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03694 - Technical Information Report
MMMMMM aylor MINNMMM..% . ; Engineering "' Consultants TECHNICAL INFORMATION REPORT for 1500 and 1600 Benson Apartments and Offices Tax Parcel No. 2023059162 Pre-application No. 05-125 Site Address: 15xx Benson Road South Renton, Washington 98055 NFM T4k O OF wAsif < . cv 4'a Q I ' O OW Z i-, ;;,,,,t 3 �, ��,, 29351 C�� • ISTS - .V 1 ` v4''''IONALE.\A� Prepared by: Lorna M. Taylor, P.E. Date: November 20, 2012 Revised: June 6, 2013 TEC Project Number:307-TFC Published for building permit record set: July 31, 2013 485 Rainier Blvd N, Ste#201, P.O. Box 1787 • Issaquah,Washington 98027 • telephone(425)391-1415 • fax(425)391-1551 Technical Information Report 1500 and 1600 Benson Apartments and Offices TABLE OF CONTENTS Section Description Page Number 1. Project Overview 1 2. Conditions and Requirements Summary 1 3. Off-Site Analysis 2 4. Flow Control and Water Quality Facility Analysis 4 and Design 5. Conveyance System Analysis and Design........ 6 6. Special Reports and Studies . 6 7. Other Permits 6 8. ESC Analysis and Design 6 9. Bond Quantities, Facility Summaries, and 9 Declaration of Covenant 10. Operations and Maintenance Manual 9 Appendices Appendix A: Figures: Figure 1. Technical Information Report (TIR) Worksheets Figure 2. Site Location Figure 3. Drainage Basins, Subbasins, & Site Characteristics Figure 4. NRCS Soils Map Appendix B: Off-site Analysis Drainage System Table and Map Appendix C: Analysis and Design: C-1 Flow Control C-2 Runoff Treatment C-3 Conveyance System C-4 Erosion Control Appendix D: Maintenance Requirements for Privately Maintained Drainage Facilities Appendix E: Bond Quantities Worksheets Appendix F: Retention/Detention Facility Summary Sheet and Sketch TEC Technical Information Report 1500 and 1600 Benson Apartments and Offices SECTION 1 PROJECT OVERVIEW This drainage Technical Information Report (TIR) is submitted to the City of Renton in accordance with the City-adopted King County Surface Water Design Manual (KCSWDM) and the City of Renton Amendments thereto (Renton Amendment). Appendix A contains a TIR worksheet for the project (Figure 1), as well as a Site Location Map (Figure 2), a Drainage Basins, Subbasins, and Site Characteristics figure (Figure 3), and a copy of the NRCS Soils map for the vicinity (Figure 4). The project will construct two multistory apartment and office buildings, just east of Benson Road South at South 15th Street. The property totals 1.88 acres. SECTION 2 CONDITIONS AND REQUIREMENTS SUMMARY The following summary describes how this new project will meet the eight "Core Requirements" and the "Special Requirements" that apply: Core Requirements 1. Discharge at the Natural Location: The site currently drains in a dispersed manner to the west/northwest to the Benson Road drainage system. The project proposes to discharge all runoff to the existing Benson Road system. 2. Off-Site Analysis: A Level 1 offsite analysis was conducted for this site as described in Section 3 and Appendix B. 3. Flow Control: The project will increase the 100-year runoff more than 0.1 cfs, and therefore is providing Conservation Flow Control assuming forested pre-developed conditions in two buried detention vaults sized per the KCSWDM. Detention sizing calculations are summarized in Section 4, and KCRTS input and files and other supporting documents are included in Appendix C.1. 4. Conveyance System: The conveyance pipes were analyzed for capacity under the anticipated backwater conditions using King County's Backwater routing program (KCBW). The pipes can safely convey the required 25-year flows with at least 6 inches of freeboard per the City Amendment. 5. Erosion and Sedimentation Control: Runoff from the construction areas will be collected and preliminarily treated in a proprietary "Baker Tank" and discharged by special permit to the sanitary sewer during construction only. The erosion control facilities will also include stabilized construction entrances, silt fencing, interceptor swales and/or dikes, and temporary catch basin protection in accordance with the KCSWDM during construction. The ESC facilities will only be removed once all exposed site surfaces have been stabilized. Other temporary erosion and sedimentation control measures will be installed as needed. 6. Maintenance and Operations: The drainage system should be regularly inspected and maintained as described in Section 10 and Appendix D. 7. Financial Guarantees and Liability: The County's Bond Quantities Worksheet will be provided for the public frontage improvements and drainage elements of the project. 8. Water Quality:The area of new and replaced Pollution Generating Impervious Surfaces (PGIS) totals 22,472 square feet, which is more than the 5,000 square foot threshold for requiring treatment. Treatment of runoff from 17,729 square feet of pavement will be provided by the soil which must meet or be amended to meet the "groundwater 1 TEC Technical Information Report 1500 and 1600 Benson Apartments and Offices protection criteria" stipulated in Exemption 4 of the Exemptions from Core Requirement #8, page 1-61 of the City Amendments. Runoff from the pavement surface that is too steeply sloping to utilize permeable pavement, will be treated in a series of two treatment catch basins, a CDS 2015-4-C hydrodynamic separator upstream for pretreatment sediment removal followed by a 48-Inch Stormfilter Manhole downstream for treatment— both located upstream of the south detention vault. Sizing calculations for the treatment facilities are included in Section 4 and Appendix C.2. Special Requirements 1. Other Adopted Area-Specific Requirements: Not Applicable. 2. Floodplain/Floodway Delineation: Not Applicable. 3. Flood Protection Facilities: Not Applicable. 4. Source Controls: Source controls are required for this multifamily residential and office project, in accordance with the King County Stormwater Pollution Prevention Manual. 5. Oil Control: Not Applicable. SECTION 3 OFF-SITE ANALYSIS The following subsections describe the inspection and evaluation of the site and its surrounding areas particularly the downstream drainage path. Task 1. Study Area Definition and Maps The figure in Appendix B shows the extent of the study area and the local topography. The Site Plan drawing shows more detailed topographic information on the project site. No runoff flows onto the site from the north, south, or west as shown on the Figure in Appendix B. Task 2. Resource Review The City's utility mapping was consulted, as well as King County's iMAP data. Following is a summary of the KCSWDM's recommended resources for review. Adopted Basin Plans - The project site is not within any adopted basin plan area, nor is there a finalized drainage study for the area. Finalized Drainage Studies - No finalized drainage studies were available for projects in the immediate vicinity. Basin Reconnaissance Summary Reports - The project site is not covered by any basin reconnaissance summary reports. Critical Drainage Area Maps - The project site is not within or adjacent to any mapped critical area. Floodplain/floodway (FEMA) Maps - The project site is not located within any FEMA mapped flood plain/floodway. Other Off-Site Analysis Reports in the same sub-basin, if available - The offsite analysis report for the Lodge at Eagle Ridge project immediately to the east was consulted. Sensitive Areas Folio - The project site is mapped with the following critical areas: SAO Erosion Hazard, Areas Susceptible to Groundwater Contamination. Drainage Complaints and Studies - There are no reports of problems in the immediate vicinity of the project. 2 TEC Technical Information Report 1500 and 1600 Benson Apartments and Offices US Department of Agriculture, King County Soils Survey - A copy of the NRCS (SCS) soils map is included in Appendix A, Figure 4. The soils are predominantly Alderwood gravelly sandy loam, 15 to 30 percent slopes. These soils have moderate to high runoff potential. Wetlands Inventory Maps - There are no wetlands systems on the site identified in the King County Wetlands Inventory. Migrating River Studies—There are no rivers on the site. Task 3. Field Inspection A Level 1 off-site inspection was conducted on January 29th, 2007. The site and its surrounds were also inspected and documented as part of field investigations for several nearby properties before that time and since. At the time of the most recent site inspection, the weather was clear and cold. Task 4. Drainage System Descriptions and Problem Descriptions The drainage tributary area extends up to, and for the northern portion of the site, onto the adjacent Lodge at Eagle Ridge property. This runoff must be taken into account in the detention sizing. Elsewhere, the land uphill of the site is served by catch basins and pipes that collect and transport runoff across the project site to Benson Road South. The site itself slopes down, steeply in places, toward the west and the Benson Road South frontage. Benson Road was cut into the hillside and slopes down to the north. There is a piped storm drain conveyance system along Benson Road, with an overflow to Talbot Road South, just north of the project property. There are several existing storm drains crossing the site, as well as other utilities including sanitary sewer, water, electrical service, cable and gas. There is an existing detention pond on the property along Benson Road, near the northern boundary. This detention pond serves the office building directly north of the proposed development and was probably designed and built to older, obsolete detention design standards. The downstream drainage system is shown on the map in Appendix B and The Offsite Analysis Drainage System Table in the same appendix describes each segment of the downstream drainage path. No drainage problems were observed or reported except for historic flooding in the vicinity of Renton Village more than '/4 mile downstream. Task 5. Mitigation of Existing or Potential Problems No existing or potential offsite drainage problems were identified; however, it should be noted that: • Water quantity impacts from the project will be mitigated using permeable pavement BMP's wherever the pavement slopes are less than 5%, together with standard detention in concrete vaults, in accordance with the King County Surface Water Design Manual (KCSWDM). • Water quality impacts from PGIS surfaces will also be mitigated using permeable pavement BMP's wherever the pavement slopes are less than 5%, and using proprietary treatment catch basins upstream of the south detention vault where pavement slopes are steep. 3 TEC Technical Information Report 1500 and 1600 Benson Apartments and Offices SECTION 4 FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN The project proposes 62,736 square feet of new impervious surface on the project site, 22,472 square feet of which is traffic pavement (PGIS), as shown on the first Figures in Appendices C-1 & C-2. Frontage improvements will be limited to curb cuts for access and utility connections. Existing Site Hydrology (Part A) The drainage on the existing site was analyzed for this project with King County's KCRTS routine assuming historic fully forested conditions per the City of Renton Flow Control Applications Map (Renton Amendment Reference 11-A). Data provided in the KCSWDM were used to determine modeling parameters. The figures in Appendix C.1 show the delineation of the areas generating runoff on the existing site. Appendix C.1 also contains the data and output from the hydrologic analyses. The site soils are predominantly classified Alderwood Gravelly Sandy Loam, 15- 30 percent slopes, with two small areas near the two northwest corners classified as Beausite gravelly sandy loam, 15 -30 percent slopes (see Figure 4 in Appendix A). Developed Site Hydrology (Part B) The developed site drainage system will discharge site runoff to the Benson Road South drainage system. The developed site conditions identified for this project and used in the KCRTS modeling are as follows: Developed Site North Detention South Detention Conditions used for Hydrologic Modeling Vault Trib. Area Vault Trib. Area Total (areas in acres areas in acres) Building 0.43 0.46 0.89 Pavement 0.00 0.20 0.20 '/2 Permeable Pavement 0.07 0.14 0.21 Sidewalk <0.01 004 0.04 Impervious Subtotal 0.50 0.74 1.24 1/2 Permeable Pavement 0.06 0.13 0.19 Landscaping 0.36 0.37 0.73 Forest(offsite) 0.21 0.00 0.21 Pervious Subtotal 0.63 0.50 1.13 Total 1.13 1.24 2.37 Permeable pavement BMP's are proposed wherever the pavement is less than 5 percent slope. This represents 17,729 square feet and these areas were modeled in KCRTS as 50% impervious and 50% grass. The driveway entrance area totals 4,351 square feet, and is too steep to use permeable pavement. Performance Standards (Part C) Detention is required because the 100-year flow is predicted by KCRTS to increase more than 0.1 cfs. Detention must meet the Conservation Flow Control Standards established in the KCSWDM, which in this case means Level 2 flow control, assuming historic forested site conditions for peak flow and duration matching. Treatment is required because the PGIS area is increasing more than 5,000 square feet. And, because the project is a multifamily land use, runoff treatment facilities would need to meet Enhanced Basic Water Quality Treatment parameters, except that the project meets the criteria 4 TEC Technical Information Report 1500 and 1600 Benson Apartments and Offices set forth in Exception 4 of the City Amendment, and so must only meet Basic Water Quality Treatment parameters as established in the KCSWDM. This exemption requires that: a) no leachable metals (e.g. galvanized metals) are currently used or proposed to be used in areas of the site exposed to the weather, AND b) a covenant is recorded that prohibits future such use of leachable metals on the site, AND c) less than 50% of the runoff draining to the proposed treatment facility is from any area of the site comprised of one or both of the following land uses: • commercial land use with an expected ADT of 100 or more vehicles per 1,000 square feet of gross building area • commercial land use involved with vehicle repair, maintenance, or sales. Because the Target Impervious Surface Area (62,936 sf) is greater than 65% of the site, BMP's are required to be applied to at least the lesser of 10 percent of the site area (0.1 x 81,918 sf= 8,192 sf) or 20 percent of the target surface area (0.2 x 62,936 sf = 12,587 sf). So, BMP's must be applied to at least 8,192 sf of impervious surface area. Conveyance features must be able to convey the predicted 25-year flows with at least 6-inches of freeboard between the water surface elevation and the structure grate. Flow Control System (Part D) Flow control is being provided in two separate detention vaults which will function completely independently. The following table summarizes the sizing requirements for the two vaults. The full KCRTS input and output data is included in Appendix C.1 Detention Vault North Detention South Detention Total Requirements Vault Vault Required storage volume 10,800 cf 17,600 cf 28,400 cf Effective storage depth 10 ft 10 ft Facility length 54 ft 88 ft 142 ft Facility width 20 ft 20 ft 40 ft Facility area 1,080 sf 1,760 sf 2,840 sf Orifice #1 diameter 0.47" (1/2") 0.47" (1/2") Orifice#2 diameter 0.86" (7/8") 0.70" (11/16") Orifice#2 height 6.00 ft 5.80 ft Water Quality (Part E) The area of new PGIS pavement totals 22,472 square feet, so water quality treatment is required. Treatment of runoff from 17,729 square feet of pavement can be provided by the permeable pavement BMP proposed for that area as long as the soil underlying the permeable pavement meets the "groundwater protection criteria" set forth in the Exceptions from Core Requirement #8 Soil Treatment Exemption 4 (see Section 1.2.8 of the City Amendments). The soil under the permeable pavement will be tested and augmented as necessary so that the first 2 feet of soil beneath the permeable pavement has a cation exchange capacity (tested using EPA Lab Method 9081) greater than 5 and an organic content (measured on a dry weight basis using ASTM D2974) greater than 0.5% AND a) has a measured infiltration rate of less than or equal to 9 inches per hour, except in groundwater protection areas where the measured rate must be less than or equal to 2.4 inches per hour, OR b) the soil must be composed of less than 25% gravel by weight with at least 75% of the soil passing the #4 sieve, and the portion passing the#4 sieve must meet one of the following gradations: 5 TEC Technical Information Report 1500 and 1600 Benson Apartments and Offices • at least 50% must pass the #40 sieve and at least 2% must pass the #100 sieve, OR • at least 25% must pass the #40 sieve and at least 5% must pass the #200 sieve. The remaining 4,351 square feet of pavement surface is too steeply sloping to utilize permeable pavement, and runoff from this area will be treated using a series of two treatment catch basins; a CDS 2015-4-C hydrodynamic separator upstream for pretreatment sediment removal and a 48-Inch Stormfilter Manhole downstream for treatment—both located upstream of the south detention vault. Because the CDS facility isn't on King County's pretreatment list, this configuration requires an adjustment to Core Requirement #6. An adjustment request is submitted under separate cover in accordance with the City Amendment Section 1.4.3. Sizing calculations for the cartridge filter are included in Appendix C-2. The 138 square foot south building dumpster concrete area will naturally drain to the adjacent permeable pavement and thus be treated. Only two small asphalt areas, and the north dumpster concrete area, totaling 392 sf will be unable to be treated due to physical constraints. Treatment of roof runoff is not required. SECTION 5 CONVEYANCE SYSTEM ANALYSIS AND DESIGN Conveyance pipes were analyzed using King County's Standard Step Backwater Analysis routine. The pipes must convey the predicted 25-year flow with at least 6-inches of freeboard. The analyses show that all pipes can convey the predicted 25-year flows and the 100-year flow can also be will be conveyed without flooding. The 100-year flows were also be modeled to be sure that significant flooding will not result under extreme runoff conditions. SECTION 6 SPECIAL REPORTS AND STUDIES A site-specific geotechnical report, dated June 23, 2012 was prepared for this project by GeoTech Consultants, Inc. This report is available under separate cover. SECTION 7 OTHER PERMITS Because the project requires clearing of greater than one acre, this project is required to obtain a Construction Stormwater General Permit from the Washington State Department of Ecology. Stormwater is proposed to be temporarily discharged to the public sanitary sewer during construction and a temporary discharge permit will be required for this. No other permits beyond those required by the City of Renton are anticipated to be required for this project. SECTION 8 CSWPPP ANALYSIS AND DESIGN ESC Analysis and Design (Part A) Proposed ESC facilities are shown on the Construction Stormwater Pollution Prevention Plan (CSWPPP). All of the proposed erosion control measures comply with KCSWDM Appendix D. Because of the sloping nature of the site and the extent of the development proposed, runoff from the proposed construction areas will be collected and treated in a proprietary "Baker Tank" and with permit approval, be discharged to the public sanitary sewer during construction. Other 6 TEC Technical Information Report 1500 and 1600 Benson Apartments and Offices erosion control facilities will include stabilized construction entrances, silt fencing, interceptor swales and/or dikes, and temporary catch basin protection in accordance with the KCSWDM during construction. The ESC facilities will only be removed once all exposed site surfaces have been stabilized. Other temporary erosion and sedimentation control measures will be installed as needed. ESC measures shown on the plans include: 1. Clearing Limits are shown on the plans and will be delineated with Survey Fencing and/or Silt Fencing. 2. Cover Measures are shown on the plans and include Plastic Covering over all soil stockpiles, Temporary and Permanent Seeding. 3. Perimeter Protection will be provided by Silt Fence as shown on the Plans. 4. Traffic Area Stabilization will be provided by Stabilized Construction Entrances as shown on the plans. 5. Sediment Retention will be provided in a Baker Tank located in the paved parking area northwest of the site. If necessary, Baker Tank(s) can be sized for Wet Season Construction using the 10-year runoff predicted for the project. All existing and proposed storm inlets in the vicinity of the project will be fitted with Storm Drain Inlet Protection Catch Basin Inserts. 6. Surface Water Collection will occur in Interceptor Swales or Dikes located along the downhill side of the grading areas. 7. Dewaterinq Control is anticipated for trenches, and foundation excavations, and per the plans, shall be pumped to the Baker Tank. 8. Dust Control will be necessary during dry months and is covered in the ESC notes. 9. Flow Control will be achieved for the ESC portion of this project the Baker Tank storage with controlled discharge. If construction occurs during the wet season, then ESC facilities must be sized in accordance with Wet Season Requirements, the sediment facilities (Baker Tanks) will need to be sized for runoff predicted from the 10-year storm modeled using 15-minute time steps (0.97 cfs). The KCRTS runoff model output and sediment trap sizing calculations are included in Appendix C. All ESC flow control sizing must be coordinated with the selected discharge options, which include the public sanitary sewer or storm drain system SWPPS Plan Design (Part B) Activities that could contribute pollutants to surface and stormwater during construction for this project include clearing and grubbing the site, grading, and soil excavation and storage. Most of the ESC measures identified in the CSWPPP (Part A) above will also address the pollutants likely to be generated by these activities. The Activity Sheets for the Pollution Prevention BMPs identified for this site and relevant BMP Info Sheets are listed below and included in Appendix E. • Activity Sheet A-1 Required BMPs for All commercial Properties • Activity Sheet A-4 Storage of Soil, Sand, and Other Erodible Materials • Activity Sheet A-27 Clearing and Grading of Land for Small Construction Projects 7 TEC Technical Information Report 1500 and 1600 Benson Apartments and Offices • BMP Info Sheet#3 Covering Options: Tarp, Roof, or Awning • BMP Info Sheet #7 Maintenance of Drainage Systems • BMP Info Sheet #10 Catch Basin Insert Since sediment is the primary pollutant of concern for this project, stormwater discharges from the site must be monitored weekly, and more frequently during periods of rainfall. The project may seek permission to discharge construction runoff to the public sanitary sewer in order to reduce the on-site treatment requirements. In the event that construction stormwater is to be discharged to the public storm drain system, then the ESC measure's performance shall be assessed by the project's ESC supervisor as stipulated in KCSWDM Section D.4: 1. IF a turbidity test of surface and storm water discharges leaving the project site is greater than the benchmark value of 25 NTU (nephelometric turbidity units) set by the Washington State Department of Ecology, but less than 250 NTU, the ESC Supervisor shall do all of the following: a) Review the ESC plan for compliance and make appropriate revisions within 7 days of the discharge that exceeded the benchmark of 25 NTU, AND b) Fully implement and maintain appropriate ESC measures as soon as possible but no later than 10 days after the discharge that exceeded the benchmark, AND c) Document ESC implementation and maintenance in the site log book. 2. IF a turbidity test of surface or storm water entering onsite wetlands, streams, or lakes indicates a turbidity level greater than 5 NTU above background when the background turbidity is 50 NTU or less, or 10% above background when the background turbidity is greater than 50 NTU, then corrective actions and/or additional measures beyond those specified in Section 1.2.5.1 shall be implemented as deemed necessary by the County inspector or onsite ESC supervisor. 3. IF discharge turbidity is 250 NTU or greater, the ESC Supervisor shall do all of the following: a) Notify the County by telephone, AND b) Review the ESC plan for compliance and make appropriate revisions within 7 days of the discharge that exceeded the benchmark of 25 NTU, AND c) Fully implement and maintain appropriate ESC measures as soon as possible but no later than 10 days after the discharge that exceeded the benchmark, AND d) Document ESC implementation and maintenance in the site log book. AND e) Continue to sample discharges until turbidity is 25 NTU or lower, or the turbidity is no more than 10% over background turbidity. 4. IF the County determines that the condition of the construction site poses a hazard to adjacent property or may adversely impact drainage facilities or water resources, THEN additional measures beyond those specified in Section 1.2.5.1 may be required by the County. The receiving water for this project is the Black/Duwamish River. Its tributary, Springbrook Creek is listed as a Category 5 polluted water of the state under the State's Clean Water Act Section 303(d) list due to dissolved oxygen content and fecal coliform contamination, not sediments/turbidity. Closer to the Duwamish River, the Black River is also listed due to fecal coliform bacteria. Copies of the Section 303(d) Map and Listings are included at the end of Appendix B. 8 TEC Technical Information Report 1500 and 1600 Benson Apartments and Offices SECTION 9 BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT King County's Bond Quantities Worksheet is included in Appendix E. King County's Facility Summary Sheets and Sketches are included in Appendix F. The City's Declaration of Covenant forms are submitted under separate cover for Inspection and Maintenance of Stormwater Facilities and BMPs and for Prohibiting Use of Leachable Metals. SECTION 10 OPERATIONS AND MAINTENANCE MANUAL The drainage facilities should be maintained as described in Appendix D (part of which was excerpted from the KCSWM Maintenance Requirements for Privately Maintained Drainage Facilities). 9 TEC APPENDIX A FIGURES 1. Technical Information Report (TIR) Worksheets 2. Site Location Map 3. Drainage Basins, Subbasins, & Site Characteristics 4. NRCS Soils Map 1 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 1 PROJECT OWNER AND j Part 2 PROJECT LOCATION AND PROJECT ENGINEER j DESCRIPTION Project Owner ( le I korL y, 4 &rf I4a j,.,jf Project Name 1511 1(0 a ?-Qns�9,�'1 Phone ?Ola ` 56'15 51i ( DDES Permit# " wh 4 CSHZ 4-eo Address Location Township -1.3 Range 5 Project Engineer LD, AA j t V Section 3 u./ 2.0 Company TE.7 t Site Address J5 Xx_ Re/150/1 t S Phone '-(2-Ci 1- 1 9 Part 3 TYPE OF PERMIT APPLICATION Part 4 OTHER REVIEWS AND PERMITS ❑ Landuse Services ❑ DFW HPA ❑ Shoreline Subdivison / Short Subd. / UPDManagement ❑ COE 404 3 Building Services ❑ DOE Dam Safety © Structural /� ommerica / SFR RockeryNault/ Clearing and Grading ❑ FEMA Floodplain ❑ ESA Section 7 CIRight-of-WayUse LI COE Wetlands CI Other LI Other Part 5 PLAN AND REPORT INFORMATION Technical Information Report Site Improvement Plan (Engr. Plans) Type of Drainage Review Ful / Targeted / Type (circle one): ull / Modified / (circle): arge Site Small Site Date(include revision U-20- t2- Date(include revision LI -20 i Z dates): dates): Date of Final: Date of Final: Part 6 ADJUSTMENT APPROVALS Type (circle one): Standard / Complex / Preapplication / Experimental/ Blanket Description: (include conditions in TIR Section 2) Date of Approval: 2009 Surface Water Design Manual 1/9/2009 1 24 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 7 MONITORING REQUIREMENTS Monitoring Required: Ye / No Describe: —; U,,t71,(z.►--,1 t�.u,�r; cons e/ Start Date: Completion Date: Part 8 SITE COMMUNITY AND DRAINAGE BASIN Community Plan : (Lt-) a t (,4pvr Special District Overlays: Drainage Basin: I la c(( 2r v.e✓ , Stormwater Requirements: C�:✓1SC✓�/C-11M ri%SW' CC-ialb j Part 9 ONSITE AND ADJACENT SENSITIVE AREAS I ❑ River/Stream j Steep Slope ❑ Lake ❑ Erosion Hazard ❑ Wetlands ❑ Landslide Hazard ❑ Closed Depression ❑ Coal Mine Hazard ❑ Floodplain ❑ Seismic Hazard ❑ Other ❑ Habitat Protection LI Part 10 SOILS Soil Type Slopes Erosion Potential IgD i5 --307., Be D15 -301 ❑ High Groundwater Table (within 5 feet) ❑ Sole Source Aquifer ❑ Other ❑ Seeps/Springs Additional Sheets Attached (1.-;(vie Chem.612 (Le ri- c,.✓c IAA L vete••SKerArcje.a ve,- 2009 Surface Water Design Manual 1/9/2009 2 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL 3/1D TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Pa IN DRAINAGE DESIGN LIMITATIONS REFERENCE LIMITATION /SITE CONSTRAINT Core 2—Offsite Analysis U Sensitive/Critical Areas U SEPA U Other U ❑ Additional Sheets Attached Part 12 TIR SUMMARY SHEET (provide one TIR Summary Sheet per Threshold Discharge Area) Threshold Discharge Area: (name or description) Sk•lc Core Requirements (all 8 apply) Discharge at Natural Location Number of Natural Discharge Locations: Offsite Analysis Level: ) 2 / 3 dated: .o-t t (;nt l.t<e rA Flow Control Level: 1 /0/ 3 or Exemption Number (incl. facility summary sheet) Small Site BMPs Conveyance System Spill containment located at: Erosion and Sediment Control ESC Site Supervisor: Contact Phone: After Hours Phone: Maintenance and Operation Responsibility: Privat / Public IfPrivate, Maintenance Log Required: Yes /No Financial Guarantees and Provided: (LW/ No Liability IS iAcl 0-C-1-.414 le r Water Quality Type. Bas / Sens. Lake / Enhanced Basicm / Bog (include facility summary sheet) or ExemptionKNo.i‘ Li 1-0 9.nlnrL-nrn_r( 613;c, Landscape Management Plan: Yes /LIVg, Special Requirements (as applicable) Area Specific Drainage Type: CDA/SDO/MDP/ BP/LMP/Shared Fac. /None Requirements Name: Floodplain/Floodway Delineation Type: Major / Minor / Exemption /101 nee 100-year Base Flood Elevation (or range): Datum: Flood Protection Facilities Describe: Source Control Describe landuse: (4- (.444/C _ (comm./industrial landuse) Describe any structural controls: 2009 Surface Water Design Manual 1/9/2009 3 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL D TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Oil Control High-use Site: Yes / No Treatment BMP: Maintenance Agreement: Yes / No with whom? Other Drainage Structures Describe: Part 13 EROSION AND SEDIMENT CONTROL REQUIREMENTS MINIMUM ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION AFTER CONSTRUCTION U Clearing Limits ® Stabilize Exposed Surfaces ❑ Cover Measures ❑ Remove and Restore Temporary ESC Facilities ® Perimeter Protection ® Clean and Remove All Silt and Debris, Ensure Traffic Area Stabilization Operation of Permanent Facilities 41 Sediment Retention U Flag Limits of SAO and open space preservation areas ❑ Surface Water Collection LI Other Dewatering Control 4. Dust Control Flow Control Part 14 STORMWATER FACILITY DESCRIPTIONS (Note: Include Facility Summary and Sketch) Flow Control Type/Description Water Quality Type/Description 11 Detention V4 Biofiltration U Infiltration ❑ Wetpool U Regional Facility Media Filtration I-trir►t Ife'S _ U Shared Facility U Oil Control 51 Flow Control (2$fim P - U Spill Control BMPs 3 Flow Control BMPs ❑ Other Pt(m. $4,- ` U Other 2009 Surface Water Design Manual 1/9/2009 4 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL �/10 TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 15 EASEMENTS/TRACTS Part 16 STRUCTURAL ANALYSIS ❑ Drainage Easement U Cast in Place Vault U Covenant Si Retaining Wall ❑ Native Growth Protection Covenant 1 Rockery >4' High ❑ Tract ❑ Structural on Steep Slope LI Other LI Other Part 17 SIGNATURE OF PROFESSIONAL ENGINEER I, or a civil engineer under my supervision, have visited the site. Actual site conditions as observed were incorporated into this worksheet and the attached Technical Information Report. To the best of my knowledge the information prpvid ere is accurate. #— - ,Z.. Signed/Date ,Kc✓ i/—?-l3 2009 Surface Water Design Manual 1/9/2009 5 Site Location Map - Figure 2 • \� � � 6 � .,r. r r` .., ^�- 1-1 # f f! ST q iff /1,/ # i , ii 1 iii, iiitti k p'. F 1 m° ., ', �f- PROJECT SITE ' ..,,E I 1 .. A, . 0 t. .Y& -e. q4 1 1 >H. k ,vrcw>x>a: ""^ w«o- wu, i �`8. f'X a- 7,-?' 1 r,xrh T, ,T: ,„.„1„.1_,.. ,.,,„ !. #.1/„.„_' 1,,.. - !.1 r.,,,,, 1././..s, ,,,, ,,,,,,,, ,• ,,, .„ , jt u g @ #; f, x 4 5 g ..,, , -,,,, 1 ,,, .c, u # p ::-''',','-:::'''''''''':,::',,, u , : ,, ,.. , , , 6 Y 8 j#Y ....1 � r ,� , i � . i1. # + 1,,,,),,,,Iii."------ ::.;* ,,. t I ',., , /C 12tuf Kt/1g C«unty S 21ST:..ST. ." .0I I 5.013ft The Information included on this map has been compiled by King County staff from a varietyof sources and is sub ect to change without notice.King County makes no representations or warranties,express or implied,as to accuracy,completeness,timeliness,or rights to the use of such information This document is not intended for use as a survey product.King County shall not be liable for any general,special,indirect,incidental,or consequential 3 damages including.but not limited to,lost revenues or lost profits resulting from the use or misuse of the information contained on this map.Any sale of King County ,j■/+ounty this map or information on this map is prohibitedexcept by written permission of King County. Date:3/5/2009 Source:King County iMAP-Property Information(hftp://www.metrokc.govIGISIiMAP) _., , ,,, . :- D a\-j;\na,fg,r e Basins, ikSub,.bas..ins & Site Cha,.,.,..,r„,..r.,.,,,..- Figure 3 1 i , ' y ," , „ k, __- __- --- -- _-- - — - i n i J ',4, . , '.,, , ,, 1 1,1.,? / ...' - ,.... ,--- • '1 I ' 1 l -- — ' ...,., ...\.. ,..,,... , ..-,-- (--- - ___.---_-_-:_---,-7_____-;=-_-:,-_-_ -_-_:.-:::----//,,,„, '4.S.\ ( : .-'-'-. ...A''.. %. ,1 __,,I. -,,L,.,,, ,,..-.--- - .:„:-:77-7. -.- ,) l'II ‘ 1 i(-.,..----..../,/:,' , P OF F SIT E T RI B. AREA;.•,,,,,i,..•..., ) .‘ . - / i i i I ' i i ,' ' :i":41t. T ii i ', (approx. 0.4 ac) 2:',.„ it ' 1 I ' ',i: 7W 1,, A 'I 1„ ( .'-, i ,,,,,,„ ,' - ,, , 1, c t., , S : i i I,-!,... 1' 11:1--) I j1 1 I . !,,‘„, t-- -,,, 1 i, , , '. ,,','..1.;, i' . -1 1,.‘ '.'.L --;,:.z.._,..'-k,. ,.,..,‘ , ,.: ..:, ki 1 4 ..,... ,.... : - ''''.2 1 j / h ,.] „ . ) ,,.. , , . ,..„, i i \1,1 ,- s '.- 1 ,.. , kil...L;; •.- 4 ''',.., \ I II‘I. ' .: '6 ,i.::,:'.3'42' '''',, , • ' ''' ''',' ' / ,''' 'I ' ' ''.,' -,. lI ) f ) i .1 It I \ '°4''''t C,',: '''''' '. ''''i.':-.:-,'A ''' 1 1 / ,..,'".„,'.„, /. il ,,,,, ,i ' ' '',,,.`4,,..,'t...;rnt-..... .f.,,','*'' .7,-, v.:,.. , 4 I .., I, i ( , /.,, , „„ k , ii, „,„, „ , ,.. , . , , , .,, , ,„ ... \ 1 , ...... -- ii ,,,,...... , . i x i, ,.._, , , , , , ,:,/, . „., ....... ., .. , . ,...,/ 1. ....., ,, \ Il \ 'I,, I, ' 1 \ .4 \ 1---`j , . Ji Exist. site dispersed '4.-2 ' i..--1:...././....1......." .,.(' , . . , discharge to Benson R,d,..A 4/ . I [ PROJECT SITE ' .4/114. '\ 't :, I 1_88 AC ' .-'‘.. \ ... - ., › i 1 1 ) I ) i i :'• ,,, 'i. l-'1 .' i II .! i .1 k ' ' ' 1 / "i % ‘ 1 I -2. ,. ...c.! .e. j i ' ( r \ ,---41 •'''''' ' ' N ' k1 6 , . .„ 9) ' . .. -. , . .. .,1 I . '•', f.. ::11•,..,,,,_.."7,_,,,,,,,',,,,,,,,.,..i,i,.•.—,,,,,,-f',-°77 1(''.7•'..i,,„,,',',,,'„-,—.'..-,,','P.P,/oi-''''_„i,_),,-.._-_.-,,..-,,i •-/,.,.,..‘,-- _ / Developed site drainage path ) 12 /4 , \ i (N, \ I i ' / ( / ( ,, . \ \ 1, .) 100pipe © 19 - e i 4,,' ,i01, .• . ,,,_ i I I i\ ..,' t \\ II t 1 1 .,.:2., k: I 1,,, ' • •-,,, 1 ,1 kl° / ? .04, \'' \ ,.,_-/ 's,,, 11 ,..,,.,,,, it, ii i ,,, ,x,,, •:. 41 ,,. 39' pipe 40. i / 1 .t., ,,,, ,tr ,..,,,,,,, N. \ j N,,,\ i . I i I i,,i,:. .,. .- ' ,,,,, -• •••,', ...7 -* s.„) ) i i° %, ' ..e.,,,,':, I\ / 1.,' ' '' I i I i, ;, v. f 1 '. 1. .‘ , • • • .. / ii . -- .,:f7-'4,.Z lc -- . Il \',-::- f ( ,:, --, ,.‘111 I I ''', \ \::.'1"..:''' ,/ ,J I I ) ,-;•..:.cv,f.'•-< \ \ ,,..- ..,,,.11.... ,,,,,., ' ' ,,-.:.1'-..,-,1 ,,,,, , \::: ,„ ,_•,, , ,.,...‘1':':••••':''''''''',..::',A,,,,,,si:f • w. t L.,' i 11 „ \ ) ,...,, \,1:,• , 11---- , , i) i 1,,,,,, iSeen'cl civ''1.,'J' 'd'i—rill'9 .r) a‘n f.,o. detailed: drainage system,. .,,,,„„,•,,•: ,,,,,. ‘1. ) detention & treatment , .,„ , .,,D annings 1 2 ft , - , • , , * -• , •'..7.-,.\'',i'' ts.i),:,•., ) 1 7” ,---- -' 1 /1 I r . . , I ......1.4kei i I 1 I I ' ,' ,, .:,subjecthtstoo thchoanogsee owfltshoocuot notice,King 't i'ti 35138King C-- t' - hasbeen compiled by King County staff fromc .c,.,. ,,, ,,,,,,.,,, The information included On thismap warranties,express or implied,as to allc;-,,, by,,,abe for any ger,'s,,l',',--pSec9iari,aigncdoirnettctain,eindciodnenthtaisl,noracpUnAsneygsuaelnetioefl L, King County County makes no representationsor This document is not intended for use as a survy product.King County she damages including,but not limited to,lrevenues or lost profits resulting from the use or misuse of the information this map or information on this map is prohibited except by written permission of King County. ,, r t Date:3;912009 Source:King County iMAP-Property Information(http://www.rnetrokc.govIGlSIIMAP) ,, r -_ County Area,Washington Soil Map—King V (Figure 4) fl1) 1z tiw i.,NN 560000 4T 28'7"V 559960559920559880 I 559840 559800 55976 '`4728'7c ' am NONNNNN NaN fro::' N \NNN m 1 N i ir, .:.74-. c, ''. 4itiot,°:1 '''' i 64 m ,,NN • v • l\ k' sig ice.' : i , +I 4-4 N 4 ' \\ ,. , N ,' kPROJECT SITE . , � �, M to 6 , ,, '`o �� " a Y pf>_ ' .. M ..,,r, ,, .., . ,„„,..„ „,, Ak-."- ' .- •-,. '1• 'i.. ' tr; 44.,',-..,, ',",' '4,4,,,A.t, '. e m ,, , t, N " Ni,, . :., , ‘,,, ;,.- .., N N N N I. m 9! p n 47 27 55" 2 47'27'55" 559760 559800 559840 559880 559920 559960 560000 iN N <V N Map Scale:1:1,800 if printed on A size(8.5"x 11")sheet N Meters N 0 15 30 60 90 //ry\/V Feet 0 50 100 200 300 USDA Natural Resources Web Soil Survey 2.1 3/6/2009 Conservation Service National Cooperative Soil Survey Page 1 of 3 Soil Map—King County Area,Washington (Figure 4) MAP LEGEND MAP INFORMATION Area of Interest(AOI) as Very Stony Spot Map Scale: 1:1,800 if printed on A size(8.5"x 11")sheet. Area of Interest(AOI) t Wet Spot The soil surveys that comprise your AOl were mapped at 1:24,000. soils Other Please rely on the bar scale on each map sheet for accurate map Soil Map Units measurements. Special Line Features Special Point Features Gully Source of Map: Natural Resources Conservation Service Q) Blowout Web Soil Survey URL: http://websoilsurvey.nres.usda.gov Short Steep Slope ® Borrow Pit Coordinate System: UTM Zone 10N NAD83 ) Clay Spot ^ Other This product is generated from the USDA-NRCS certified data as of Political Features the version date(s)listed below. Closed Depression Cities Soil Survey Area: King County Area,Washington X Gravel Pit I 1 PLSS Township and Survey Area Data: Version 4, Nov 21,2006 Gravelly Spot Range Date(s)aerial images were photographed: 7/24/2006 PLSS Section ▪ Landfill The orthophoto or other base map on which the soil lines were Water Features compiled and digitizedprobablydiffers from the background A. Lava Flow Oceans pg g imagery displayed on these maps.As a result,some minor shifting Marsh or swamp Streams and Canals of map unit boundaries may be evident. Mine or Quarry Transportation p Miscellaneous Water Rails © Perennial Water ,,hp Interstate Highways v Rock Outcrop US Routes { Saline Spot Major Roads Sandy Spot Local Roads Severely Eroded Spot Q Sinkhole 3> Slide or Slip Rt Sodic Spot E Spoil Area { Stony Spot USDA Natural Resources Web Soil Survey 2.1 3/6/2009 ;MU Conservation Service National Cooperative Soil Survey Page 2 of 3 10/0 Soil Map—King County Area,Washington Figure 4 Map Unit Legend King County Area,Washington(WA633) Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI AgC Alderwood gravelly sandy loam,6 to 15 4.5 29.0% percent slopes AgD Alderwood gravelly sandy loam,15 to 30 5.9 38.1% percent slopes BeD Beausite gravelly sandy loam,15 to 30 5.1 32.9% percent slopes Totals for Area of Interest 15.6 100.0% L,D;a Natural Resources Web Soil Survey 2.1 3/6/2009 Conservation Service National Cooperative Soil Survey Page 3 of 3 APPENDIX B OFF-SITE ANALYSIS DRAINAGE SYSTEM TABLE AND MAP OFF-SITE ANALYSIS DRAINAGE SYSTEM TABLE SURFACE WATER DESIGN MANUAL, CORE REQUIREMENT#2 Basin: Black River Subbasin Name: Rolling Hills Subbasin Number: Symbol Drainage Component Drainage Component Slope Distance from Existing Potential Problems Observations of field inspector, Type, Name, and Size Description site discharge Problems resource reviewer, or resident see map Type:sheet flow,Swale, drainage basin,vegetation,cover; % '/4 ml=1,320 ft constrictions, under capacity, ponding, tributary area, likelihood of problem, stream, channel,pipe, depth,type of sensitive area, overtopping,flooding, habitat or organism overflow pathways, potential impacts pond; Size:diameter, volume destruction,scouring, bank sloughing, surface area sedimentation, incision,other erosion A-B Pipe 12"CMP E side of Benson Rd S 5.8 0' (pipe None None This pipe is undocumented on drainage conveyance. along the City's GIS&drainage frontage) maps. The City GIS shows a system just S of"A"which drains W to Puget Dr. S. B-C Pipe 12"CMP E side of Benson Rd S 6.0 0' (pipe None None This pipe is undocumented on drainage conveyance. along the City's GIS and drainage frontage) maps. C-D Pipe 12"CMP E side of Benson Rd S 3.3 0' — 155' None None Ditto above. drainage conveyance,w/ add'n of pond outlet from E D-E Pipe 12"CMP E side of Benson Rd S 5.4 155'—213' None None Ditto above. drainage conveyance. E-F Pipe 12"RCP E side of Benson Rd S 6.9 213'—303' None None Ditto above. Survey shows this drainage conveyance w/ system carries on to the N as addition of runoff from E 12"RCP,but it is not (Lodge @ Eagle Ridge). documented. F-G Pipe 18"RCP Crosses Benson Rd to W ? 303' —553' None None This pipe is undocumented on onto private property w/ the City's GIS and drainage add'n of runoff from E. maps. G-H Pipe 18"RCP Crosses private property ? 553' —653' None None This pipe is undocumented on (presumed) and connects to the city the City's GIS and drainage system described under maps. "observations..." for A-B. H-I Pipe 36"CMP, Parallels Talbot Rd 0.3 653' —793' None None No invert elev. info., length 1.046— 1.029 from City GIS maps. I-J Pipe 42"CMP, Crosses Talbot Rd 793' —933' None None Ditto above. 1.029— 1.023 J-K Pipe 42", 1.023 -? Flows N on W side of 933' — 1,193' None None Ditto above. Talbot Rd S. L-M Pipe 42",?— 1.020 Flows N along Talbot Rd S 1,193' — None Flooding Historic flooding problems under I-405 1.423' reported downstream 98-4\inB04 F4r - 17 T23N,R5E W 1/2 : ,.,, T, 3.08 - 11 1 'I . I 1 j III, LA ,, -, -- I '1 '..-..-••-•-.01 SA'. _ / • 3.0 3.17 \ 4.,9 , ki1 I . i ! 4 • I.1.------ . 1,999 2062 i, 2.993 Lt..,4,4.015 f ii,1.079 4 0,. .4.°Th 4474 !" 4*(1. 4.0741 1 I r ( i or ill I 1 111111 I, nig rule gi ,i i mu I 1111W1 lid= • ft ..4 w ., .`III 1.082 An1.08 ., r. 1084 0.8,90.1• i.086. . ix, 1•.: 1. 1,087 :1.092 4.069 4.011 ' / 4.1 / i --- 087 C----- tog ',,,.it.,/, i P444' ' E Hill h Oil , i I IIM KUM Ka ABM Inn IL' i IV Mil NMI ...,.. . ...„..,... 4.,..e:,‘ --.417 - " Vi IR * (), i ) ri MINNS 1.058 1.057 1.097 // 1 illrie 1..1 4 '.1" i / ---N„ , 1,,ga li4.„,„4 ,,iiir miliob,„ 4090 let9! 05$ : id, ),..,T.714110 . . iiiiii ae.ir.- ';..,..7. ,00 4., ' 440 NI 4.041 \ --A 0 =4..98 1 1.054 ii ii i C) 11111111r el -4 1.099 41 Av,, \.\:,1 - /., \-'1'>'\''''' ).1-4)--c)'' '[. -11./.1'71 c--!, :111111111::11 ill toi. lig *110 ll 1.102 1.055 * '011.e..,. ,'17 .,1'.. • Wing! Elm , ( .ii ---v-1 ' ' 01 i. ";,,,4 . ,/,///2 , s:',..,...„ 1„- ) - ' : / / ' / l.,, , . . , , ‘ , . ..,...4 h 1// ' / t -' . , c, \..\- '''' 1 5-ig 1.007 / ./ • • IbL, .\\..., ,,,,,--, , , i i it_ -, • ...........111.082 / . / \\\‘,....'* \ -.4401_11111122.11111111111111111111144. C •,\.) ( 1.009 1..08 • .. / :: ri Z \\ ' ,I .‘ r %I, ..- \ - . . 13 1.022 l .,,....."N ,...." \ ) 1* -1M1hVi ) • \ 1.011 t \ ' I/ ell 0; 43 A ll ' \ \ \ \ .• .\ ' \ \ -i lc \ 4-,'' SP71, , ....._. • '', ^ I ' Ler tl' ar"44( ' It e r .1 .........„ )„......_;,.. .. .. „ . 4.025 4.021 1 ( ,.......„, i 11# i _ _ \--•,s. ,1 ,y, I e \ c 1.021: PAIN ---,1 , .• PIM . \ -... MOM 1--- ,.//-\\• ,\x-,c2..„2/1, \\\\ L ig nag ‘) 1 "%At imEm111,0. -- ' nillil • . ,, ) i 114 I ',, \. .. /-:-"'•-•-"--- .....-----.238- \ 1 i . 1 r 1. . i i - ........ .1 \119144 )11,0 (Or - rsj I: ./(1 \ 1 1 i 1 \ - 831/ I t - • / _ \ • \\ ,S.. i 1 1 ' \....t_.' -4...-' 1-c-\',) \ . .; / , h-L-. - • 1 i ,1 1, 1 i W4 1 ' 7, 031 .Aillid4 -. Ye, ! '1 ) 1 V.031 ti ii , i tmlir., i r_ 1, 1 i ( 1, , --, N.- ...., .), \ \ in 111 r"s ' \. PROJECT SITE ‘,1 ' ) 1 1, :,`,---- IllmoL )41• ; ) , 1 / i ___..„ t--T-, / . , 1 1 i 1.... \ i 4 nu__ 5 1 t24 41 • ak. ' '' .i. 4- .P7 . ' - -- \ Vi-r-_-- \\_ pi NEM A.* ., 61 9 ! ,', 1 ', a-- - ., ' , , , / SIM m .., 1 t S, ! • --<• /.. // ---- , . : , --- -. _ ' __- - ',. ' -- ,' f' ,u ; '1,,, 1 ‘. , . , , , . . V 1 '; '''''14;.1. ---- .-/ . --: .,., _ i 1,. ; , •, I ( 0 3.001(014, CI: VIM MINIL-A ILiiito,_ ....--------"46‘ * '-' • '-, , ***.' \ \... --' ----11r 1 `6 t9 , / ' ) • ‘ . .1 1 ----r- r 1 ., *. 1 7 SMWAR 11 I/ OFFSITE ANALYSIS DRAINAGE SYSTEM MAP \,..- 2.070 / 4 -,...........,,„,_i *, \ ,• / ' ._.t , .,/} • . ... •--- Scale: 1 "=400' ' ' ' ' )- - . . -/ . 4.........,—.. go \i \•\ .i, ,\ I 2.082.."4 __ 14_ ir41,16 1 .81_ mil ,. i 1 ), , „,p'( i \i' , i . . • • oil 3.b.: . ....... 3.,018 ",._ / 3.023. / ,." •• • ) 11 i ------ 'k 44 .1 , ---\ (,i c / \ . 1 ,., \ i4 L'---\, ril 911:01 3.079 ........ Map Output Page 1 of I Section 303(d) Map I , .,, i I'_ �y i .rp -lip:, I ,L i i _, , i 41r.Dr5� ,un 'tr n 1 \)/f Beaton t laUNan4 fps u.v�t.iry L ��'� ti r,:(-: _ f ' p. rp k '1 i Fli, I 1 I e E Legend n i tL ake�IVVashdngt`ol� 0,r t; Eg Category 5 Sediments J f 1 !±1 / . Category 5 Waters ' p 1 i ' � � ' ■ Category 5 Waters 7 +? � v of category 5 Waters , i • u J' `j 'aha rangy, 'I .76.41 Superfund Sites Pucet Sound , r 1 r Highways �JY I y r ce 9 ti� f ., US Highway III ! �? \ Interstate i L eft '?x ,, iii . t' '? ; .; ; County 509 i s+m'l p;'f r `— TownshiptRan'ge/Section it 1 , 3 11 Estuary Names /1'' , :,/_ •BLACK RIVER r�4 1 Water Bodies J .o :Ups c, _ Reservoir Tub+L 7h g - ` 4' ` l j -. —! r (limier , -�. - Vit3 'Riven q ' III Marsh j Darn t `i 4 a'3 -- 's/' !tock PROJECT LOCATION; Vii; 0 . � z',_., ,_ ` _ D Impoundment } n Land PRINGBROOK CREEK -..., n Wator Bati`:.r.eke - 4 oAt - it �+f Streams � S,5 L t� Ari !'-i�Tidks r' , i' ' (' co, . „1- _, ' f: tV fel;r 02430 '-4 ,, )1, ,‘ Pan+heri 3 m f �_,re�n'River��.ir 'i UI a �' ",,, ,, _ '`,'�T,l`yy� `M ' tl _ * :a _a v fly !6. Narn hake . CJark-Lake. i , t ' ,r, . 1:--)". :\ \ \ '' - t iaanwitk� 5)*. �' � . ` �' 04 1a .� ,L<iks vidian } 4btapLathd by the WA State f�partment of EcolagQ � 9 d/' http://apps.ecy.wa.gov/servlet/com.esri.esrimap.Esrimap?ServiceName=state ov&Client... 11/20/2012 Ly, Category 5: Polluted Waters/303(d) List Rec Listing NameParameter Medium Waterbody ID Lower Upper IDAddress Address SPRINGBROOK (MILL) Dissolved '1 1'7705 CREEK OxygenWater 1222256474521 1.444 3.465 2 13155 SPRINGBROOK (MILL) Fecal Coliform Water 1222256474521 1.444 3.465 CREEK County Rec 1County Name! Township/Range/Section Rec Township Township Township Range Range Range Section Number Fraction Direction Number Fraction Direction Number 0 N 04 0 E 24 Streams Rec Lat/Long ID Name 1222256474521 Black River Category 5: Polluted Waters/303(d) List Rec Listing ID Name Parameter Medium Waterbody ID Lower Address Upper Address 1 12567 BLACK RIVER Fecal Coliform Water 1222256474521 0.245 1.444 County Rec County Name 1 King Township/Range/Section Township Township Township Range Range Range Section IRec Number Fraction Direction Number Fraction Direction Number 11 23 O N 04 0 E 13 Water Bodies Rec Lat/Long ID Name Feature Type 1 1222435474754 421 APPENDIX C ANALYSIS AND DESIGN APPENDIX C-1 DETENTION FACILITIES DESIGN 5 f o o ` BC f o EKIS f H QPan7_ M]E 1'3 o CFFOCES (NORTH DET[ NTo ) e` :, �,; k •FFSITE , , ', ar y p" TRIBUTARY AREA rn -. '� ' ORTH DETENTION - / "� "'� ,,. --` —si .3x.....yii IV, 944,. <'� �. 1=. TRIBUTARY AREA �:F ' Y F t A t5��' z Nt iii, .r r r ..t\,,, ,h.-,. , t //fir _ kl . ✓✓✓/// /"0 a"r"r'i''r 9ai4 t, " d -�. ,.k+ r i /'4. r r= w NORTH BUILDING / -`£A `: , ,—, , ' '`r se ,wf � ; N 1t ck , t ..2 k C aIru t _ // "aQ...� • i rvi. t .rr�S,,:' ,; �4,:'-',-;=—..-,',,N\,-,, ; ..... 4 .s u _ It // ,, - ' �� •ER, .. •LE -/ , ��,. µ ^4 I 72– - ^-� —�l' si; �/ ,,,x,s- y, s`' %.'.,.. ROAD f , 0160, ' ,ma {SI 44234 r sn la roq•.°3c1[ .u': EXISTING SF (AC): PROPOSED SF (AC): IMPERVIOUS PERVIOUS Z.- FOREST: 49,300 (1.13 AC) BLDG: 18,806 (0.43 AC) 18,806 (0.43) Z e , PERM. PAVE: 5,797 (0.13 AC) 2,899 (0.07) 2,898 (0.06) :-..1/4_ TOTAL: 49,300 (1.13 AC) SIDEWALK: 226 (NEG.) 226 (NEG.) 0 FOREST: 8,967 (0.21 AC) 8,967 (0.21) LANDSCAPE: 15,504 (0.36 AC) 15,504 (0.36) TOTAL: 49,300 (1.13 AC) 22,233 (0.50) 27,067 (0.63) j 50 100 mmilimid SCALE: 1" = 100 ft. /4- /11 sumpksl5 !l' / 1500 & 1600 Benson Apartments & offices (N Detention) tl, 1k) Pck QS t tr -/%^-1,) Summary of 15-minute Predicted Runoff 4/8/13 Flow Frequency Analysis LogPearson III Coefficients Time Series File:existl5.tsf Mean= -1.485 StdDev= 0.262 Project Location:Sea-Tac Skew= 1. 598 ---Annual Peak Flow Rates--- Flow Frequency Analysis Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period � Computed Peaks 0.252 ,UO 100.00 0.990 Computed Peaks 0.175 50.00 0.980 Computed Peaks 0.121 25.00 0.960 Computed Peaks 0.073 10.00 0.900 SSI"Ni Computed Peaks 0.066 8.00 0.875 Computed Peaks 0.049 5.00 0.800 Computed Peaks 0.028 2.00 0. 500 Computed Peaks 0.021 1.30 0.231 Flow Frequency Analysis LogPearson III Coefficients Time Series File:devl5.tsf Mean= -0. 532 StdDev= 0.168 Project Location:Sea-Tac Skew= 1.463 ---Annual Peak Flow Rates--- Flow Frequency Analysis Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period Computed Peaks 1.05 Q1oD 100.00 0.990 Computed Peaks 0.842 50.00 0.980 Computed Peaks 0.670 25.00 0.960 Computed Peaks 0.491 10.00 0.900 Computed Peaks 0.462 8.00 0.875 Computed Peaks 0.384 5.00 0.800 / Computed Peaks 0.268 2.00 0. 500 Computed Peaks 0.218 1.30 0.231 Increase in Q100 = 0.80 cfs (> 0.1 cfs) for only a portion of the site, so detention is required. Page 1 vaultl5 KCRTS Program. . .File Directory: C:\KC_SWDM\KC_DATA\ t 3k f t I,JPUT [C] CREATE a new Time Series ST I15'NU t 11 _ 1.13 0.00 0.000000 Till Forest 0.00 0.00 0.000000 Till Pasture -. 0.00 0.00 0.000000 Till Grass 0.00 0.00 0.000000 Outwash Forest 0.00 0.00 0.000000 Outwash Pasture 0.00 0.00 0.000000 Outwash Grass ! x :R.J1 0.00 0.00 0.000000 wetland JJJ 0.00 0.00 0.000000 Impervious existl5.tsf F 1.00000 F [T] Enter the Analysis TOOLS Module [P] Compute PEAKS and Flow Frequencies existl5.tsf existl5.pks [R] RETURN to Previous Menu [C] CREATE a new Time Series ST 0.21 0.00 0.000000 Till Forest 0.00 0.00 0.000000 Till Pasture 0.42 0.00 0.000000 Till Grass 0.000.00 0.000000 Outwash Forest 0.00 0.00 0.000000 Outwash Pasture �� 0.00 0.00 0.000000 Outwash Grass 0.00 0.00 0.000000 Wetland 0.50 0.00 0.000000 Impervious devl5.tsf F 1.00000 F [T] Enter the Analysis TOOLS Module [P] Compute PEAKS and Flow Frequencies devl5.tsf devl5.pks [R] RETURN to Previous Menu [x] eXit KCRTS Program Page 1 N- 41/1Z sumpks 1500 & 1600 Benson Apartments & Offices (N Detention) Aftj N PL f\� ( ,12,L_Y) Summary of Predicted Runoff 4/8/13 Flow Frequency Analysis LogPearson III Coefficients Time Series File:exist.tsf Mean= -1. 563 StdDev= 0.233 Project Location:Sea-Tac Skew= -0.132 ---Annual Peak Flow Rates--- Flow Frequency Analysis Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period Computed Peaks 0.090 100.00 0.990 Computed Peaks 0.079 50.00 0.980 Computed Peaks 0.068 25.00 0.960 Computed Peaks 0.054 10.00 0.900 Computed Peaks 0.051 8.00 0.875 /�' �� ��� Computed Peaks 0.043 5.00 0.800 / Computed Peaks 0.028 2.00 0. 500 Computed Peaks 0.018 1.30 0.231 Flow Frequency Analysis Log Pearson III Coefficients Time Series File:dev.tsf Mean= -0.805 StdDev= 0.117 Project Location:Sea-Tac Skew= 0.390 ---Annual Peak Flow Rates--- Flow Frequency Analysis Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period Computed Peaks 0.316 100.00 0.990 Computed Peaks 0.287 50.00 0.980 Computed Peaks 0.259 25.00 0.960 Computed Peaks 0.223 10.00 0.900 + Computed Peaks 0.216 8.00 0.875 //lc 'Ai Computed Peaks 0.195 5.00 0.800 Computed Peaks 0.154 2.00 0. 500 Computed Peaks 0.127 1. 30 0.231 Level 2 Detention Vault (10') Int size=[0.079-(0.028'0. 5)]/(36-1) =0.002 1st Int.=0.028*0. 5 =0.014 Qmax=(4/3'0.014) =0.019 Orif(2)=3/4'10 =7. 5' Page 1 N- 5/ QZ vault KCC:\KCRSWDM\KTS CCrDATA\.File Directory: `, elb �� i L)P'J,,.,. ci [C] CREATE a new Time Series 'v 1� ST ' 1.13 0.00 0.000000 Ti 11 Forest 1 ,)O2�--Y ► - 0.00 0.00 0.000000 Till Pasture 0.00 0.00 0.000000 Till Grass 0.00 0.00 0.000000 outwash Forest 0.00 0.00 0.000000 Outwash Pasture 0.00 0.00 0.000000 Outwash Grass 0‘ 111`311 0.00 0.00 0.000000 wetland 0.00 0.00 0.000000 Impervious exiSt.tsf F 1.00000 T [T] Enter the Analysis TOOLS Module [P] Compute PEAKS and Flow Frequencies exist.tsf exist.pks [R] RETURN to Previous Menu [C] CREATE a new Time Series ST 0.21 0.00 0.000000 Till Forest 0.00 0.00 0.000000 Till Pasture 0.42 0.00 0.000000 Till Grass 0.00 0.00 0.000000 Outwash Forest 0.00 0.00 0.000000 Outwash Pasture J 0.00 0.00 0.000000 Outwash Grass 1 ,--",./ Lt� c;.,ti 0.00 0.00 0.000000 wetland 0. 50 0.00 0.000000 Impervious dev.tsf F 1.00000 T [T] Enter the Analysis TOOLS Module [P] Compute PEAKS and Flow Frequencies dev.tsf dev.pks [R] RETURN to Previous Menu [X] eXit KCRTS Program Page 1 - 6/ ,v 1500 & 1600 Benson Apartments & Offices (N Detention) te �t ReMQ (LvT// Retenn3 tion/Detention Facility 'N Type of Facility: Detention Vault f \ tN Facility Length: 54.00 ft nl Facility Width: 20.00 ft Facility Area: 1080. sq. ft Effective Storage Depth: 10.00 ft Stage 0 Elevation: 0.00 ft Storage Volume: 10800. cu. ft Riser Head: 10.00 ft Riser Diameter: 12.00 inches Number of orifices: 2 Full Head Pipe Orifice # Height Diameter Discharge Diameter (ft) (in) (CFS) (in) 1 0.00 0.47 0.019 2 6.00 0.86 0.040 4.0 Top Notch Weir: None Outflow Rating Curve: None Stage Elevation Storage Discharge Percolation (ft) (ft) (cu. ft) (ac-ft) (cfs) (cfs) 0.00 0.00 0. 0.000 0.000 0.00 0.01 0.01 11. 0.000 0.001 0.00 0.02 0.02 22. 0.000 0.001 0.00 0.03 0.03 32. 0.001 0.001 0.00 0.04 0.04 43. 0.001 0.001 0.00 0.21 0.21 227. 0.005 0.003 0.00 0.38 0.38 410. 0.009 0.004 0.00 0.55 0.55 594. 0.014 0.004 0.00 0.72 0.72 778. 0.018 0.005 0.00 0.89 0.89 961. 0.022 0.006 0.00 1.06 1.06 1145. 0.026 0.006 0.00 1.23 1.23 1328. 0.030 0.007 0.00 1.40 1.40 1512. 0.035 0.007 0.00 1.57 1.57 1696. 0.039 0.008 0.00 1.74 1.74 1879. 0.043 0.008 0.00 1.91 1.91 2063. 0.047 0.008 0.00 2.08 2.08 2246. 0.052 0.009 0.00 2.25 2.25 2430. 0.056 0.009 0.00 2.42 2.42 2614. 0.060 0.009 0.00 2.59 2.59 2797. 0.064 0.010 0.00 2.76 2.76 2981. 0.068 0.010 0.00 2.93 2.93 3164. 0.073 0.010 0.00 3.09 3.09 3337. 0.077 0.011 0.00 3.26 3.26 3521. 0.081 0.011 0.00 3.43 3.43 3704. 0.085 0.011 0.00 3.60 3.60 3888. 0.089 0.011 0.00 3.77 3.77 4072. 0.093 0.012 0.00 3.94 3.94 4255. 0.098 0.012 0.00 4.11 4.11 4439. 0.102 0.012 0.00 4.28 4.28 4622. 0.106 0.012 0.00 4.45 4.45 4806. 0.110 0.013 0.00 4.62 4.62 4990. 0.115 0.013 0.00 4.79 4.79 5173. 0.119 0.013 0.00 4.96 4.965357. 0.123 0.013 0.00 5.13 5.13 5540. 0.127 0.014 0.00 5.30 5.30 5724. 0.131 0.014 0.00 5.47 5.47 5908. 0.136 0.014 0.00 5.64 5.64 6091. 0.140 0.014 0.00 5.81 5.81 6275. 0.144 0.014 0.00 5.98 5.98 6458. 0.148 0.015 0.00 6.00 6.00 6480. 0.149 0.015 0.00 6.01 6.01 6491. 0.149 0.015 0.00 6.02 6.02 6502. 0.149 0.015 0.00 6.03 6.03 6512. 0.150 0.016 0.00 6.04 6.04 6523. 0.150 0.019 0.00 6.05 6.05 6534. 0.150 0.019 0.00 6.06 6.06 6545. 0.150 0.020 0.00 6.07 6.07 6556. 0.150 0.020 0.00 6.24 6.24 6739. 0.155 0.025 0.00 6.41 6.41 6923. 0.159 0.028 0.00 6.58 6.58 7106. 0.163 0.031 0.00 6.75 6.75 7290. 0.167 0.033 0.00 6.92 6.92 7474. 0.172 0.035 0.00 7.09 7.09 7657. 0.176 0.037 0.00 7.26 7.26 7841. 0.180 0.039 0.00 7.43 7.43 8024. 0.184 0.040 0.00 7. 60 7.60 8208. 0.188 0.042 0.00 7.77 7.77 8392. 0.193 0.043 0.00 7.94 7.94 8575. 0.197 0.045 0.00 8.11 8.11 8759. 0.201 0.046 0.00 8.28 8.28 8942. 0.205 0.047 0.00 8.44 8.44 9115. 0.209 0.049 0.00 8.61 8.61 9299. 0.213 0.050 0.00 8.78 8.78 9482. 0.218 0.051 0.00 8.95 8.95 9666. 0.222 0.052 0.00 9.12 9.12 9850. 0.226 0.054 0.00 9.29 9.29 10033. 0.230 0.055 0.00 9.46 9.46 10217. 0.235 0.056 0.00 9.63 9.63 10400. 0.239 0.057 0.00 9.80 9.80 10584. 0.243 0.058 0.00 9.97 9.97 10768. 0.247 0.059 0.00 10.00 10.00 10800. 0.248 0.059 0.00 10.10 10.10 10908. 0.250 0.368 0.00 10.20 10.20 11016. 0.253 0.931 0.00 10.30 10.30 11124. 0.255 1.660 0.00 10.40 10.40 11232. 0.258 2.450 0.00 10.50 10.50 11340. 0.260 2.740 0.00 10.60 10.60 11448. 0.263 2.990 0.00 10.70 10.70 11556. 0.265 3.230 0.00 10.80 10.80 11664. 0.268 3.450 0.00 10.90 10.90 11772. 0.270 3.650 0.00 11.00 11.00 11880. 0.273 3.850 0.00 11.10 11.10 11988. 0.275 4.030 0.00 11.20 11.20 12096. 0.278 4.210 0.00 11.30 11.30 12204. 0.280 4.380 0.00 11.40 11.40 12312. 0.283 4.540 0.00 11.50 11.50 12420. 0.285 4.700 0.00 11.60 11.60 12528. 0.288 4.850 0.00 11.70 11.70 12636. 0.290 5.000 0.00 Hyd Inflow Outflow Peak Storage Target Calc Stage Elev (Cu-Ft) (Ac-Ft) 1 0.17 0.09 0.06 9.82 9.82 10609. 0.244 2 0.20 ******* 0.06 9.68 9.68 10459. 0.240 3 0.30 ******* 0.05 9.27 9.27 10014. 0.230 4 0.21 ******* 0.05 8.20 8.20 8852. 0.203 5 0.17 ******* 0.05 8.06 8.06 8708. 0.200 6 0.25 ******* 0.04 7.41 7.41 8008. 0.184 7 0.12 ******* 0.01 5.99 5.99 6474. 0.149 8 0.11 ******* 0.01 4.59 4.59 4954. 0.114 N - i,- Route Time Series through Facility Inflow Time Series File:dev.tsf Outflow Time Series File:rdout Inflow/Outflow Analysis Peak Inflow Discharge: 0.301 CFS at 6:00 on Jan 9 in 1990 Peak Outflow Discharge: 0.059 CFS at 21:00 on Feb 9 in 1951 Peak Reservoir Stage: 9.90 Ft Peak Reservoir Elev: 9.90 Ft Peak Reservoir Storage: 10695. Cu-Ft 0.246 Ac-Ft Flow Frequency Analysis LogPearson III Coefficients Time Series File:rdout.tsf Mean= -1.667 StdDev= 0.245 Project Location:Sea-Tac Skew= 0.326 ---Annual Peak Flow Rates--- Flow Frequency Analysis Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) (ft) Period 0.013 38 2/22/49 22:00 0.059 9.90 1 89.50 0.989 0.033 14 3/05/50 6:00 0.057 9.69 2 32.13 0.969 0.059 1 2/09/51 21:00 0.055 9.27 3 19.58 0.949 0.012 43 2/04/52 8:00 0.050 8.59 4 14.08 0.929 0.014 31 1/23/53 8:00 0.049 8.51 5 10.99 0.909 0.017 27 1/07/54 20:00 0.047 8.20 6 9.01 0.889 0.014 32 2/08/55 23:00 0.046 8.06 7 7.64 0.869 0.040 11 1/06/56 11:00 0.045 7.96 8 6.63 0.849 0.014 33 2/26/57 12:00 0.045 7.93 9 5.86 0.829 0.027 20 1/17/58 7:00 0.041 7.53 10 5.24 0.809 0.013 39 1/27/59 1:00 0.040 7.35 11 4.75 0.789 0.050 4 11/21/59 5:00 0.036 6.98 12 4.34 0.769 0.031 17 11/24/60 11:00 0.034 6.87 13 3.99 0.749 0.011 47 12/24/61 6:00 0.033 6.79 14 3.70 0.729 0.018 26 11/27/62 5:00 0.032 6.68 15 3.44 0.709 0.022 24 11/19/63 17:00 0.032 6.66 16 3.22 0.690 0.032 15 12/01/64 2:00 0.031 6.62 17 3.03 0.670 0.014 36 1/07/66 4:00 0.030 6.50 18 2.85 0.650 0.025 22 12/15/66 8:00 0.027 6.37 19 2.70 0.630 0.014 34 1/20/68 22:00 0.027 6.35 20 2.56 0.610 0.014 35 12/11/68 10:00 0.026 6.29 21 2.44 0.590 0.020 25 1/27/70 4:00 0.025 6.26 22 2.32 0.570 0.015 28 12/07/70 13:00 0.023 6.17 23 2.22 0.550 0.047 6 3/06/72 22:00 0.022 6.15 24 2.13 0.530 0.034 13 12/26/72 6:00 0.020 6.07 25 2.04 0.510 0.026 21 1/16/74 18:00 0.018 6.04 26 1.96 0.490 0.014 37 12/27/74 22:00 0.017 6.03 27 1.89 0.470 0.015 29 12/04/75 9:00 0.015 6.02 28 1.82 0.450 0.010 49 8/26/77 7:00 0.015 5.91 29 1.75 0.430 0.030 18 12/15/77 18:00 0.014 5.83 30 1.70 0.410 0.011 48 2/13/79 0:00 0.014 5.78 31 1.64 0.390 0.045 9 12/17/79 20:00 0.014 5.76 32 1.59 0.370 0.014 30 12/30/80 23:00 0.014 5.73 33 1.54 0.350 0.041 10 10/06/81 18:00 0.014 5.51 34 1.49 0.330 0.023 23 1/08/83 1:00 0.014 5.38 35 1.45 0.310 0.012 42 12/10/83 20:00 0.014 5.33 36 1.41 0.291 0.012 40 11/04/84 1:00 0.014 5.12 37 1.37 0.271 0.036 12 1/19/86 1:00 0.013 4.80 38 1.33 0.251 0.046 7 11/24/86 8:00 0.013 4.76 39 1.30 0.231 0.012 41 12/10/87 8:00 0.012 4.04 40 1.27 0.211 0.012 44 11/05/88 22:00 0.012 3.86 41 1.24 0.191 0.055 3 1/09/90 14:00 0.012 3.86 42 1.21 0.171 0.049 5 4/05/91 6:00 0.012 3.85 43 1.18 0.151 0.027 19 1/31/92 6:00 0.012 3.77 44 1.15 0.131 4 _ (4/IL 0.011 46 3/23/93 18:00 0.012 3.76 45 1.12 0.111 0.010 50 2/17/94 22:00 0.011 3.68 46 1.10 0.091 0.032 16 12/27/94 7:00 0.011 3.36 47 1.08 0.071 0.057 2 2/09/96 4:00 0.011 3.13 48 1.05 0.051 0.045 8 1/02/97 12:00 0.010 2.91 49 1.03 0.031 0.012 45 10/30/97 16:00 0.010 2.80 50 1.01 0.011 Computed Peaks 0.091 10.01 100.00 0.990 Computed Peaks 0.075 10.01 50.00 0.980 Computed Peaks 0.061 10.00 25.00 0.960 Computed Peaks 0.045 7.95 10.00 0.900 Computed Peaks 0.042 7.61 8.00 0.875 Computed Peaks 0.034 6.85 5.00 0.800 Computed Peaks 0.021 6.10 2.00 0.500 Computed Peaks 0.014 5.12 1.30 0.231 Flow Duration from Time Series File:rdout.tsf Cutoff Count Frequency CDF Exceedence_Probability CFS $ $ $ 0.001 222118 50.712 50.712 49.288 0.493E+00 0.002 53663 12.252 62.964 37.036 0.370E+00 0.004 50613 11.555 74.519 25.481 0.255E+00 0.006 22872 5.222 79.741 20.259 0.203E+00 0.007 29724 6.786 86.527 13.473 0.135E+00 0.009 19887 4.540 91.068 8.932 0.893E-01 0.011 17352 3.962 95.029 4.971 0.497E-01 0.012 11678 2.666 97.696 2.304 0.230E-01 0.014 4547 1.038 98.734 1.266 0.127E-01 0.015 3835 0.876 99.609 0.391 0.391E-02 0.017 49 0.011 99.621 0.379 0.379E-02 0.019 23 0.005 99.626 0.374 0.374E-02 0.020 131 0.030 99.656 0.344 0.344E-02 0.022 156 0.036 99.691 0.309 0.309E-02 0.024 130 0.030 99.721 0.279 0.279E-02 0.025 109 0.025 99.746 0.254 0.254E-02 0.027 135 0.031 99.777 0.223 0.223E-02 0.028 111 0.025 99.802 0.198 0.198E-02 0.030 99 0.023 99.825 0.175 0.175E-02 0.032 90 0.021 99.845 0.155 0.155E-02 0.033 100 0.023 99.868 0.132 0.132E-02 0.035 74 0.017 99.885 0.115 0.115E-02 0.037 80 0.018 99.903 0.097 0.968E-03 0.038 62 0.014 99.917 0.083 0.826E-03 0.040 75 0.017 99.934 0.066 0.655E-03 0.041 41 0.009 99.944 0.056 0.562E-03 0.043 39 0.009 99.953 0.047 0.473E-03 0.045 43 0.010 99.963 0.037 0.374E-03 0.046 41 0.009 99.972 0.028 0.281E-03 0.048 22 0.005 99.977 0.023 0.231E-03 0.049 19 0.004 99.981 0.019 0.187E-03 0.051 21 0.005 99.986 0.014 0.139E-03 0.053 15 0.003 99.989 0.011 0.105E-03 0.054 10 0.002 99.992 0.008 0.822E-04 0.056 18 0.004 99.996 0.004 0.411E-04 0.058 12 0.003 99.999 0.001 0.137E-04 Duration Comparison Anaylsis Base File: exist.tsf New File: rdout.tsf Cutoff Units: Discharge in CFS Fraction of Time Check of Tolerance Cutoff Base New %Change Probability Base New %Change 0.014 I 0.97E-02 0.12E-01 26.0 I 0.97E-02 0.014 0.014 0.4 0.019 I 0.50E-02 0.37E-02 -24.9 1 0.50E-02 0.019 0.015 -22.2 it'- '°1,1, 0.023 0.28E-02 0.28E-02 -1.4 0.28E-02 0.023 0.023 -0.8 0.028 0.17E-02 0.20E-02 19.6 0.17E-02 0.028 0.031 8.9 0.033 0.10E-02 0.14E-02 29.4 0.10E-02 0.033 0.036 8.7 0.038 0.67E-03 0.86E-03 27.1 0.67E-03 0.038 0.040 4.9 0.043 0.45E-03 0.51E-03 14.4 0.45E-03 0.043 0.044 2.6 0.047 0.30E-03 0.24E-03 -21.1 0.30E-03 0.047 0.046 -3.2 0.052 0.21E-03 0.12E-03 -45.7 0.21E-03 0.052 0.049 -6.3 0.057 0.12E-03 0.27E-04 -76.5 0.12E-03 0.057 0.052 -8.4 0.062 0.59E-04 0.00E+00 -100.0 0.59E-04 0.062 0.055 -10.8 0.066 0.32E-04 0.00E+00 -100.0 0.32E-04 0.066 0.057 -14.6 0.071 0.68E-05 0.00E+00 -100.0 0.68E-05 0.071 0.058 -17.8 0.076 0.23E-05 0.00E+00 -100.0 0.23E-05 0.076 0.059 -22.7 Maximum positive excursion = 0.003 cfs ( 9.3%) 4%0%1 o k_, occurring at 0.029 cfs on the Base Data:exist.tsf and at 0.031 cfs on the New Data:rdout.tsf Maximum negative excursion = 0.006 cfs (-27.4%) occurring at 0.021 cfs on the Base Data:exist.tsf and at 0.015 cfs on the New Data:rdout.tsf Return Period 2 5 10 20 E L — 50 10Q _ o rdout.pks in Sea-Tac • exist.pks j�� � . ...-4r...- 4, .�—�� R N DETTa•ril oiv VAu.0-.-" rr o o i �' o •i•oao ° �' . °• -- � - 0 U — • o 00-0 0 0 J.-_ • o - 2 10 Z �- --- - - co -- — — —— - ' - • U -• L 103 I I I I 1 I ----1— , - I , 1 1 2 5 10 20 30 40 50 60 70 80 90 95 98 99 Cumulative Probability CO o- rdout.dur o target.dur . ti • • • u_ a) CD o • CD. o • , AILoo • • • • 0 Q • I O 1 i ! 1 I I 1 1 ! 1 I I I 1 i I I [ I I I I i ! I I I I 1 1 1 1111 I I 1 1 1 1111 10-6 10-5 104 103 102 10-1100 .- Probability Exceedence N z 6 0 82, z_ j off D FRIED QPQTti-1,`•JME = o CFFTICES (ROUTH DD[VENT ON) „ Ltr o ,,\ ' �' Jo, I r = } ';';''':4;'"k4c PE BLE SOUTH DETENTION' TRIBUTARY AREA� r — MENT _I I�I, .7--- � �' 19 •, a "^f / %11.--''''.:-0:1-4.,-;‘, " ® �"#i "Ai3 ,', VVI _! \ M ,k, \\j. a .''' .v..�MM@� '. * •—r\, i ® �}� /j-%F° 'c w��� .j //e'/e-'NU ,./1;^/j/ iat �`.r'rs- ,r \ // as ` L � . -t o- — EXISTING SF (AC): PROPOSED SF (AC): IMPERMEABLE PERMEABLE FOREST: 53,825 (1.24 AC) BLDG: 19,966 (0.46 AC) 19,966 (0.46) 2ED PAVEMENT: 4,351 (0.10 AC) 4,351 (0.10) PERM. PAVE.: 11,932 (0.27) 5,966 (0.14) 5,966 (0.13) tA SIDEWALK: 1,658 (0.04 AC) 1,658 (0.04) I LANDSCAPE: 15,918 (0.37 AC) 15,918 (0.37) TOTAL: 53,825 (1.24 AC) 31,941 (0.74) 21,884 (0.50) o so loo I nsimmi SCALE: 1" = 100 ft. S- %___ sumpksl5 �. OS( (5- -M f, 1500 & 1600 Benson Apartments & Offices (S Detention) S- iNI Summary of 15-Minute Time steps Predicted Runoff 4/8/13 Flow Frequency Analysis LogPearson III Coefficients Time Series File:existl5.tsf Mean= -1.445 StdDev= 0.262 Project Location:Sea-Tac Skew= 1. 597 ---Annual Peak Flow Rates--- Flow Frequency Analysis Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period Q Computed Peaks 0.277 ,0v 100.00 0.990 -, Computed Peaks 0.192 50.00 0.980 Computed Peaks 0.132 25.00 0.960 R Computed Peaks 0.080 10.00 0.900 ll tic, Computed Peaks 0.072 8.00 0.875 Computed Peaks 0.054 5.00 0.800 Computed Peaks 0.031 2.00 0. 500 Computed Peaks 0.023 1.30 0.231 Flow Frequency Analysis LogPearson III Coefficients Time Series File:devl5.tsf Mean= -0.376 StdDev= 0.162 Project Location:Sea-Tac skew= 1.364 ---Annual Peak Flow Rates--- Flow Frequency Analysis Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period Computed Peaks 1.41Q 100.00 0.990 Computed Peaks 1.15 (uL) 50.00 0.980 \\ Computed Peaks 0.927 25.00 0.960 _ Computed Peaks 0.692 10.00 0.900 , Computed Peaks 0.653 8.00 0.875 + Computed Peaks 0. 548 5.00 0.800 Computed Peaks 0.388 2.00 0. 500 Computed Peaks 0.316 1.30 0.231 Page 1 '1 Z vault 15 5 'RPV NGV DA' ""4 KCRTS Program. . . File Directory: C:\KC_SWDM\KC_DATA\ 15- aV\ pN« 6'�tR ,S Ca-to [C] CREATE a new Time Series ST 1.24 0.00 0.000000 Till Forest 0.00 0.00 0.000000 Till Pasture 0.00 0.00 0.000000 Till Grass 0.00 0.00 0.000000 Outwash Forest / 0.00 0.00 0.000000 Outwash Pasture {S 1tJ( 0.00 0.00 0.000000 Outwash Grass 0.00 0.00 0.000000 Wetland 0.00 0.00 0.000000 Impervious existl5.tsf F 1.00000 F [T] Enter the Analysis TOOLS Module [P] Compute PEAKS and Flow Frequencies existl5.tsf existl5.pks [R] RETURN to Previous Menu [C] CREATE a new Time Series ST 0.00 0.00 0.000000 Till Forest 0.00 0.00 0.000000 Till Pasture 0. 50 0.00 0.000000 Till Grass 0.00 0.00 0.000000 Outwash Forest 0.00 0.00 0.000000 Outwash Pasture ,,,; ,.-' l r 0.00 0.00 0.000000 Outwash Grass 0.00 0.00 0.000000 Wetland 0.74 0.00 0.000000 Impervious devl5.tsf F 1.00000 F [T] Enter the Analysis TOOLS Module [P] Compute PEAKS and Flow Frequencies devl5.tsf devl5.pks [R] RETURN to Previous Menu [X] eXit KCRTS Program Page 1 sumpks « -Si^Ill -0 1500 & 1600 Benson Apartments & offices (S Detention) Summary of Predicted Runoff 0 Y t t_oS 4/8/13 Flow Frequency Analysis LogPearson III Coefficients Time Series File:exist.tsf Mean= -1. 522 StdDev= 0.232 Project Location:Sea-Tac Skew= -0.138 ---Annual Peak Flow Rates--- Flow Frequency Analysis Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period Computed Peaks 0.099 100.00 0.990 Computed Peaks 0.086 50.00 0.980 Computed Peaks 0.075 25.00 0.960 �'S'��(A Computed Peaks 0.059 10.00 0.900 . Computed Peaks 0.056 8.00 0.875 Computed Peaks 0.047 5.00 0.800 computed Peaks 0.030 2.00 0. 500 Computed Peaks 0.020 1.30 0.231 Flow Frequency Analysis LogPearson III Coefficients Time Series File:dev.tsf Mean= -0.658 StdDev= 0.111 Project Location:Sea-Tac Skew= 0.424 ---Annual Peak Flow Rates--- Flow Frequency Analysis Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period Computed Peaks 0.431 100.00 0.990 \ Computed Peaks 0.393 50.00 0.980 t 0 Computed Peaks 0.356 25.00 0.960 Computed Peaks 0.308 10.00 0.900 Computed Peaks 0.298 8.00 0.875 Computed Peaks 0.271 5.00 0.800 Computed Peaks 0.216 2.00 0. 500 I Computed Peaks 0.181 1.30 0.231 Level 2 Detention vault (10') Int Size=[0.086-(0.030;°0. 5)]/(36-1) =0.002 1st Int.=0.030*0. 5 =0.015 Qmax=(4/3"0.015) =0.020 orif(2)=3/4*10.0 =7. 5' Page 1 S_ 5 2- vault KCRTS Program. . . File Directory: C:\KC_SWDM\KC_DATA\ clVtS1 1 NA-1r. A [C] CREATE a new Time Series ST � � I7M(: SmS 1.24 0.00 0.000000 Till Forest 0.00 0.00 0.000000 Till Pasture 0.00 0.00 0.000000 Till Grass 0.00 0.00 0.000000 outwash Forest 0.00 0.00 0.000000 Outwash Pasture 07)N4i 0.00 0.00 0.000000 outwash Grass I 0.00 0.00 0.000000 wetland / 0.00 0.00 0.000000 Impervious exist.tsf F 1.00000 T [T] Enter the Analysis TOOLS Module [P] Compute PEAKS and Flow Frequencies exist.tsf exist.pks [R] RETURN to Previous Menu [C] CREATE a new Time Series ST 0.00 0.00 0.000000 Till Forest 0.00 0.00 0.000000 Till Pasture 0. 50 0.00 0.000000 Till Grass 0.00 0.00 0.000000 Outwash Forest 'Y 0.00 0.00 0.000000 Outwash Pasture si' :' 0.00 0.00 0.000000 Outwash Grass 0.00 0.00 0.000000 wetland 0.74 0.00 0.000000 Impervious dev.tsf F 1.00000 T [T] Enter the Analysis TOOLS Module [P] Compute PEAKS and Flow Frequencies dev.tsf dev.pks [R] RETURN to Previous Menu [X] eXit KCRTS Program Page 1 C- 9/( 1500 & 1600 Benson Apartments & Offices (S Detention) SAllEjl..37 ON [u1Y 4/8/13 Retention/Detention Facility i '/ / Type of Facility: Detention Vault � `.t�V Facility Length: 88.00 ft Facility Width: 20.00 ft Facility Area: 1760. sq. ft Effective Storage Depth: 10.00 ft Stage 0 Elevation: 0.00 ft Storage Volume: 17600. cu. ft Riser Head: 10.00 ft Riser Diameter: 12.00 inches Number of orifices: 2 Full Head Pipe Orifice # Height Diameter Discharge Diameter (ft) (in) (CFS) (in) 1 0.00 0.47 0.019 2 5.80 0.70 0.027 4.0 Top Notch Weir: None Outflow Rating Curve: None Stage Elevation Storage Discharge Percolation (ft) (ft) (cu. ft) (ac-ft) (cfs) (cfs) 0.00 0.00 0. 0.000 0.000 0.00 0.01 0.01 18. 0.000 0.001 0.00 0.02 0.02 35. 0.001 0.001 0.00 0.03 0.03 53. 0.001 0.001 0.00 0.04 0.04 70. 0.002 0.001 0.00 0.21 0.21 370. 0.008 0.003 0.00 0.38 0.38 669. 0.015 0.004 0.00 0.55 0.55 968. 0.022 0.004 0.00 0.72 0.72 1267. 0.029 0.005 0.00 0.89 0.89 1566. 0.036 0.006 0.00 1.06 1.06 1866. 0.043 0.006 0.00 1.23 1.23 2165. 0.050 0.007 0.00 1.40 1.40 2464. 0.057 0.007 0.00 1.57 1.57 2763. 0.063 0.008 0.00 1.74 1.74 3062. 0.070 0.008 0.00 1.91 1.91 3362. 0.077 0.008 0.00 2.08 2.08 3661. 0.084 0.009 0.00 2.25 2.25 3960. 0.091 0.009 0.00 2.42 2.42 4259. 0.098 0.009 0.00 2.59 2.59 4558. 0.105 0.010 0.00 2.76 2.76 4858. 0.112 0.010 0.00 2.93 2.93 5157. 0.118 0.010 0.00 3.09 3.09 5438. 0.125 0.011 0.00 3.26 3.26 5738. 0.132 0.011 0.00 3.43 3.43 6037. 0.139 0.011 0.00 3.60 3.60 6336. 0.145 0.011 0.00 3.77 3.77 6635. 0.152 0.012 0.00 3.94 3.94 6934. 0.159 0.012 0.00 4.11 4.11 7234. 0.166 0.012 0.00 4.28 4.28 7533. 0.173 0.012 0.00 4.45 4.45 7832. 0.180 0.013 0.00 4.62 4.62 8131. 0.187 0.013 0.00 4.79 4.79 8430. 0.194 0.013 0.00 4.96 4.96 8730. 0.200 0.013 0.00 5.13 5.13 9029. 0.207 0.014 0.00 5.30 5.30 9328. 0.214 0.014 0.00 5.47 5.47 9627. 0.221 0.014 0.00 5.64 5.64 9926. 0.228 0.014 0.00 5.80 5.80 10208. 0.234 0.014 0.00 5.81 5.81 10226. 0.235 0.015 0.00 5.82 5.82 10243. 0.235 0.015 0.00 5.83 5.83 10261. 0.236 0.016 0.00 5.84 5.84 10278. 0.236 0.017 0.00 5.85 5.85 10296. 0.236 0.017 0.00 5.86 5.86 10314. 0.237 0.018 0.00 6.03 6.03 10613. 0.244 0.021 0.00 6.20 6.20 10912. 0.251 0.023 0.00 6.37 6.37 11211. 0.257 0.025 0.00 6.54 6.54 11510. 0.264 0.027 0.00 6.71 6.71 11810. 0.271 0.028 0.00 6.88 6.88 12109. 0.278 0.029 0.00 7.04 7.04 12390. 0.284 0.031 0.00 7.21 7.21 12690. 0.291 0.032 0.00 7.38 7.38 12989. 0.298 0.033 0.00 7.55 7.55 13288. 0.305 0.034 0.00 7.72 7.72 13587. 0.312 0.035 0.00 7.89 7.89 13886. 0.319 0.036 0.00 8.06 8.06 14186. 0.326 0.037 0.00 8.23 8.23 14485. 0.333 0.038 0.00 8.40 8.40 14784. 0.339 0.039 0.00 8.57 8.57 15083. 0.346 0.040 0.00 8.74 8.74 15382. 0.353 0.041 0.00 8.91 8.91 15682. 0.360 0.041 0.00 9.08 9.08 15981. 0.367 0.042 0.00 9.25 9.25 16280. 0.374 0.043 0.00 9.42 9.42 16579. 0.381 0.044 0.00 9.59 9.59 16878. 0.387 0.044 0.00 9.76 9.76 17178. 0.394 0.045 0.00 9.93 9.93 17477. 0.401 0.046 0.00 10.00 10.00 17600. 0.404 0.046 0.00 10.10 10.10 17776. 0.408 0.355 0.00 10.20 10.20 17952. 0.412 0.918 0.00 10.30 10.30 18128. 0.416 1.650 0.00 10.40 10.40 18304. 0.420 2.440 0.00 10.50 10.50 18480. 0.424 2.720 0.00 10.60 10.60 18656. 0.428 2.980 0.00 10.70 10.70 18832. 0.432 3.210 0.00 10.80 10.80 19008. 0.436 3.430 0.00 10.90 10.90 19184. 0.440 3.640 0.00 11.00 11.00 19360. 0.444 3.830 0.00 11.10 11.10 19536. 0.448 4.020 0.00 11.20 11.20 19712. 0.453 4.190 0.00 11.30 11.30 19888. 0.457 4.360 0.00 11.40 11.40 20064. 0.461 4.530 0.00 11.50 11.50 20240. 0.465 4.680 0.00 11.60 11.60 20416. 0.469 4.840 0.00 11.70 11.70 20592. 0.473 4.980 0.00 11.80 11.80 20768. 0.477 5.130 0.00 Hyd Inflow Outflow Peak Storage Target Calc Stage Elev (Cu-Ft) (Ac-Ft) 1 0.23 0.10 0.08 10.01 10.01 17619. 0.404 2 0.26 ******* 0.04 9.57 9.57 16845. 0.387 3 0.25 ******* 0.04 8.83 8.83 15548. 0.357 4 0.29 ******* 0.04 8.56 8.56 15074. 0.346 5 0.24 ******* 0.04 8.50 8.50 14961. 0.343 6 0.21 ******* 0.03 7.67 7.67 13501. 0.310 7 0.19 ******* 0.02 6.03 6.03 10613. 0.244 8 0.23 ******* 0.01 4.98 4.98 8772. 0.201 Route Time Series through Facility Inflow Time Series File:dev.tsf Outflow Time Series File:rdout Inflow/Outflow Analysis Peak Inflow Discharge: 0.403 CFS at 6:00 on Jan 9 in 1990 Peak Outflow Discharge: 0.087 CFS at 20:00 on Feb 9 in 1951 Peak Reservoir Stage: 10.01 Ft Peak Reservoir Elev: 10.01 Ft Peak Reservoir Storage: 17623. Cu-Ft 0.405 Ac-Ft Flow Frequency Analysis LogPearson III Coefficients Time Series File:rdout.tsf Mean= -1.667 StdDev= 0.218 Project Location:Sea-Tac Skew= 0.303 ---Annual Peak Flow Rates--- Flow Frequency Analysis Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) (ft) Period 0.013 38 2/22/49 22:00 0.087 10.01 1 89.50 0.989 0.028 16 3/05/50 7:00 0.044 9.58 2 32.13 0.969 0.087 1 2/09/51 20:00 0.041 8.83 3 19.58 0.949 0.012 43 2/04/52 8:00 0.041 8.73 4 14.08 0.929 0.027 20 1/18/53 21:00 0.040 8.57 5 10.99 0.909 0.014 33 1/07/54 21:00 0.040 8.56 6 9.01 0.889 0.013 39 11/19/54 20:00 0.040 8.50 7 7.64 0.869 0.035 10 1/06/56 12:00 0.039 8.38 8 6.63 0.849 0.014 35 3/10/57 4:00 0.036 7.87 9 5.86 0.829 0.023 24 1/17/58 8:00 0.035 7.67 10 5.24 0.809 0.014 36 1/27/59 1:00 0.034 7.58 11 4.75 0.789 0.039 8 11/21/59 7:00 0.033 7.30 12 4.34 0.769 0.031 15 11/24/60 16:00 0.032 7.24 13 3.99 0.749 0.012 44 12/24/61 6:00 0.032 7.19 14 3.70 0.729 0.023 25 11/30/62 19:00 0.031 7.02 15 3.44 0.709 0.028 17 11/19/63 17:00 0.028 6.74 16 3.22 0.690 0.032 13 12/01/64 8:00 0.028 6.71 17 3.03 0.670 0.021 28 1/07/66 3:00 0.028 6.63 18 2.85 0.650 0.027 19 12/13/66 15:00 0.027 6.60 19 2.70 0.630 0.014 32 1/20/68 22:00 0.027 6.55 20 2.56 0.610 0.019 30 12/11/68 7:00 0.026 6.48 21 2.44 0.590 0.026 21 1/27/70 4:00 0.025 6.41 22 2.32 0.570 0.019 31 12/07/70 12:00 0.025 6.40 23 2.22 0.550 0.040 6 3/06/72 23:00 0.023 6.20 24 2.13 0.530 0.033 12 12/26/72 6:00 0.023 6.17 25 2.04 0.510 0.022 26 1/18/74 18:00 0.022 6.09 26 1.96 0.490 0.013 37 1/14/75 1:00 0.021 6.05 27 1.89 0.470 0.014 34 12/04/75 8:00 0.021 6.03 28 1.82 0.450 0.011 49 8/26/77 8:00 0.020 5.98 29 1.75 0.430 0.028 18 12/15/77 19:00 0.019 5.91 30 1.70 0.410 0.011 48 2/13/79 1:00 0.019 5.90 31 1.64 0.390 0.041 3 12/18/79 4:00 0.014 5.74 32 1.59 0.370 0.020 29 12/30/80 22:00 0.014 5.62 33 1.54 0.350 0.034 11 10/06/81 20:00 0.014 5.56 34 1.49 0.330 0.021 27 1/08/83 3:00 0.014 5.44 35 1.45 0.310 0.012 45 12/13/83 8:00 0.014 5.31 36 1.41 0.291 0.012 42 11/11/84 9:00 0.013 5.04 37 1.37 0.271 0.025 23 1/19/86 4:00 0.013 4.98 38 1.33 0.251 0.036 9 11/24/86 9:00 0.013 4.95 39 1.30 0.231 0.013 40 12/10/87 8:00 0.013 4.79 40 1.27 0.211 0.012 46 11/05/88 23:00 0.013 4.47 41 1.24 0.191 0.041 4 1/09/90 17:00 0.012 4.14 42 1.21 0.171 0.040 5 11/24/90 17:00 0.012 4.05 43 1.18 0.151 0.025 22 1/31/92 7:00 0.012 3.99 44 1.15 0.131 0.011 47 1/26/93 5:00 0.012 3.96 45 1.12 0.111 0.010 50 2/17/94 23:00 0.012 3.94 46 1.10 0.091 0.032 14 12/27/94 7:00 0.011 3.62 47 1.08 0.071 0.044 2 2/09/96 5:00 0.011 3.21 48 1.05 0.051 0.040 7 1/02/97 13:00 0.011 3.10 49 1.03 0.031 0.013 41 1/25/98 0:00 0.010 2.93 50 1.01 0.011 Computed Peaks 0.077 10.01 100.00 0.990 Computed Peaks 0.065 10.01 50.00 0.980 Computed Peaks 0.055 10.00 25.00 0.960 Computed Peaks 0.042 9.00 10.00 0.900 Computed Peaks 0.039 8.42 8.00 0.875 Computed Peaks 0.033 7.31 5.00 0.800 Computed Peaks 0.021 6.03 2.00 0.500 Computed Peaks 0.015 5.81 1.30 0.231 Flow Duration from Time Series File:rdout.tsf Cutoff Count Frequency CDF Exceedence_Probability CFS $ $ $ 0.001 204052 46.587 46.587 53.413 0.534E+00 0.004 57381 13.101 59.688 40.312 0.403E+00 0.006 69899 15.959 75.647 24.353 0.244E+00 0.008 44560 10.174 85.820 14.180 0.142E+00 0.011 28825 6.581 92.401 7.599 0.760E-01 0.013 24566 5.609 98.010 1.990 0.199E-01 0.016 5369 1.226 99.236 0.764 0.764E-02 0.018 205 0.047 99.282 0.718 0.718E-02 0.021 610 0.139 99.422 0.578 0.578E-02 0.023 550 0.126 99.547 0.453 0.453E-02 0.025 465 0.106 99.653 0.347 0.347E-02 0.028 415 0.095 99.748 0.252 0.252E-02 0.030 296 0.068 99.816 0.184 0.184E-02 0.033 266 0.061 99.876 0.124 0.124E-02 0.035 176 0.040 99.917 0.083 0.833E-03 0.037 113 0.026 99.942 0.058 0.575E-03 0.040 126 0.029 99.971 0.029 0.288E-03 0.042 64 0.015 99.986 0.014 0.142E-03 0.045 41 0.009 99.995 0.005 0.479E-04 0.047 18 0.004 99.999 0.001 0.685E-05 0.050 1 0.000 100.000 0.000 0.457E-05 0.052 0 0.000 100.000 0.000 0.457E-05 0.054 0 0.000 100.000 0.000 0.457E-05 0.057 0 0.000 100.000 0.000 0.457E-05 0.059 1 0.000 100.000 0.000 0.228E-05 0.062 0 0.000 100.000 0.000 0.228E-05 0.064 0 0.000 100.000 0.000 0.228E-05 0.066 0 0.000 100.000 0.000 0.228E-05 0.069 0 0.000 100.000 0.000 0.228E-05 0.071 0 0.000 100.000 0.000 0.228E-05 0.074 0 0.000 100.000 0.000 0.228E-05 0.076 0 0.000 100.000 0.000 0.228E-05 0.079 0 0.000 100.000 0.000 0.228E-05 0.081 0 0.000 100.000 0.000 0.228E-05 0.083 0 0.000 100.000 0.000 0.228E-05 0.086 0 0.000 100.000 0.000 0.228E-05 Duration Comparison Anaylsis Base File: exist.tsf New File: rdout.tsf Cutoff Units: Discharge in CFS Fraction of Time Check of Tolerance Cutoff Base New %Change Probability Base New %Change 0.015 I 0.10E-01 0.79E-02 -22.8 I 0.10E-01 0.015 0.014 -5.7 0.020 I 0.51E-02 0.60E-02 17.6 I 0.51E-02 0.020 0.022 8.3 0.025 1 0.30E-02 0.35E-02 17.2 1 0.30E-02 0.025 0.027 6.2 F' �t 0.031 0.18E-02 0.18E-02 -0.3 I 0.18E-02 0.031 0.031 -0.2 0.036 0.11E-02 0.72E-03 -34.2 I 0.11E-02 0.036 0.034 -6.4 0.041 0.68E-03 0.16E-03 -76.3 I 0.68E-03 0.041 0.036 -12.1 0.046 0.46E-03 0.68E-05 -98.5 I 0.46E-03 0.046 0.038 -17.3 0.052 0.31E-03 0.46E-05 -98.5 I 0.31E-03 0.052 0.040 -23.2 0.057 0.22E-03 0.46E-05 -97.9 I 0.22E-03 0.057 0.041 -28.1 0.062 0.12E-03 0.23E-05 -98.0 I 0.12E-03 0.062 0.043 -30.2 0.067 0.62E-04 0.23E-05 -96.3 I 0.62E-04 0.067 0.044 -34.5 0.073 0.34E-04 0.23E-05 -93.3 I 0.34E-04 0.073 0.045 -37.7 0.078 0.68E-05 0.23E-05 -66.7 I 0.68E-05 0.078 0.048 -37.9 0.083 0.23E-05 0.23E-05 0.0 I 0.23E-05 0.083 0.087 4.3 Maximum positive excursion = 0.007 cfs ( 8.4%) 'L (Q% fl L occurring at 0.080 cfs on the Base Data:exist.tsf and at 0.087 cfs on the New Data:rdout.tsf Maximum negative excursion = 0.032 cfs (-40.8%) occurring at 0.078 cfs on the Base Data:exist.tsf and at 0.046 cfs on the New Data:rdout.tsf Return Period 2 5 10 20 50 10Q rdout.pks in Sea-Tac ® exist.pks �� Y • • •-- //— / • moi i - i - i Lo ��✓s- /� ..--- 0 • -- • o , T• oo,-0— 0• •� o •� 0Oo 0,— ea,,,,,, li.::-:---.)-‘a c-r:14-1 — • 00000 00 u_ -- —---0 0000 0 ___-•o--- • 0 _0-0'0 0 a) o 0 0 10 — m U _ - (0 o • -- kfi 103I I i I I i I I i i i I 1 2 5 10 20 30 40 50 60 70 80 90 95 98 99 r Cumulative Probability 0 0 rdout.dur target.dur 10% co ♦ ' De7 1T1 k) VAt,t�.:7" o _ _ UuehrY tai Mitrz)En— U- U_ a) 0) co = R • U) • oo • • a V • O ♦ N • • 1 o • o 11111111-5 i l i Iliil i 11111-3 i l i i ilii i i i i III ! ' i i i I. 10-6 10 5 10 10 3 10 2 10-1 10° V Probability Exceedence APPENDIX C-2 TREATMENT FACILITIES DESIGN aC� -, � � � � n - oCLU\ii � cam - - :\I u J J _ J (WjQ1ET auza-A-v TREA- E 1T FADL.r_v TRIBUTARY UTARY AREAS) v ,'�~_ , /y_. SOUTH PGIS PERMEABLE zee PAVEMENT AREA 1 NORTH PGIS PERMEABLE ai _ r ri: EXISTING (8,7 3 SF) PAVEMENT AREA Y,e- —== ROAD (5,797 SF) — _ � - --- -- ,- - a SOUTH PGIS — _ �` i `PAVEMENT AREA >5% TI — J4351SF) 1L.` l„Y ; �'4:/11; b �' \� ` \ / / 7_..{ ";. €sty \\\\\ N '. \ I'o` 1 ' �\ \� 01 ma \'} // `tM"1\''.*I1:4*1."ii,'" ,r \\ 4\ R� ` w _.,_ ® `,.O '/' / I {}/' /:,, / / . t �, -, �/ ` // / /. / }�- t` n ''' — �� '—� /� _�.--^ i ,/' i / �� 1 . . - - _ I v -/ ,,.% , ,_ al �� BSONRonvs°" /� 'i SOUTH PGIS PERMEABLE ____ PAVEMENT AREA 2 I z: ,� — 3,139 SF) i i _ 44 S` Z4girg::4z ._� , ._. PGIS AREAS SF (AC): PERMEABLE PAVEMENT: 17,729 (0.41 AC)* z ASPHALT >5%: 4,351 (0.10 AC) OTHER ISOLATED ASPHALT Sc CONCRETE: 392 (0.01 AC) TOTAL PCIS: 22,472 (0.52 AC) o 5O 100 *120 SF OF CONCRETE DRAINS TO HERE (INCLUDED IN 392 SF TALLY) SCALE: 1" = 100 ft. �y dev15 Flow Frequency Analysis Time Series File:devl5.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- Flow Frequency Analysis Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period 0.048 6 8/27/01 18:00 0.118 1 100.00 0.990 0.033 8 9/17/02 17:45 0.090 2 25.00 0.960 0.090 2 12/08/02 17:15 0.065 3 10.00 0.900 0.038 7 8/23/04 14:30 0.053 4 5.00 0.800 0.051 5 10/28/04 16:00 0.051 5 3.00 0.667 0.053 4 10/27/05 10:45 0.048 6 2.00 0. 500 0.065 3 10/25/06 22:45 0.038 7 1.30 0.231 0.118 1 1/09/08 6:30 0.033 8 1.10 0.091 Computed Peaks 0.108 50.00 0.980 1500/1600 Benson South Pavement Area Entrance Runoff Calcs. 6/6/13 South CB Stormfilter N(flow)=Q(trt)*[(449gpm/cfs)/Q(trt) gpm/cart] Q(trt)=0.35*Q(2) Q(trt)=0.35(0.048) Q(trt)=0.0168 cfs N(flow)=0.0168*(449/7. 5) N(flow)=1.0 cartridges Page 1 devl5 KCRTS Program. . . File Directory: C:\KC_SWDM\KC_DATA\ [C] CREATE a new Time Series ST 0.00 0.00 0.000000 Till Forest 0.00 0.00 0.000000 Till Pasture 0.00 0.00 0.000000 Till Grass 0.00 0.00 0.000000 outwash Forest 0.00 0.00 0.000000 outwash Pasture 0.00 0.00 0.000000 outwash Grass 0.00 0.00 0.000000 wetland 0.10 0.00 0.000000 Impervious devl5.tsf T 1.00000 F [T] Enter the Analysis TOOLS Module [P] Compute PEAKS and Flow Frequencies devl5.tsf devl5.pks [R] RETURN to Previous Menu [X] exit KCRTS Program Page 1 4! Lj ail Determining Number of ► iv a ri Cartridges for Flow Based ENGINEERED SOLUTIONS Systems CONTECH Stormwater Solutions Inc. Engineer: CRH Date 6/6/2013 Site Information Project Name Eagle Ridge Project State Washington Project Location Renton Drainage Area, Ad 0.10 ac Impervious Area,Ai 0.10 ac Pervious Area, Ap 0.00 % Impervious 100% Runoff Coefficient, Rc 0.95 Water quality flow 0.02 cfs Peak storm flow 1.80 cfs Max Bypass Filter System Filtration brand StormFilter Cartridge height 18 in Specific Flow Rate 1.00 gpm/ft` Flow rate per cartridge 7.5 gpm SUMMARY Number of Cartridges 1 ©2006 CONTECH Stormwater Solutions contechstormwater.com 1 of 1 APPENDIX C-3 CONVEYANCE FACILITIES DESIGN Pli A G AI :D 0FIaCOND ,,,- y - N - u -v-vs QscirOoJu l�a�� C�B�dL .7Q�]C� � �� CB10 CD9 _ CB #s k� RIM 89.16 RIM 187.30 f CB ;7 1 IE 186.16 `�� -,. EXISTING RIM 186.77` f IE 184 70 RIM 186.75 ROAD IE 183.88 CB 14 �r _ IE 182.52 `�� ` RIM 181.50 _ 1 I E 179.00 _`` ' • — TI — --- _ � RIM 176 8 1 1 J � \% IEC 173.755 BLa� �; A { i � CB ;5 4 �: ` _ : �. (TRI$ TO �� \-\:\.\ -.. -\'"--';''',d /� � �\�v-. ,(NIm //� 2/ ��r6,� \ EM •�i .�,� , � 179 19 _ ,< ,Aye �� 494,E d "'£ j/ •.. t 1,;96;51TRIB � v .- /- �rfi? /AULT / CB J 4 i CB 11 d-- r � ; RIM 182.05 \ -‘--,e,/... /-_ " - 173.22 IE 168.70 I IE 170.65 f = ��N� ILTER CB ;2.'' Ap S01/1.14 ........ / „ i 173.40 VORT CB 3 I • i RIM 173. RIM 173.54 �., ."�, '_ —�= XISIING CB CB ;1 IE 170.54 ,,,,,,,,..7 7 ' RIM 161.72 RIM 164.48 _� — _` ! t, IE 158.10 IE 158.18 2 0 50 100 SCALE: 1" = 100 ft. r. G/ Conveyance Calculations Project: Eagle Ridge Offices and Condominiums Proj.#: 307-TFC Date: 4/8/2013 Use area weighted flows from KCRTS 15-minute analysis for conveyance calcs. Discharge Pipe from South Detention Vault filename: svltout Conveys entire flow from this basin Overflow 169.1 Qum= 1.5 cfs Length Dia Pipe Type Outlet-IE Inlet-IE Inlet Type O.F. Elev. Bnd Ang. Str. Dia. Q-Ratio 1 15.00 12.00 1 158.10 158.18 5 164.48 35.00 2 0.00 57.00 12.00 1 158.28 159.10 5 8" Pipe from Driveway Entrance filename: svltinl Conveys flow from 4,400 sf of parking and entrance blvd (about 8% of S basin tributary area) Overflow 179.19 Qioo = 0.12 cfs (.08*1.5) # Length Dia Pipe Type Outlet-IE Inlet-IE Inlet Type O.F. Elev. Bnd Ang. Str. Dia. Q-Ratio 2 3.00 8.00 1 168.10 168.13 5 173.40 90.00 4 0.00 3 11.00 8.00 1 170.43 170.54 5 173.54 45.00 4 0.00 4 11.00 8.00 1 170.54 170.65 5 173.22 80.00 2 0.50 5 50.00 8.00 1 170.75 176.09 5 8" Pipe from Upper Driveway filename: svltinl Conveys flow from 8,800 sf of parking and entrance drive + S bldg 19,966sf(about 54% of S basin tributary area) Overflow 189.16 Qioo = 0.81 cfs (.54*1.5) Length Dia Pipe Type Outlet-IE Inlet-IE Inlet Type O.F. Elev. Bnd Ang. Str. Dia. Q-Ratio 6 12.00 12.00 1 168.10 173.75 5 176.85 2.00 2 0.37 Z:\JOBS\300-399\307-tfc\TIR\Drainage CalcsConveyance 4/8/2013 f/ 7 53.00 8.00 1 173.85 182.52 5 Jf f0 186.75 40.00 2 0.33 8 68.00 8.00 1 182.42 183.88 5 186.77 0.00 2 0.50 9 36.00 8.00 1 183.88 184.70 5 187.30 0.00 2 1.00 10 189.16 8.00 1 184.80 186.16 5 Discharge Pipe from North Detention Vault filename: nvltout Conveys entire flow from this basin Overflow 179.06 Qmo= 1.1 cfs # Length Dia Pipe Type Outlet-IE Inlet-IE Inlet Type O.F. Elev. Bnd Ang. Str. Dia. Q-Ratio 11 12.00 12.00 1 168.97 169.06 5 8" Pipe from North Parking Area filename: nvltinl Conveys flow from entire N basin tributary area) Overflow 181 am= 1.1 cfs # Length Dia Pipe Type Outlet-IE Inlet-IE Inlet Type O.F. Elev. Bnd Ang. Str. Dia. Q-Ratio 14 15.00 8.00 1 177.64 179.00 5 Z:\JOBS\300-399\307-tfc\TIR\Drainage CalcsConveyance 4/8/2013 tqi svltout KING COUNTY DEPARTMENT OF NATURAL RESOURCES Water and Land Resources Division BACKWATER ANALYSIS PROGRAM Version 6.00 File Opened for Reading:svltout.bwp File Opened for Writing:svltout.doc BACKWATER COMPUTER PROGRAM FOR PIPES Pipe data from file:svltout.bwp Surcharge condition at intermediate junctions Tailwater Elevation:159.1 feet Discharge Range:0. 5 to 3. Step of 0. 5 [cfs] Overflow Elevation:169.1 feet Weir:NONE Upstream Velocity:l. feet/sec PIPE NO. 1: 15 LF - 12"CP @ 0. 53% OUTLET: 158.10 INLET: 158.18 INTYP: 5 JUNC NO. 1: OVERFLOW-EL: 164.48 BEND: 35 DEG DIA/WIDTH: 2.0 Q-RATIO: 0.00 Q(CFS) HW(FT) HW ELEV. N-FAC DC DN TW DO DE HWO HWI is it it dr***** itd....,..„.,..'.r*e'r'rit**it**:r it i;***...,***it it it*i;:,::**it*it i; ....*•*it it it it it*it****it**it::..****it 0. 50 0.94 159.12 * 0.012 0.30 0.29 1.00 1.00 0.93 0.94 0.40 1.00 0.95 159.13 0.012 0.43 0.42 1.00 1.00 0.93 0.95 0. 57 1. 50 0.99 159.17 0.012 0. 52 0. 52 1.00 1.00 0.94 0.99 0.72 2.00 1.04 159.22 s, 0.012 0.61 0.63 1.00 1.00 0.96 1.04 0.84 2. 50 1.10 159.28 0.012 0.68 0.74 1.00 1.00 0.98 1.10 0.96 3.00 1.18 159. 36 * 0.012 0.75 0.90 1.00 1.00 1.01 1.18 1.08 PIPE NO. 2: 57 LF - 12"CP @ -0.32% OUTLET: 158.28 INLET: 158.10 INTYP: 5 Q(CFS) HW(FT) HW ELEV. N-FAC DC DN TW DO DE HWO HWI .r*****is*i.is**** .:*i.********it4:*******•*it**it****$r****dr'...,*************** k::................ 0.50 1.04 159. 14 0.012 0.30 0.00 0.84 0.84 1.04 1.03 0.39 1.00 1.10 159.20 0.012 0.43 0.00 0.85 0.85 1.08 1.10 0. 58 1.50 1.23 159.33 * 0.012 0. 52 0.00 0.89 0.89 1.16 1.23 0.75 2.00 1.41 159. 51 0.012 0.61 0.00 0.94 0.94 1.27 1.41 0.91 2.50 1.64 159.74 * 0.012 0.68 0.00 1.00 1.00 1.42 1.64 1.07 3.00 1.93 160.03 0.012 0.75 0.00 1.08 1.08 1.61 1.93 1.23 File Opened for Writing:svltout.bwt Save results to HW/TW file:svltout.bwt Exit KCBW Program KING COUNTY DEPARTMENT OF NATURAL RESOURCES Water and Land Resources Division BACKWATER ANALYSIS PROGRAM Version 6.00 Page 1 q0 svltin1 KING COUNTY DEPARTMENT OF NATURAL RESOURCES Water and Land Resources Division BACKWATER ANALYSIS PROGRAM Version 6.00 File Opened for Reading:svltinl.bwp File Opened for Writing:svltinl.doc BACKWATER COMPUTER PROGRAM FOR PIPES Pipe data from file:svltinl.bwp Surcharge condition at intermediate junctions Tailwater Elevation:I09.I feet Discharge Range:0. 5 to 2. Step of 0.5 [cfs] Overflow Elevation:179.I9 feet Weir:NONE Upstream Velocity:l' feet/sec PIPE NO. 1: 3 LF - 8^[P @ I.00& OUTLET: I68.I0 INLET: I68.13 INTYP: 5 JUNC NO. 1: OVERFLOW-EL: I73.40 BEND: 90 DEG DIA/WIDTH: 4.0 Q-RATIO: 0.00 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI ***********w******^**^****w*******^^***^*^^***+^**w^************»***^******+*a* 0. 50 I.04 169.I7 * 0.012 0.34 0.29 1.00 1.00 0.98 I.04 0.49 1.00 1.22 169. 35 * 0.0I2 0.48 0.44 I.00 1.00 0.99 I.22 0.8I 1. 50 1. 53 169.66 * 0.0I2 0. 58 0.67 1.00 1.00 I.01 1. 53 1.27 2.00 1.97 170.I0 * 0.012 0.63 0.67 1.00 1.00 1.04 1.97 1.91 PIPE NO. 2: 11 LF - 8"CP @ 1.00% OUTLET: I70.43 INLET: I70. 54 INTYP: 5 JUNC NO. 2: OVERFLOW-EL: 173. 54 BEND: 45 DEG DIA/WIDTH: 4.0 Q-RATIO: 0.00 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI *****a****^*^***++**+^****+***+++*^^***^*+**+*****^*****a+^^*^****+*^^********* 0.50 0.46 171.00 * 0.0I2 0.34 0.29 0.00 0.29 0.34 ***** 0'46 1.00 0.69 I7I.23 * 0.0I2 0.48 0.44 0.00 0.44 0.48 «^^+* 0.69 1. 50 1.00 171. 54 * 0.012 0.58 0.67 0.00 0. 58 0.64 0.91 I.00 2.00 1.44 I71.98 * 0.0I2 0.63 0.67 0.00 0.63 0.79 1.24 1.44 PIPE NO. 3: 11 LF - 8"CP @ 1.00% OUTLET: 170. 54 INLET: 170.85 INTYP: 5 JUNC NO. 3: OVERFLOW-EL: I73.22 BEND: 80 DEG DIA/WIDTH: 2.0 Q-RATIO: 0' 50 Q(CFS) HW(FT) Hw ELEV. + N-FAC DC DN TW DO DE HWO HWI ***^*++*x**********+*^******+*******+***^^****+*^+*^+^******+*+**^^********w*** 0. 50 0.48 171.13 * 0.012 0.34 0.29 0.46 0.46 0. 34 *^*** 0.48 1.00 0.86 171. 51 * 0.0I2 0.48 0.44 0.69 0.69 0.64 0.86 0.79 1.50 1. 52 172.I7 * 0.012 0.58 0.67 1.00 I.00 I.04 1. 52 1.23 2.00 2.44 173'09 * 0.012 0.63 0.67 1.44 1.44 1. 59 2.44 1.84 PIPE NO. 4: 50 LF - 8^[P @ 8.68% OUTLET: 170.75 INLET: 175.09 INTYP: 5 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HwZ *+*+^**^**********a*^^*^****+************^a**^*^^*^+^**^******^*+**^^*******^^* 0.33 0.33 175.42 * 0.012 0.27 0.14 0.38 0.38 0.27 ***^* 0.33 0.67 0. 53 175.62 * 0.012 0.39 0.I9 0.76 0.76 0.39 ***** 0. 53 1.00 0.73 175.82 * 0.012 0.48 0.24 1.42 1.42 0.48 ***** 0.73 1.33 0.98 176.07 * 0.012 0. 55 0.28 2.34 2.34 0. 55 *+^** 0.98 Page 1 svltinl File opened for writing:svltinl.bwt save results to Hw/TW file:svltinl.bwt Exit KCBW Program KING COUNTY DEPARTMENT OF NATURAL RESOURCES water and Land Resources Division BACKWATER ANALYSIS PROGRAM version 6.00 Page 2 7f) (10 svltin2 KING COUNTY DEPARTMENT OF NATURAL RESOURCES Water and Land Resources Division BACKWATER ANALYSIS PROGRAM Version 6.00 File Opened for Reading:svltin2.bwp File Opened for Writing:svltin2.doc BACKWATER COMPUTER PROGRAM FOR PIPES Pipe data from file:svltin2.bwp Surcharge condition at intermediate junctions Tailwater Elevation:169.1 feet Discharge Range:0. 5 to 2. Step of 0. 5 [cfs] Overflow Elevation:189.16 feet Weir:NONE Upstream velocity:l. feet/sec PIPE NO. 1: 12 LF - 12"CP @ 47.08% OUTLET: 168.10 INLET: 173.75 INTYP: 5 JUNC NO. 1: OVERFLOW-EL: 176.85 BEND: 2 DEG DIA/WIDTH: 2.0 Q-RATIO: 0.37 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI ..******........*****ire....* ***'..*..**R*******..*****************:':*****..******:r****.......... 0. 50 0. 30 174.05 * 0.012 0.30 0.10 1.00 1.00 0. 30 ***** 0.16 1.00 0.43 174.18 * 0.012 0.43 0.14 1.00 1.00 0.43 -r*';."r 0.31 1.50 0. 52 174.27 * 0.012 0. 52 0.17 1.00 1.00 0. 52 ***** 0.42 2.00 0.61 174.36 * 0.012 0.61 0.19 1.00 1.00 0.61 ***** 0.49 PIPE NO. 2: 53 LF - 8"CP @ 16.36% OUTLET: 173.85 INLET: 182. 52 INTYP: 5 JUNC NO. 2: OVERFLOW-EL: 186.75 BEND: 40 DEG DIA/WIDTH: 2.0 Q-RATIO: 0.33 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI *****4.........*ti.........***......**...,*......................***,...........'r:,...,.,...........,......................***..**..*** 0.36 0. 34 182.86 * 0.012 0.29 0.12 0.20 0.20 0.29 ***** 0.34 0.73 0. 56 183.08 * 0.012 0.41 0.17 0.33 0.33 0.41 ***** 0. 56 1.09 0.78 183.30 * 0.012 0. 50 0.21 0.42 0.42 0. 50 ***** 0.78 1.46 1.09 183.61 * 0.012 0. 57 0.24 0. 51 0. 51 0. 57 ***** 1.09 PIPE NO. 3: 68 LF - 8"CP @ 2.15% OUTLET: 182.42 INLET: 183.88 INTYP: 5 JUNC NO. 3: OVERFLOW-EL: 186.77 BEND: 0 DEG DIA/WIDTH: 2.0 Q-RATIO: 0. 50 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI *****i.*** *R....***d.*****..****d.**'.r'.********** *'.r'.;*****..*********?.*....***d.********* 0.27 0.33 184.21 * 0.012 0.25 0.18 0.44 0.44 0.25 ***** 0.33 0. 55 0.49 184. 37 * 0.012 0.35 0.25 0.66 0.66 0.35 ***** 0.49 0.82 0.64 184. 52 * 0.012 0.43 0.31 0.88 0.88 0.43 ***** 0.64 1.10 0. 79 184.67 * 0.012 0.50 0.37 1.19 1.19 0. 50 ***** 0.79 PIPE NO. 4: 36 LF - 8"CP @ 2.28% OUTLET: 183.88 INLET: 184.70 INTYP: 5 JUNC NO. 4: OVERFLOW-EL: 187.30 BEND: 0 DEG DIA/WIDTH: 2.0 Q-RATIO: 1.00 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI ***********************:r*..**********4;**********;***************..************** 0.18 0.26 184.96 * 0.012 0.20 0.14 0.33 0.33 0.20 ***** 0.26 0.37 0.39 185.09 0.012 0.29 0.20 0.49 0.49 0.29 ***** 0.39 0. 55 0. 50 185.20 * 0.012 0.35 0.25 0.64 0.64 0. 35 ***** 0. 50 Page 1 afro svltin2 0.73 0.60 185.30 * 0.012 0.41 0.29 0.79 0.79 0.41 ***** 0.60 PIPE NO. 5: 189 LF - 8"CP @ 0.72% OUTLET: 184.80 INLET: 186.16 INTYP: 5 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI *:r'rir'.ririririr:r*•'.r****ir'r::'.r;Y'r'.rir'.rir'rir**** rir:rir*irir* ***irir'r******'..•iririri ****iririr*******i;irir*** 0.09 0.17 186.33 * 0.012 0.14 0.13 0.16 0.16 0.14 ***** 0.17 0.18 0.25 186.41 * 0.012 0.20 0.19 0.29 0.29 0.20 ***** 0.25 0.27 0.32 186.48 * 0.012 0.25 0.23 0.40 0.40 0.25 ***** 0.32 0.37 0.38 186. 54 * 0.012 0.29 0.27 0. 50 0.50 0.29 ***** 0.38 File Opened for Writing:svltin2.bwt Save results to HW/TW file:svltin2.bwt Exit KCBW Program KING COUNTY DEPARTMENT OF NATURAL RESOURCES Water and Land Resources Division BACKWATER ANALYSIS PROGRAM Version 6.00 Page 2 nvltout KING COUNTY DEPARTMENT OF NATURAL RESOURCES Water and Land Resources Division BACKWATER ANALYSIS PROGRAM Version 6.00 File Opened for Reading:nvltout.bwp File Opened for writing:nvltout.doc BACKWATER COMPUTER PROGRAM FOR PIPES Pipe data from file:nvltout.bwp Surcharge condition at intermediate junctions Tailwater Elevation:169.7 feet Discharge Range:0. 5 to 3. Step of 0. 5 [cfs] Overflow Elevation:179.06 feet Weir:NONE Upstream Velocity:l. feet/sec PIPE NO. 1: 12 LF - 12"CP @ 0.75% OUTLET: 168.97 INLET: 169.06 INTYP: 5 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI **********i.** **........**** ***....................*4........,.,*..**......******k**- ***.,..*****'.......'.r** 0. 50 0.65 169.71 * 0.012 0.30 0.27 0.73 0.73 0.64 0.65 0.38 1.00 0.71 169.77 * 0.012 0.43 0.38 0.73 0.73 0.64 0.71 0. 58 1. 50 0.81 169.87 * 0.012 0. 52 0.47 0.73 0.73 0.64 0.81 0.74 2.00 0.96 170.02 * 0.012 0.61 0. 56 0.73 0.73 0.63 0.96 0.90 2.50 1.06 170.12 * 0.012 0.68 0.65 0.73 0.73 0.68 ****'r 1.06 3.00 1.23 170.29 * 0.012 0.75 0.74 0.73 0.74 0.75 *** 1.23 File Opened for Writing:nvltout.bwt Save results to HW/TW file:nvltout.bwt Exit KCBW Program KING COUNTY DEPARTMENT OF NATURAL RESOURCES Water and Land Resources Division BACKWATER ANALYSIS PROGRAM Version 6.00 Page 1 rD1(0 nvltinl KING COUNTY DEPARTMENT OF NATURAL RESOURCES Water and Land Resources Division BACKWATER ANALYSIS PROGRAM Version 6.00 File Opened for Reading:nvltinl.bwp File Opened for Writing:nvltinl.doc BACKWATER COMPUTER PROGRAM FOR PIPES Pipe data from file:nvltinl.bwp Surcharge condition at intermediate junctions Tailwater Elevation:179.06 feet Discharge Range:0. 5 to 2. Step of 0. 5 [cfs] Overflow Elevation:181. feet Weir:NONE Upstream Velocity:l. feet/sec PIPE NO. 1: 15 LF - 8"CP @ 9.07% OUTLET: 177.64 INLET: 179.00 INTYP: 5 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI ******** ************:Y ***** ;4':',: *************'.:::::':* ir* **':'.:::'.:a:************i::Y** 0. 50 0.44 179.44 0.012 0.34 0.17 1.42 1.42 0.34 °**** 0.44 1.00 0.73 179.73 * 0.012 0.48 0.23 1.42 1.42 0.48 ***** 0.73 1. 50 1.14 180.14 * 0.012 0. 58 0.29 1.42 1.42 0. 58 ***** 1.14 2.00 1.71 180.71 * 0.012 0.63 0.34 1.42 1.42 0.63 ***** 1.71 File Opened for Writing:nvltinl.bwt Save results to HW/TW file:nvltinl.bwt Exit KCBW Program KING COUNTY DEPARTMENT OF NATURAL RESOURCES Water and Land Resources Division BACKWATER ANALYSIS PROGRAM Version 6.00 Page 1 APPENDIX C-4 EROSION CONTROL FACILITIES DESIGN ` 50 0 0 - I0 Eof SUN QFL J M EN—s o Oo �C�Es QEoSooN c�oN� oLI i7A r / , .-\. -o)-- ,/ 'S�4C ,.,,%:,,,,,...,/ " �.., tv,.y . \I/ � �\ AF; ,• \ �/ y + tomI� . 5 \\\ J.Y. b y , ti ;. n�'„` ,N,::'`^ ^..-_.... " .�,",�',::ate--T- -_ O'f',) - zx s a t‘t ���"`� ,17.17..„,--=_,- ------.1. _.:.., `f:>...Yu'� _ - "• \ \ r— 2^t". �yy ,/,. ce J .. .. ^rte.�<.. .^^.._^ ,. �� .t \ .,� •.. ...� If �.... .,,. ... �-c� �� �����`-vim —^ \� �\\, ��� r ..% /....„ ..,.. ... h I ,. \�,I,,�\ �\ yt..� my{aCuK a&' .' + \C, '>1}�3Ia+#• � "Sv h.~ \.._._ '.. \ A r syr tri •yam r# ,moi 4 '� v ._... c' °s tsi ..„.z. _ .......„_ ,.... \fie+ �j t+ ��- I � \ ...\_-„,.....„\\N,, ;_\_.;,,, ,-;....., ,,.,,. -' ♦ f ## e.''1,1.A: d i n K aim .,-.6\ b c Kv A �' �k.„,,,�\ ,�• i''',--' � ' 1 1, A a s ,� ' $ ii,"K* ._ � / ig ; 2 ,..„./,,,,; }y�uim yt • t— ( l a\ _`'• '*tk ]k" Y,w,„„.,.wti- _� RO �'' EN t i K *' . 0.0.„v -' OUTLINE OF AREA TRIBUTARY TO - SA {S i , BAKER TANK SETTLEMENT AND _.."'J nc,; f 4 µ.t MA, rrr +'..t. 7 FLOW CONTROL,:: AREA TRIBUTARY TO PROPOPSED BAKER TANK MITIGATION = 115,971 SF (2.66 ACRES) z e) 0 50 100 I SCALE: 1" = 100 ft. Flow Frequency Analysis 2/3 Time Series File:escl5.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- Flow Frequency Analysis Flow Rate Rank Time of Peak -- Peaks-- Rank Return Prob ta203 I Oki 6OL. (CFS) (CFS) Period 1.27 6 8/27/01 18:00 3.51 1 100.00 0.990 Ci: 0.885 8 9/17/02 17:45 2.56 2 25.00 0.960 1� .5 2.56 2 12/08/02 17:15 1.74 3 10.00 0.900 1.02 7 8/23/04 14:30 1.46 4 5.00 0.800 1.38 5 10/28/04 16:00 1.38 5 3.00 0.667 1.46 4 10/27/05 10:45 1.27 6 2.00 0.500 de-- QZ 1.74 3 10/25/06 22:45 1.02 7 1.30 0.231 3.51 1 1/09/08 6:30 0.885 8 1.10 0.091 Computed Peaks 3.19 50.00 0.980 Sediment Pond Sizing: SA=2080`Q2 SA=2080`1.27 SA=2,642 sf >> space available, so use Baker Tanks KCRTS Program...File Directory: ?!3 C:\KC_SWDM\KC_DATA\ [C]CREATE a new Time Series ST 0.21 0.00 0.000000 Till Forest pstu N Cou-rt?Oc-- 0.00 0.00 0.000000 Till Pasture 0.70 0.00 0.000000 Till Grass I pLer- Dyk-FA 0.00 0.00 0.000000 Outwash Forest 0.00 0.00 0.000000 Outwash Pasture 0.00 0.00 0.000000 Outwash Grass 0.00 0.00 0.000000 Wetland 2.66 0.00 0.000000 Impervious esc15.tsf T 1.00000 F [T] Enter the Analysis TOOLS Module [P]Compute PEAKS and Flow Frequencies esc15.tsf esc15.pks [R] RETURN to Previous Menu [X]eXit KCRTS Program APPENDIX D MAINTENANCE REQUIREMENTS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES MAINTENANCE AND OPERATIONS MANUAL FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES ADDRESS: 1500 & 1600 Benson Road South Renton, Washington RETENTION/DETENTION FACILITY YI 3 The purpose of the detention vaults is to reduce the rate of runoff from the developed portions of the property to historic levels. Water can flow freely into the vaults, but orifices in the outflow risers restrict the outflow. When the inflow exceeds the capacity of the orifices, the excess water is "stored" in the vaults and released slowly after the storm abates. In order to function properly, the vaults must also be kept free of accumulated sediment. The outlet pipes also must be kept clean, as even a partial blockage could significantly impact the ability of a facility to store runoff. The facilities should be visually inspected for sediment accumulation and blockages at least once each year and also after every major storm greater than or equal to a 10-year return frequency. STORMWATER MANAGEMENT CARTRIDGE FILTER MANHOLE AND CDS HYDRODYNAMIC TREATMENT FACILITIES The hydrodynamic separation and cartridge filter treatment facilities should be inspected and maintained in accordance with the manufacturer's recommendations (attached). CONVEYANCE SYSTEMS Pipes transport runoff from one place to another, in this case from catch basins and cartridge filters to the vaults, then to the downstream drainage system. To work properly, pipes must be kept free of silt and other debris. If pipes become blocked, surface flooding will usually occur. CATCH BASINS AND AREA DRAINS Catch basins collect surface drainage and direct it into storm conveyance pipes. They help prevent downstream drainage problems by trapping sediment and other debris that would otherwise flow downstream with the runoff. It is important to keep catch basins clean so accumulated silt is not flushed out during a significant storm. Also, if the outflow pipe becomes blocked with debris, surface flooding will usually occur. All catch basins should be inspected at least once each year and after major storms. Area drains convey runoff directly into conveyance pipes. To prevent surface flooding, their surface grates must be kept free of litter and debris. If dirt or other sediment gets into the pipes and they become blocked, the pipes will need to be cleaned, either manually or using a Vactor truck. PERMEABLE PAVEMENT Permeable pavements must be inspected after one major storm each year to make sure it is working properly. Prolonged ponding or standing water on the pavement surface is a sign that the system is defective and may need to be replaced. If this occurs, contact the pavement installer or the King County Water and Land Resources Division for further instructions. A typical permeable pavement system has a life expectancy of approximately 25-years. To help extend the useful life of the system, the surface of the permeable pavement should be kept clean and free of leaves, debris, and sediment through regular sweeping or vacuum sweeping. The owner is responsible for the repair of all ruts, deformation, and/or broken paving units. The following tables identify maintenance issues, which should be addressed regularly, describing possible problems with the drainage system and their respective solutions. 1 z APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL,CONVEYANCE,AND WQ FACILITIES /(3 NO. 3-DETENTION TANKS AND VAULTS Maintenance Defect or Problem Conditions When Maintenance is Needed Results Expected When Component Maintenance is Performed Storage Area Plugged Air Vents One-half of the cross section of a vent is blocked Vents free of debris and sediment at any point with debris and sediment. Debris and Sediment Accumulated sediment depth exceeds 10%of All sediment and debris removed the diameter of the storage area for%length of from storage area. storage vault or any point depth exceeds 15%of diameter. Example:72-inch storage tank would require cleaning when sediment reaches depth of 7 inches for more than'/z length of tank. Joints Between Any crack allowing material to be transported into All joint between tank/pipe sections Tank/Pipe Section facility. are sealed Tank Pipe Bent Out of Any part of tank/pipe is bent out of shape more Tank/pipe repaired or replaced to Shape than 10%of its design shape. design. Vault Structure Damage to Wall, Cracks wider than%-inch and any evidence of Vault replaced or repaired to design Frame, Bottom, soil particles entering the structure through the specifications. and/or Top Slab cracks,or maintenance inspection personnel determines that the vault is not structurally sound. Damaged Pipe Joints Cracks wider than%-inch at the joint of any No cracks more than 1A-inch wide at inlet/outlet pipe or any evidence of soil particles the joint of the inlet/outlet pipe. entering the vault through the walls. Manhole Cover Not in Place Cover is missing or only partially in place.Any Manhole is closed. open manhole requires maintenance. Locking Mechanism Mechanism cannot be opened by one Mechanism opens with proper tools. Not Working maintenance person with proper tools.Bolts into frame have less than 1/2 inch of thread(may not apply to self-locking lids.) Cover Difficult to One maintenance person cannot remove lid after Cover can be removed and Remove applying 801bs of lift. Intent is to keep cover from reinstalled by one maintenance sealing off access to maintenance. person. Ladder Rungs Unsafe King County Safety Office and/or maintenance Ladder meets design standards. person judges that ladder is unsafe due to Allows maintenance person safe missing rungs, misalignment, rust,or cracks. access. Large access Gaps, Doesn't Cover Large access doors not flat and/or access hole Doors closes flat and covers access doors/plate Completely not completely covered. NOTE however that hole completely. grated doors are acceptable. Lifting Rings Missing, Lifting rings not capable of lifting weight of door Lifting rings sufficient to remove lid. Rusted or lid. 1/24/2005 2005 Surface Water Design Manual—Appendix A A-4 APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL,CONVEYANCE,AND WQ FACILITIES 3�3 NO. 4-CONTROL STRUCTURE/FLOW RESTRICTOR Maintenance Defect or Problem Condition When Maintenance is Needed Results Expected When Component Maintenance is Performed General Trash and Debris Distance between debris build-up and bottom of All trash and debris removed. (Includes Sediment) orifice plate is less than 1.5 feet. Structural Damage Structure is not securely attached to manhole Structure securely attached to wall wall and outlet pipe structure should support at and outlet pipe. least 1,000 lbs of up or down pressure. Structure is not in upright position(allow up to Structure in correct position. 10%from plumb). Connections to outlet pipe are not watertight and Connections to outlet pipe are water show signs of rust. tight;structure repaired or replaced and works as designed. Any holes--other than designed holes—in the Structure has no holes other than structure. designed holes. Cleanout Gate Damaged or Missing Cleanout gate is not watertight or is missing. Gate is watertight and works as designed. Gate cannot be moved up and down by one Gate moves up and down easily and maintenance person. is watertight. Chain/rod leading to gate is missing or damaged. Chain is in place and works as designed. Gate is rusted over 50%of its surface area. Gate is repaired or replaced to meet design standards. Orifice Plate Damaged or Missing Control device is not working properly due to Plate is in place and works as missing,out of place,or bent orifice plate. designed. Obstructions Any trash,debris,sediment,or vegetation Plate is free of all obstructions and blocking the plate. works as designed. Overflow Pipe Obstructions Any trash or debris blocking(or having the Pipe is free of all obstructions and potential of blocking)the overflow pipe. works as designed. Manhole See"Detention Tanks See"Detention Tanks and Vaults"Table No. 3 See"Detention Tanks and Vaults" and Vaults" Table No. 3 2005 Surface Water Design Manual–Appendix A 1/24/2005 A-5 94 APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL,CONVEYANCE,AND WQ FACILITIES 3 NO. 5-CATCH BASINS Maintenance Defect or Problem Conditions When Maintenance is Needed Results Expected When Component Maintenance is performed General Trash&Debris Trash or debris of more than 1/2 cubic foot which No Trash or debris located (Includes Sediment) is located immediately in front of the catch basin immediately in front of catch basin opening or is blocking capacity of the basin by opening. more than 10%. Trash or debris(in the basin)that exceeds 1/3 the No trash or debris in the catch depth from the bottom of basin to invert the basin. lowest pipe into or out of the basin. Trash or debris in any inlet or outlet pipe blocking Inlet and outlet pipes free of trash or more than 1/3 of its height. debris. Dead animals or vegetation that could generate No dead animals or vegetation odors that could cause complaints or dangerous present within the catch basin. gases(e.g.,methane). Deposits of garbage exceeding 1 cubic foot in No condition present which would volume. attract or support the breeding of insects or rodents. Structure Damage to Comer of frame extends more than%inch past Frame is even with curb. Frame and/or Top curb face into the street(If applicable). Slab Top slab has holes larger than 2 square inches Top slab is free of holes and cracks. or cracks wider than'/4 inch(intent is to make sure all material is running into basin). Frame not sitting flush on top slab, i.e., Frame is sitting flush on top slab. separation of more than%inch of the frame from the top slab. Cracks in Basin Cracks wider than'/7 inch and longer than 3 feet, Basin replaced or repaired to design Walls/Bottom any evidence of soil particles entering catch standards. basin through cracks,or maintenance person judges that structure is unsound. Cracks wider than'A inch and longer than 1 foot No cracks more than 1/4 inch wide at at the joint of any inlet/outlet pipe or any the joint of inlet/outlet pipe. evidence of soil particles entering catch basin through cracks. Settlement/ Basin has settled more than 1 inch or has rotated Basin replaced or repaired to design Misalignment more than 2 inches out of alignment. standards. Fire Hazard Presence of chemicals such as natural gas,oil No flammable chemicals present. and gasoline. Vegetation Vegetation growing across and blocking more No vegetation blocking opening to than 10%of the basin opening. basin. Vegetation growing in inlet/outlet pipe joints that No vegetation or root growth is more than 6 inches tall and less than 6 inches present. apart. Pollution Nonflammable chemicals of more than'/z cubic No pollution present other than foot per three feet of basin length. surface film. Catch Basin Cover Cover Not in Place Cover is missing or only partially in place.Any Catch basin cover is closed open catch basin requires maintenance. Locking Mechanism Mechanism cannot be opened by on Mechanism opens with proper tools. Not Working maintenance person with proper tools. Bolts into frame have less than''A inch of thread. Cover Difficult to One maintenance person cannot remove lid after Cover can be removed by one Remove applying 80 lbs.of lift;intent is keep cover from maintenance person. sealing off access to maintenance. Ladder Ladder Rungs Unsafe Ladder is unsafe due to missing rungs, Ladder meets design standards and misalignment,rust, cracks,or sharp edges. allows maintenance person safe access. 1/24/2005 2005 Surface Water Design Manual—Appendix A A-6 APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL,CONVEYANCE,AND WQ FACILITIES 5�3 NO. 5-CATCH BASINS Maintenance Defect or Problem Conditions When Maintenance is Needed Results Expected When Component Maintenance is performed Metal Grates Unsafe Grate Grate with opening wider than 7/8 inch. Grate opening meets design (If Applicable) Opening standards. Trash and Debris Trash and debris that is blocking more than 20% Grate free of trash and debris. of grate surface. Damaged or Missing. Grate missing or broken member(s)of the grate. Grate is in place and meets design standards. NO. 6- DEBRIS BARRIERS (E.G., TRASH RACKS) Maintenance Defect or Problem Condition When Maintenance is Needed Results Expected When Component Maintenance is Performed. General Trash and Debris Trash or debris that is plugging more than 20% Barrier clear to receive capacity of the openings in the barrier. flow. Metal Damaged/Missing Bars are bent out of shape more than 3 inches. Bars in place with no bends more Bars. than 3/4 inch. Bars are missing or entire barrier missing. Bars in place according to design. Bars are loose and rust is causing 50% Repair or replace barrier to design deterioration to any part of barrier. standards. NO. 7-ENERGY DISSIPATERS Maintenance Defect or Problem Conditions When Maintenance is Needed Results Expected When Component Maintenance is Performed. External: Rock Pad Missing or Moved Only one layer of rock exists above native soil in Replace rocks to design standards. Rock area five square feet or larger,or any exposure of native soil. Dispersion Trench Pipe Plugged with Accumulated sediment that exceeds 20%of the Pipe cleaned/flushed so that it Sediment design depth. matches design. Not Discharging Visual evidence of water discharging at Trench must be redesigned or Water Properly concentrated points along trench(normal rebuilt to standards. condition is a"sheet flow"of water along trench). Intent is to prevent erosion damage. Perforations Plugged. Over'/2 of perforations in pipe are plugged with Clean or replace perforated pipe. debris and sediment. Water Flows Out Top Maintenance person observes water flowing out Facility must be rebuilt or of"Distributor"Catch during any storm less than the design storm or redesigned to standards. Basin. its causing or appears likely to cause damage. Receiving Area Over- Water in receiving area is causing or has No danger of landslides. Saturated potential of causing landslide problems. Internal: Manhole/Chamber Worn or Damaged Structure dissipating flow deteriorates to'A or Replace structure to design Post.Baffles,Side of original size or any concentrated worn spot standards. Chamber exceeding one square foot which would make structure unsound. 2005 Surface Water Design Manual—Appendix A 1/24/2005 A-7 APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL,CONVEYANCE,AND WQ FACILITIES ' +. NO. 10-CONVEYANCE PIPES AND DITCHES Maintenance Defect or Problem Conditions When Maintenance is Needed Results Expected When Component Maintenance is Performed Pipes Sediment&Debris Accumulated sediment that exceeds 20%of the Pipe cleaned of all sediment and diameter of the pipe. debris. Vegetation Vegetation that reduces free movement of water All vegetation removed so water through pipes. flows freely through pipes. Damaged Protective coating is damaged;rust is causing Pipe repaired or replaced. more than 50%deterioration to any part of pipe. Any dent that decreases the cross section area Pipe repaired or replaced. of pipe by more than 20%. Open Ditches Trash&Debris Trash and debris exceeds 1 cubic foot per 1,000 Trash and debris cleared from square feet of ditch and slopes. ditches. Sediment Accumulated sediment that exceeds 20%of the Ditch cleaned/flushed of all design depth. sediment and debris so that it matches design. Vegetation Vegetation that reduces free movement of water Water flows freely through ditches. through ditches. Erosion Damage to See"Detention Ponds"Table No. 1 See"Detention Ponds"Table No. 1 Slopes Rock Lining Out of Maintenance person can see native soil beneath Replace rocks to design standards. Place or Missing(If the rock lining. Applicable). NO. 11 -GROUNDS (LANDSCAPING) Maintenance Defect or Problem Conditions When Maintenance is Needed Results Expected When Component Maintenance is Performed General Weeds Weeds growing in more than 20%of the Weeds present in less than 5%of (Nonpoisonous,not landscaped area(trees and shrubs only). the landscaped area. noxious) Safety Hazard Any presence of poison ivy or other poisonous No poisonous vegetation present in vegetation. landscaped area. Trash or Litter Paper,cans, bottles,totaling more than 1 cubic Area clear of litter. foot within a landscaped area(trees and shrubs only)of 1,000 square feet. Trees and Shrubs Damaged Limbs or parts of trees or shrubs that are split or Trees and shrubs with less than 5% broken which affect more than 25%of the total of total foliage with split or broken foliage of the tree or shrub. limbs. Trees or shrubs that have been blown down or Tree or shrub in place free of injury. knocked over. Trees or shrubs which are not adequately Tree or shrub in place and supported or are leaning over,causing exposure adequately supported;remove any of the roots. dead or diseased trees. 2005 Surface Water Design Manual—Appendix A 1/24/2005 A-9 7 APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL,CONVEYANCE,AND WQ FACILITIES 13 NO. 20-STORMFILTER° Maintenance Defect or Problem Condition When Maintenance is Needed Recommended Maintenance to Component Correct Problem Media Section Sediment Sediment depth exceeds 0.25 inches. No sediment deposits that would Accumulation on impede permeability of the compost Media. media. Trash/Debris Trash and debris accumulated on compost filter Trash and debris removed from the Accumulation bed. compost filter bed. First Chamber Sediment Sediment depth exceeds 6 inches in first No sediment deposits in vault Accumulation chamber. bottom of first chamber. Drain Pipes Clean- Sediment When drain pipes,clean-outs, become full with Remove the accumulated material Outs Accumulation sediment and/or debris. from the facilities. NO. 21 -STORMFILTER°(CARTRIDGE TYPE) Maintenance Defect or Problem Condition When Maintenance is Needed Recommended Maintenance to Component Correct Problem Compost Media Plugged Drawdown of water through the media takes Replace media cartridges. longer than 1 hour,and/or overflow occurs frequently. Short Circuiting Flows do not properly enter filter cartridges. Replace filter cartridges. Pipes Damaged Any part of the pipes that are crushed,damaged Pipe repaired and/or replaced. due to corrosion and/or settlement. Access Cover Damaged/Not Cover cannot be opened,one person cannot Cover repaired to proper working Working open the cover,corrosion/deformation of cover. specifications or replaced. Vault Structure Damage to Wall, Cracks wider than 1/4-inch and any evidence of Vault replaced or repaired to design Frame, Bottom, soil particles entering the structure through the specifications. and/or Top Slab cracks,or maintenance/inspection personnel determines that the vault is not structurally sound. Damaged Pipe Joints Cracks wider than'/3-inch at the joint of any No cracks more than'/.-inch wide at inlet/outlet pipe or any evidence of soil particles the joint of the inlet/outlet pipe. entering the vault through the walls. Baffles Damaged Baffles corroding,cracking warping,and/or Repair or replace baffles to showing signs of failure as determined by specification. maintenance/inspection person. Access Ladder Damaged Ladder is corroded or deteriorated,not Ladder replaced or repaired and functioning properly,missing rungs,cracks,and meets specifications,and is safe to misaligned. use as determined by inspection personnel. 2005 Surface Water Design Manual—Appendix A 1/24/2005 A-17 A��ii \IT!'Al> Important: Inspection should be performed by a person who is erro:d��i i'�n The sto,mwaterManagement y► CONSTRUCTION PRODUCTS INC. StormFilter familiar with the StormFilter treatment unit. 1. If applicable,set up safety equipment to protect and notify surrounding vehicle and pedestrian traffic. StormFilter Maintenance Guidelines 2.Visually inspect the external condition of the unit and take notes Maintenance requirements and frequency are dependent on the concerning defects/problems. pollutant load characteristics of each site, and may be required in 3. Open the access portals to the vault and allow the system vent. the event of a chemical spill or due to excessive sediment loading. 4.Without entering the vault,visually inspect the inside of the unit, Maintenance Procedures and note accumulations of liquids and solids. Although there are other effective maintenance options, CONTECH 5. Be sure to record the level of sediment build-up on the floor of recommends the following two step procedure: the vault, in the forebay, and on top of the cartridges. If flow is occurring, note the flow of water per drainage pipe. Record 1. Inspection: Determine the need for maintenance. all observations. Digital pictures are valuable for historical 2. Maintenance: Cartridge replacement and sediment removal. documentation. Inspection and Maintenance Activity Timing 6.Close and fasten the access portals. At least one scheduled inspection activity should take place per year 7. Remove safety equipment. with maintenance following as warranted. 8.If appropriate, make notes about the local drainage area relative First, inspection should be done before the winter season. During to ongoing construction, erosion problems, or high loading of which,the need for maintenance should be determined and, if other materials to the system. disposal during maintenance will be required, samples of the 9. Discuss conditions that suggest maintenance and make decision accumulated sediments and media should be obtained. as to weather or not maintenance is needed. Second, if warranted, maintenance should be performed during Maintenance Decision Tree periods of dry weather. The need for maintenance is typically based on results of the inspection. In addition,you should check the condition of the StormFilter unit Use the following as a general guide. (Other factors,such as regulatory after major storms for potential damage caused by high flows and requirements, may need to be considered) for high sediment accumulation. It may be necessary to adjust the 1.Sediment loading on the vault floor. If >4" of accumulated inspection/maintenance activity schedule depending on the actual sediment,then go to maintenance. operating conditions encountered by the system. 2.Sediment loading on top of the cartridge. If >1/4" of Generally, inspection activities can be conducted at any time, and accumulation, then go to maintenance. maintenance should occur when flows into the system are unlikely. 3.Submerged cartridges. If >4" of static water in the cartridge Maintenance Activity Frequency bay for more that 24 hrs after end of rain event,then go to Maintenance is performed on an as needed basis, based on maintenance. inspection. Average maintenance lifecycle is 1-3 years. The primary 4. Plugged media. If pore space between media granules is absent, factor controlling timing of maintenance of the StormFilter is then go to maintenance. sediment loading. Until appropriate timeline is determined, use the 5. Bypass condition. If inspection is conducted during an average following: rain fall event and StormFilter remains in bypass condition Inspection: (water over the internal outlet baffle wall or submerged One time per year cartridges), then go to maintenance. After major storms 6. Hazardous material release. If hazardous material release (automotive fluids or other) is reported,then go to Maintenance: maintenance. As needed 7. Pronounced scum line. If pronounced scum line(say>_ 1/4" Per regulatory requirement thick)is present above top cap,then go to maintenance. In the event of a chemical spill 8.Calendar Lifecycle. If system has not been maintained for 3 Inspection Procedures years,then go to maintenance. Assumptions: It is desirable to inspect during a storm to observe the relative flow through the filter cartridges. If the submerged cartridges are No rainfall for 24 hours or more. severely plugged,then typically large amounts of sediments will be No upstream detention (at least not draining into StormFilter). present and very little flow will be discharged from the drainage Structure is online. Outlet pipe is clear of obstruction. Construction pipes. If this is the case,then maintenance is warranted and the bypass is plugged. cartridges need to be replaced. Maintenance Warning: In the case of a spill, the worker should abort inspection Depending on the configuration of the particular system,workers activities until the proper guidance is obtained. Notify the will be required to enter the vault to perform the maintenance. local hazard control agency and CONTECH immediately. To conduct an inspection: 1 Cl/13 Important: If vault entry is required, OSHA rules for confined space Method 2: entry must be followed. A. Enter the vault using appropriate confined space protocols. Filter cartridge replacement should occur during dry weather. It may be necessary to plug the filter inlet pipe if base flow is occurring. B. Unscrew the cartridge cap. Repfacementtartridges can be delivered to the site or customers C. Remove the cartridge hood screws(3)hood and float. facility. Contact CONTECH for more information. D. At location under structure access,tip the cartridge on its Warning: In the case of a spill, the worker should abort side. maintenance activities until the proper guidance is obtained. Notify the local hazard control agency and CONTECH immediately. Important: Note that cartridges containing media other than the leaf media require unscrewing from their threaded To conduct cartridge replacement and sediment removal: connectors.Take care not to damage the manifold 1.If applicable, set up safety equipment to protect workers and connectors.This connector should remain installed in the pedestrians from site hazards. manifold and capped if necessary. 2.Visually inspect the external condition of the unit and take notes E. Empty the cartridge onto the vault floor. Reassemble the concerning defects/problems. empty cartridge. 3.Open the doors(access portals)to the vault and allow the system to vent. F. Set the empty, used cartridge aside or load onto the hauling truck. 4.Without entering the vault, give the inside of the unit, including components,a general condition inspection. G. Continue steps a through E until all cartridges have been 5.Make notes about the external and internal condition of removed. the vault. Give particular attention to recording the level of 8. Remove accumulated sediment from the floor of the vault and sediment build-up on the floor of the vault, in the forebay, and from the forebay. Use vacuum truck for highest effectiveness. on top of the internal components. 9. Once the sediments are removed, assess the condition of the 6.Using appropriate equipment offload the replacement cartridges vault and the connectors.The connectors are short sections (up to 150 lbs.each)and set aside. of 2-inch schedule 40 PVC,or threaded schedule 80 PVC that 7.Remove used cartridges from the vault using one of the should protrude about 1" above the floor of the vault. Lightly following methods: wash down the vault interior. Method 1: a. Replace any damaged connectors. A. This activity will require that workers enter the vault to remove the cartridges from the under drain manifold and 10. Using the vacuum truck boom,crane,or tripod, lower and place them under the vault opening for lifting (removal). install the new cartridges.Take care not to damage connections. Unscrew(counterclockwise rotations)each filter cartridge 11. Close and fasten the door. from the underdrain connector. Roll the loose cartridge,on 12. Remove safety equipment. edge,to a convenient spot beneath the vault access. 13. Finally, dispose of the accumulated materials in accordance with Using appropriate hoisting equipment, attach a cable from applicable regulations. Make arrangements to return the used the boom, crane, or tripod to the loose cartridge. Contact empty cartridges to CONTECH. CONTECH for suggested attachment devices. Material Disposal Important: Cartridges containing leaf media (CSF)do not The accumulated sediment must be handled and disposed of in require unscrewing from their connectors. Do not accordance with regulatory protocols. It is possible for sediments damage the manifold connectors.They should remain to contain measurable concentrations of heavy metals and organic installed in the manifold and can be capped during the chemicals. Areas with the greatest potential for high pollutant maintenance activity to prevent sediments from entering loading include industrial areas and heavily traveled roads. the under drain manifold. Sediments and water must be disposed of in accordance with B. Remove the used cartridges(up to 250 lbs.)from the vault. applicable waste disposal regulations. Coordinate disposal of solids and liquids as part of your maintenance procedure. Contact the Important:Avoid damaging the cartridges during removal and local public works department to inquire how they disposes of their installation. street waste residuals. C. Set the used cartridge aside or load onto the hauling truck. D. Continue steps A through C until all cartridges have been removed. ©2007 CONTECH Stormwater Solutions 800.338.1122 www.contech-cpi.com Nothing in this catalog should be construed as an expressed warranty or an implied warranty of merchantability or fitness for any particular purpose. See the CONTECH standard quotation or acknowledgement for applicable warranties and other terms and conditions of sale. The product(s)described may be protected by one or more of the following US patents: 5,322,629;5,624,576;5,707,527;5,759,415;5,788,848;5,985,157; 6,027,639;6,350,374;6,406,218;6,641,720;6,511,595;6,649,048;6,991,114;6,998,038;7,186,058;related foreign patents or other patents pending. 2 CONSTRUCTION PRODUCTS INC. CDS° Inspection and Maintenance Guide t/ itpT,.. .41A. II 't ilki, i1 .,/ fi'l -1 „ , , „ , i < . 42i4f7' 44,t\f‘V;):71.„,1. -ov,;:.:§11,A'''''''''',-40A:14. ,.. 'r '7 gg 7:01' D , ,., c -- .1 -e 117.4, i)., ""A'rt'",). i , ,.. ,,,,,. c ... , ,.:. :;,.,„,; ,,,, ...„ g�}� , �s. , 'Of 31 7{; S Id£'!1, ,: '' 1 ,a}q T4s. } i' Ali ' :;,.-"r,....,',.`" ' G.+ ?.��S..- • 3 4 ! ,Y a� �7i.M'.MrZra;,gYffw r` '�rr/ ISki' k k �� arYSea..r..—^' s¢ s 04. -.1',-'1',.•.•:::',',.,;!,...4--4•,..•,.$1',4‘,...,, ;k d u ' 1%�°g , .ret/ "' r¢,444 „ • -I.I1 •• 7 IIIIII6\\ CDS TECHNOLOGIES 11113 Maintenance Cleaning The CDS system should be inspected at regular intervals and Cleaning of a CDS systems should be done during dry weather maintained when necessary to ensure optimum performance. conditions when no flow is entering the system.The use of a The rate at which the system collects pollutants will depend more vacuum truck is generally the most effective and convenient heavily on site activities than the size of the unit. For example, method of removing pollutants from the system. Simply remove unstable soils or heavy winter sanding will cause the grit chamber the manhole covers and insert the vacuum hose into the sump. to fill more quickly but regular sweeping of paved surfaces will The system should be completely drained down and the sump slow accumulation. fully evacuated of sediment.The area outside the screen should also be cleaned out if pollutant build-up exists in this area. Inspection In installations where the risk of petroleum spills is small, liquid Inspection is the key to effective maintenance and is easily contaminants may not accumulate as quickly as sediment. performed. Pollutant transport and deposition may vary from However, the system should be cleaned out immediately in year to year and regular inspections will help ensure that the the event of an oil or gasoline spill should be cleaned out system is cleaned out at the appropriate time. At a minimum, immediately. Motor oil and other hydrocarbons that accumulate inspections should be performed twice per year(e.g. spring on a more routine basis should be removed when an appreciable and fall)however more frequent inspections may be necessary layer has been captured. To remove these pollutants, it may in climates where winter sanding operations may lead to rapid be preferable to use absorbent pads since they are usually less accumulations,or in equipment washdown areas. Installations expensive to dispose than the oil/water emulsion that may be should also be inspected more frequently where excessive created by vacuuming the oily layer.Trash and debris can be amounts of trash are expected. netted out to separate it from the other pollutants. The screen The visual inspection should ascertain that the system should be power washed to ensure it is free of trash and debris. components are in working order and that there are no Manhole covers should be securely seated following cleaning blockages or obstructions in the inlet and separation screen. activities to prevent leakage of runoff into the system from above The inspection should also quantify the accumulation of and also to ensure that proper safety precautions have been hydrocarbons, trash, and sediment in the system. Measuring followed. Confined space entry procedures need to be followed pollutant accumulation can be done with a calibrated dipstick, if physical access is required. Disposal of all material removed tape measure or other measuring instrument. If absorbent from the CDS system should be done in accordance with local material is used for enhanced removal of hydrocarbons, the level regulations. In many jurisdictions,disposal of the sediments may of discoloration of the sorbent material should also be identified be handled in the same manner as the disposal of sediments during inspection. It is useful and often required as part of an removed from catch basins or deep sump manholes. operating permit to keep a record of each inspection. A simple form for doing so is provided. Access to the CDS unit is typically achieved through two manhole access covers. One opening allows for inspection and cleanout of the separation chamber(cylinder and screen)and isolated sump. The other allows for inspection and cleanout of sediment captured and retained outside the screen. For deep units, a single manhole access point would allows both sump cleanout and access outside the screen. • The CDS system should be cleaned when the level of sediment has reached 75%of capacity in the isolated sump or when an appreciable level of hydrocarbons and trash has accumulated. If absorbent material is used, it should be replaced when . • significant discoloration has occurred. Performance will not be impacted until 100%of the sump capacity is exceeded however it is recommended that the system be cleaned prior to that for easier removal of sediment. The level of sediment is easily determined by measuring from finished grade down to the top of the sediment pile. To avoid underestimating the level of sediment in the chamber,the measuring device must be lowered to the top of the sediment pile carefully. Particles at the top of r �.� the pile typically offer less resistance to the end of the rod than '41-.1.1;‘•` '. w„. • consolidated particles toward the bottom of the pile. Once this .. measurement is recorded, it should be compared to the as-built drawing for the unit to determine weather the height of the sediment pile off the bottom of the sump floor exceeds 75%of 3 s zap. t ,� , the total height of isolated sump. a w: , ,q > 4 {A g ter g z/i 3 CDS Diameter Distance from Water Surface Sediment Model to Top of Sediment Pile Storage Capacity ft m ft m yd3 m3 CDS2015-4 4 1.2 3.0 0.9 0.5 0.4 CDS2020 5 1.5 3.5 1.1 1.3 1.0 CDS3020 6 1.8 4.0 1.2 2.1 1.6 CDS3035 6 1.8 5.0 1.5 2.1 1.6 CDS4040 8 2.4 5.7 1.7 5.6 4.3 Table 1:CDS Maintenance Indicators and Sediment Storage Capacities . �S • : .'�'`}�� ti �YyT�� y ate. ut� i", '', .1.0.4. q�.9 ., '' " � k ^° r/ 1 y+ ri� ° r>s : F g y40 41, �` •Aa 4 rf't( ww+ '� 4' s-ski.i' .w3`i+ f k _ .. ii:'.' 4.ii:..',•• 4,-,%. ,. J-71t ,4,4x4,4,:c;i7,1-:71,71,75-0-,, ,,-,,.„:-:,,,f.,1,: 4',*.;rt4.15e' is:., ar� � i it t �',.1 4:- -' . t /C _t :,4-4. ' "y A �- ‘'''47:1-:.r Cjrg,L.--- 914 - R - 1 � - a I - supper • Drawings and specifications are available at www.contechstormwatercom. • Site-specific design support is available from our engineers. T2010 CONTECH Stormwater Solutions CONTECH Construction Products Inc provides site solutions for the civil engineering industry, CONTECH's portfolio indudes bridges,drainage,sanitary sewer,stormwater and earth stabilization products.For information on other CONTECH division offerings,visit contech- cpi.com or call 800.338.1122 Nothing in this catalog should be construed as an expressed warranty or an implied warranty of merchantability or fitness for any particularpurpose.See the CONTECH standard quotation or acknowledgement for applicable warranties and other terms and conditions of sake. The product(s)described may be protected by one or more of the following US patents: 5,322,629;5,624,576;5,707,527;5,759,415;5,788,848;5,985,157;6,027,639;6. 350,374; A \ITCApJ` 6,406,218;6,641,720;6,511,595;6,649,048;6,991,114;6,998,038;7,186,058;7,296,692; 1%..';'4‘4 i��!7 7,297,266;7,517,450 related foreign patents or other patents pending. CONSTRUCTION PRODUCTS ina 800.925.5240 cdsMaintenance 01/10 contechstormwateccom 130 CDS Inspection & Maintenance Log CDS Model: Location: Water Floatable Describe Maintenance Date depth to Layer Maintenance Comments Personnel sediment' Thickness' Performed 1. The water depth to sediment is determined by taking two measurements with a stadia rod:one measurement from the manhole opening to the top of the sediment pile and the other from the manhole opening to the water surface. If the difference between these measurements is less than eighteen inches the system should be cleaned out. Note:To avoid underestimating the volume of sediment in the chamber,the measuring device must be carefully lowered to the top of the sediment pile. 2. For optimum performance,the system should be cleaned out when the floating hydrocarbon layer accumulates to an appreciable thickness.In the event of an oil spill,the system should be cleaned immediately. I APPENDIX E BOND QUANTITIES WORKSHEETS Site Improvement Bond Quantity Worksheet Web date: 12/02/2008 La King County Department of Development & Environmental Services 900 Oakesdale Avenue Southwest Renton, Washington 98057-5212 For alternate formats, call 206-296-6600. 206-296-6600 TTY 206-296-7217 Project Name: 1500 and 1600 Benson Apartments and Offices Date: 4/8/2013 Location: 15xx Benson Road South Project No.: 05-125 Activity No.: Note: All prices include labor, equipment, materials, overhead and Clearing greater than or equal to 5,000 board feet of timber? profit. Prices are from RS Means data adjusted for the Seattle area or from local sources if not included in the RS Means database. yes x no If yes, Forest Practice Permit Number: (RCW 76.09) Page 1 of 9 Unit prices updated: 02/12/02 Version: 11/26/2008 Bond Quantities Report Date: 4/8/2013 Site Improvement Bond Quantity Worksheet Web date 12/02/2008 Unit #of Reference# Price Unit Quantity Applications Cost EROSION/SEDIMENT CONTROL Number Backfill &compaction-embankment ESC-1 $ 5.62 CY Check dams,4"minus rock ESC-2 SWDM 5.4.6.3 $ 67.51 Each Crushed surfacing 1 1/4" minus ESC-3 WSDOT 9-03.9(3) $ 85.45 CY Ditching ESC-4 $ 8.08 CY Excavation-bulk ESC-5 $ 1.50 CY Fence, silt ESC-6 SWDM 5.4.3.1 $ 1.38 LF 920 1 1270 Fence,Temporary(NGPE) ESC-7 $ 1.38 LF Hydroseeding ESC-8 SWDM 5.4.2.4 $ 0.59 SY 4840 1 2856 Jute Mesh ESC-9 SWDM 5.4.2.2 $ 1.45 SY Mulch, by hand, straw, 3"deep ESC-10 SWDM 5.4.2.1 $ 2.01 SY Mulch, by machine, straw,2"deep ESC-11 SWDM 5.4.2.1 $ 0.53 SY 4840 1 2565 Piping,temporary, CPP, 6" ESC-12 $ 10.70 LF Piping,temporary, CPP, 8" ESC-13 $ 16.10 LF Piping, temporary, CPP, 12" ESC-14 $ 20.70 LF Plastic covering, 6mm thick, sandbagged ESC-15 SWDM 5.4.2.3 $ 2.30 SY 2000 1 4600 Rip Rap, machine placed; slopes ESC-16 WSDOT 9-13.1(2) $ 39.08 CY Rock Construction Entrance, 50'x15'x1' ESC-17 SWDM 5.4.4.1 $ 1,464.34 Each Rock Construction Entrance, 100'x15'x1' ESC-18 SWDM 5.4.4.1 $ 2,928.68 Each 3 1 8786 Sediment pond riser assembly ESC-19 SWDM 5.4.5.2 $ 1,949.38 Each Sediment trap, 5' high berm ESC-20 SWDM 5.4.5.1 $ 17.91 LF Sed.trap,5'high, riprapped spillway berm section ESC-21 SWDM 5.4.5.1 $ 68.54 LF Seeding, by hand ESC-22 SWDM 5.4.2.4 $ 0.51 SY Sodding, 1"deep, level ground ESC-23 SWDM 5.4.2.5 $ 6.03 SY Sodding, 1"deep, sloped ground ESC-24 SWDM 5.4.2.5 $ 7.45 SY TESC Supervisor ESC-25 $ 74.75 HR 40 1 2990 Water truck, dust control ESC-26 SWDM 5.4.7 $ 97.75 HR 20 1 1955 WRITE-IN-ITEMS **** (see page 9) Baker Tank per week $ 1,000 00 Each 16 1 16000 I ESC SUBTOTAL: $ 41,021.44 30%CONTINGENCY&MOBILIZATION: $ 12,306.43 ESC TOTAL: $ 53,327.87 COLUMN: A Page 2 of 9 Unit prices updated: 02/12/02 Version: 11/26/2008 Bond Quantities Report Date: 4/8/2013 Site Improvement BciPi Quantity Worksheet Webda.z/zoos Existing Future Public Private Quantity Completed Right-of-Way Road Improvements Improvements (Bond Reduction)* &Drainage Facilities Quant. Unit Price _ Unit Quant. Cost Quant. - Cost Quant. Cost Complete Cost GENERAL ITEMS No. Backfill&Compaction-embankment GI-1 $ 5.62 CY Backfill&Compaction-trench GI-2 $ 8.53 CY 170 1,450.10 Clear/Remove Brush,by hand GI-3 $ 0.36 SY Clearing/Grubbing/Tree Removal GI-4 $ 8,876.16 Acre 2.16 19,172.51 Excavation-bulk GI-5 $ 1.50 CY 13482 20,223.00 Excavation-Trench GI-6 $ 4.06 CY 227 921.62 Fencing,cedar,6'high GI-7 $ 18.55 LF Fencing,chain link,vinyl coated, 6'high GI-8 $ 13.44 LF Fencing,chain link,gate,vinyl coated, 2 GI-9 $ 1,271.81 Each Fencing,split rail,3'high GI-10 $ 12.12 LF Fill&compact-common barrow GI-11 $ 22.57 CY 2000 45,140.00 Fill&compact-gravel base GI-12 $ 25.48 CY Fill&compact-screened topsoil GI-13 $ 37.85 CY Gabion, 12"deep,stone filled mesh GI-14 $ 54.31 SY Gabion, 18"deep,stone filled mesh GI-15 $ 74.85 SY Gabion,36"deep,stone filled mesh GI-16 $ 132.48 SY Grading,fine,by hand GI-17 $ 2.02 SY Grading,fine,with grader GI-18 $ 0.95 SY Monuments,3'long GI-19 $ 135.13 Each Sensitive Areas Sign GI-20 $ 2.88 Each Sodding, 1"deep,sloped ground GI-21 $ 7.46 SY Surveying,line&grade GI-22 $ 788.26 Day Surveying,lot location/lines GI-23 $ 1,556.64 Acre Traffic control crew(2 flaggers) GI-24 $ 85.18 HR 40 3,407.20 Trail,4"chipped wood GI-25 $ 7.59 SY Trail,4"crushed cinder GI-26 $ 8.33 SY Trail,4"top course GI-27 $ 8.19 SY Wall,retaining,concrete GI-28 $ 44.16 SF 7931 350,232.96 Wall,rockery GI-29 $ 9.49 SF 68 645.32 Page 3 of 9 SUBTOTAL 441,192.71 Unit prices updated: 02/12/02 *KCC 27A authorizes only one bond reduction. Version: 11/26/08 Bond Quantities Report Date:4/8/2013 • Site Improvement B Web da 2/2008 p Quantity Worksheet Existing Future Public Private Bond Reduction* Right-of-way Road Improvements Improvements &Drainage Facilities Quant. Unit Price Unit Quant. Cost Quant, Cost Quant. Cost Complete Cost ROAD IMPROVEMENT No.; AC Grinding,4'wide machine<1000sy RI-1 S 28.00 SY AC Grinding,4'wide machine 1000-200C RI-2 $ 15.00 SY AC Grinding,4'wide machine>2000sy RI-3 $ 7.00 SY AC Removal/Disposal/Repair RI-4 $ 67.50 SY Barricade,type I RI-5 $ 30.03 LF Barricade,type III(Permanent) RI-6 $ 45.05 LF Curb&Gutter,rolled RI-7 $ 17.00 LF Curb&Gutter,vertical RI-8 $ 12.50 LF 1300 16,250.00 Curb and Gutter,demolition and disposa RI-9 $ 18.00 LF Curb,extruded asphalt RI-10 $ 5.50 LF Curb,extruded concrete RI-11 $ 7.00 LF Sawcut,asphalt,3"depth RI-12 $ 1.85 LF 30 55.50 Sawcut,concrete,per 1"depth RI-13 $ 1.69 LF Sealant,asphalt RI-14 $ 1.25 LF 30 37.50 Shoulder,AC, (see AC road unit price) RI-15 $ - SY Shoulder,gravel,4"thick RI-16 $ 15.00 SY Sidewalk,4"thick RI-17 $ 35.00 SY 200 7,000.00 Sidewalk,4"thick,demolition and dispos RI-18 $ 29.50 SY Sidewalk,5"thick RI-19 $ 38.50 SY Sidewalk,5"thick,demolition and dispos RI-20 $ 37.50 SY Sign,handicap RI-21 $ 85.28 Each Striping,per stall RI-22 $ 5.82 Each 50 291.00 Striping,thermoplastic,(for crosswalk) RI-23 $ 2.38 SF Striping,4"reflectorized line RI-24 $ 0.25 LF 1 Page 4 of 9 SUBTOTAL 93.00 23,541.00 Unit prices updated: 02/12/02 *KCC 27A authorizes only one bond reduction. Version: 11/26/08 Bond Quantities Report Date:4/8/2013 Site Improvement Bc Quantity Worksheet Web da 2/2008 Existing Future Public Private Bond Reduction* Right-of-way Road Improvements Improvements &Drainage Facilities Quant. Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Complete Cost ROAD SURFACING (4"Rock=2.5 base&1.5"top course) For'93 KCRS(6.5"Rock=5"base&1.5"top course) For KCRS'93,(additional 2.5"base)add RS- 1 $ 3.60 SY AC Overlay, 1.5"AC RS-2 $ 11.25 SY AC Overlay,2"AC RS-3 $ 15.00 SY AC Road,2",4"rock,First 2500 SY RS-4 $ 21.00 SY 2500 52,500.00 AC Road,2",4"rock,Qty.over 2500SY RS-5 $ 19.00 SY 65 1,235.00 _ AC Road,3",4"rock,First 2500 SY RS-6 $ 23.30 SY AC Road,3",4"rock,Qty.over 2500 SY RS-7 $ 21.00 SY AC Road,5",First 2500 SY RS-8 $ 27.60 SY AC Road,5",Qty.Over 2500 SY RS-9 $ 25.00 SY AC Road,6",First 2500 SY RS-1C $ 33.10 SY AC Road,6",Qty.Over 2500 SY RS-11 $ 30.00 SY Asphalt Treated Base,4"thick RS-12 $ 20.00 SY Gravel Road,4"rock,First 2500 SY RS-13 $ 15.00 SY 130 1,950.00 Gravel Road,4"rock,Qty.over 2500 SY RS-14 $ 8.50 SY PCC Road,5",no base,over 2500 SY RS-15 $ 27.00 SY PCC Road, 6",no base,over 2500 SY RS-18 $ 25.50 SY Thickened Edge RS-17 $ 8.60 LF Page 5 of 9 SUBTOTAL 55,685.00 Unit prices updated: 02/12/02 *KCC 27A authorizes only one bond reduction. Version: 11/26/08 Bond Quantities Report Date:4/8/2013 • Site Improvement B Webda 2/2008 p Quantity Worksheet '� Existing Future Public Private Bond Reduction* Right-of-way Road Improvements Improvements &Drainage Facilities Quant. Unit Price Unit _ Quant. Cost Quant. Cost Quant. Cost Complete Cost DRAINAGE (CPP=Corrugated Plastic Pipe. N12 or Equivalent) For Culvert prices, Average of 4'cover was assumed Assume perforated PVC is same price as solid pipe. Access Road, R/D D-1 $ 21.00 SY _ Bollards-fixed D-2 $ 240.74 Each Bollards-removable D-3 $ 452.34 Each *(CBs include frame and lid) CB Type I D-4 $ 1,257.64 Each 12 15,091.68 CB Type IL D-5 $ 1,433.59 Each CB Type II,48"diameter D-6 $ 2,033.57 Each 3 6,100.71 for additional depth over 4' D-7 $ 436.52 FT CB Type II,54"diameter D-8 $ 2,192.54 Each for additional depth over 4' D-9 $ 486.53 FT CB Type II,60"diameter D-10 $ 2,351.52 Each for additional depth over 4' D-11 $ 536.54 FT CB Type II,72"diameter D-12 $ 3,212.64 Each for additional depth over 4' D-13 $ 692.21 FT Through-curb Inlet Framework(Add) D-14 $ 366.09 Each Cleanout,PVC,4" D-15 $ 130.55 Each Cleanout,PVC,6" D-16 $ 174.90 Each Cleanout,PVC,8" D-17 $ 224.19 Each Culvert,PVC,4" D-18 $ 8.64 LF Culvert,PVC,6" D-19 $ 12.60 LF Culvert,PVC, 8" D-20 $ 13.33 LF Culvert,PVC, 12" D-21 $ 21.77 LF Culvert,CMP,8" D-22 $ 17.25 LF Culvert,CMP,12" D-23 $ 26.45 LF Culvert,CMP,15" D-24 $ 32.73 LF Culvert,CMP, 18" D-25 $ 37.74 LF Culvert,CMP,24" D-26 $ 53.33 LF Culvert,CMP,30" D-27 $ 71.45 LF Culvert,CMP,36" D-28 $ 112.11 LF Culvert,CMP,48" D-29 $ 140.83 LF Culvert,CMP,60" D-30 $ 235.45 LF Culvert,CMP,72" D-31 $ 302.58 LF Page 6 of 9 SUBTOTAL 21,192.39 Unit prices updated: 02/12/02 *KCC 27A authorizes only one bond reduction. Version: 11/26/08 Bond Quantities Report Date:4/8/2013 Site Improvement 13( Quantity Worksheet Web da 2,2008 Existing Future Public Private Bond Reduction* Right-of-way Road Improvements Improvements DRAINAGE CONTINUED &Drainage Facilities Quant. No. _ Unit Price Unit Quant. Cost _ Quant. Cost Quant. Cost Complete Cost Culvert,Concrete,8" D-32 $ 21.02 LF Culvert,Concrete, 12" D-33 $ 30.05 LF Culvert,Concrete, 15" D-34 $ 37.34 LF Culvert,Concrete, 18" D-35 $ 44.51 LF Culvert,Concrete,24" D-36 $ 61.07 LF Culvert,Concrete,30" D-37 $ 104.18 LF Culvert,Concrete,36" D-38 $ 137.63 LF Culvert,Concrete,42" D-39 $ 158.42 LF Culvert,Concrete,48" D-40 $ 175.94 LF Culvert,CPP,6" D-41 $ 10.70 LF 76 813.2 Culvert,CPP,8" D-42 $ 16.10 LF 247 3976.7 Culvert,CPP, 12" D-43 $ 20.70 LF 528 10929.6 Culvert,CPP, 15" D-44 $ 23.00 LF Culvert,CPP, 18" D-45 $ 27.60 LF Culvert,CPP,24" D-46 $ 36.80 LF Culvert,CPP,30" D-47 $ 48.30 LF Culvert,CPP,36" D-48 $ 55.20 LF Ditching D-49 $ 8.08 CY Flow Dispersal Trench (1,436 base+) D-50 $ 25.99 LF French Drain (3'depth) D-51 $ 22.60 LF Geotextile,laid in trench,polypropylene ,D-52, $ 2.40 SY Infiltration pond testing D-53 $ 74.75 HR Mid-tank Access Riser,48"dia, 6'deep D-54 $ 1,605.40 Each Pond Overflow Spillway D-55 $ 14.01 SY Restrictor/Oil Separator, 12" D-56 $ 1,045.19 Each 2 2090.38 Restrictor/Oil Separator, 15" D-57 $ 1,095.56 Each Restrictor/Oil Separator, 18" D-58 $ 1,146.16 Each Riprap,placed D-59 $ 39.08 CY Tank End Reducer(36"diameter) D-60 $ 1,000.50 Each Trash Rack, 12" D-61 $ 211.97 Each Trash Rack, 15" D-62 $ 237.27 Each Trash Rack, 18" D-63 $ 268.89 Each Trash Rack,21" D-64 $ 306.84 Each Page 7 of 9 SUBTOTAL 17809.88 Unit prices updated: 02/12/02 *KCC 27A authorizes only one bond reduction. Version: 11/26/08 Bond Quantities Report Date:4/8/2013 Site Improvement Bc Quantity Worksheet Web da )2/2008 Existing Future Public Private Bond Reduction* Right-of-way Road Improvements Improvements &Drainage Facilities Quant. Unit Price _ Unit Quant. Price Quant. Cost Quant. Cost Complete Cost PARKING LOT SURFACING No. 2"AC,2"top course rock&4"borrow PL-1 $ 21.00 SY 2"AC, 1.5" top course&2.5"base cour PL-2 $ 28.00 SY 4"select borrow PL-3 $ 4.55 SY 1.5"top course rock&2.5"base course PL-4 $ 11.41 SY UTILITY POLES & STREET LIGHTING Utility pole relocation costs must be accompanied by Franchise Utility's Cost Statement Utility Pole(s)Relocation UP-1 Lump Sum Street Light Poles w/Luminaires UP-2 Each WRITE-IN-ITEMS (Such as detention/water quality vaults.) No. Detention Vault WI-1 $ 5.00 CF 38400 192,000.00 Stormfilter Insert WI-2 $ 4,000.00 EA 1 4,000.00 Vortsentry Insert WI-3 $ 4,000.00 EA 1 4,000.00 WI-4 LF WI-5 FT WI-6 WI-7 WI-8 WI-9 w)-io SUBTOTAL 200,000.00 SUBTOTAL(SUM ALL PAGES): 93.00 759,420.98 30%CONTINGENCY&MOBILIZATION: 27.90 227,826.29 GRANDTOTAL: 120.90 987,247.27 COLUMN: B C D E Page 8 of 9 Unit prices updated: 02/12/02 *KCC 27A authorizes only one bond reduction. Version: 11/26/08 Bond Quantities Report Date:4/8/2013 Web date: 12/02/2008 Site Improvement Bond Quantity Worksheet Original bond computations prepared by: Name: Lorna M Taylor Date: 4/8/2013 PE Registration Number: 29351 Tel.#: 425-391-1415 Firm Name: TEC, Inc. Address: 485 Rainier Blvd N., #102, PO Box 1787, Issaquah, WA 98027 Project No: 05-125 ROAD IMPROVEMENTS&DRAINAGE FACILITIES FINANCIAL GUARANTEE REQUIREMENTS PERFORMANCE BOND* PUBLIC ROAD&DRAINAGE AMOUNT BOND*AMOUNT MAINTENANCE/DEFECT BOND* REQUIRED AT RECORDING OR Stabilization/Erosion Sediment Control (ESC) (A) $ 53,327.9 TEMPORARY OCCUPANCY*** Existing Right-of-Way Improvements (B) $ 120.9 Future Public Road Improvements& Drainage Facilities (C) $ - Private Improvements (D) $ 987,247.3 Calculated Quantity Completed (E) $ - Total Right-of Way and/or Site Restoration Bond*/** (A+B) $ 53,448.8 (First$7,500 of bond*shall be cash.) Performance Bond*Amount (A+B+C+D) = TOTAL (T) $ 1,040,696.0 T x 0.30 $ 312,208.8 OR Minimum bond*amount is$1000. Reduced Performance Bond*Total*** (T-E) $ 1,040,696.0 Use larger of Tx30%or(T-E) (B+C)x Maintenance/Defect Bond*Total 0.25= $ 30.2 NAME OF PERSON PREPARING BOND*REDUCTION: Date: *NOTE: The word"bond"as used in this document means any financial guarantee acceptable to King County. **NOTE: KCC 27A authorizes right of way and site restoration bonds to be combined when both are required. The restoration requirement shall include the total cost for all TESC as a minimum, not a maximum. In addition,corrective work,both on-and off-site needs to be included. Quantities shall reflect worse case scenarios not just minimum requirements. For example,if a salmonid stream may be damaged,some estimated costs for restoration needs to be reflected in this amount. The 30%contingency and mobilization costs are computed in this quantity. ***NOTE: Per KCC 27A,total bond amounts remaining after reduction shall not be less than 30%of the original amount(T)or as revised by major design changes. SURETY BOND RIDER NOTE: If a bond rider is used,minimum additional performance bond shall be $ 987,247.3 (C+D)-E REQUIRED BOND*AMOUNTS ARE SUBJECT TO REVIEW AND MODIFICATION BY DDES Page 9 of 9 Unit prices updated: 02/12/02 Check out the DDES Web site at www.kingcountvgov/permits Version: 11/26/08 Bond Quantities Report Date: 4/8/2013 APPENDIX F RETENTION/DETENTION FACILITY SUMMARY SHEETS & SKETCHES KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL e3 STORMWATER FACILITY SUMMARY SHEET DDES Permit Number / /./a/eTh (provide one Stormwater Facility Summary Sheet per Natural Discharge Location) Overview: Project Name /5710 4xt9 /6'0O , AJcoAl.4W-Ei7 1/ 1Tc 44/D ac-iiaj Date //- 2o-- /2-- Downstream ZDownstream Drainage Basins Major Basin Name a> L ,e /2,, Immediate Basin Name tic tA/4 mcz_f Flow Control: Flow Control Facility Name/Number Nt,er/ j- E NpOiL '(r Facility Location _ow /1012rh/ "6(44 £o7 Oen iJf 4,1 J9m.J4 If none, Flow control provided in regional/shared facility(give location) No flow control required Exemption number General Facility Information: Type/Number of detention facilities: Type/Number of infiltration facilities: ponds ponds vaults tanks tanks trenches Control Structure Location hk-73/(A/ VAULT Type of Control Structure 7-- f/c,U,p Number of Orifices/Restrictions 2- Size of Orifice/Restriction: No. 1 a',7 No. 2 f). No. 3 No. 4 Flow Control Performance Standard /f -9)OA/ 2009 Surface Water Design Manual 1/9/2009 1 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL 2/G Live Storage Volume /Ll, N�( 't Depth l0 / Volume Factor of Safety Z '4411PiVJI./TTlfi_j Number of Acres Served /, / 3 Number of Lots Dam Safety Regulations (Washington State Department of Ecology) Reservoir Volume above natural grade Depth of Reservoir above natural grade Facility Summary Sheet Sketch All detention, infiltration and water quality facilities must include a detailed sketch. (11"x17" reduced size plan sheets may be used) /-OLL.O`ud/ ado /244z- 2009 Surface Water Design Manual 1/9/2009 2 te 54g P- • ir VENTILATION PIPE es (TYPICAL 4 CORNERS) 1 PRECAST_______-3\ GLIM-.- ,_, SD OUT 1:, I SUMP I -179.06 IA I I _/169.06 • cl -------4.—"" f.r.— — • _ 168.06 SD IN/ PM 'e SMINi-5 . • • • • • . . • - • . . . . ' • . • . . . ' ' . • • . . . RIM 180.87. • . HANDHOLDS AND • = ,..---- -4 . • . • . lay...179.0167_,.:8114 181:196/DST9'wG.SNoPER2_Koo6C R.S • FINISHED GRADE GRAVEL ACCESS ROAD • : — 1 g__ __,w IE IN 177.06 - = --IR.— a— . .----- ---- -- ______ ---- ' .— --,--- 2.b 0 :„.......----SEE CONTROL STRUCTURE — _ . • .0 • DETAIL.THIS SHEET • • . • - . • • • 168 0 - '''•-BOTTOM OF MEE(BACKGROUND) . -i7-‘-IE OUT W.- 169.06 • . _ • • . • . . . ip,. . ...*N..N"-PRECJST: SUMP • . • • • • ' ' . . . . . . . . . • . • . . . • • - . . • • • • • • • . . . . . . . ' ' • . • • • . ' . • . . . • . . . PROD F NORTH DETENTION VAULT SCALE. 1 =2O KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL 9/8 STORMWATER FACILITY SUMMARY SHEET DDES Permit Number Sou (provide one Stormwater Facility Summary Sheet per Natural Discharge Location) Overview: Project Name /SZYM'10/10001b .0A/ JJ44f/) 26 J Date It- ZD 'a-- Downstream aZDownstream Drainage Basins Major Basin Name 34Cle le i. Immediate Basin Name Rot-cm/4 /5' Flow Control: Flow Control Facility Name/Number f(Urn ii l7pni („7,41A L_7 Facility Location Ezz/Mr cDlr-1/J)49 i 4 GOT, SjC, 6F Sou77 evc.Om / If none, Flow control provided in regional/shared facility (give location) No flow control required Exemption number General Facility Information: Type/Number of detention facilities: Type/Number of infiltration facilities: ponds ponds vaults tanks tanks trenches Control Structure Location him/iv vI i'-r Type of Control Structure 7 -r/Cdp Number of Orifices/Restrictions Size of Orifice/Restriction: No. 1 di. No. 2 670 " No. 3 No. 4 Flow Control Performance Standard (vn/S2v477 dAt 2009 Surface Water Design Manual 1/9/2009 1 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL /g Live� Storage Volume / 7 j,,OO c; Depth /0 Volume Factor of Safety IN4DM Number of Acres Served /. 21 Number of Lots Dam Safety Regulations (Washington State Department of Ecology) Reservoir Volume above natural grade Depth of Reservoir above natural grade Facility Summary Sheet Sketch All detention, infiltration and water quality facilities must include a detailed sketch. (11"x17" reduced size plan sheets may be used) FOI.LowiAJ‘ E 2009 Surface Water Design Manual 1/9/2009 2 4:1 88.0' SO IN I RD INp iVENTILATION ) 4 -169.10 b " ` 1 1r _A PRECAST ,..._n,--- _SUMP -- J-159.10 �vr����i—158.61 tii 4'�J 158.11 I SD OUT PIAN ze SD iN 1 A1 '177:56_ .EXISiINC GRADE _i FINISHED GRADE _ . RI=176.54 � �.. .170;60. _ _ . . . _ . . _ . . . ELEV.189.1 HANDHOLDS ANDS`�` . ... ' STEPS PER K.C.R.S. � -IE:IN 166.02 O .NO.2-006 SEE CONTROL SIRUCIURE • . 2 ti 0 m DE1NL THIS SHEET 0�n e • e 15861 • -IE OUT 159• .10 • .801T011 OF NEE(BAC(GROUND) • 158.11 . .''''''-PRECAST • • • • . . .. .. SUMP _ . _ _ _ _ _ PROFILE SOUTH DETENTION VAULT SCALE 1"=20' KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL 7/3 Water Quality: Type/Number of water quality facilitiesBMPs: biofiltration swale sand filter(basic or large) (regular/wet/or continuous inflow) sand filter, linear(basic or large) combined detention/wetpond sand filter vault(basic or large) (wetpond portion basic or large) sand bed depth (inches) combined detention/wetvault stormwater wetland filter strip / storm filter )flow dispersion wetpond`(basicor larges farm management plan wetvault landscape management plan Is facility Lined? oil/water separator If so, what marker is used above (baffle or coalescing plate) Liner? catch basin inserts: Manufacturer pre-settling pond pre-settling structure: Manufacturer high flow bypass structure (e.g., flow-splitter catch basin) source controls Design Information //- Water Quality design flow _ b'. Q Z C/s. , _ _ r_— Water Quality treated volume (sandfilter) Water Quality storage volume (wetpool) ax-4/2 ail 'S• Facility Summary Sheet Sketch / /7W— s/f7j 2009 Surface Water Design Manual 1/9/2009 3 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL `3/e All detention, infiltration and water quality facilities must include a detailed sketch. (11"x17" reduced size plan sheets may be used) 2009 Surface Water Design Manual 1/9/2009 4