NE 12TH ST K CATCH BASIN TYPE 2 N/A 470’ NO SEDIMENTATION CITY OF RENTON MANHOLE L PIPE 36” 2% 470’-600’ NO SEDIMENTATION CONVEYANCE UNDER NE 12TH ST M CATCH BASIN TYPE 2 N/A 600’ NO SEDIMENTATION CITY OF RENTON MANHOLE N PIPE 36” 2% 600’-800’ NO SEDIMENTATION CONVEYANCE ALONG NE 12TH ST O CATCH BASIN TYPE 2 N/A 800’ NO SEDIMENTATION CITY OF RENTON MANHOLE AT 28 Hundred Unit Lot Subdivision Technical Information Report 11/15/19 Page 8 Sym bol Drainage Component Type, Name, and Size Drainage Component Description Slope Distance from site discharge Existing Problems Potential Problems Observations of field inspector, resource reviewer, or resident see map Type: sheet flow, swale, stream, channel, pipe, pond; Size: diameter, surface area drainage basin, vegetation, cover, depth, type of sensitive area, volume % ¼ ml = 1,320 ft. constrictions, under capacity, ponding, overtopping, flooding, habitat or organism destruction, scouring, bank sloughing, sedimentation, incision, other erosion tributary area, likelihood of problem, overflow pathways, potential impacts INTERSECTION OF EDMONDS AVE NE AND NE 12TH ST P PIPE 18” 2% 800’-850’ NO SEDIMENTATION CONVEYANCE ALONG EDMONDS AVE NE Q CATCH BASIN TYPE 2 N/A 850’ NO SEDIMENTATION CITY OF RENTON MANHOLE R PIPE 18” 2% 850’-1000’ NO SEDIMENTATION CONVEYANCE ALONG EDMONDS AVE NE S CATCH BASIN TYPE 2 N/A 1000’ NO SEDIMENTATION CITY OF RENTON MANHOLE T PIPE 18” 2% 1000’-1150’ NO SEDIMENTATION CONVEYANCE ALONG EDMONDS AVE NE U CATCH BASIN TYPE 2 N/A 1150’ NO SEDIMENTATION CITY OF RENTON MANHOLE V PIPE 18” 2% 1150’-1320’ NO SEDIMENTATION CONVEYANCE ALONG EDMONDS AVE NE 28 Hundred Unit Lot Subdivision Technical Information Report 11/15/19 Page 9 Figure 5: Downstream Map Photo 1: Looking South from Harrington Ave NE/NE 13th St.—Subject property on the left 28 Hundred Unit Lot Subdivision Technical Information Report 11/15/19 Page 10 Photo 2: Intersection of Harrington Ave NE & NE 12th St.—CB at point (A) Photo 3: looking west from NE 12th St. towards intersection of Edmonds Ave NE 28 Hundred Unit Lot Subdivision Technical Information Report 11/15/19 Page 11 IV. FLOW CONTROL, LOW IMPACT DESIGN (LID) AND WATER QUALITY FACILITY ANALYSIS AND DESIGN Existing Site Hydrology (Part A): The project site presently consists of two parcels totaling 0.66 acres with existing houses/garages with sidewalks and driveways—the remaining area is covered with lawn and a few trees. The site generally slopes down from the north to south at approximately 1%. The existing site conditions consist of stormwater runoff infiltrating into the onsite soil, and draining off to the southwestern property corner into the existing NE 12th Street storm system. Surface water runoff from adjacent properties to the west likely drain onto the site. This runoff is directed into open space vegetated areas and will likely cause little to no impact to the site. See Section III of this report for a full Level 1 Downstream Analysis of the project site. See Figure 10 for a map of the existing site conditions. Developed Site Hydrology (Part B): All developed stormwater runoff will be discharged to the natural locations identified in the Offsite Analysis. Both existing and proposed surface areas are detailed in Table 1, and the full WWHM outputs are attached in Appendix A of this report. Surface areas tributary to the full infiltration BMPs (Per Figure 6: Basin Map) are subtracted from the WWHM model per Table 1.2.9.A On-Site BMP Sizing Credits. The Soil Amendment BMP will be implemented for all onsite vegetated areas per Appendix C.2.13 of the 2017 RSWDM. Areas meeting these criteria are modeled as “pasture” rather than “lawn”. Refer to Figures 10 and 11 for Existing and Developed Conditions Maps. Area Breakdown Existing Proposed Condition Measured (AC) Modeled (AC) Measured (AC) Modeled (AC) Lawn: 0.480 0.050 0.257 0.000 Pasture: 0.000 0.000 0.000 0.257 Onsite Road: 0.070 0.070 0.122 0.000 Offsite Road: 0.023 0.000 0.023 0.000 Onsite Sidewalk: 0.000 0.000 0.075 0.000 Offsite Sidewalk: 0.027 0.027 0.005 0.000 Roof: 0.110 0.110 0.204 0.000 Total Area: 0.711 0.257 0.687 0.257 Table 1: Area Breakdown Performance Standards (Part C): Per the Flow Control Application Map in the 2017 City of Renton Surface Water Design Manual, this project site is within the “Peak Rate Flow Control Standard (Existing Site Conditions)” area. In this area, flow control facilities are required to match the existing conditions 2-, 10-, and 100-year peak- rate runoff from the site. This site is designed to comply with the Small Subdivision Project BMP Requirements detailed in Section 1.2.9.3.1 of the 2017 RSWDM. Flow Control System (Part D): Per the City of Renton review comments, the feasibility of on-site BMPs must be assessed for plat infrastructure improvements per Section 1.2.9.3.2 of the RSWDM. The plat infrastructure 28 Hundred Unit Lot Subdivision Technical Information Report 11/15/19 Page 12 improvements evaluated include the road, driveway, sidewalks, and impervious surfaces other than the residential roofs. Flow Control BMPs have been considered in order of preference as prescribed. Full Dispersion: Infeasible; the site design does not allow for minimum required native vegetated flowpath lengths for full dispersion BMPs. Full Infiltration: Feasible; per the attached Infiltration Evaluation by Earth Solution NW, LLC. · Full infiltration of a portion of the plat infrastructure improvements is proposed for the development in the form of Gravel Filled Trenches per Appendix C.2.2.3. These trenches have been designed to meet all of the applicable design guidelines and will serve to fully infiltrate all plat infrastructure improvements. Soil Amendment: Feasible; soil quality and depth shall be retained and reestablished as necessary for the developed site. · Soil Amendment for all of the non-native pervious surfaces created by the development is proposed for the site per Appendix C.2.13. Full Infiltration of 8,903 SF of rooftop area, 5,330 SF of road area, and 2,462 SF of onsite sidewalk area is proposed for the site in the form of Gravel Filled Trenches for Full Infiltration per Appendix C.2.2.3. Per the Geotech report, the site is underlain with medium sands and requires a 30-foot-long section per 1,000 SF of impervious area infiltrated. Four separate trenches, each 5-feet in width, have been sized for their respective impervious tributary areas. Table 2 shows the trench sizing calculations. All four of these infiltration trenches are designed to overflow through a proposed connection into the existing NE 12th Street storm drain system. All proposed residential rooftops will be comprised of non-leachable materials per the City of Renton requirements. A declaration of covenant ensuring this is included in Appendix F. See the engineering plan set for further details. BASIN IMPERVIOUS TRIBUTARY AREA (SF) TRENCH REQUIRED (2' WIDE) (LF) TRENCH REQUIRED (5' WIDE) (LF) TRENCH PROVIDED (5' WIDE) (LF) A 3515 105.45 42.18 45 B 4027 120.81 48.324 50 C 3268 98.04 39.216 40 D 5885 176.55 70.62 75 Table 2: Full Infiltration Trench Sizing The remaining portion of the site improvements are located within proposed public right of way dedications and will be not be tributary to the on-site flow control system. These elements will drain stormwater runoff to the existing within the NE 13th Street, Harrington Avenue NE, and NE 12th Street drainage systems. Per Figure 7, the proposed project shows a peak flow increase of less than 0.15 CFS and meets the Flow Control exemption detailed in Section 1.2.3 of the 2017 City of RSWDM. Therefore, the use of further flow control BMPs are not required for the project development. 28 Hundred Unit Lot Subdivision Technical Information Report 11/15/19 Page 13 Figure 6: Basin Map 28 Hundred Unit Lot Subdivision Technical Information Report 11/15/19 Page 14 Figure 7: Flow Frequencies Water Quality System (Part E): Stormwater runoff from all developed pollution-generating impervious surfaces (PGIS) must be treated for Enhanced Water quality per the 2017 CRSWDM. A Biopod manufactured by Oldcastle will provide the required treatment. This filtration device has been sized using the On-line facility WWHM water quality outputs (Figure 8) for the proposed PGIS. This design has been approved per an email from Jonathan Chavez, P.E. for the City of Renton. See Figure 9 for structure details and Appendix E for the Biopod Submittal Package. Figure 8: Water Quality Outputs 28 Hundred Unit Lot Subdivision Technical Information Report 11/15/19 Page 15 Figure 9: Biopod Detail 28 Hundred Unit Lot Subdivision Technical Information Report 11/15/19 Page 18 V. CONVEYANCE SYSTEM ANALYSIS AND DESIGN Treated flows from the site will drain into the existing NE 12th Street storm drainage system. Per the City of Renton comments, the critical conveyance pipe is the 8” concrete outfall pipe within the NE 12th Street system. A simplified inlet-controlled analysis shows that this pipe has a maximum flow capacity of approximately 0.6286 CFS for the 8” pipe. Per Table 4.2.1.A1 of the RSWDM, this pipe is required to have a minimum full flow velocity at design flow of 3.0 fps. The Table 3 conveyance calculations show that the pipe possesses a full flow velocity of 5.321 fps, meeting this requirement. Assuming the worst-case, that the infiltration trenches are inoperative, 100-year flow for the un-detained developed condition is about 0.354 CFS. Per Table 3, the pipe capacity of 0.6286 CFS is approximately 1.8 times the maximum calculated flow. See Appendix A for full WWHM outputs. Table 3: Conveyance Calculations VI. SPECIAL REPORTS AND STUDIES Infiltration Evaluation Proposed Harrington Glade Townhomes 2800 Northeast 12th Street Renton, Washington, dated August 1, 2014, and prepared by Earth Solutions NW. See Appendix B. VII. OTHER PERMITS Building permits will be required. 28 Hundred Unit Lot Subdivision Technical Information Report 11/15/19 Page 19 VIII. CSWPPP ANALYSIS AND DESIGN Description 1. Preserve Vegetation/Mark Clearing Limits a. The clearing limits are shown at the adjacent property lines. High visibility orange fencing is shown at the clearing limits and around retained trees. b. Retain the duff layer, native top soil and natural vegetation in an undisturbed state to the maximum degree practicable. 2. Establish Construction Access a. The existing driveways will be utilized for access and parking. b. If sediment is tracked off site, the affected roadways are to be cleaned thoroughly at the end of each day. 3. Control Sediment a. The proposed sediment trap can be used to control flow rates during construction of the house and infrastructure improvements. b. Silt fence will also be utilized to control sediment and protect adjacent properties. 4. Install Sediment Controls a. The proposed sediment can be used to control sediment during construction of the house and infrastructure improvements. b. Silt fence will also be utilized to control sediment and protect adjacent properties. 5. Stabilize Soils a. Stabilize expose and unworked soils. Soils must not remain exposed and unworked for more than the time periods set forth below to prevent erosion: · During the dry season (May 1 – September 30): 7 days · During the wet season (October 1 – April 30): 2 days · Stabilize soils at the end of the shift before a holiday or weekend if needed based on the weather forecast. b. Stockpiled soils to be covered with plastic. c. All disturbed areas shall be stabilized with landscaping or some other method prior to final construction approval. 6. Protect Slopes Design and construct cut-and-fill slopes in a manner to minimize erosion. 7. Protect Drain Inlets a. Protect storm drain inlets made operable during construction so that stormwater runoff does not enter the conveyance system without first being filtered or treated to remove sediment. b. Clean or remove and replace inlet protection devices when sediment has filled one third of 28 Hundred Unit Lot Subdivision Technical Information Report 11/15/19 Page 20 the available storage (unless a different standard is specified by the product manufacturer). 8. Stabilize Channels and Outlets No channels or outlets are proposed. 9. Control Pollutants a. Design, install, implement and maintain effective pollution prevention measures to minimize the discharge of pollutants. b. Handle and dispose all pollutants, including waste materials and demolition debris that occur on-site in a manner that does not cause contamination of stormwater. c. Provide cover, containment, and protection from vandalism for all chemicals, liquid products, petroleum products, and other materials that have the potential to pose a threat to human health or the environment. On-site fueling tanks must include secondary containment. Secondary containment means placing tanks or containers within an impervious structure capable of containing 110% of the volume contained in the largest tank within the containment structure. Double-walled tanks do not require additional secondary containment. d. Conduct maintenance, fueling and repair of heavy equipment and vehicles using spill prevention and control measures. Clean contaminated surfaces immediately following any spill incident. e. Discharge wheel wash or tire bath wastewater to a separate on-site treatment system that prevents discharge to surface water, such as closed-loop recirculation or upland application, or to the sanitary sewer, with local sewer district approval. f. Apply fertilizers and pesticides in a manner and at application rates that will not result in loss of chemical to stormwater runoff. Follow manufacturers’ label requirements for application rates and procedures. g. Use BMPs to prevent contamination of stormwater runoff by pH modifying sources. The sources for this contamination include, but are not limited to: bulk cement, cement kiln dust, fly ash, new concrete washing and curing waters, waste streams generated from concrete grinding and sawing, exposed aggregate processes, dewatering concrete vaults, concrete pumping and mixer washout waters. h. Adjust the pH of stormwater if necessary to prevent violations of water quality standards. i. Assure that washout of concrete trucks is performed off-site or in designated concrete washout areas only. Do not wash out concrete trucks onto the ground, or into storm drains, open ditches, streets, or streams. Do not dump excess concrete on-site, except in designated concrete washout areas. Concrete spillage or concrete discharge to surface waters of the State is prohibited. j. Obtain written approval from Ecology before using chemical treatment other than CO2 or dry ice to adjust pH. 28 Hundred Unit Lot Subdivision Technical Information Report 11/15/19 Page 21 10. Control Dewatering Describe the BMPs to be used to manage turbid water resulting from any dewatering of foundations, excavations, etc. Pumping any water offsite is not allowed without prior approval from the City of Issaquah. Dewatering is not anticipated at this site. 11. Maintain BMPs a. Maintain and repair all temporary and permanent erosion and sediment control BMPs as needed to assure continued performance of their intended function in accordance with BMP specifications. b. Remove all temporary erosion and sediment control BMPs within 30 days after achieving final site stabilization or after the temporary BMPs are no longer needed. All disturbed areas shall be stabilized with landscaping or some other method prior to final construction approval. 12. Manage the Project Maintain an updated SWPPP IX. BOND QUANTITIES, FACILITY SUMMARIES, & DECLARATION OF COVENANT See Appendix C for Bond Quantities Worksheet, and Appendix F for a Declaration of Covenant. X. OPERATIONS AND MAINTENANCE MANUAL See Appendix D for an O&M Manual prepared for the project. 28 Hundred Unit Lot Subdivision Technical Information Report 11/15/19 Appendix A WWHM2012 Output WWHM2012 PROJECT REPORT 16663 - Tang 11/13/2019 3:11:45 PM Page 2 General Model Information Project Name:16663 - Tang Site Name: Site Address: City: Report Date:11/13/2019 Gage:Seatac Data Start:1948/10/01 Data End:2009/09/30 Timestep:15 Minute Precip Scale:1.000 Version Date:2019/09/13 Version:4.2.17 POC Thresholds Low Flow Threshold for POC1:50 Percent of the 2 Year High Flow Threshold for POC1:50 Year 16663 - Tang 11/13/2019 3:11:45 PM Page 3 Landuse Basin Data Predeveloped Land Use Basin 1 Bypass:No GroundWater:No Pervious Land Use acre C, Lawn, Flat 0.057 Pervious Total 0.057 Impervious Land Use acre ROADS FLAT 0.07 ROOF TOPS FLAT 0.11 SIDEWALKS FLAT 0.016 Impervious Total 0.196 Basin Total 0.253 Element Flows To: Surface Interflow Groundwater 16663 - Tang 11/13/2019 3:11:45 PM Page 4 Mitigated Land Use Basin 1 Bypass:No GroundWater:No Pervious Land Use acre C, Pasture, Flat 0.253 Pervious Total 0.253 Impervious Land Use acre Impervious Total 0 Basin Total 0.253 Element Flows To: Surface Interflow Groundwater 16663 - Tang 11/13/2019 3:11:45 PM Page 5 Routing Elements Predeveloped Routing 16663 - Tang 11/13/2019 3:11:45 PM Page 6 Mitigated Routing 16663 - Tang 11/13/2019 3:11:45 PM Page 7 Analysis Results POC 1 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area:0.057 Total Impervious Area:0.196 Mitigated Landuse Totals for POC #1 Total Pervious Area:0.253 Total Impervious Area:0 Flow Frequency Method:Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.078367 5 year 0.100307 10 year 0.115366 25 year 0.135057 50 year 0.150235 100 year 0.165866 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.008867 5 year 0.015224 10 year 0.020317 25 year 0.027765 50 year 0.034057 100 year 0.040996 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 0.105 0.012 1950 0.106 0.014 1951 0.065 0.018 1952 0.054 0.006 1953 0.059 0.005 1954 0.064 0.007 1955 0.072 0.011 1956 0.071 0.009 1957 0.082 0.009 1958 0.064 0.008 16663 - Tang 11/13/2019 3:12:16 PM Page 8 1959 0.063 0.007 1960 0.068 0.014 1961 0.070 0.007 1962 0.058 0.005 1963 0.067 0.007 1964 0.063 0.009 1965 0.085 0.007 1966 0.055 0.006 1967 0.095 0.015 1968 0.109 0.008 1969 0.078 0.008 1970 0.073 0.006 1971 0.087 0.008 1972 0.095 0.014 1973 0.052 0.006 1974 0.081 0.008 1975 0.087 0.011 1976 0.063 0.008 1977 0.064 0.002 1978 0.078 0.006 1979 0.107 0.004 1980 0.107 0.022 1981 0.081 0.006 1982 0.117 0.015 1983 0.092 0.009 1984 0.059 0.006 1985 0.081 0.003 1986 0.069 0.014 1987 0.106 0.013 1988 0.063 0.006 1989 0.079 0.004 1990 0.155 0.044 1991 0.120 0.018 1992 0.059 0.007 1993 0.050 0.007 1994 0.053 0.003 1995 0.072 0.009 1996 0.081 0.023 1997 0.077 0.017 1998 0.074 0.007 1999 0.160 0.028 2000 0.078 0.006 2001 0.082 0.002 2002 0.103 0.010 2003 0.080 0.014 2004 0.149 0.014 2005 0.068 0.010 2006 0.061 0.010 2007 0.140 0.036 2008 0.118 0.031 2009 0.097 0.014 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.1597 0.0443 2 0.1546 0.0361 3 0.1486 0.0310 16663 - Tang 11/13/2019 3:12:16 PM Page 9 4 0.1398 0.0276 5 0.1198 0.0226 6 0.1176 0.0223 7 0.1172 0.0179 8 0.1087 0.0176 9 0.1075 0.0167 10 0.1069 0.0150 11 0.1060 0.0145 12 0.1059 0.0144 13 0.1051 0.0143 14 0.1033 0.0142 15 0.0967 0.0141 16 0.0955 0.0138 17 0.0948 0.0137 18 0.0917 0.0137 19 0.0873 0.0133 20 0.0873 0.0121 21 0.0854 0.0112 22 0.0824 0.0106 23 0.0822 0.0100 24 0.0815 0.0097 25 0.0814 0.0096 26 0.0808 0.0094 27 0.0806 0.0093 28 0.0802 0.0089 29 0.0791 0.0089 30 0.0782 0.0085 31 0.0780 0.0084 32 0.0777 0.0083 33 0.0771 0.0079 34 0.0744 0.0079 35 0.0732 0.0077 36 0.0718 0.0077 37 0.0715 0.0072 38 0.0706 0.0072 39 0.0697 0.0070 40 0.0691 0.0069 41 0.0681 0.0068 42 0.0676 0.0068 43 0.0675 0.0067 44 0.0654 0.0065 45 0.0641 0.0065 46 0.0638 0.0064 47 0.0637 0.0062 48 0.0635 0.0061 49 0.0633 0.0059 50 0.0632 0.0058 51 0.0625 0.0057 52 0.0610 0.0056 53 0.0592 0.0056 54 0.0588 0.0050 55 0.0587 0.0046 56 0.0585 0.0039 57 0.0550 0.0036 58 0.0544 0.0034 59 0.0528 0.0028 60 0.0519 0.0022 61 0.0497 0.0017 16663 - Tang 11/13/2019 3:12:16 PM Page 10 16663 - Tang 11/13/2019 3:12:16 PM Page 11 Duration Flows The Facility PASSED Flow(cfs)Predev Mit Percentage Pass/Fail 0.0392 1698 1 0 Pass 0.0403 1557 1 0 Pass 0.0414 1410 1 0 Pass 0.0425 1271 1 0 Pass 0.0437 1134 1 0 Pass 0.0448 1039 0 0 Pass 0.0459 952 0 0 Pass 0.0470 873 0 0 Pass 0.0482 795 0 0 Pass 0.0493 732 0 0 Pass 0.0504 670 0 0 Pass 0.0515 621 0 0 Pass 0.0526 573 0 0 Pass 0.0538 535 0 0 Pass 0.0549 498 0 0 Pass 0.0560 454 0 0 Pass 0.0571 414 0 0 Pass 0.0583 387 0 0 Pass 0.0594 362 0 0 Pass 0.0605 344 0 0 Pass 0.0616 319 0 0 Pass 0.0627 295 0 0 Pass 0.0639 273 0 0 Pass 0.0650 254 0 0 Pass 0.0661 237 0 0 Pass 0.0672 225 0 0 Pass 0.0683 207 0 0 Pass 0.0695 197 0 0 Pass 0.0706 185 0 0 Pass 0.0717 170 0 0 Pass 0.0728 158 0 0 Pass 0.0740 147 0 0 Pass 0.0751 140 0 0 Pass 0.0762 130 0 0 Pass 0.0773 125 0 0 Pass 0.0784 114 0 0 Pass 0.0796 109 0 0 Pass 0.0807 104 0 0 Pass 0.0818 95 0 0 Pass 0.0829 88 0 0 Pass 0.0841 82 0 0 Pass 0.0852 81 0 0 Pass 0.0863 79 0 0 Pass 0.0874 76 0 0 Pass 0.0885 73 0 0 Pass 0.0897 68 0 0 Pass 0.0908 65 0 0 Pass 0.0919 62 0 0 Pass 0.0930 57 0 0 Pass 0.0941 55 0 0 Pass 0.0953 52 0 0 Pass 0.0964 48 0 0 Pass 0.0975 47 0 0 Pass 16663 - Tang 11/13/2019 3:12:16 PM Page 12 0.0986 45 0 0 Pass 0.0998 41 0 0 Pass 0.1009 40 0 0 Pass 0.1020 39 0 0 Pass 0.1031 33 0 0 Pass 0.1042 31 0 0 Pass 0.1054 29 0 0 Pass 0.1065 27 0 0 Pass 0.1076 22 0 0 Pass 0.1087 22 0 0 Pass 0.1099 20 0 0 Pass 0.1110 18 0 0 Pass 0.1121 16 0 0 Pass 0.1132 16 0 0 Pass 0.1143 15 0 0 Pass 0.1155 14 0 0 Pass 0.1166 13 0 0 Pass 0.1177 10 0 0 Pass 0.1188 9 0 0 Pass 0.1199 8 0 0 Pass 0.1211 8 0 0 Pass 0.1222 8 0 0 Pass 0.1233 8 0 0 Pass 0.1244 8 0 0 Pass 0.1256 8 0 0 Pass 0.1267 8 0 0 Pass 0.1278 8 0 0 Pass 0.1289 8 0 0 Pass 0.1300 8 0 0 Pass 0.1312 8 0 0 Pass 0.1323 7 0 0 Pass 0.1334 7 0 0 Pass 0.1345 7 0 0 Pass 0.1357 7 0 0 Pass 0.1368 7 0 0 Pass 0.1379 6 0 0 Pass 0.1390 6 0 0 Pass 0.1401 5 0 0 Pass 0.1413 5 0 0 Pass 0.1424 4 0 0 Pass 0.1435 4 0 0 Pass 0.1446 4 0 0 Pass 0.1457 4 0 0 Pass 0.1469 3 0 0 Pass 0.1480 3 0 0 Pass 0.1491 2 0 0 Pass 0.1502 2 0 0 Pass 16663 - Tang 11/13/2019 3:12:16 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. 16663 - Tang 11/13/2019 3:12:16 PM Page 14 LID Report 16663 - Tang 11/13/2019 3:12:25 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. 16663 - Tang 11/13/2019 3:12:25 PM Page 16 Appendix Predeveloped Schematic 16663 - Tang 11/13/2019 3:12:25 PM Page 17 Mitigated Schematic 16663 - Tang 11/13/2019 3:12:26 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 16663 - Tang.wdm MESSU 25 Pre16663 - Tang.MES 27 Pre16663 - Tang.L61 28 Pre16663 - Tang.L62 30 POC16663 - Tang1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 16 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 Basin 1 MAX 1 2 30 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 501 1 1 END TIMESERIES END COPY GENER OPCODE # # OPCD *** END OPCODE PARM # # K *** END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 16 C, Lawn, Flat 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 16 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 ********* 16663 - Tang 11/13/2019 3:12:26 PM Page 19 16 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 *** 16 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 16 0 4.5 0.03 400 0.05 0.5 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 16 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 16 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 16 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 0 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 16663 - Tang 11/13/2019 3:12:26 PM Page 20 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# *** Basin 1*** PERLND 16 0.057 COPY 501 12 PERLND 16 0.057 COPY 501 13 IMPLND 1 0.07 COPY 501 15 IMPLND 4 0.11 COPY 501 15 IMPLND 8 0.016 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 *** 16663 - Tang 11/13/2019 3:12:26 PM Page 21 # - # 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 16663 - Tang 11/13/2019 3:12:26 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 16663 - Tang.wdm MESSU 25 Mit16663 - Tang.MES 27 Mit16663 - Tang.L61 28 Mit16663 - Tang.L62 30 POC16663 - Tang1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 13 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Basin 1 MAX 1 2 30 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 501 1 1 END TIMESERIES END COPY GENER OPCODE # # OPCD *** END OPCODE PARM # # K *** END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 13 C, Pasture, Flat 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 13 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 ********* 13 0 0 4 0 0 0 0 0 0 0 0 0 1 9 END PRINT-INFO 16663 - Tang 11/13/2019 3:12:26 PM Page 23 PWAT-PARM1 <PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 13 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 13 0 4.5 0.06 400 0.05 0.5 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 13 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 13 0.15 0.4 0.3 6 0.5 0.4 END PWAT-PARM4 PWAT-STATE1 <PLS > *** Initial conditions at start of simulation ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 *** # - # *** CEPS SURS UZS IFWS LZS AGWS GWVS 13 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 16663 - Tang 11/13/2019 3:12:26 PM Page 24 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Basin 1*** PERLND 13 0.253 COPY 501 12 PERLND 13 0.253 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 16663 - Tang 11/13/2019 3:12:26 PM Page 25 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 END MASS-LINK END RUN 16663 - Tang 11/13/2019 3:12:26 PM Page 26 Predeveloped HSPF Message File 16663 - Tang 11/13/2019 3:12:26 PM Page 27 Mitigated HSPF Message File 16663 - Tang 11/13/2019 3:12:26 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. 2005-2019; 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 16663 - Tang Water Quality 11/13/2019 1:34:26 PM Page 2 General Model Information Project Name:16663 - Tang Water Quality Site Name: Site Address: City: Report Date:11/13/2019 Gage:Seatac Data Start:1948/10/01 Data End:2009/09/30 Timestep:15 Minute Precip Scale:1.000 Version Date:2019/09/13 Version:4.2.17 POC Thresholds Low Flow Threshold for POC1:50 Percent of the 2 Year High Flow Threshold for POC1:50 Year 16663 - Tang Water Quality 11/13/2019 1:34:26 PM Page 3 Landuse Basin Data Predeveloped Land Use Basin 1 Bypass:No GroundWater:No Pervious Land Use acre C, Lawn, Flat 0.07 Pervious Total 0.07 Impervious Land Use acre ROADS FLAT 0.07 Impervious Total 0.07 Basin Total 0.14 Element Flows To: Surface Interflow Groundwater 16663 - Tang Water Quality 11/13/2019 1:34:26 PM Page 4 Mitigated Land Use Basin 1 Bypass:No GroundWater:No Pervious Land Use acre Pervious Total 0 Impervious Land Use acre ROADS FLAT 0.14 Impervious Total 0.14 Basin Total 0.14 Element Flows To: Surface Interflow Groundwater 16663 - Tang Water Quality 11/13/2019 1:34:26 PM Page 5 Routing Elements Predeveloped Routing 16663 - Tang Water Quality 11/13/2019 1:34:26 PM Page 6 Mitigated Routing 16663 - Tang Water Quality 11/13/2019 1:34:26 PM Page 7 Analysis Results POC 1 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area:0.07 Total Impervious Area:0.07 Mitigated Landuse Totals for POC #1 Total Pervious Area:0 Total Impervious Area:0.14 Flow Frequency Method:Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.031376 5 year 0.041761 10 year 0.049107 25 year 0.058941 50 year 0.06668 100 year 0.074782 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.053377 5 year 0.067421 10 year 0.076964 25 year 0.089341 50 year 0.098815 100 year 0.108518 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 0.045 0.069 1950 0.042 0.075 1951 0.028 0.043 1952 0.020 0.038 1953 0.022 0.041 1954 0.025 0.043 1955 0.028 0.049 1956 0.028 0.048 1957 0.034 0.055 1958 0.025 0.044 16663 - Tang Water Quality 11/13/2019 1:34:56 PM Page 8 1959 0.023 0.045 1960 0.029 0.044 1961 0.028 0.047 1962 0.022 0.041 1963 0.027 0.045 1964 0.025 0.045 1965 0.036 0.057 1966 0.021 0.038 1967 0.042 0.065 1968 0.043 0.074 1969 0.033 0.052 1970 0.029 0.050 1971 0.035 0.059 1972 0.042 0.061 1973 0.019 0.037 1974 0.033 0.054 1975 0.035 0.062 1976 0.026 0.042 1977 0.024 0.045 1978 0.030 0.056 1979 0.039 0.076 1980 0.048 0.068 1981 0.032 0.056 1982 0.050 0.079 1983 0.035 0.064 1984 0.023 0.040 1985 0.032 0.056 1986 0.028 0.048 1987 0.039 0.074 1988 0.023 0.045 1989 0.028 0.056 1990 0.074 0.095 1991 0.054 0.076 1992 0.023 0.040 1993 0.019 0.035 1994 0.019 0.038 1995 0.028 0.049 1996 0.035 0.053 1997 0.032 0.051 1998 0.028 0.052 1999 0.067 0.106 2000 0.031 0.053 2001 0.030 0.058 2002 0.044 0.068 2003 0.034 0.053 2004 0.062 0.099 2005 0.028 0.045 2006 0.026 0.040 2007 0.066 0.093 2008 0.053 0.075 2009 0.035 0.069 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.0739 0.1060 2 0.0669 0.0992 3 0.0665 0.0951 16663 - Tang Water Quality 11/13/2019 1:34:56 PM Page 9 4 0.0616 0.0927 5 0.0544 0.0787 6 0.0534 0.0760 7 0.0498 0.0760 8 0.0481 0.0747 9 0.0447 0.0747 10 0.0443 0.0744 11 0.0431 0.0741 12 0.0420 0.0691 13 0.0418 0.0690 14 0.0416 0.0682 15 0.0395 0.0676 16 0.0393 0.0652 17 0.0359 0.0640 18 0.0349 0.0623 19 0.0348 0.0612 20 0.0347 0.0593 21 0.0347 0.0580 22 0.0345 0.0566 23 0.0345 0.0565 24 0.0342 0.0558 25 0.0333 0.0557 26 0.0325 0.0555 27 0.0324 0.0549 28 0.0322 0.0541 29 0.0319 0.0528 30 0.0315 0.0526 31 0.0303 0.0525 32 0.0302 0.0518 33 0.0292 0.0515 34 0.0290 0.0511 35 0.0284 0.0497 36 0.0284 0.0495 37 0.0283 0.0492 38 0.0282 0.0484 39 0.0279 0.0482 40 0.0279 0.0469 41 0.0278 0.0454 42 0.0277 0.0454 43 0.0277 0.0453 44 0.0275 0.0452 45 0.0260 0.0452 46 0.0257 0.0445 47 0.0255 0.0444 48 0.0252 0.0443 49 0.0246 0.0434 50 0.0243 0.0432 51 0.0235 0.0419 52 0.0233 0.0415 53 0.0227 0.0409 54 0.0226 0.0404 55 0.0219 0.0400 56 0.0216 0.0400 57 0.0214 0.0384 58 0.0200 0.0378 59 0.0188 0.0377 60 0.0188 0.0371 61 0.0188 0.0346 16663 - Tang Water Quality 11/13/2019 1:34:56 PM Page 10 16663 - Tang Water Quality 11/13/2019 1:34:56 PM Page 11 Duration Flows Flow(cfs)Predev Mit Percentage Pass/Fail 0.0157 1561 8945 573 Fail 0.0162 1399 8282 591 Fail 0.0167 1245 7578 608 Fail 0.0172 1122 6966 620 Fail 0.0177 1008 6425 637 Fail 0.0183 906 5942 655 Fail 0.0188 819 5518 673 Fail 0.0193 738 5086 689 Fail 0.0198 676 4688 693 Fail 0.0203 614 4338 706 Fail 0.0208 566 4021 710 Fail 0.0214 515 3730 724 Fail 0.0219 473 3471 733 Fail 0.0224 440 3245 737 Fail 0.0229 405 3039 750 Fail 0.0234 373 2819 755 Fail 0.0239 350 2612 746 Fail 0.0244 327 2449 748 Fail 0.0250 306 2297 750 Fail 0.0255 285 2138 750 Fail 0.0260 263 1989 756 Fail 0.0265 248 1849 745 Fail 0.0270 227 1727 760 Fail 0.0275 211 1616 765 Fail 0.0280 193 1495 774 Fail 0.0286 177 1393 787 Fail 0.0291 163 1312 804 Fail 0.0296 152 1228 807 Fail 0.0301 143 1143 799 Fail 0.0306 135 1060 785 Fail 0.0311 129 995 771 Fail 0.0317 120 941 784 Fail 0.0322 112 882 787 Fail 0.0327 107 842 786 Fail 0.0332 105 796 758 Fail 0.0337 100 746 746 Fail 0.0342 94 709 754 Fail 0.0347 85 663 780 Fail 0.0353 80 621 776 Fail 0.0358 76 595 782 Fail 0.0363 73 562 769 Fail 0.0368 71 539 759 Fail 0.0373 66 510 772 Fail 0.0378 63 475 753 Fail 0.0384 62 450 725 Fail 0.0389 59 425 720 Fail 0.0394 53 408 769 Fail 0.0399 52 386 742 Fail 0.0404 50 367 734 Fail 0.0409 45 351 780 Fail 0.0414 45 331 735 Fail 0.0420 41 317 773 Fail 0.0425 35 302 862 Fail 0.0430 33 287 869 Fail 16663 - Tang Water Quality 11/13/2019 1:34:56 PM Page 12 0.0435 32 270 843 Fail 0.0440 32 260 812 Fail 0.0445 29 247 851 Fail 0.0450 27 235 870 Fail 0.0456 26 223 857 Fail 0.0461 24 213 887 Fail 0.0466 23 204 886 Fail 0.0471 23 193 839 Fail 0.0476 22 181 822 Fail 0.0481 19 178 936 Fail 0.0487 19 171 900 Fail 0.0492 18 165 916 Fail 0.0497 17 152 894 Fail 0.0502 15 145 966 Fail 0.0507 15 139 926 Fail 0.0512 15 136 906 Fail 0.0517 15 128 853 Fail 0.0523 14 122 871 Fail 0.0528 11 114 1036 Fail 0.0533 11 110 1000 Fail 0.0538 9 107 1188 Fail 0.0543 9 105 1166 Fail 0.0548 8 103 1287 Fail 0.0553 7 98 1400 Fail 0.0559 7 92 1314 Fail 0.0564 7 89 1271 Fail 0.0569 7 84 1200 Fail 0.0574 7 83 1185 Fail 0.0579 7 74 1057 Fail 0.0584 7 72 1028 Fail 0.0590 6 68 1133 Fail 0.0595 5 66 1320 Fail 0.0600 5 65 1300 Fail 0.0605 5 63 1260 Fail 0.0610 5 62 1240 Fail 0.0615 5 59 1180 Fail 0.0620 3 57 1900 Fail 0.0626 3 54 1800 Fail 0.0631 3 54 1800 Fail 0.0636 3 53 1766 Fail 0.0641 3 51 1700 Fail 0.0646 3 50 1666 Fail 0.0651 3 48 1600 Fail 0.0656 3 45 1500 Fail 0.0662 3 44 1466 Fail 0.0667 2 42 2100 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. 16663 - Tang Water Quality 11/13/2019 1:34:56 PM Page 13 Water Quality Water Quality BMP Flow and Volume for POC #1 On-line facility volume:0.0172 acre-feet On-line facility target flow:0.0227 cfs. Adjusted for 15 min:0.0227 cfs. Off-line facility target flow:0.0128 cfs. Adjusted for 15 min:0.0128 cfs. 16663 - Tang Water Quality 11/13/2019 1:34:56 PM Page 14 LID Report 16663 - Tang Water Quality 11/13/2019 1:35:05 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. 16663 - Tang Water Quality 11/13/2019 1:35:05 PM Page 16 Appendix Predeveloped Schematic 16663 - Tang Water Quality 11/13/2019 1:35:05 PM Page 17 Mitigated Schematic 16663 - Tang Water Quality 11/13/2019 1:35:06 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 16663 - Tang Water Quality.wdm MESSU 25 Pre16663 - Tang Water Quality.MES 27 Pre16663 - Tang Water Quality.L61 28 Pre16663 - Tang Water Quality.L62 30 POC16663 - Tang Water Quality1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 16 IMPLND 1 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Basin 1 MAX 1 2 30 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 501 1 1 END TIMESERIES END COPY GENER OPCODE # # OPCD *** END OPCODE PARM # # K *** END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 16 C, Lawn, Flat 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 16 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 ********* 16 0 0 4 0 0 0 0 0 0 0 0 0 1 9 END PRINT-INFO 16663 - Tang Water Quality 11/13/2019 1:35:06 PM Page 19 PWAT-PARM1 <PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 16 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 16 0 4.5 0.03 400 0.05 0.5 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 16 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 16 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 16 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 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 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 16663 - Tang Water Quality 11/13/2019 1:35:06 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# *** Basin 1*** PERLND 16 0.07 COPY 501 12 PERLND 16 0.07 COPY 501 13 IMPLND 1 0.07 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 SPEC-ACTIONS 16663 - Tang Water Quality 11/13/2019 1:35:06 PM Page 21 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 16663 - Tang Water Quality 11/13/2019 1:35:06 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 16663 - Tang Water Quality.wdm MESSU 25 Mit16663 - Tang Water Quality.MES 27 Mit16663 - Tang Water Quality.L61 28 Mit16663 - Tang Water Quality.L62 30 POC16663 - Tang Water Quality1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 IMPLND 1 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Basin 1 MAX 1 2 30 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 501 1 1 END TIMESERIES END COPY GENER OPCODE # # OPCD *** END OPCODE PARM # # K *** END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* END PRINT-INFO PWAT-PARM1 <PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 16663 - Tang Water Quality 11/13/2019 1:35:06 PM Page 23 END PWAT-PARM1 PWAT-PARM2 <PLS > PWATER input info: Part 2 *** # - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 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 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 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 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 END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS 1 0 0 END IWAT-STATE1 END IMPLND 16663 - Tang Water Quality 11/13/2019 1:35:06 PM Page 24 SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Basin 1*** IMPLND 1 0.14 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 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 16663 - Tang Water Quality 11/13/2019 1:35:06 PM Page 25 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 15 IMPLND IWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 15 END MASS-LINK END RUN 16663 - Tang Water Quality 11/13/2019 1:35:06 PM Page 26 Predeveloped HSPF Message File 16663 - Tang Water Quality 11/13/2019 1:35:06 PM Page 27 Mitigated HSPF Message File 16663 - Tang Water Quality 11/13/2019 1:35:06 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. 2005-2019; 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 28 Hundred Unit Lot Subdivision Technical Information Report 11/15/19 Appendix B Infiltration Evaluation by Earth Solution NW, LLC dated August 26, 2014 28 Hundred Unit Lot Subdivision Technical Information Report 11/15/19 Appendix C Site Improvement Bond Quantity Worksheet 28 Hundred Unit Lot Subdivision Technical Information Report 11/15/19 Appendix D Operations and Maintenance Manual 28 Hundred Unit Lot Subdivision Technical Information Report 11/15/19 Appendix E Biopod Submittal Package 28 Hundred Unit Lot Subdivision Technical Information Report 11/15/19 Appendix F Declaration of Covenant Yves, Tang 722780-1690, 722780-1695 x C19004381 C19004381 TED-40-4082 x Lots 25 and 26, block 46, corrected plat of Renton Highlands no. 2, and addition to the city of Renton, according to the plat thereof, recorded in volume 57 of plats, pages 92 through 98, inclusive, in King County, Washington November 19 Yves, Tang 28,692 / 30,063 (SF)C19004381 2800 & 2801 NE 12th Street, Renton, WA 7227801690, 7227801695 30,063 (SF)17,663 (SF) Infiltration Trenches, Biopod Filtration Device MAINTENANCE INSTRUCTIONS FOR FULL INFILTRATION Your property contains an on-site BMP (best management practice) called “full infiltration,” which was installed to mitigate the stormwater quantity and quality impacts of some or all of the impervious surfaces on your property. Full infiltration is a method of soaking runoff from impervious area (such as paved areas and roofs) into the ground. If properly installed and maintained per Appendix A of the City of Renton’s Surface Water Design Manual, full infiltration can manage runoff so that a majority of precipitation events are absorbed. Infiltration devices, such as gravel filled trenches, drywells, and ground surface depressions, facilitate this process by putting runoff in direct contact with the soil and holding the runoff long enough to soak most of it into the ground. To be successful, the soil condition around the infiltration device must be reliably able to soak water into the ground for a reasonable number of years. Infiltration Devices The infiltration devices used on your property include the following as indicated on the site plan (CHECK THE BOX(ES) THAT APPLY): gravel filled trenches, drywells, ground surface depressions. MAINTENANCE RESTRICTIONS The size, placement, and composition of these devices as depicted by the site plan and design details must be maintained and may not be changed without written approval from the City of Renton or through a future development permit from the City of Renton. INSPECTION FREQUENCY AND MAINTENANCE GUIDELINES Infiltration devices must be inspected annually and after major storm events to identify and repair any physical defects. Maintenance and operation of the system should focus on ensuring the system’s viability by preventing sediment-laden flows from entering the device. Excessive sedimentation will result in a plugged or non-functioning facility. If the infiltration device has a catch basin, sediment accumulation must be removed on a yearly basis or more frequently if necessary. Prolonged ponding around or atop a device may indicate a plugged facility. If the device becomes plugged, it must be replaced. Keeping the areas that drain to infiltration devices well swept and clean will enhance the longevity of these devices. For roofs, frequent cleaning of gutters will reduce sediment loads to these devices. x RECORDING REQUIREMENT These full infiltration on-site BMP maintenance and operation instructions must be recorded as an attachment to the required declaration of covenant and grant of easement per Requirement 3 of Section C.1.3.4 of the City of Renton Surface Water Design Manual. The intent of these instructions is to explain to future property owners, the purpose of the BMP and how it must be maintained and operated. These instructions are intended to be a minimum; the City of Renton may require additional instructions based on site-specific conditions. See the City of Renton’s Surface Water Design Manual website for additional information and updates. TYPICAL FULL INFILTRATION APPLICATIONS 6" 24" 12" 24" WASHED ROCK 1 1 2"- 3 4" LEVEL INFILTRATION TRENCH SECTION A NTS PLAN VIEW NTS SECTION VIEW NTS VARIES A A 6" 6" 4" RIGID OR 6" FLEXIBLE PERFORATED PIPE CB SUMP w/SOLID LID ROOF DRAIN 4" RIGID OR 6" FLEXIBLE PERFORATED PIPE OVERFLOW SPLASH BLOCK ROOF DRAIN CB SUMP w/SOLID LID 12" FINE MESH SCREEN SETBACK FROM BUILDING 5' MIN. 1' MIN. 1' MIN. FILTER FABRIC COMPACTED BACKFILL 4" RIGID OR 6" FLEXIBLE PERFORATED PIPE 11 2" - 3 4" WASHED ROCK MIN. 1' ABOVE SEASONAL HIGH GROUNDWATER TABLE, SEE SECTION C.2.2.2 TRENCH SETBACK FROM BUILDING AS REQUIRED, 15' MIN. D R I V E W A Y X-SECTION NTS 2' MIN. FILTER STRIP SEE SECTIONS 6.3.4 & 6.3.5 18" MIN. 6" MIN. 3/4" TO 1-1/2" WASHED DRAIN ROCK GRASS OVERFLOW NOTE: SEE C.2.2.3 FOR TRENCH LENGTHS, TRENCH SPACING AND SITE LIMITATIONS MIN. 1' ABOVE SEASONAL HIGH GROUNDWATER TABLE, SEE SECTION C.2.2.2 X-SECTION NTS GRASS 2' MIN. 18" MIN. 6" MIN. 3/4" TO 1-1/2" WASHED DRAIN ROCK OVERFLOW 15' MIN. AS REQUIRED, SEE C.2.2.3 FROM ROOF N S T T SMIN. 1' ABOVE SEASONAL HIGH GROUNDWATER TABLE, SEE SECTION C.2.2.2 HOUSE FLOW 48 INCH DIAMETER HOLE FILLED WITH 1 1 2" - 3" WASHED DRAIN ROCK SECTION NTS MARK CENTER OF HOLE WITH 1" CAPPED PVC OR OTHER MEANS FLUSH WITH SURFACE ROOF DOWNSPOUT OVERFLOW SPLASH BLOCK TOPSOIL FINE MESH SCREEN MIN. 4" DIA. PVC PIPE SIDES OF HOLE LINED WITH FILTER FABRIC CATCH BASIN (YARD DRAIN) 15' MIN. AS REQUIRED, SEE SECTION C.2.2.3 VARIES 1' MIN. MIN. 1' ABOVE SEASONAL HIGH GROUNDWATER TABLE, SEE SECTION C.2.2.2 5' MIN. SETBACK FROM BUILDING FLOW PLAN VIEW NTS HOUSE ROOF DOWNSPOUT ROOF DOWNSPOUT CATCH BASIN (YARD DRAIN) 48 INCH DIAMETER HOLE FILLED WITH 1 1 2" - 3" WASHED DRAIN ROCK Form Revised 12/12/06 1 RECORDING REQUESTED BY AND WHEN RECORDED MAIL TO: DECLARATION OF COVENANT PROHIBITING USE OF LEACHABLE METALS Grantor: _ Grantee: City of Renton Legal Description: _________________________________________________________________________________ _________________________________________________________________________________ Additional Legal(s) on: Assessor's Tax Parcel ID#: IN CONSIDERATION of the approved City of Renton ________________________ permit for application file No. relating to real property legally described above, the undersigned as Grantor(s), declares(declare) that the above described property is hereby established as having a prohibition on the use of leachable metals on those portions of the property exposed to the weather for the purpose of limiting metals in stormwater flows and is subject to the following restrictions. The Grantor(s) hereby covenants(covenant) and agrees(agree) as follows: no leachable metal surfaces exposed to the weather will be allowed on the property. Leachable metal surfaces means a surface area that consists of or is coated with a non-ferrous metal that is soluble in water. Common leachable metal surfaces include, but are not limited to, galvanized steel roofing, gutters, flashing, Yves, Tang Lots 25 and 26, block 46, corrected plat of Renton Highlands no. 2, 722780-1690, 722780-1695 and addition to the city of Renton, according to the plat thereof, recorded in volume 57 of plats, pages 92 through 98, inclusive, in King County, Washington C19004381 Construction Form Revised 12/12/06 2 downspouts, guardrails, light posts, and copper roofing. City of Renton or its municipal successors shall have a nonexclusive perpetual access easement on the Property in order to ingress and egress over the Property for the sole purposes of inspecting and monitoring that no leachable metal is present on the Property. This easement/restriction is binding upon the Grantor(s), its heirs, successors, and assigns unless or until a new drainage or site plan is reviewed and approved by the City of Renton or its successor. Form Revised 12/12/06 3 IN WITNESS WHEREOF, this Declaration of Covenant is executed this _____ day of ____________________, 20_____. GRANTOR, owner of the Property GRANTOR, owner of the Property STATE OF WASHINGTON ) COUNTY OF KING )ss. On this day personally appeared before me: _____________________________________________, to me known to be the individual(s) described in and who executed the within and foregoing instrument and acknowledged that they signed the same as their free and voluntary act and deed, for the uses and purposes therein stated. Given under my hand and official seal this _____ day of ____________________, 20_____. Printed name Notary Public in and for the State of Washington, residing at My appointment expires November 19 Yves, Tang