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Home My WebLink AboutTED4003034r R-30.31 Honey Crest Technical Information Report Submitted to: City of Renton 1055 South Grady Way Renton, WA 98055 Me Prepared by: W A C� o� Sh'I�� Haozous Engineering, P.S. 9957171StAvenue SE Renton, WA 98059 Tel. (425) 235-2707 �0 28576 , Fax (425)254-0579 ONAL September 30, 2001 EXPIRES: 2/19/ 03 Revised July 8, 2002 From: Allen Quynn To: Henninger, Arneta Date: 8/16/02 4:01PM Subject: Honey Crest Dainage Review My comments are as follows: 1. In reviewing the KCRTS output in Appendix B.2 of the pond design, I noticed that the first cutoff in the Duration Comparison Analysis has a %change of 2.4%. The Run Off Time Series Section of the manual allows a % change equal to 0.0 or less. Applicant will need to make corrections to pond design as necessary to satisfy the above requirement. 2. The backwater analysis spreadsheet in Fig. C.1.1 shows a headwater elevation for CB9 of 412.89 and a rim elevation of 413.11 or a difference of 0.22 feet. A minimum of 0.5 feet of freeboard is required when analyzing the 25-year storm event. Similarly, CB10 has only a 0.09 feet of freeboard. Applicant will need to revise design to meet the minimum freeboard requirement. 3. I did not see any design calculations for the emergency spillway. Otherwise, the drainage report and design plans look fine. CC: Straka, Ronald - - Ronald Straka - Mylar Signatures From: Jessica Briere To: Abdoul Gafour; Corey W Thomas; David Christensen; Ronald Straka Date: 10/4/02 10:33AM Subject: Mylar Signatures Please come to Carrie's desk area to sign/approve the mylars for "Honey Crest Plat". For questions/comments see the project manager Arneta H. Thank you. CC: Arneta Henninger; Carrie Olson -Davis Honey Crest Technical Information Report iY OF RENTON '"'WED 700/- wovwr 9 SERVICE Submitted to: City of Renton 1055 South Grady Way Renton, WA 98055 wPrepared by: g� a C� s�l�?� Haozous Engineering, P.S. 9957 171St Avenue SE Cne — (A- Renton, WA 98059 U r Tel. (425) 235-2707 �0 � 28576 � ��v Fax (425) 254-0579 �s �ISTER� G~ �-� a SI ANAL September 30, 2001 EXPIRES: 2/19/ 03 Revised July 8, 2002 TABLE OF CONTENTS 1. Project Overview..............................................................................................................1-1 2. Conditions and Requirements Summary ........................................................................... 2-1 3. Offsite Analysis................................................................................................................. 3-1 4. Flow Control and Water Quality Facility Analysis and Design ........................................ 4-1 5. Conveyance System Analysis and Design........................................................................ 5-1 6. Special Reports and Studies.............................................................................................. 6-1 7. Other Permits.................................................................................................................... 7-1 8. ESC Analysis and Design......................:.......................................................................... 8-1 9. Bond Quantities and Facility Summaries.......................................................................... 9-1 10. Operations and Maintenance Manual........................................................................... 10-1 11. References.....................................................................................................................11-1 LIST OF TABLES Table 1. Description of Downstream Conveyance System ................................................... 3-4 Table 2. Existing and Developed Site Basin Conditions...................................................... 4-2 Table 3. Summary of Performance Standards....................................................................... 4-3 Table 4. Wet Pond Sizing Calculations................................................................................ 4-8 Table 5. Summary of Special Reports and Studies............................................................... 6-1 Table 6. Summary of Other Permits Required...................................................................... 7-1 Table 7. Summary of Maintenance Requirements for Stormwater Facilities .....................10-1 H LIST OF FIGURES Figure1. TIR Worksheet......................................................................................................1-2 Figure2. Vicinity Map..........................................................................................................1-5 Figure 3: Drainage Basins.....................................................................................................1-6 Figure4. Soils Map...............................................................................................................1-7 Figure 5. Downstream Conveyance System......................................................................... 3-3 Figure 6. Stormwater System Design.................................................................................... 4-5 Figure 7. Flow Duration Curves for R/D.............................................................................. 4-6 Figure 8. Erosion and Sedimentation Control Plan .............................................................. 8-2 Figure 9. Site Improvement Fee Calculation Worksheet...................................................... 9-2 Figure 10. Flow Control and Water Quality Facility Summary ............................................ 9-3 APPENDICES Appendix A. Downstream System Appendix B. Stormwater R/D System Design Appendix C. Conveyance Calculations Appendix D. Hydrologic Model Documentation Appendix E. Proposed Site Plan U Project Description A summary of the Honey Crest project is provided in the TIR Worksheet (Figure 1). This preliminary technical information report (TIR) addresses the design of stormwater facilities and the offsite drainage analysis for the Honey Crest project. The Honey Crest project is a proposed residential development located within the City of Renton in King County (Figure 2). The proposal for development includes building 18 single-family dwellings and maintaining one existing dwelling on 3.1 acres. An existing single-family dwelling will be preserved and included in the plat design. The proposed site plan is provided in Appendix E. Site Description The site is located within the Cedar River watershed (King County Department of Natural Resources, 1997). The project address is 4210 NE 9th Place. The project is located east of Union Avenue and south of NE 9 h Court. The site is relatively flat. The elevation of the site ranges from 417 feet in the northwest corner to 411 feet in the southwest corner. The only distinct flow path from the site is near a pipe leaving the southwest corner of the property (Figure 3). Cover types on the site include those associated with four single-family residences, second growth forest, and areas of dense briars (Photo 1 in Appendix A.1). Based on King County Soil Survey (U.S. Department of Agriculture, 1973) the site consists of Alderwood soils (Figure 4). Drainage from an approximately 1.1-acre tributary subbasin to the west sheet flows towards the site and church property. The downstream drainage course passes through the church property to the south, then through the Honey Dew Elementary School property, and eventually discharges to a tributary of the Cedar River (King County Department of Parks, Planning, and Resources, 1990). A detailed assessment of the downstream conveyance system is provided in Section 3. Stormwater Design Under developed conditions, stormwater from the site will be collected and treated to basic water quality standards in a combined wetpond/detention pond. Level 2 R/D standards are required by the City of Renton and recommended by Lower Cedar River Basin and Nonpoint Action Plan. The natural discharge location from the site will be maintained at the outlet of the proposed stormwater pond. An agreement with the Renton Church of the Nazarene allows the stormwater pond to be constructed on the church property. The pond has been designed to provide Level 2 detention for runoff from future improvements on the church property that include up to 0.82 acres of new impervious area. The wetpond volume in the pond is sized to treat runoff from the proposed Honey Crest development, the offsite tributary area, and the entire area of the church property that drains to the pond, including future improvements. Runoff from these areas is currently untreated. 1-1 Honey Crest TM —July 2002 Figure 1. TIR Worksheet TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 1 PROJECT OWNER AND PROJECT ENGINEER Project Owner: Honey Crest LLC. Address: C/o: John Petersen Honey Crest LLC. 4720 200 Street SW Lynwood, WA 98046 Phone: (206) 423-6986 Project Engineer: Ed McCarthy, P.E. Company: Haozous Engineering, P.S. Address/Phone: 9957 171s' Avenue SE Renton, WA 98059 (425) 235-2707 Part 3 TYPE OF PERMIT APPLICATION Residential ❑X Grading Part 2 PROJECT LOCATION AND DESCRIPTION Project Name: Honey Crest Location: The project address is 4210 NE 91h Place. The project is located east of Union Avenue and south of NE 91h Court. Township: 23N Range: 5E Section: 10 Description: The proposal for development includes building 18 single-family dwellings and preserving one dwelling on 3.10 acres. Part4 OTHER REVIEWS AND PERMITS ❑ DFW HPA ❑ Wetlands ❑ National Pollutant Discharge Elimination System (NPDES) Stormwater Permit ❑ Forest Practices Class IV General Part5 SITE COMMUNITY AND DRAINAGE BASIN Community: City of Renton Drainage Basin: Maplewood Creek of the Lower Cedar River Watershed Part 6 SITE CHARACTERISTICS ❑ River: N/A ❑ Steep Slopes: N/A ❑ Stream: N/A ❑ Floodplain: N/A ❑ Critical Stream Reach: N/A 0 Wetlands: Church property wetland ❑ Depressions/Swales: N/A ❑ Seeps/Springs: N/A ❑ Lake: N/A ❑ High Groundwater Table: N/A ❑ Groundwater Recharqe: N/A FAR Part 7 SOILS Soil Type Slopes Alderwood Moderate Part 9 ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION ❑ Sedimentation Facilities ❑X Stabilized Construction Entrance 0 Perimeter Runoff Control 0 Cover Practices 0 Construction Sequence Part10 SURFACE WATER SYSTEM Erosion Potential Erosive Velocities LIMITATION/SITE CONSTRAINT Onsite treatment - basic standards Level 2 RID standards MINIMUM ESC REQUIREMENTS AFTER CONSTRUCTION ❑X Stabilize Exposed Surface 0 Remove and Restore Temporary ESC Facilities ❑X Clean and Remove All Silt and Debris 0 Ensure Operation of Permanent Facilities ❑X Wetpond onsite Basic water quality treatment ❑X RID Pond Level 2 RID standards are proposed Facility Related Site Design Considerations: Reference Facility Design Consideration 1-3 Part 11 STRUCTURAL ANALYSIS ❑ Rockery > 4' High: N/A ❑ Berms > 6': N/A Part 12 EASEMENTS/TRACTS ❑x Drainage Easement ❑ Access Easement ❑ Native Growth Protection Easement ❑ Sensitive areas ❑X Stormwater tracts Part 13 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 attachments. To the best of my knowledge the information provided here is accurate. L 44 J 6--� --�'VP2 Sig d/Dat I-4 N O V N C 00 w It � a r SITE 4 b .i�� •6� :� .i�� *% :rod' {.:=• (; GIAVE# L P!'{ v - PYP'`od; r AgC r.. I ter. } �,,,. _ - k • SCALE: 1:24 000 1" = 2,000' TITLE M� 5J� Q� M(� j� j�J�(� F.S.Figure 4. Soils Map HAOOZOOW rIIUV�IIII�ERIIIIIVo FN PAGE DATE 1-7 9/26/01 �.... c .. a zt,��..a A summary of conditions and requirements for the project are presented in this section. The following is a summary of core and special requirements from the 1998 King County Surface Water Design Manual: Core Requirement 1: Discharge at the Natural Location The natural discharge location from the site will be maintained at the outlet of the proposed stormwater pond. Core Requirement 2: Off -site Analysis A Level 1 downstream drainage analysis is presented in Section 3. Core Requirement 3: Runoff Control Level 2 R/D standards are required for the site. Core Requirement 4: Conveyance System The onsite stormwater conveyance system and offsite improvements will be designed to convey the 25-year storm. Core Requirement 5: Erosion/Sedimentation Control Plan Proposed erosion/sedimentation control procedures are described in Section 8. Core Requirement 6: Maintenance and Operation The proposed system for managing stormwater will be maintained and operated by a homeowners association and/or the Renton Church of the Nazarene. Recommended maintenance activities are provided in Section 10. Core Requirement 7: Bonds and Liability Bonds and liability requirements are presented in Section 9. Core Requirement 8: Water Quality As described in Section 5.E, basic water quality standards apply to the site. A basic wetpond will provide water quality treatment for stormwater collected from the site and 2-1 Honey Crest TM —July 2002 offsite improvements. The wetpond has been sized to provide treatment from the entire church property that drains to the pond. Special Requirement 1: Other Adopted Area -Specific Requirements The site is within the Cedar River Basin. Basin -wide requirements recommended by the Lower Cedar River Basin and Nonpoint Action Plan apply to the site. Based on City of Renton maps, the site is surrounded by parcels within a Zone 2 Aquifer Protection Area, but is not identified as being within such a zone (Figure A.2.1 in Appendix A.2). Special Requirement 2: Delineation of 100-Year Floodplain The site is not within a 100-year floodplain. Special Requirement 3: Flood Protection Facilities The project does not contain nor is it adjacent to a flood protection facility. Special Requirement 4: Source Controls Source controls are not proposed for the development. Special Requirement 5: Oil Control The proposed development does not meet the definition of a high -use site requiring oil control. 2-2 Honey Crest 77R —July 2002 3: Offsite A ijjyS s A downstream drainage analysis for the site is presented in this section. The drainage course from the site was assessed on 8/14/01 and 8/27/01. Rainfall occurred on the day prior to the 8/27/01 site visit. The downstream conveyance system is described below and illustrated in Figure 5. Further descriptions of downstream structures are summarized in Table 1. A wet weather follow-up investigation of the Honey Crest site was conducted on April 9, 2002. Rainfall occurred shortly prior to the site visit. Puddles had formed along the gravel road that enters the site. Neither ponded nor flowing water were observed within the pervious portions of or along its boundaries. Upstream Drainage The topography of the site and surrounding area is flat (Photo 1 in Appendix A.1). Based on the site's topographic map, it appears that drainage from residential lots adjacent to the site's west boundary sheet flows towards the site (Location 1 in Figure 5). Runoff from areas north of the site is intercepted by NE 9`h Court (Location 2). Mission Hills subdivision is located east of the site (Location 3) and has its own stormwater collection system. Runoff from the southern portion of the site appears to sheet flow towards the property to the south, owned by the Renton Church of the Nazarene (Location 4). However, the primary discharge location from the site is from the southwest corner of the site (Location 5). Runoff from this low area of the site flows to a ditch along the south boundary of the site and subsequently to a pipe system on the church property to the south as described below. Downstream Drainage Course From the southwest corner of the site, runoff flows to an open channel/ditch along the south boundary of the site (Location 6). The ditch is somewhat constricted by yard debris as is flows west a short distance and then into an 8-inch diameter CMP (Location 7). The 8-inch diameter CMP flows to the southeast and connects to the stormwater system on the Renton Church of the Nazarene property. The conveyance system is 12-inch diameter CMP along the church parking lot (Locations 8 and 9). A 48-inch diameter Type 2 catch basin contains a 12-inch diameter CMP riser that apparently acts as an oil/water separator for the parking lot. From this catch basin, a 12-inch diameter CMP (Location 10) conveys drainage to an outfall to the east on the church property (Location 11). The storm system outfall is in the buffer of a Class 3 wetland (Photo 2 in Appendix A.1). At the outlet of the wetland, the area of the site comprises approximately 15 percent of the tributary basin. From the wetland, runoff flows to the south and is conveyed under the Honey Dew Elementary play fields through an 18-inch diameter pipe (Locations 12-14; Photo 3 in Appendix A.1). This section of the conveyance system was upgraded when the Mission Hills plat was constructed (Harmsen & Associates, Inc., 1992). From the play fields, the pipe system connects to a catch basin on the south side of NE 8 h Street (Location 15) and then crosses between two lots within the Orchards plat to a catch basin on the north side of NE 7a' Place (Location 16). This catch basin has approximately 6 inches of sediment. The pipe system then 3-1 Honey Crest 77R—July 2002 connects to a catch basin on the south side of NE 7th Place (Location 17). From this catch basin, a 20-inch diameter pipe conveys drainage to the south (Location 18) and then turns west (Location 19). The 20-inch diameter pipe outfalls in an open channel/wetland (Location 20; Photo 4 in Appendix A.1). The open channel flows through an on-line stormwater facility that was constructed as part of the Orchards plat (Location 21). Downstream Drainage Complaints Previous downstream drainage analyses for Mission Hills (Harmsen & Associates, Inc., 1992) and the Orchards were reviewed. Conveyance constrictions were described by Harmsen & Associates, Inc. at the Honey Dew Elementary School. The pipe system that crosses the athletic fields of the schoolyard used to be 12-inch diameter and poorly maintained. This pipe system has since been upsized to 18-inch diameter and appeared to be in good condition. 3-2 Homey Crest 77R—July 2002 4- j4V LEGEND Location ID Culvert Ditch Catch Basin Sheet Flow SCALE: I" = 250' TITLE Figure S. Downstream Conveyance HAOZOW EMUMEERM. F.S. System it PAGE DATE 3-3 1 9/26/01 Table 1. Description of Downstream Conveyance System Site Visits on 8/14/01 and 9/26/01 Basin: Maplewood Creek Tributary of the Cedar River Weather: Sunny Location Drainage Drainage Slope Distance from Existing Potential Observations of Field ID Component Type, Component Site Discharge Problems Problems Inspector, Resource Name, and Size Description Reviewer, or Resident See Fig. 5 Type: sheet flow, swale, drainage basin, 1/4 mile=1,320 ft constrictions, under capacity, ponding, tributary area, likelihood of stream, channel, pipe. vegetation, cover, depth, (%) (FT) overtopping, scouring, bank sloughing, problem, overflow Size: diameter, width type of sensitive area sedimentation, incision, other erosion pathways, potential impacts I Sheet flow onto site Residential lots 1-3 West boundary of located to the west of site the site 2 Sheet flow from Road stormwater 1-3 North boundary subbasin north of site collection system of site collected by road storm along NE 9a' Ct system 3 Mission Hills Existing stormwater 1-3 East boundary of Runoff collected and subdivision system site conveyed to Mission Hills stormwater system 4 Sheet flow from site Sheet flow likely 1-3 South boundary Sheet flow onto church occurs across portion of site property is collected by of south boundary of storm collection pipe in site church parking lot 5 SheWshallow flow Main discharge 1 Southeast corner Most of the sheet flow from site location from site of site from interior of property Rely flows to this low spot on the site 6 Ditch Ditch along south 1 0-20 No signs of Yard waste and debris in Width: 2-6' boundary conveys erosion or ditch reducing the ditch Depth: 1-2' drainage to 8-inch overtopping capacity Side slope. 3:1 diameter CMP pipe 7 8-inch diameter CMP Conveys drainage to 1 20-50 pipe church stormwater system Table I (continued) Basin: Maplewood Creek Tributary of the Cedar River Location Drainage Drainage Slope Distance from Existing Potential Observations of Field ID Component Type, Component Site Discharge Problems Problems Inspector, Resource Name, and Size Description Reviewer, or Resident See Fig. 5 Type: sheet flow, swale, drainage basin, 1/4 mile=1,320 ft constrictions, under capacity, ponding, tributary area, likelihood of stream, channel, pipe. vegetation, cover, depth, (%) (FT) overtopping, scouring, bank sloughing, problem, overflow Size: diameter, width type of sensitive area sedimentation, incision, other erosion pathways, potential impacts 8 12-inch diameter CMP Church stormwater 1 50-400 Connects to CB in system eastern portion of parking lot 9 12-inch diameter CMP Church stormwater 1 400-530 Connects to 48-inch system diameter manhole with 12-inch riser for oil/water separator 10 12-inch diameter CMP Church stormwater 2 530-700 Discharges to Class 3 system wetland/buffer in dense briars; outfall not located 11 Wetland Class 3 wetland 1 700-800 Buffer along west Wetland discharges to boundary of pipe system at north wetland has been boundary of Honey Dew disturbed Elementary School 12 18-inch diameter N 12 Inlet to pipe l 800-820 Connects to manhole at pipe conveyance system north edge of athletic field 13 18-inch diameter N12 Honey Dew 1 820-1,030 Connects to manhole in pipe Elementary School middle of athletic field; pipe conveyance manhole lid covered system with soil/turf 14 18-inch diameter N12 Honey Dew 1 1,030-1,230 Connects to manhole at pipe Elementary School south edge of athletic pipe conveyance field system Table 1 (continued) Basin: Maplewood Creek Tributary of the Cedar River Location Drainage Drainage Slope Distance from Existing Potential Observations of Field ID Component Type, Component Site Discharge Problems Problems Inspector, Resource Name, and Size Description Reviewer, or Resident See Pig. 5 Type: sheet flow, swale, drainage basin, 1/4 mile=1,320 ft constrictions, under capacity, ponding, tributary area, likelihood of stream, channel, pipe. vegetation, cover, depth, (%) (FT) overtopping, scouring, bank sloughing, problem, overflow Size: diameter, width type of sensitive area sedimentation, incision, other erosion pathways. potential impacts 15 18-inch diameter N 12 Connects to CB on 1-2 1,230-1,300 pipe south side of NE 81h St 16 18-inch diameter N12 Connects to CB on 1-2 1,300-1,450 Outlet pipe from pipe north side of NE 7`h PI CB is 1/3 full with sediment 17 18-inch diameter N12 Connects to CB on 1-2 1,450-1,480 pipe south side of NE 7'h Pl 18 20-inch diameter N 12 Connects to CB 1-2 1,480-1,600 pipe between NE 7`h PI and NE 7`r' St 19 20-inch diameter N 12 Outfalls to 1-2 1,600-1,900 pipe wetland/channel 20 Outfall of 20-inch 1-2 1,900 No signs of diameter N12 pipe erosions; potential overtopping onto adjacent lawn with backwater conditions 21 Wetland/channel 1-2 1,900-1,950 22 R/D pond in the 1-2 1,950-2,250 western portion of the Orchards Part A: Existing Hydrology Cover types on the northern portion of the site include lawn areas, roofs, driveways, and a gravel access road associated with single-family residences. The southern portion of the site is forested. Cover types and areas used in the stormwater design for existing onsite conditions are summarized in Table 2. The site is relatively flat (Figure 3). The only distinct flow path from the site is near a pipe leaving the southwest corner of the property. Sheet flow across the southern boundary of the site also likely occurs under heavy rainfall. Drainage from the site (subbasin "siteex") is collected in a pipe system on the church property to the south. Drainage from residential lots adjacent to the southern portion of the west boundary of sheet flows towards the site and the neighboring church drainage system. Part B: Developed Site Hydrology The proposal for development includes building 18 single-family dwellings and maintaining one existing dwelling. The proposed site plan is provided in Appendix E. Under developed conditions, the Honey Crest site will consist of 1.43 acres of grass and 1.67 acres of impervious area. Cover type areas for developed onsite conditions are summarized in Table 2. The pond is also designed to manage runoff from 0.82 acre of incremental impervious area on the church property. Under developed conditions, stormwater from the Honey Crest site (subbasin "sitede") will be collected and treated to basic water quality standards in a combined wetpond/detention pond located on the church property to the south. The natural discharge location of upstream tributary areas and the site will be maintained under developed conditions. Runoff from offsite upstream areas that currently flows to the western portion of the site will be collected in the site's stormwater system. Level 2 R/D standards are required by the King County Flow Application Maps and recommended by the Lower Cedar River Basin and Nonpoint Action Plan. Stormwater from the site will be collected and conveyed to the Level 2 stormwater facility. The pond has also been designed to provide Level 2 detention for runoff from future improvements on the church property. These improvements include adding up to 0.82 acre of impervious area. It is assumed that up to 0.42 acre that is currently gravel will be either paved or used for a building footprint sometime in the future. Stormwater from the pond will be discharged from its control structure to the wetland buffer on the church property, southeast of the site. 4-1 Honey Crest M—July 2002 Table 2. Existing and Developed Site Basin Conditions Existing Conditions Subbasins KCRTS Till forest Gravel Wetland 7111--grass Impery Total Basin (AC) (AC) (AC) (A0 (A0 (AC) Site siteex 1.78 0.22 - 0.92 0.18 3.10 Offsite Tributary Area trib 0.13 0.14 - 0.78 0.08 1.13 Church churchex - 0.42 - 2.48 1.29 4.18 Total 1.91 0.78 - 4.18 1.55 8.41 Note: Gravel areas were modeled in KCRTS as 50% till grass and 50% impervious. Developed Conditions Subbasins KCRTS Till forest Gravel Wetland 77111-grass Impery Total Basin (AC) (AC) 00 (AC) (AC) (AC) Onsite Lots/Road sitede - - - 1.43 1.67 3.10 Offsite Tributary Area trib 0.13 0.14 - 0.78 0.08 1.13 Church churchde - - - 1.97 1.71 3.68 R/D Pond churchde - I - I - 1 0.30 1 0.20 1 0.50 Total 0.13 1 0.14 1 - 1 4.48 1 3.66 1 8.41 Note: Gravel areas were modeled in KCRTS as 50% till grass and 50% impervious. G-�- '.L5 GL Alr../ I fOVIftt 4-2 Part C: Performance Standards A summary of flow control, conveyance, and water quality treatment performance standards for the project is presented in Table 3, below. Table 3. Summary of Performance Standards Category Performance Standard Source Flow Control Level 2 PUD ■ City of Renton Conveyance System Capacity Provide conveyance for developed 25-year storm ■ Surface Water Design Manual Section 1.2.4.1 Water Quality Treatment Menu Basic water quality treatment; a wetpond is proposed ■ City of Renton Source Control None proposed ■ Not applicable Oil Control The site does not meet the definition of a high -use site ■ Surface Water Design Manual Section 1.3.5 4-3 Honey Crest TM—J*2002 Part D: Flow Control System KCRTS was used to design the proposed stormwater facility. Procedures and design criteria specified in the 1998 King County Surface Water Design Manual were followed for hydrologic modeling. Descriptions of the stormwater system and details of the design analysis are provided below. A plan view of the stormwater system for the site is provided in Figure 6. For stormwater facility designs, the reduced KCRTS time series data set was used for the Sea- Tac rainfall region with a correction factor of 1.0. Documentation of the KCRTS input and output including descriptions of executable files, reservoirs, and times series is listed in Appendix D. Stormwater from the development will be managed with a combined wetpond/detention facility. Level 2 R/D standards are proposed for the single discharge location on the site. The facility shown in Figure 6 meets Level 2 R/D criteria and basic water quality requirements. The facility has been designed to accommodate up to 0.82 acre of new impervious area at the Renton Church of the Nazarene. Flow duration curves at the outlet of the pond are provided in Figure 7. Peak flow rates for the discharge location, for existing and developed site conditions, follow Figure 7. The duration curves and peak flow rates, shown for existing and developed conditions, indicate that Level 2 R/D criteria are met at the outlet of the R/D facility. The stormwater facility requires approximately 25,889 cubic feet of live storage, excluding a factor of safety, to meet Level 2 R/D standards. A factor of safety of approximately 10 percent has been added for a total required volume of 28,478 cubic feet. Part E: Water Quality System Basic water quality standards apply to the site. A wetpond will provide treatment for the Honey Crest site, offsite tributary areas to the site, and for all areas of the Renton Church of the Nazarene property that drain to the pond, including future improvements. Runoff from the church property is currently untreated. The required wetpond volume was determined using equations provided in Chapter 6 of the 1998 Surface Water Design Manual. Basin areas, annual runoff volumes, Vb/Vr ratios, and required volume for the wetpond are given in Table 4. 4-4 Honey Crest TIR-July 2002 ` ASAIaLTD UP. / ofa 4. E411. ij 4 I ,�7. / 60.00 I \I ( LOT 17 IL i 0 '� I.E. ar IIIiW-406.n li 11 1 , +++ via IN aoaEcxa 6 .1. / I co 11 j C0 --- -- ?:.�1:� ucn •, ,; ...,.; SAGA rert.aaMcwe y ' 7DPr 41dalS w .+,-�; l LOT 16 •'rA• 4N'A •L".,, •3'•' �s. 4; 4;{� / ' ' 47! /J 41Ica •44. \ NOOSE 409.44 _ — 1N6 sAR. SEwaKN RNIDIA EIFV.=414.11 I.E.%U IE_ 409.QB _ l� QB 4 a / - / 1 11�P� �} i;C PLAT OF TH P 40Bra1 - WSSIONHIMS / 12 I 4 _ 40X91 -/ / VOLUME 167 PAGE 39 lE- 44MQ * / / / 1 � .Do 1 / LOT IS LOT 14 LOT 13 LOT 12 LOT 11 CB a / \ 1 I Will- It w / IE- 401L / / 1� TEat, � - �E/ _ - _ -_ -- -_ -- rRAE4pMDR� N 8.24'51'N 41-- -- -- -- -- _ Pam J / N0115E 1 \ op- 41 1 413Bd \ \ \ NOR1N LINE N,/2, S -5 AE- 40XL ' IE- 407.Qe 12 \ ♦ $R1/4, NRI/4, 1023.5 �6 \ / -- - - iE- 40X48 IE_ 183 I - / \ ExsrwiGCB / 414 \ I.E.I.I?" P RBT= 409.16 EMSTNIi O \/ I E. 12" CMP REA= .16 w �� _ _ EASTIN6 C6 LE.ir04►EAS1-406.99 I.E. 12"P 407.16 'FA491G01 ` \ RIM =411.52 �'. ! LE. B"OMP SAUSN=40N.66 I.E. 12'CMP-407.16 RIM 713A2 6'jMPR6t=40?'9 \ I.E. 6'CMP NORM�MA.99 .. P N.N.=405.75 \ \ �SS R^ 45a63 / LE. 12" EAST 409.54 J.ZI /Carry/ f \ \ \ /� 6' QRl/SHED SIARFAIXIVG IPfWb QET Yql- Zq,47d CF � , , I I� \ /BOTWM CVARSE PROM QET VtX- 2JL;IW CF - .!L 1'D \ RWID NET Vt'X- 24761 CF I FR" NET WX- 24900 CF - d db / \ \ DEG W/ENN SUFES 2:1 I \ \ c \ NET NVIEWOR SCOPES &I I I I ( ( \ \ WET PO11D CELL QIYIDEiP BERAa 2:1 I / \ ( ENIEWW BEW SLOPES- 1-1 I Ir ( G BM � col L. ♦I co W N O n 1.2 1 0.4 0.2 no n .l .4 1.00E-05 1.00E-04 1.00E-03 1.00E-02 1.00E-01 1.00E+00 Probability of Exceedence Figure 7. Flow Duration Curves for R/D. Duration curves are shown at pond outlet. The pond is designed to meet Level 2 R/D standards. 4-6 1.2 1 W. in LL U 0.6 3 0 LL 0.4 0.2 Le] `c V 1.00E-05 1.00E-04 1.00E-03 1.00E-02 1.00E-01 1.00E+00 Probability of Exceedence Figure 7. Flow Duration Curves for RID. Duration curves are shown at pond outlet. The pond is designed to meet Level 2 RID standards. 4-6 Predeveloped Peak Flow Rates Flow Frequency Analysis Time Series File:totex.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates --- Flow Rate Rank Time of Peak (CFS) 0.954 4 2/09/01 2:00 0.654 7 1/05/02 16:00 1.16 2 2/27/03 7:00 0.570 8 8/26/04 2:00 0.710 6 10/28/04 16:00 1.01 3 1/18/06 16:00 0.931 5 11/24/06 3:00 2.02 1 1/09/08 6:00 Computed Peaks Developed Peak Flow Rates Flow Frequency Analysis Time Series File:rdout.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates --- Flow Rate Rank Time of Peak (CFS) 0.987 3 2/09/01 16:00 0.302 7 1/05/02 18:00 0.582 5 3/06/03 20:00 0.275 8 8/23/04 23:00 0.480 6 1/05/05 10:00 0.926 4 1/18/06 21:00 1.13 2 11/24/06 5:00 2.31 1 1/09/08 9:00 Computed Peaks Horsey Crest 77R -July 2002 -----Flow Frequency Analysis------- - - Peaks - - Rank Return Prob (CFS) Period 2.02 1 100.00 0.990 1.16 2 25.00 0.960 1.01 3 10.00 0.900 0.954 4 5.00 0.800 0.931 5 3.00 0.667 0.710 6 2.00 0.500 0.654 7 1.30 0.231 0.570 8 1.10 0.091 1.73 50.00 0.980 -Flow Frequency Analysis------ - - Peaks - - Rank Return Prob (CFS) (ft) Period 2.31 3.09 1 100.00 0.990 1.13 2.79 2 25.00 0.960 0.987 2.74 3 10.00 0.900 0.926 2.71 4 5.00 0.800 0.582 2.42 5 3.00 0.667 0.480 1.87 6 2.00 0.500 0.302 1.20 7 1.30 0.231 0.275 1.00 8 1.10 0.091 1.92 3.03 50.00 0.980 4-7 Table B.1.1. Stormwater Pond Overflow Design Date: 8/29/02 R/D Facility: Honey Crest KCRTS Filename: lev2.rdf Contributing Time Series: totdev15.tsf Overflow protection structure: outlet control structure riser (Rl) Emergency overflow structure: emergency spillway Qd.igr, (CFS): 6.85 (KCRTS 15-minute peak rate) Top of Control Structure Riser (FT) 408.00 Min. Top of Berm (FT) 409.00 Structure Capacity Elevation WSE Structure Size Units Head (FT) (CFS) (Fr) (FT) Design Operation Riser R1 24 inches 0.10 408.00 408.10 Primary Overflow Riser RI 24 inches 0.50 6.89 408.00 408.50 Secondary Inlet Jailhouse window 98 inches 0.40 6.88 408.10 408.50 Emergency Overflow Spillway' 23 feet 0.20 6.85 408.50 408.70 Head (FI') Design Head above Required Freeboard: Riser 0.10 Primary Overflow or Secondary Inlet Head 0.40 Spillway Head 0.20 Spillway Freeboard 0.30 Total Required Freeboard 1.00 'Spillway Design: Spillway design is based on Equation 5-3 of the KCSWDM: L= [Q./(3.21 *H112), -2.4H Where: Qloo = 6.85 cfs H = 0.20 feet Therefore: L = 23 feet Appendix B.2 KCRTS Pond Design Retention/Detention Facility Type of Facility: Detention Pond Side Slope: 2.00 H:1V Pond Bottom Length: 170.88 ft Pond Bottom Width: 42.72 ft Pond Bottom Area: 7300. sq. ft Top Area at 1 ft. FB: 10974. sq. ft 0.252 acres Effective Storage Depth: 3.00 ft Stage 0 Elevation: 405.00 ft Storage Volume: 25889. cu. ft 0.594 ac-ft Riser Head: 3.00 ft Riser Diameter: 24.00 inches Number of orifices: 2 Full Head Pipe Orifice # Height Diameter Discharge Diameter (ft) (in) (CFS) (in) 1 0.00 3.19 0.478 2 1.40 2.35 0.189 6.0 Top Notch Weir: Rectangular Length: 12.00 in Weir Height: 2.50 ft Outflow Rating Curve: None Stage Elevation Storage Discharge Percolation Surf Area (ft) (ft) (cu. ft) (ac-ft) (cfs) (cfs) (sq. ft) 0.00 405.00 0. 0.000 0.000 0.00 7300. 0.03 405.03 219. 0.005 0.050 0.00 7326. 0.07 405.07 513. 0.012 0.071 0.00 7360. 0.10 405.10 734. 0.017 0.087 0.00 7386. 0.13 405.13 956. 0.022 0.101 0.00 7411. 0.17 405.17 1253. 0.029 0.113 0.00 7446. 0.20 405.20 1477. 0.034 0.123 0.00 7472. 0.23 405.23 1702. 0.039 0.133 0.00 7497. 0.27 405.27 2002. 0.046 0.142 0.00 7532. 0.37 405.37 2760. 0.063 0.167 0.00 7618. 0.47 405.47 3526. 0.081 0.188 0.00 7705. 0.57 405.57 4301. 0.099 0.208 0.00 7792. 0.67 405.67 5084. 0.117 0.225 0.00 7880. 0.77 405.77 5877. 0.135 0.242 0.00 7967. 0.87 405.87 6678. 0.153 0.257 0.00 8055. 0.97 405.97 7488. 0.172 0.271 0.00 8144. 1.07 406.07 8307. 0.191 0.285 0.00 8233. 1.17 406.17 9134. 0.210 0.298 0.00 8322. 1.27 406.27 9971. 0.229 0.311 0.00 8411. 1.37 406.37 10817. 0.248 0.323 0.00 8501. 1.40 406.40 11072. 0.254 0.327 0.00 8528. 1.42 406.42 11243. 0.258 0.331 0.00 8546. 1.45 406.45 11499. 0.264 0.338 0.00 8573. 1.47 406.47 11671. 0.268 0.348 0.00 8591. Honey Crest TIR-July 2002 R 1.50 406.50 11929. 0.274 0.360 0.00 8618. 1.52 406.52 12102. 0.278 0.375 0.00 8636. 1.55 406.55 12361. 0.284 0.392 0.00 8663. 1.57 406.57 12535. 0.288 0.408 0.00 8681. 1.60 406.60 12795. 0.294 0.415 0.00 8708. 1.62 406.62 12970. 0.298 0.422 0.00 8726. 1.72 406.72 13847. 0.318 0.447 0.00 8817. 1.82 406.82 14733. 0.338 0.470 0.00 8908. 1.92 406.92 15629. 0.359 0.491 0.00 8999. 2.02 407.02 16533. 0.380 0.510 0.00 9091. 2.12 407.12 17447. 0.401 0.529 0.00 9183. 2.22 407.22 18370. 0.422 0.547 0.00 9276. 2.32 407.32 19302. 0.443 0.564 0.00 9368. 2.42 407.42 20243. 0.465 0.581 0.00 9461. 2.50 407.50 21003. 0.482 0.594 0.00 9536. 2.56 407.56 21577. 0.495 0.654 0.00 9592. 2.63 407.63 22251. 0.511 0.755 0.00 9658. 2.69 407.69 22832. 0.524 0.880 0.00 9714. 2.75 407.75 23417. 0.538 1.020 0.00 9771. 2.81 407.81 24005. 0.551 1.180 0.00 9827. 2.88 407.88 24695. 0.567 1.360 0.00 9893. 2.94 407.94 25290. 0.581 1.540 0.00 9950. 3.00 408.00 25889. 0.594 1.730 0.00 10007. 3.10 408.10 26894. 0.617 2.360 0.00 10102. 3.20 408.20 27909. 0.641 3.500 0.00 10198. 3.30 408.30 28934. 0.664 4.970 0.00 10294. 3.40 408.40 29968. 0.688 6.710 0.00 10390. 3.50 408.50 31012. 0.712 8.690 0.00 10486. 3.60 408.60 32065. 0.736 10.860 0.00 10583. 3.70 408.70 33129. 0.761 13.230 0.00 10680. 3.80 408.80 34201. 0.785 15.370 0.00 10778. 3.90 408.90 35284. 0.810 16.200 0.00 10876. 4.00 409.00 36377. 0.835 16.990 0.00 10974. 4.10 409.10 37479. 0.860 17.740 0.00 11072. 4.20 409.20 38591. 0.886 18.450 0.00 11171. 4.30 409.30 39713. 0.912 19.140 0.00 11270. 4.40 409.40 40845. 0.938 19.800 0.00 11369. 4.50 409.50 41987. 0.964 20.440 0.00 11469. 4.60 409.60 43139. 0.990 21.060 0.00 11569. 4.70 409.70 44301. 1.017 21.660 0.00 11669. 4.80 409.80 45472. 1.044 22.240 0.00 11770. 4.90 409.90 46655. 1.071 22.810 0.00 11871. 5.00 410.00 47847. 1.098 23.360 0.00 11972. Hyd Inflow Outflow Peak Storage Target Calc Stage Elev (Cu-Ft) (Ac-Ft) 1 2.74 ******* 2.32 3.09 408.09 26825. 0.616 2 1.31 ******* 1.13 2.79 407.79 23808. 0.547 3 1.32 ******* 0.99 2.74 407.74 23279. 0.534 4 1.39 ******* 0.93 2.71 407.71 23023. 0.529 5 1.60 ******* 0.58 2.43 407.43 20295. 0.466 6 0.81 ******* 0.48 1.87 406.87 15149. 0.348 7 1.01 ******* 0.30 1.20 406.20 9425. 0.216 8 1.01 ******* 0.27 1.00 406.00 7705. 0.177 ---------------------------------- Route Time Series through Facility Inflow Time Series File:totdev.tsf Homey Crest TIR -July 2002 Outflow Time Series File:rdout Inflow/Outflow Analysis Peak Inflow Discharge: 2.74 CFS at Peak Outflow Discharge: 2.32 CFS at Peak Reservoir Stage: 3.09 Ft Peak Reservoir Elev: 408.09 Ft Peak Reservoir Storage: 26825. Cu-Ft 0.616 Ac-Ft Flow Frequency Analysis Time Series File:rdout.tsf Project Location:Sea-Tac 6:00 on Jan 9 in Year 8 9:00 on Jan 9 in Year 8 ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- FlowRate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) (ft) Period 0.987 3 2/09/01 16:00 2.31 3.09 1 100.00 0.990 0.302 7 1/05/02 18:00 1.13 2.79 2 25.00 0.960 0.582 5 3/06/03 20:00 0.987 2.74 3 10.00 0.900 0.275 8 8/23/04 23:00 0.926 2.71 4 5.00 0.800 0.480 6 1/05/05 10:00 0.582 2.42 5 3.00 0.667 0.926 4 1/18/06 21:00 0.480 1.87 6 2.00 0.500 1.13 2 11/24/06 5:00 0.302 1.20 7 1.30 0.231 2.31 1 1/09/08 9:00 0.275 1.00 8 1.10 0.091 Computed Peaks 1.92 3.03 50.00 0.980 Flow Duration from Time Series File:rdout.tsf Cutoff Count Frequency CDF Exceedence_Probability CFS % $ % 0.016 47465 77.405 77.405 22.595 0.226E+00 0.047 5236 8.539 85.944 14.056 0.141E+00 0.079 2871 4.682 90.626 9.374 0.937E-01 0.110 1802 2.939 93.565 6.435 0.644E-01 0.142 1347 2.197 95.762 4.238 0.424E-01 0.173 902 1.471 97.233 2.767 0.277E-01 0.205 522 0.851 98.084 1.916 0.192E-01 0.236 410 0.669 98.752 1.248 0.125E-01 0.267 277 0.452 99.204 0.796 0.796E-02 0.299 139 0.227 99.431 0.569 0.569E-02 0.330 105 0.171 99.602 0.398 0.398E-02 0.362 38 0.062 99.664 0.336 0.336E-02 0.393 18 0.029 99.693 0.307 0.307E-02 0.425 33 0.054 99.747 0.253 0.253E-02 0.456 39 0.064 99.811 0.189 0.189E-02 0.488 18 0.029 99.840 0.160 0.160E-02 0.519 26 0.042 99.883 0.117 0.117E-02 0.550 16 0.026 99.909 0.091 0.913E-03 0.582 21 0.034 99.943 0.057 0.571E-03 0.613 6 0.010 99.953 0.047 0.473E-03 0.645 0 0.000 99.953 0.047 0.473E-03 0.676 4 0.007 99.959 0.041 0.408E-03 0.708 2 0.003 99.962 0.038 0.375E-03 0.739 3 0.005 99.967 0.033 0.326E-03 0.771 2 0.003 99.971 0.029 0.294E-03 0.802 3 0.005 99.976 0.024 0.245E-03 0.833 0 0.000 99.976 0.024 0.245E-03 0.865 3 0.005 99.980 0.020 0.196E-03 Honey Crest TIR -July 2002 0.896 5 0.008 99.989 0.928 2 0.003 99.992 0.959 1 0.002 99.993 0.991 2 0.003 99.997 1.02 0 0.000 99.997 1.05 1 0.002 99.998 1.08 0 0.000 99.998 1.12 0 0.000 99.998 Duration Comparison Anaylsis Base File: totex.tsf New File: rdout.tsf Cutoff Units: Discharge in CFS -----Fraction of Time----- CutoffBase New %Change 0.360 I 0.34E-02 0.34E-02 0.0 0.422 I 0.24E-02 0.26E-02 9.0 0.483 I 0.17E-02 0.16E-02 -7.5 0.544 I 0.13E-02 0.95E-03 -25.6 0.606 i 0.96E-03 0.47E-03 -50.8 0.667 I 0.60E-03 0.42E-03 -29.7 0.728 I 0.41E-03 0.34E-03 -16.0 0.789 I 0.29E-03 0.24E-03 -16.7 0.851 I 0.20E-03 0.20E-03 0.0 0.912 I 0.11E-03 0.11E-03 0.0 0.973 I 0.65E-04 0.65E-04 0.0 1.03 I 0.33E-04 0.33E-04 0.0 1.10 I 0.16E-04 0.16E-04 0.0 0.011 0.114E-03 0.008 0.815E-04 0.007 0.652E-04 0.003 0.326E-04 0.003 0.326E-04 0.002 0.163E-04 0.002 0.163E-04 0.002 0.163E-04 ---------Check of Tolerance------- ProbabilityBase New %Change 0.34E-02 0.360 0.360 0.0 0.24E-02 0.422 0.431 2.3 0.17E-02 0.483 0.470 -2.6 0.13E-02 0.544 0.512 -6.0 0.96E-03 0.606 0.539 -10.9 0.60E-03 0.667 0.581 -12.9 0.41E-03 0.728 0.676 -7.1 0.29E-03 0.789 0.772 -2.2 0.20E-03 0.851 0.866 1.8 0.11E-03 0.912 0.912 0.0 0.65E-04 0.973 0.979 0.6 0.33E-04 1.03 1.04 0.2 0.16E-04 1.10 1.12 2.6 Maximum positive excursion = 0.075 cfs ( 7.1%) occurring at 1.05 cfs on the Base Data:totex.tsf and at 1.12 cfs on the New Data:rdout.tsf Maximum negative excursion = 0.115 cfs (-16.3$) occurring at 0.705 cfs on the Base Data:totex.tsf and at 0.590 cfs on the New Data:rdout.tsf Honey Crr&TIR-July 2002 Flow Frequency Analysis Time Series File:totdev.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- FlowRate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period 1.32 5 2/09/01 2:00 2.74 1 100.00 0.990 1.01 8 1/05/02 16:00 1.60 2 25.00 0.960 1.60 2 2/27/03 7:00 1.47 3 10.00 0.900 1.01 7 8/26/04 2:00 1.39 4 5.00 0.800 1.24 6 10/28/04 16:00 1.32 5 3.00 0.667 1.39 4 1/18/06 16:00 1.24 6 2.00 0.500 1.47 3 10/26/06 0:00 1.01 7 1.30 0.231 2.74 1 1/09/08 6:00 1.01 8 1.10 0.091 Computed Peaks 2.36 50.00 0.980 Flow Frequency Analysis Time Series File:rdout.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- FlowRate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) (ft) Period 0.987 3 2/09/01 16:00 2.31 3.09 1 100.00 0.990 0.302 7 1/05/02 18:00 1.13 2.79 2 25.00 0.960 0.582 5 3/06/03 20:00 0.987 2.74 3 10.00 0.900 0.275 8 8/23/04 23:00 0.926 2.71 4 5.00 0.800 0.480 6 1/05/05 10:00 0.582 2.42 5 3.00 0.667 0.926 4 1/18/06 21:00 0.480 1.87 6 2.00 0.500 1.13 2 11/24/06 5:00 0.302 1.20 7 1.30 0.231 2.31 1 1/09/08 9:00 0.275 1.00 8 1.10 0.091 Computed Peaks 1.92 3.03 50.00 0.980 Flow Frequency Analysis Time Series File:sitede15.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- FlowRate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period 0.796 6 8/27/01 18:00 2.69 1 100.00 0.990 0.589 8 1/05/02 15:00 1.82 2 25.00 0.960 1.82 2 12/08/02 17:15 1.13 3 10.00 0.900 0.641 7 8/23/04 14:30 1.13 4 5.00 0.800 1.13 3 11/17/04 5:00 0.983 5 3.00 0.667 0.983 5 10/27/05 10:45 0.796 6 2.00 0.500 1.13 4 10/25/06 22:45 0.641 7 1.30 0.231 2.69 1 1/09/08 6:30 0.589 8 1.10 0.091 Computed Peaks 2.40 50.00 0.980 M Honey Crest TTR-July 2002 Predeveloped Peak Flow Rates Flow Frequency Analysis Time Series File:totex.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates --- Flow Rate Rank Time of Peak (CFS) 0.954 4 2/09/01 2:00 0.654 7 1/05/02 16:00 1.16 2 2/27/03 7:00 0.570 8 8/26/04 2:00 0.710 6 10/28/04 16:00 1.01 3 1/18/06 16:00 0.931 5 11/24/06 3:00 2.02 1 1/09/08 6:00 Computed Peaks Developed Peak Flow Rates Flow Frequency Analysis Time Series File:rdout.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates --- Flow Rate Rank Time of Peak (CFS) 0.988 3 2/09/01 16:00 0.297 7 1/05/02 18:00 0.577 5 3/06/03 20:00 0.271 8 8/23/04 23:00 0.475 6 1/05/05 10:00 0.927 4 1/18/06 21:00 1.14 2 11/24/06 5:00 2.32 1 1/09/08 9:00 Computed Peaks ----Flow Frequency Analysis------- - - Peaks - - Rank Return Prob (CFS) Period 2.02 1 100.00 0.990 1.16 2 25.00 0.960 1.01 3 10.00 0.900 0.954 4 5.00 0.800 0.931 5 3.00 0.667 0.710 6 2.00 0.500 0.654 7 1.30 0.231 0.570 8 1.10 0.091 1.73 50.00 0.980 -----Flow Frequency Analysis------- - - Peaks - - Rank Return Prob (CFS) (ft) Period 2.32 3.09 1 100.00 0.990 1.14 2.80 2 25.00 0.960 0.988 2.74 3 10.00 0.900 0.927 2.71 4 5.00 0.800 0.577 2.46 5 3.00 0.667 0.475 1.89 6 2.00 0.500 0.297 1.22 7 1.30 0.231 0.271 1.01 8 1.10 0.091 1.92 3.03 50.00 0.980 4-7 Honey Crest TOR -July 2002 Table 4. Wet Pond Sizing Calculations Runoff Wetpond Wet Pond Till Forest Till Grass Impervious Total Area Volume VbNr Volume ;Facility (AC) (AC) (AC) (AC) (C'F) (CF) Onite Stormwater Pond Residential Lots/Onite Road 0.00 1.43 1.67 3.10 3,174 3.0 9,523 Offsite Tributary Area 0.13 0.85 0.15 1.13 / 619 3.0 1,858 Church 0.00 2.08 2.11 4.19 -, 4,127 3.0 12,381 Total 0.13 4.36 3.93 8.42 7,920 23,761 Mean annual storm = 0.47 Note: Impervious area of Honey Crest lots is assumed to be 54 percent with a density of 6.5 dwelling units/acre. 4-8 5. Conveyance System Analysis and Design A �y�' £R Stormwater RID System Conveyance The onsite stormwater system will be designed to convey the 25-year peak flow rate for onsite conveyance systems upstream of the stormwater facility. A conceptual design of the conveyance system is shown in Figure 6 of Section 4. Conveyance calculations for the system from the Honey Crest site to the proposed stormwater pond on the church site are provided in Appendix C.1. Figure C.1.1 presents backwater calculations for the trunk line and branches of the storm conveyance system. Figure C.1.2 illustrates the subbasins contributing to the individual catch basins on the site. Tables C.1.1 and C.1.2 document flow rate calculations using the Rational Method. 5-1 HoneyCrr& M—J*2002 6. Special Reports and Studies A summary of special reports and studies conducted for Honey Crest is presented below. Table 5. Summary of Special Reports and Studies Study/Report Date Conducted Geotechnical/soils Report of Geotechnical Investigation, Proposed Honeycrest April 2001 Development, Renton, Washington (S&EE) Wetlands Wetland Delineation and Report (J.S. Jones and Associates, Inc.) February 2001 Floodplains Groundwater N/A Anadromous fisheries impacts N/A f, 6-1 Honey Crest 77—July2M July 2002 N/A N/A 7. Other Permits A summary of permits required for the Honey Crest project is listed in the table below. Table 6. Summary of Other Permits Required Permit Required Regulating AgencyY Onsite Sewage Disposal No Seattle/King County Department of Health Onsite Well Developer/Local Agency No Agreement Seattle/King County Department of Health Washington State Department of Transportation Hydraulic Project Approval No -- Washington State Department of Fish and v Wildlife NPDES Stormwater No Washington State Department of Ecology Forest Practices Yes Washington State Department of Natural Resources Section 10, 401, 404 No United States Army Corps of Engineers 7-1 Haney Crest M—July 2002 Construction activities required to develop the site will include the following: ■ clearing and grading, ■ demolition of existing structures, ■ earthwork (excavation, filling, hauling), and ■ paving. An erosion and sedimentation control plan for the project is provided in Figure 8. Construction best management practices (BMPs) have been selected for each of the particular types of anticipated construction activities. Implementing proven BMPs at construction locations, such as minimizing exposed soil surfaces, and controlling erosion and sedimentation will reduce potential impacts on surface water. BMPs for the proposed types of construction activities are outlined below. Clearing Limits To prevent disturbance of project areas not designated for construction, a construction clearing limits fence or silt fence will be installed by the Contractor. These fences will be installed prior to clearing and grading activities where appropriate. Cover Measures Temporary and permanent cover measures will be provided by the Contractor to protect disturbed areas. Mulching will be used to provide immediate temporary protection from erosion and to enhance plant growth. Plastic covering may be used in order to protect cut and fill slopes and stockpiles and/or to encourage grass growth in newly seeded areas. Perimeter Protection In order to reduce the transport of sediment off -site, the Contractor will install filter fences as indicated on the drawings prior to grading activities. Equipment Parking and Storage of Materials Parking areas for vehicles and equipment on the construction site should be covered with gravel to prevent erosion and tracking of the underlying soil. Machinery and vehicles should be well maintained. In the event of a spill or leak of toxic materials, the incident should be reported to the Construction Site Supervisor and actions should immediately be taken to contain and cleanup the materials. &1 Honey Crest 7M—July 2002 \ -k_Mg Qf1VA 14 I I 4 r I I I II I I i 1 1 I 1 I I I I I I I I I � II 1 1 1 I 1 1 1 gat Z SCALE: 1" = 80' TITLE Figure 8. Erosion and Sedimentation Control Plan ' CJ��r\uJ �_PAGE DATE 8.2 7/24/02 Traffic Area Stabilization Stabilized pads of quarry spalls will be installed by the Contractor at all egress points from the project site to reduce the amount of sediment transported onto paved roads or other off -site areas by motor vehicles. Sediment Retention Sediment retention will be provided by silt fencing at the locations and dimensions shown on the drawings and shall be maintained by the Contractor. The permanent stormwater pond will be constructed prior to clearing and grading the Honey Crest site such that it can be used as a sediment pond. Wet Season Construction If soils are exposed during the period of October 1 to March 31, the Contractor will mulch and seed as much disturbed area as possible by the first week of October in order to provide grass cover for the wet season. The Contractor will also conform to the following wet season special provisions: ■ Apply cover measures to disturbed areas that are to remain unworked for more than two days. ■ Provide on -site stockpiles of cover materials sufficient to cover all disturbed areas. ■ Seed all areas that are to be unworked during the wet season by the end of the first week of October. ■ Apply mulch to all seeded areas for protection. ■ Provide construction road and parking lot stabilization areas for all sites. Maintenance The Contractor will maintain and review all TESC measures on a regular basis. Final Stabilization Prior to obtaining final construction approval, the site shall be stabilized, the structural TESC measures removed, and drainage facilities cleaned. Disturbed areas of the site should be vegetated or otherwise permanently stabilized. At a minimum, disturbed areas should be seeded and mulched to provide a high likelihood that sufficient cover will develop shortly after final approval. 8-3 Honey Crest 7M —July 2002 d' lk sir ?h ! i r } at" ' r ♦'Elul _ r -• 1- - P l�:-�'�: iT + c * i ��, C . ��_.r+�' ,-r•K�_� �;� r� ..per-'� ,� ?�`.�� _:* >� ► >}+ �s.e � �`{ '`� ' - �-�14� � � ��, . {•�`.��_' ! �, {r'�_ l•° _r .�'T 1• .�_ ,. `t 'fir* 46 Vol TO Li y� �!R Y��l� � �'I'j if r � :. J'4. F�r�LL �._ ,- i L'r ..�- K *. F. M1' Y .�•.� '•- . h� s , r -14 1 {Y .r rl .F ti :t h it f•4 F �5icle' ti- r-I:_ .lt r- ►. f iSl �..T. �,i ; •rL�S aE4 � `\ riL�� t y. 'yam+ � 1. � �` i i I_ • �� ' r ,� �'• -"� �' �y :- �L : _ 4 'S.. •.' ' ' • S +'' �'*aj': �, �'r�- .,� ,, �. • :i. �l �!ir�i��' ,Z t. ''� y(��'Xi. + r�'. t ' 1� -¢ �, _ �i F ~ y - -}4�• �. ,` ram, �+ t �c �.r�' � �4 :`�. �� S4"' a1 _ t '+� • r� ' �- s "� ti,� � r�'- r ' � ,re.•--,_ , r ��[� r ( ~ t �. � . �' � � �?• '-a �i` �-'. _ �.. �:� +�r, 't•t,r i i� 4.��i; i t`' i '}�!r'• �; �` ' •_ � {' _ ¢'..��,,,`,.w ^~SF Q+,�� rt 11 4 �•r� ;'i+_V .'!JI, �. • `` -a Lr 14 � ~�� •�1 "y w� � _ � �� t', '�•5`r, .. �.... �r• ,..e. �'� Z •,r i'T�' y,• :+g ��a f :• 1 yC I•S. �L � �4 •� �_3 G ry .� r`. •}i - � � �.Ry�., � _,' f � � �i , '� .; •��:-Jjj��F� �, rF� �• • t '�Y- "r5 � �' •;r t � a � � •' of i^-'' Y d�Y'� ri�i�./"� t a .,•may .y � •fF f,�j 5 :e�s`i�`4rS� � r=, '•��. f' 9 9 Bond Quantities and Facility Summaries A bond quantities worksheet for the project will be provided upon approval of the final engineering plans. A summary of onsite conveyance and water quality facilities is given in Figure 10. The facilities will be privately owned and maintained. 9-1 Honey Crest 77R—July 2002 Figure 9. Site Improvement Fee Calculation Worksheet (to be completed for construction permit) PUBLIC WORKS CONSTRUCTION PERMIT INSPECTION/APPROVAL FEE CALCULATION WORKSHEET 50% INSPECTION/APPROVAL FEES PER ORDINANCE NO.4345 PROJECT NAME: Honey Crest 1. Estimate the total cost of offsite and onsite improvements for water lines, sewer lines, stormwater facilities, and roadway improvements for your project. Enter estimated costs in items (A) through (D) below. (A) Water $ (B) Sewer $ (C) Stormwater $ (Includes On -Site Pavement) (D) Roadway $ (Street, sidewalks, street lighting, etc.) (E) Total Improvements $ (A) + (B) + (C) + (D) = (E 2. Calculate 50% inspection/approval fee for total improvements, as follows: (F) 2.5% of First $100,000 of (E) $ (G) 2% of over $100,000 but $ less than $200,000 of (E) (H) 1.5% of over $200,000 of (E) $ (I) Total 50% Inspection/Approval $ Fee: (F) + (G) + (H) = (I) 3. Breakdown of 50% Inspection/Approval Fees is performed as follows: (J) 50% Water Fee $ ((A) \ (E)) x (I) _ (J) (K) 50% Sewer Fee $ ((B) \ (E)) x (1) _ (K) (L) 50% Stormwater Fee $ ((C) \ (E)) x (1) = (L) (M) 50% Roadway Fee: ((D) \ (E)) x (I) = (M) 9-2 Honey Crest TIR—July 2002 401/343.90.00.02 401/343.90.00.01 401/343.90.00.03 $ 000/343.20.00.00 Figure 10. Flow Control and Water Quality Facility Summary Development: Honey Crest Date: 7-8-02 Location: King County Township 23N, Range 5E, Section 10 ENGINEER DEVELOPER Name: Ed McCarthyName: John Petersen Firm: Haozous Engineering, P.S. Firm: Honey Crest LLC. Address: 9957 171" Avenue SE Renton, WA 98059 Address: 4720 200 Street SW Lynwood, WA 98046 Phone: 425 235-2707 Phone: 206) 423-6986 Developed Site: 3.10 Acres Number of detention facilities on site: 1 Combined Wetpond/R/D Number of lots: 18 new single-family residences Number of infiltration facilities on site: 0 Downstream Drainage Basins Immediate Major Basin Lower Cedar River Maplewood Creek Cedar River Number & type of water quality facilities on site: biofiltration swale (regular/wet/ or sand filter (basic or large?) continuous inflow?) sand filter, linear (basic or large?) 1 combined detention/WQ ponds sand filter vault (basic or large?) flow dispersion trenches wetvault combined detention/wetvault energy dissipation structure compost filter Basic pond (basic or large?) filter strip landscape management plan oil/water separator (baffle or coalescing plate?) catch basin inserts: Manufacturer pre -settling pond pre -settling structure: Manufacturer flow-splitter catch basin DESIGN INFORMATION INDIVIDUAL BASIN Maplewood Creek Water Quality Design Volume (CF) 23,761 Onsite Area (AC) Offsite Area AC) 3.10 5.31 Type of Storage Facility Combined We nd/R/D Figure 10 (continued) DESIGN INFORMATION INDIVIDUAL BASIN Maplewood Creek Required Live Storage Volume (CF) Including 10% FOS 28,478 Predevelo ed Runoff Rates 25-year (CFS)** 1.16 Post-R/D Developed Runoff Rates 25-year (CFS)** 1.14 * * Based on KCRTS 1-hour peak rates for the proposed developed and offsite areas. r `e'MMitzt$ e- a'- The conveyance and water quality facilities for Honey Crest will be privately maintained. The facilities do not contain non-standard features. The table below specifies the maintenance requirements for each component of the stormwater facility being constructed. Applicable maintenance requirements, taken from the 1998 Surface Water Design Manual, are referenced to the pages that follow. Table 7. Summary of Maintenance Requirements for Stormwater Facilities Maintenance Requirement ■ No. 1 — Detention Ponds ■ No. 4 — Control Structure Restrictor ■ No. 5 — Catch Basins ■ No. 6 — Debris Barriers ■ No. 10 — Conveyance Systems ■ No. 13 — Water Quality Facilities — Wetponds 10-1 Honey Crest TM —July 2002 10. 1 - DETENTION PONDS Maintenance Defect Conditions When Maintenance Component Is Needed Results Expected When Maintenance Is Performed General Trash & Debris Any trash and debris which exceed 1 cubic foot Trash and debris cleared from site. per 1,000 square feet (this is about equal to the amount of trash it would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Poisonous Vegetation Any poisonous or nuisance vegetation which No danger of poisonous vegetation may constitute a hazard to County personnel or where County personnel or the the public. public might normally be. (Coordination with Seattle -King County Health Department) Pollution Oil, gasoline, or other contaminants of one No contaminants present other than gallon or more or any amount found that could: a surface film. (Coordination with 1) cause damage to plant, animal, or marine life, Seattle/King County Health 2) constitute a fire hazard: or 3) be flushed Department) downstream during rain storms. Unmowed Grass/ If facility is located in private residential area. When mowing is needed. Ground Cover mowing is needed when grass exceeds 18 grass/ground cover should be inches in height. In other areas, the general mowed to 2 inches in height. policy is to make the pond site match adjacent Mowing of selected higher use ground cover and terrain as long as there is no areas rather than the entire slope interference with the function of the facility. may be acceptable for some situations. Rodent Holes Any evidence of rodent holes if facility is acting Rodents destroyed and dam or as a dam or berm, or any evidence of water berm repaired. (Coordination with piping through dam or berm via rodent holes. Seattle/King County Health Department) Insects When insects such as wasps and hornets Insects destroyed or removed from interfere with maintenance activities- site. Tree Growth Tree growth does not allow maintenance access Trees do not hinder maintenance or interferes with maintenance activity (i.e.. slope activities. Selectively cultivate trees mowing, silt removal, vactoring, or equipment such as alders for firewood. movements). If trees are not interfering with access, leave trees alone. Side Slopes of Pond Erosion Eroded damage over 2 inches deep where Slopes should be stabilized by cause of damage is still present or where there using appropriate erosion control is potential for continued erosion. measure(s), e.g., rock reinforcement, planting of grass, compaction. Storage Area Sediment Accumulated sediment that exceeds 10% of the Sediment cleaned out to designed designed pond depth. pond shape and depth, pond re- seeded if necessary to control erosion Pond Dikes Settlements Any part of dike which has settled 4 inches lower Dike should be built back to the than the design elevation. design elevation. Emergency Rock Missing Only one layer of rock exists above native soil in Replace rocks to design standards. Overflow/Spillway area five square feet or larger, or any exposure of native soil at the top of out flow path of spillway. Rip -rap on inside slopes need not be replaced. 10-2 NO.4 - CONTROL STRUCTURE/FLOW RESTRICTOR aintenance Defect component Condition When Maintenance is Needed Results Expected When 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 1-1/2 feet. Structural Damage Structure is not securely attached to manhole wall Structure securely attached to and outlet pipe structure should support at least wall and outlet pipe. 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 show signs of rust. water tight, structure repaired or replaced and works as designed. Any holes --other than designed holes --in the Structure has no holes other structure. than 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 maintenance person. and is watertight Chain 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 blocking the plate. and works as designed. Overflow Pipe Obstructions Any trash or debris blocking (or having the Pipe is free of all obstructions potential of blocking) the overflow pipe. and works as designed. Manhole See "Closed Detention Systems" Standards No. 3 See "Closed Detention Systems' Standards No. 3 Catch Basin See "Catch Basins" Standards No. 5 See 'Catch Basins" Standards No. 5 10-3 NO.5 - CATCH BASINS laintenance Defect %.omponent General 0 Conditions When Maintenance is Needed Results Expected When Maintenance is performed Trash & Debris Trash or debris of more than 1/2 cubic foot which is No Trash or debris located (Includes Sediment) located immediately in front of the catch basin immediately in front of catch opening or is blocking capacity of the basin by basin 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 lowest basin. pipe into or out of the basin. Trash or debris in any inlet or outlet pipe blocking more than 1/3 of its height. Dead animals or vegetation that could generate odors that could cause complaints or dangerous gases (e.g., methane). Deposits of garbage exceeding 1 cubic foot in volume Structure Damage to Corner of frame extends more than 3/4 inch past Frame and/or Top Slab curb face into the street (If applicable). Top slab has holes larger than 2 square inches or cracks wider than 1/4 inch (intent is to make sure all material is running into basin). Frame not sitting flush on top slab, i.e., separation of more than 3/4 inch of the frame from the top slab. Inlet and outlet pipes free of trash or debris. No dead animals or vegetation present within the catch basin. No condition present which would attract or support the breeding of insects or rodents. Frame is even with curb. Top slab is free of holes and cracks. Frame is sitting flush on top slab. Cracks in Basin Walls/ Cracks wider than 1/2 inch and longer than 3 feet, Basin replaced or repaired to Bottom any evidence of soil particles entering catch basin design standards. through cracks, or maintenance person judges that structure is unsound. Cracks wider than 1/2 inch and longer than 1 foot No cracks more than 1/4 inch at the joint of any inlet/ outlet pipe or any evidence wide at the joint of inlet/outlet of soil particles entering catch basin through pipe. cracks. Sediment/ Basin has settled more than 1 inch or has rotated Basin replaced or repaired to Misalignment more than 2 inches out of alignment. design standards. 10-d NO.5 - CATCH BASINS (CONTINUED) aintenance Defect Conditions When Maintenance is Results Expected When —amponent Needed Maintenance is performed Fire Hazard Presence of chemicals such as natural gas, oil and No flammable chemicals gasoline. present. Vegetation Vegetation growing across and blocking more than No vegetation blocking opening 10% of the basin opening. to basin. Vegetation growing in inlet/outlet pipe joints that is No vegetation or root growth more than six inches tall and less than six inches present. apart. Pollution Nonflammable chemicals of more than 1/2 cubic foot No pollution present other than per three feet of basin length. surface film. Catch Basin Cover Cover Not in Place Cover is missing or only partially in place. Any open Catch basin cover is closed catch basin requires maintenance. Locking Mechanism Mechanism cannot be opened by on maintenance Mechanism opens with proper Not Working person with proper tools. Bolts into frame have less tools. than 1/2 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 Ladder is unsafe due to missing rungs, misalignment, Ladder meets design standards Unsafe rust, cracks, or sharp edges. and allows maintenance person safe access. etal Grates Grate with opening wider than 7/8 inch. Grate opening meets design Applicable) standards. Trash and Debris Trash and debris that is blocking more than 20% of Grate free of trash and debris. grate surface. Damaged or Grate missing or broken member(s) of the grate. Grate is in place and meets Missing. design standards. NO. 6 DEBRIS BARRIERS (E.G., TRASH RACKS) Maintenance Components Defect Condition When Maintenance is Needed Results Expected When Maintenance is Performed. General Trash and Debris Trash or debris that is plugging more than 20% of Barrier clear to receive capacity 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% deterioration Repair or replace barrier to to any part of barrier. design standards. I0-5 NO. 10 - CONVEYANCE SYSTEMS (PIPES & DITCHES) Paintenance Defect Conditions When Maintenance is Results Expected When Component Needed Maintenance is Performed Pipes Sediment & Debris Accumulated sediment that exceeds 20% of the Pipe cleaned of all sediment diameter of the pipe. and 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 of Pipe repaired or replaced. 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 through ditches. ditches. Erosion Damage to See "Ponds" Standard No. 1 See "Ponds" Standard No. 1 Slopes Rock Lining Out of Maintenance person can see native soil beneath Replace rocks to design Place or Missing (if the rock lining. standards. Applicable). Atch Basins See "Catch Basins: Standard No. 5 See "Catch Basins" Standard No. 5 Debris Barriers See "Debris Barriers" Standard No.6 See "Debris Barriers" Standard (e.g., Trash Rack) No. 6 10-6 NO.13- WATER QUALITY FACILITIES Vetponds Jlaintenance Defect Condition When Maintenance is Component Needed Wetpond Vegetation Trash and Debris Inlet/ Outlet Pipe Sediment Accumulation in Pond Bottom Oil Sheen on Water Erosion Settlement of Pond Dike/ Berm Rock Window Overflow Spillway Vegetation such as grass and weeds need to be mowed when it starts to impede aesthetics of pond Mowing is generally required when height exceeds 18-inches. Mowed vegetation should be removed from areas where it could enter the pond. either when the pond level rises, or by rainfall runoff. Accumulation that exceeds 1 CIF per 1000-SF of pond area. Inlet/ Outlet pipe clogged with sediment and/ or debris material. Sediment accumulations in pond bottom that exceeds the depth of sediment zone plus 6-inches, usually the first cell. Prevalent and visible oil sheen. Results Expected When Maintenance is Performed Vegetation should be mowed to 4 to 5 inches in height. Trees and bushes should be removed where they are interfering with pond maintenance activities Trash and debris removed from pond. No clogging or blockage in the inlet and outlet piping. Removal of sediment from pond bottom. Removal of sediment from pond bottom. Erosion of the pond's side slopes and/ or scouring of Slopes should be stabilized by the pond bottom, that exceeds 6-inches, or where using proper erosion control continued erosion is prevalent measures. and repair methods Any part of these components that has settled 4- Dike/ berm is repaired to inches or lower than the design elevation. or specifications. inspector determines dike/ berm is unsound Rock window is clogged with sediment. Window is free of sediment and Rock is missing and soil is exposed at top of spillway or outside slope. debris. Replace rocks to specifications. f 11. References Harmsen & Associates, Inc., 1992. Mission Hills Subdivision, Renton, Washington, Conceptual Drainage Plan. Monroe, Wash. J.S. Jones and Associates, Inc. February 2001. Wetland Investigation, Proposed Honeycrest Development, Renton, Washington. King County Department of Natural Resources, 1998. King County Surface Water Design Manual. Seattle. King County Department of Natural Resources, 1997. Lower Cedar River Basin and Nonpoint Pollution Action Plan. Seattle. Soil & Environmental Engineers, Inc., April 3, 2001. Report of Geotechnical Investigation, Proposed Honeycrest Development, Renton, Washington. Redmond, Wash. U.S. Department of Agriculture, Soil Conservation Service, 1973. Soil Survey of King County Area, Washington. Seattle. Honey Crest TM —July 2002 Appendix A. Downstream System Appendix A.1 Photographs of the Downstream System Appendix A.2 Aquifer Protection Areas Appendix A.3 Lower Cedar River Subbasin Map Honey crest TM-J*2002 ♦ Photo Number 1 Date of Photo: 8/23/01 Location: Northeast portion of site looking west. Description: G ravel access road into existing homes. �j ♦ Photo Number 2 Date of Photo: 8/16/01 Location: Location 10 in Figure 5, looking east. Description: Edge of Class 3 wetland buffer on church Droverty southeast of site. M , .�n�1J'+Gil�r PI 41 ikrt�f�q+� I • ,, � r fr, r ,. ,'u N„, ,y,. tar ''� ., v� rr.., r".S� + y�N�WI. �i� " ` � `. �4, Honey Crest - Offsite Drainage System ♦ Photo Number 3 Date of Photo: 8/27/01 Location: Location 14 in Figure 5, looking north. Description: An 18-inch diameter storm pipe leaves the wetland on the church property and crosses the athletic field of the Honeydew Elementary School. ♦ Photo Number 4 Date of Photo: 8/27/01 Location: Location 21 in Figure 5, looking at channel substrate. Description: A 20-inch diameter pipe discharges to a wetland channel at this location, upstream of the westerly R/D pond of the Orchards. rid i'�Y +r• � � 1• I,j 's. VIVA' '. �"�� Y} t�� its A. �+N d►� ,.fir"r ' �-•'�`.•. � eti ,"�"�' -: e Honey Crest - Offsite Drainage System Appendix A.l Photographs of the Downstream System R� zf' Honey Crest 77R —July 2002 AppendixA.2 Aquifer Protection Areal MIZ e e Homey Crest 77R — July 2002 c O m m S f'y Ct S21� � ��I�oStUuNE 20th �fF 5 E21st Ij e� LS St z I L _ NE 187H z o pSt n E 17th _ a E V 1�th cr F7 ay C0 R _ > j= '.6'r St. v. C E 'th- S G C C NE 14th St St, Z Z N' 12th St � z F¢ R 5 I a+• P R z O x s a NE Z �' NE 1Gth w. 1 g NE 10th PI. $ Ct. b E 0,il PI x NE lothSt,: N 901 F�0 ��--� lh C, NE g\b PI i s `.\1 m � E 8th PI, SE 116th 4X � + E � � + T St 3 g gn t NE 8th St, o o s NE ath A NE 7th St. _ NE 1N 5\.7a Zc. SE 121st St NE 7th pp x x NE 6th z m> q� a f6fh Q 6 S �� a 4'E <' E 6717d� 6,�, S• a m r o NE Slh Ctzo, . 171. v z �__-- NE 3td � � a NE 2nd'St 5 SE 1 nd ti� r SE, St Pr I a a � I �J Source: City of Renton FA TITLE Figure A.2.1. Aquifer Protection Areas Appendix A.3 Lower cedar River Subbasin Honey Crest 77R — July 2002 14— Location ♦ jl I ; • ' I • Map �� o • 7;1 - - ♦ _ ._ I `. ---=-- --- 1 MW3 _ 1 � ` I W2 0. • SITE 150 e 0.2 s • —�- 3120.3 NE 4,h s'—I .. : .-�_.... ---�� ■ \ o / ISO! • ; .r ♦, URBAN GROW IFJ, '.3120.2 0 - - \ �1312• � d --I ♦ � 1 lk • J2 #4 2- 3122.1 03 10 • 0.6 11 3122.2 •�• `, 06 — -----------�♦ • ♦ L23—�• ••••..� ••••••..••, ...... . ��- j i 3.2 .. 0299 , ♦ o. • 3.. 9 ^1 .- \ `---•,' ^/ ,A ��'E R 101 URBAN 42 9.6 SA �. _ ^1R a0 r �, A- - d s.e 07 38 \ Dfl Oo od 6.0 f s r_—_—_—_—. '• �� GROWTH AREA . Source: Lower Cedar River Basin and Nonpoint Pollution Action Plan, King County DNR, 1997 TITLE AQOZOW EMWEEG{ M V3. Figure A.3.1. Maplewood & Orting Hills Subbasins Appendix B. Stormwater R/D System Design°{ Appendix B.1 Stormwater Facility Control and Overflow Design Appendix B.2 KCRTS Pond Design Honey Crest M-.hdy2002 Appendix B.1 Stormwater Facility Control and Overflow Design Honey crest 77R—July 2002 a O O SOLID LOCKING LID, SEE STD DINGS INFORMATION PLATE, SEE DETAIL BR29. BOLT FRAME TO TOP SLAB, SEE NOTE 1 RIM ELEV - 410.0 C - OSHA CONFINED SPACE NOTICE VERTICAL BAR GRATE FOR SECONDARY INLET, SEE NOTES 7 R 8 100 YR W.S. OVERFLOW ELEV - 408.0 ELEV - 408.1 NOTCH ELEV - 407.5 rt ELEV - 406.4 18' LCPE INLET -n 24'0 RISER SECONDARY INLET INFORMATION PLATE, (� CURVE TO MATCH C ORIFICE DLA - 2.35' WALL 1 .5' CD SHEAR GATE WITH CONTROL ROD MIN CONTROL. POINT, SEE FOR CLEiWOUT/DRAIN (ROD BENT DRAINAGE STRUCTURE AS RE0'D FOR VERTICAL ALIGNMENT TABLE WITH COVER). SEE STD DWG BR05, ELEV - 405A 18' LCPE OUTLET 98' Q 18"0 LCPE OUTLET HANDHOLDS, STEPS OR UDDER, 404.0 ---- PIPE, IE - 405.0 a SEE STD LING B--01 Z PIPE SUPPORT, TYP / Q 403.0 SEE NOTE 4 C CB TYPE SEE OF PIPE 4D . B-OI STD. DWG. B-01F k BROS ATTACHED BY o 24'0 RISER '+ AND 2 4-0 /ALLOW 0 401 0 SS.SI.D BOLTS TO ELBOW RFSTRICTOR 0 REMOVAL W/ ORIFICE RESTRO PATE L/V� •� PLANVIEW n SECTION VIEW ORIFICEDIA ORIFICE oA - 3.15' 9 c 0 c CD Table B.1.1. Stormwater Pond Overflow Design Date: 7/18/02 R/D Facility: Honey Crest KCRTS Filename: lev2.rdf Contributing Time Series: totdevl5.tsf Overflow protection structure: outlet control structure riser (R1) Emergency overflow structure: emergency spillway Qde,ig, (CFS): 6.85 (KCRTS 15-minute peak rate) Top of Control Structure Riser (FT) 408.00 Min. Top of Berm (FT) 409.00 Structure Capacity Elevation WSE Structure Size Units Head (FT) (CFS) (FT) (FT) Design Operation Riser RI 24 inches 0.10 408.00 408.10 Primary Overflow Riser RI 24 inches 0.50 6.89 408.00 408.50 Secondary Inlet Jailhouse window 98 inches 0.40 6.88 408.10 408.50 Emergency Overflow Spillway 23 feet 0.20 6.85 408.50 408.70 Head Design Head above (FT) Required Freeboard.- Riser 0.10 Primary Overflow or Secondary Inlet Head 0.40 Spillway Head 0.20 Spillway Freeboard 0.30 Total Required Freeboard 1.00 Table B.1.2. Wetpond Outlet Pipe Design Date: 7/8/02 Wetpond Facility Permanent WSE (FT) Qwq (CFS) Outlet Pipe Dia. (IN) Check for Inlet Control: HW/D from Fig. 4.3.1.13 of Design Manual MIN HW (FT) 0.75 Inlet Control WSE (FT) 405.75 Check for Outlet Control. dc/D from Fig. 4.3.1.F of '`"_ '`. Design Manual, dc (FT) 0.38 T (FT) 1.30 A (SQ FT) 0.36 V (FT/S) 2.98 Vh (FT) 0.14 Outlet Control WSE (FT) 405.51 Overflow WSE (FT) 405.75 Primary Overflow Structure Elev. (FT) 408.00 Overflow WSE < Overflow Structure Elev. ? OK Note: Calculations above follow the design procedure outlined on p. 6-70 of the KCSWM 1998 Surface Water Design Manual. Shaded areas denote spreadsheet inputs APPendiz B.� KRTSPoies► Retention/Detention Facility Retention/Detention Facility Type of Facility: Detention Pond Side Slope: 2.00 H:1V Pond Bottom Length: 170.88 ft Pond Bottom Width: 42.72. ft Pond Bottom Area: 7300. sq. ft Top Area at 1 ft. FB: 10974. sq. ft 0.252 acres Effective Storage Depth: 3.00 ft Stage 0 Elevation: 405.00 ft Storage Volume: 25889. cu. ft 0.594 ac-ft Riser Head: 3.00 ft Riser Diameter: 24.00 inches Number of orifices: 2 Full Head Pipe Orifice # Height Diameter Discharge Diameter (ft) (in) (CFS) (in) 1 2; 0.00 3.15 0.450 2 \ 1.40 2.35 0.177 6.0 Top Notch Weir: Rectangular Length: 12.00 in Weir Height: ft Outflow Rating Curve: None Stage Elevation Storage Discharge Percolation Surf Area (ft) (ft) (cu. ft) (ac-ft) (cfs) (cfs) (sq. ft) 0.00 405.00 0. 0.000 0.000 0.00 7300. 0.03 405.03 219. 0.005 0.049 0.00 7326. 0.07 405.07 513. 0.012 0.069 0.00 7360. 0.10 405.10 734. 0.017 0.084 0.00 7386. 0.13 405.13 956. 0.022 0.098 0.00 7411. 0.16 405.16 1179. 0.027 0.109 0.00 7437. 0.20 405.20 1477. 0.034 0.119 0.00 7472. 0.23 405.23 1702. 0.039 0.129 0.00 7497. 0.26 405.26 1927. 0.044 0.138 0.00 7523. 0.36 405.36 2684. 0.062 0.162 0.00 7610. 0.46 405.46 3449. 0.079 0.183 0.00 7696. 0.56 405.56 4223. 0.097 0.202 0.00 7783. 0.66 405.66 5006. 0.115 0.219 0.00 7871. 0.76 405.76 5797. 0.133 0.235 0.00 7959. 0.86 405.86 6597. 0.151 0.250 0.00 8047. 0.96 405.96 7406. 0.170 0.264 0.00 8135. 1.06 406.06 8224. 0.189 0.277 0.00 8224. 1.16 406.16 9051. 0.208 0.290 0.00 8313. 1.26 406.26 9887. 0.227 0.302 0.00 8402. 1.36 406.36 10732. 0.246 0.314 0.00 8492. 1.40 406.40 11072. 0.254 0.318 0.00 8528. Honey Crest MZR July 2002 1.42 406.42 11243. 0.258 0.323 0.00 8546. 1.45 406.45 11499. 0.264 0.330 0.00 8573. 1.47 406.47 11671. 0.268 0.339 0.00 8591. 1.50 406.50 11929. 0.274 0.352 0.00 8618. 1.52 406.52 12102. 0.278 0.367 0.00 8636. 1.55 406.55 12361. 0.284 0.384 0.00 8663. 1.57 406.57 12535. 0.288 0.399 0.00 8681. 1.60 406.60 12795. 0.294 0.406 0.00 8708. 1.62 406.62 12970. 0.298 0.413 0.00 8726. 1.72 406.72 13847. 0.318 0.438 0.00 8817. 1.82 406.82 14733. 0.338 0.460 0.00 8908. 1.92 406.92 15629. 0.359 0.481 0.00 8999. 2.02 407.02 16533. 0.380 0.501 0.00 9091. 2.12 407.12 17447. 0.401 0.519 0.00 9183. 2.22 407.22 18370. 0.422 0.537 0.00 9276. 2.32 407.32 19302. 0.443 0.554 0.00 9368. 2.42 407.42 20243. 0.465 0.570 0.00 9461. 2.50 407.50 21003. 0.482 0.583 0.00 9536. 2.56 407.56 21577. 0.495 0.643 0.00 9592. 2.63 407.63 22251. 0.511 0.744 0.00 9658. 2.69 407.69 22832. 0.524 0.869 0.00 9714. 2.75 407.75 23417. 0.538 1.010 0.00 9771. 2.81 407.81 24005. 0.551 1.170 0.00 9827. 2.88 407.88 24695. 0.567 1.350 0.00 9893. 2.94 407.94 25290. 0.581 1.530 0.00 9950. 3.00 408.00 25889. 0.594 1.720 0.00 10007. 3.10 408.10 26894. 0.617 2.350 0.00 10102. 3.20 408.20 27909. 0.641 3.490 0.00 10198. 3.30 408.30 28934. 0.664 4.960 0.00 10294. 3.40 408.40 29968. 0.688 6.700 0.00 10390. 3.50 408.50 31012. 0.712 8.670 0.00 10486. 3.60 408.60 32065. 0.736 10.850 0.00 10583. 3.70 408.70 33128. 0.761 13.220 0.00 10680. 3.80 408.80 34201. 0.785 15.350 0.00 10778. 3.90 408.90 35284. 0.810 16.190 0.00 10876. 4.00 409.00 36377. 0.835 16.970 0.00 10974. 4•.10 409.10 37479. 0.860 17.720 0.00 11072. 4.20 409.20 38591. 0.886 18.440 0.00 11171. 4.30 409.30 39713. 0.912 19.130 0.00 11270. 4.40 409.40 40845. 0.938 19.790 0.00 11369. 4.50 409.50 41987. 0.964 20.430 0.00 11469. 4.60 409.60 43139. 0.990 21.050 0.00 11569. 4.70 409.70 44301. 1.017 21.650 0.00 11669. 4.80 409.80 45472. 1.044 22.230 0.00 11770. 4.90 409.90 46654. 1.071 22.790 0.00 11871. 5.00 410.00 47847. 1.098 23.350 0.00 11972. Hyd Inflow Outflow Peak Storage Target Calc Stage Elev (Cu-Ft) (Ac-Ft) 1 2.74 ******* 2.32 3.09 408.09 26844. 0.616 2 1.31 ******* 1.14 2.80 407.80� 23881. 0.548 3 1.32 ******* 0.99 2.74 407.74 23327. 0.536 4 1.39 ******* 0.93 2.71 407.71 23072. 0.530 5 1.60 ******* 0.58 2.46 407.46 20635. 0.474 6 0.81 ******* 0.48 1.89 406.89 15384. 0.353 7 1.01 ******* 0.30 1.22 406.22 9530. 0.219 8 1.01 ******* 0.27 1.01 406.01 7831. 0.180 Honey Crva TIR - July 2002 Route Time Series through Facility Inflow Time Series File:totdev.tsf Outflow Time Series File:rdout Inflow/Outflow Analysis Peak Inflow Discharge: 2.74 CFS at 6:00 on Jan 9 in Year 8 Peak Outflow Discharge: 2.32 CFS at 9:00 on Jan 9 in Year 8 Peak Reservoir Stage: 3.09 Ft Peak Reservoir Elev: 408.09 Ft Peak Reservoir Storage: 26844. Cu-Ft 0.616 Ac-Ft Flow Frequency Analysis Time Series File:rdout.tsf J Project Location:Sea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- FlowRate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) (ft) Period 0.988 3 2/09/01 16:00 2.32 3.09 1 100.00 0.990 0.297 7 1/05/02 18:00 1.14 2.80 2 25.00 0.960 0.577 5 3/06/03 20:00 0.988 2.74 3 10.00 0.900 0.271 8 8/23/04 23:00 0.927 2.71 4 5.00 0.800 0.475 6 1/05/05 10:00 0.577 2.46 5 3.00 0.667 0.927 4 1/18/06 21:00 0.475 1.89 6 2.00 0.500 1.14 2 11/24/06 5:00 0.297 1.22 7 1.30 0.231 2.32 1 1/09/08 9:00 0.271 1.01 8 1.10 0.091 Computed Peaks 1.92 3.03 50.00 0.980 Flow Duration from Time Series File:rdout.tsf Cutoff Count Frequency CDF Exceedence_Probability CFS % % % 0.016 47652 77.710 77.710 22.290 0.223E+00 0.048 4922 8.027 85.737 14.263 0.143E+00 0.080 3038 4.954 90.691 9.309 0.931E-01 0.111 1786 2.913 93.604 6.396 0.640E-01 0.143 1356 2.211 95.815 4.185 0.418E-01 0.175 919 1.499 97.314 2.686 0.269E-01 0.206 517 0.843 98.157 1.843 0.184E-01 0.238 417 0.680 98.837 1.163 0.116E-01 0.270 246 0.401 99.238 0.762 0.762E-02 0.301 150 0.245 99.483 0.517 0.517E-02 0.333 84 0.137 99.620 0.380 0.380E-02 0.365 22 0.036 99.656 0.344 0.344E-02 0.397 19* 0.031 99.687 0.313 0.313E-02 0.428 45 0.073 99.760 0.240 0.240E-02 0.460 36 0.059 99.819 0.181 0.181E-02 0.492 20 0.033 99.852 0.148 0.148E-02 0.523 27 0.044 99.896 0.104 0.104E-02 0.555 17 0.028 99.923 0.077 0.766E-03 0.587 18 0.029 99.953 0.047 0.473E-03 0.619 0 0.000 99.953 0.047 0.473E-03 0.650 1 0.002 99.954 0.046 0.457E-03 0.682 3 0.005 99.959 0.041 0.408E-03 0.714 2 0.003 99.962 0.038 0.375E-03 0.745 3 0.005 99.967 0.033 0.326E-03 0.777 4 0.007 99.974 0.026 0.261E-03 0.809 1 0.002 99.976 0.024 0.245E-03 0.841 2 0.003 99.979 0.021 0.212E-03 Honey Crest TIR-J* 2002 0.872 3 0.005 99.984 0.016 0.163E-03 0.904 3 0.005 99.989 0.011 0.114E-03 0.936 2 0.003 99.992 0.008 0.815E-04 0.967 1 0.002 99.993 0.007 0.652E-04 0.999 2 0.003 99.997 0.003 0.326E-04 1.03 0 0.000 99.997 0.003 0.326E-04 1.06 1 0.002 99.998 0.002 0.163E-04 1.09 0 0.000 99.998 0.002 0.163E-04 1.13 0 0.000 99.998 0.002 0.163E-04 Inflow/Outflow Analysis Peak Inflow Discharge: 2.74 CFS at 6:00 on Jan 9 in Year 8 Peak Outflow Discharge: 2.32 CFS at 9:00 on Jan 9 in Year 8 Peak Reservoir Stage: 3.09 Ft Peak Reservoir Elev: 408.09 Ft Peak Reservoir Storage: 26844. Cu-Ft 0.616 Ac-Ft Flow Frequency Analysis Time Series File:rdout.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- FlowRate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) (ft) Period 0.988 3 2/09/01 16:00 2.32 3.09 1 100.00 0.990 0.297 7 1/05/02 18:00 1.14 2.80 2 25.00 0.960 0.577 5 3/06/03 20:00 0.988 2.74 3 10.00 0.900 0.271 8 8/23/04 23:00 0.927 2.71 4 5.00 0.800 0.475 6 1/05/05 10:00 0.577 2.46 5 3.00 0.667 0.927 4 1/18/06 21:00 0.475 1.89 6 2.00 0.500 1.14 2 11/24/06 5:00 0.297 1.22 7 1.30 0.231 2.32 1 1/09/08 9:00 0.271 1.01 8 1.10 0.091 Computed Peaks 1.92 3.03 50.00 0.980 Flow Duration from Time Series File:rdout.tsf Cutoff Count Frequency CDF Exceedence_Probability CFS % % % 0.016 47652 77.710 77.710 22.290 0.223E+00 0.048 4922 8.027 85.737 14.263 0.143E+00 0.080 3038 4.954 90.691 9.309 0.931E-01 0.111 1786 2.913 93.604 6.396 0.640E-01 0.143 1356 2.211 95.815 4.185 0.418E-01 0.175 919 1.499 97.314 2.686 0.269E-01 0.206 517 0.843 98.157 1.843 0.184E-01 0.238 417 0.680 98.837 1.163 0.116E-01 0.270 246 0.401 99.238 0.762 0.762E-02 0.301 150 0.245 99.483 0.517 0.517E-02 0.333 84 0.137 99.620 0.380 0.380E-02 0.365 22 0.036 99.656 0.344 0.344E-02 0.397 19 0.031 99.687 0.313 0.313E-02 0.428 45 0.073 99.760 0.240 0.240E-02 0.460 36 0.059 99.819 0.181 0.181E-02 0.492 20 0.033 99.852 0.148 0.148E-02 0.523 27 0.044 99.896 0.104 0.104E-02 0.555 17 0.028 99.923 0.077 0.766E-03 0.587 18 0.029 99.953 0.047 0.473E-03 0.619 0 0.000 99.953 0.047 0.473E-03 Haney Crest TIR - July 2002 0.650 1 0.002 0.682 3 0.005 0.714 2 0.003 0.745 3 0.005 0.777 4 0.007 0.809 1 0.002 0.841 2 0.003 0.872 3 0.005 0.904 3 0.005 0.936 2 0.003 0.967 1 0.002 0.999 2 0.003 1.03 0 0.000 1.06 1 0.002 1.09 0 0.000 1.13 0 0.000 Duration Comparison Anaylsis Base File: totex.tsf New File: rdout.tsf 99.954 99.959 99.962 99.967 99.974 99.976 99.979 99.984 99.989 99.992 99.993 99.997 99.997 99.998 99.998 99.998 Cutoff Units: Discharge in CFS Cutoff 0.360 0.422 0.483 0.544 0.606 0.667 0.728 0.789 0.851 0.912 0.973 1.03 1.10 -----Fraction of Time----- BaseNew %Change 0.34E-02 0.35E-02 3.8 0.24E-02 0.26E-02 8.3 0.17E-02 0.16E-02 -8.4 0.13E-02 0.93E-03 -26.9 0.96E-03 0.47E-03 -50.8 0.60E-03 0.44E-03 -27.0 0.41E-03 0.36E-03 -12.0 0.29E-03 0.26E-03 -11.1 0.20E-03 0.20E-03 0.0 0.11E-03 0.11E-03 0.0 0.65E-04 0.65E-04 0.0 0.33E-04 0.33E-04 0.0 0.16E-04 0.16E-04 0.0 0.046 0.457E-03 0.041 0.408E-03 0.038 0.375E-03 0.033 0.326E-03 0.026 0.261E-03 0.024 0.245E-03 0.021 0.212E-03 0.016 0.163E-03 0.011 0.114E-03 0.008 0.815E-04 0.007 0.652E-04 0.003 0.326E-04 0.003 0.326E-04 0.002 0.163E-04 0.002 0.163E-04 0.002 0.163E-04 ---------Check of Probability Base 0.34E-02 0.360 0.24E-02 0.422 0.17E-02 0.483 0.13E-02 0.544 0.96E-03 0.606 0.60E-03 0.667 0.41E-03 0.728 0.29E-03 0.789 0.20E-03 0.851 0.11E-03 0.912 0.65E-04 0.973 0.33E-04 1.03 0.16E-04 1.10 Maximum positive excursion = 0.084 cfs ( 8.0%) occurring at 1.05 cfs on the Base Data:totex.tsf and at 1.13 cfs on the New Data:rdout.tsf Maximum negative excursion = 0.121 cfs (-17.1%) occurring at 0.705 cfs on the Base Data:totex.tsf and at 0.584 cfs on the New Data:rdout.tsf Honey Crest TIR-July 2002 Tolerance------- New%Change 0.369 !2.�-' 0.429 7 0.466 -3.6 0.507 -6.9 0.537 -11.4 0.575 -13.8 0.690 -5.3 0.772 -2.2 0.868 2.0 0.924 1.3 0.985 1.2 1.06 2.6 1.13 3.5 Appendix C. Co� Calculations Appendix C.1 Stormwater System Conveyance Appendix C.2 KCRTS Time Series Calculations Appendix C.3 KCRTS Peak Flow Rates Honey Crest TM —July 2W2 Appendix CA Stormwater System Conveyance Honey Cres177R - July 2002 v1.2 Project: Honey Crest Figure C.I.I. Backwater Analysis for Conveyance System Date: 07/24/02 Revised 9/4/02 Onsite Conveyance Improvements: R/D Pond to CB8 I n c c 7 O n 1 r) 1O2 1d 1r, 1R 17 1R iCs�1111 Pipe Barrel Barrel Barrel Friction Entrance Entrance Entrance Exit, Exit OutletInlet; Inlet Approach <_ i Bend Junctions HW 1'op Added Q' KI HL ft Pipe Segment Q (cfs) Length (ft) Size (m) "n" Value Outlet Elev (ft) Inlet Elev (ft) Area sf Velocity f s Vel Head ft TW Elev ft Loss ft HGL Elev ft) HL Coef HL ft HL. Coef HL ft Cntrl. Elev ft Control HW/D Cntrl. Elev ft Vel. Head ft Defi. ML HL ft Elev. (ft) Upstream Struct CB to CB Pond CB1 9.64 208 18 0.012 402.50 401.80 1.767 5.45 0.46 407.80 1.48 409.28 0.50 0.23 1.00 0.46 409.97 1:45 409.97 0.22 90 1.32 0.29 5.29 0.36 0.08 410.12 413.68 .............................................................................................................................................................................................................................................................................................................................................................. C61 C62 4.63 57 15 0.012 407.08 408.00 1.227 3.77 0.22 410.12 0.25 410.37 0.50 0.11 1.00 0.22 410.70 0.8 � 409.06 0.22 90 1.32 0.29 0:00 0.00 410.77 414.82 C62 ..................... C63 ................. 4.63 . 92 15 0.012 .................................................................................................................................................................................................................................................6.. 408.00 408.46 1.227 3.7 0.22 410.77 0.40 411.17 0.50 0.11 1.00 0.22 411.5 . 0.85 409.53 0.22 90 1.32 0.29 0:00 0.00 411.57 413.42 ................................................................................................................................................................................................................................................................................................................................................................... CB3 CB4 4.63 90 15 0.012 408.46 408.91 1.227 3.77 0.22 411.57 0.39 411.96 0.50 0.11 1.00 0.22 412.30 . . 0.85 409.98 0.09 0 0.02 0.00 3.23 0:43 0.04 412.25 413.69 ...........4.................................................................................................... CB4 CB5 1.88 105 12 0.012 ......................................................................................................................................................................................................................................... 408.91 409.44 0.785 2.40 0.09 412.25 0.25 412.49 0.50 0.04 1.00 0.09 412.63 0:70_ 410:14 0.02 0 0.02 0:00 1.15 0:39 0.01 412.61 413.05 CB5 CB6 0.95 124 12 0.012 409.44 410.06 0.785 1.21 0.02 412.61 0.07 412.69 0.50 0.01 1.00 0:02 412.72 . 0.51 ........................................................................................................................................................................................ 410.57 0.02 90 1.32 0.02 0.14 0.12 0.00 412.73 414.90 .................................................................................................................................................................................................................................................................................................................................. CB6 C67 0.84 79 12 0.012 410.06 410.45 0.785 1.07 0.02 412.73 0.04 412.77 0.50 0.01 1.00 0.02 412.80 0.48 410.93 0.00 0 002 0.00 0.50 0.38 0.00 412.79 413.83 ......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................... CB7 C68 0.38 150 12 0.012 410.45 411.20 0.785 0.49 0.00 412.79 0.01 412.81 0.50 0.00 1.00 0.00 412.81 0.34 ..... 411.54 0.06 0 0.02 0.00 0.38 0.55 0.03 412.79 414.48 ....................................................................................................................................................................................................................... 0.000 2.00 0.06 NOTES: 1. All pipe material is assumed to be LCPE 2. Flow rates (Q) are based on KCRTS Rational Method. 3. Entrance loss coefficients are from Table 4.3.1.E for LCPE pipe, headwall with square edge entrance. 4. Exit loss coefficients are based on Figure 4.2.1.1, Column (14) and ASCE Manual "Design and Construction of Sanitary and Storm Sewers". 1970, page 107. Onsite Conveyance Improvements: C64 to CB10 n o n C a 7 A 1 r) 1R 17 19 20 Pipe Barrel Barrel Barrel Friction Entrance :i11,'' Entrance ;') Exit Outlet Inlet Approach 'Bend Bend Bend Junctions HW Top Added Q Q3 KI HL ft Pipe Segment Q (cfs) Length (ft) Size in "n" Value Outlet Elev (ft) Inlet Elev ft Area sf Velocity f s Vel Head ft TW Elev ft Loss ft HGL Elev ft j Cie .., HL ft 1 L. Coef HL ft Cntrl. Elev ft Control HW/D' - Cntrl. Elev ft Vel. Head ft Defl. de HL ef, HL ft Elev. ft Upstream Structure CB to CB CB4 �,b4/A zuu 118 15 u u i) 4,_O.zu 409.50 1.227 2.12 0.07 0.16 412.41 0.50 0.03 1 00 0.07 412.51 0.62 410.28 0.01 0 0 02 0.00 1 87 0 44 0.01 412.50 413 11 ...............................................................................................................................................................................................................................................A CB4B 0.73 32 12 0.012 409.50 409.66 0.785 0.93 0.01 12.50 0.01 412.52 0.50 0.01 1.00 0.01 412.54 0.45 410.11 0.01 90 1,32 0.01 0.73 0.55 0.00 412.54 413.07 ............................................... .0 . 2 0012 409.50 40...0.01 L412.25 12.54 0.01 412.55 0.50 ................. 0.00 1.00 ........ 0.01 ...... 412.56 ................... ... 0.38 410.04 ................. 0.06 .................... 90 ........... 1.32 ........ 0.08 ......... 0.73 ..............-- 0.70 ...... 0.04 ...... 12.62........................................................................................................................................................................................................................................................... ................. .................. 0.000 2.00 0.06 Onsite Conveyance Improvements: CB5 to CB 11 1 n G CZ 7 n a 1n 11 1d 1.9; IF; 17 18 19 20 Pipe Barrel Barrel Barrel Friction Entrance _Mtzzk Entrance Exit Outlet Inlet Inlet Approach Bend' Bend Bend Junctions HW 3, Pipe Segment Q Length Size "n" Outlet Elev Inlet Elev Area Velocity Vel Head TW Elev Loss HGL Elev f HL HL Cntrl. Elev Control Cntrl. Elev Vel. Head-. Defl. HL HL Added Q KI HL Elev (12 S� J ft� ft ft HW/D ' ft ft de Coef' ft Q3 ft ft P, CB to CB r B 1 OC42 32 0.012 409 44 409.60 0.785 0.53 0 00 412 61 0 00 412.62 0 0.00 1.00 0.00 412.62 0.36 409.96 0.06 0 0 0 �......................... 0.00 0..4.2 . 0 55 0.03 412.60 413 05 ......... ................................................................................................................................................................................................................................................................................................................................................................. 0.000 2.00 0.06 9/8/2002 Honey Crest HGL v1.xls Page 1 4:55 PM - lect: Honey Crest ;ure C.1.1. Backwater Analysis for Conveyance System Date: 07/24/02 Onsite Conveyance Improvements: R/D Pond to CB8 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 iG"�r] 18 19 20 Pipe Barrel Barrel Barrel Friction Entrance _ = "' Entrance Exit Outlet Inlet Approach .Bend Ben'" ; Bend Junctions HW Pipe Segment Q cfs Length ft Size in "W' Value Outlet Elev ft Inlet Elev ft Area sf Velocity (fps) Vel Head ft TW Elev ft Loss ft HGL Elev ft HL ft HL ft Cntrl. Elev ft ✓ Cntrl. Elev ft Vel. Head ft " ,Defl. ` d HL Coef� HL ft KI HL ft Elev. ft CB to CB Pond CB1 9.43 208 18 0.012 402.50 407.80 1.767 5.34 0.44 407.80 1.42 409.22 0.50 0.22 1.00 0.44 409.88 1.41 409.92 0.21 90 1.32 0.27 5.01 0.35 0.07 .. 410.06 . ..................... 413.68 . . .................................................................................... C81 C62 4.46 ... 57 . 15 .. . ....................................................... 0.012 407.08 ........................................ 408.00 . 1.227 3.63 ............................................................................. 0.21 410.06 0.23 410.29 . ........................................................................ 0.50 . 0.10 . 1.00 . 0.21 ........................................................ . 410.59 0.83 409.04 . . . .. ..................... 0.21 . ........... . 90 .............................................................. 9.32 . 0.28 . 0.00 0.00 410.66 . . 414.82 .................................................................. CB2 CB3 4.54 ............................................................................. 92 15 . 0.012 . . ... 408.00 .. .. . 408.46 ............................................ 1.227 .. 3.70 .................. . 0.21 .. ......................................................... 410.66 0.38 . 411.05 ........ ............... ... .. 0.50 ........ .. .... . 0.11 . ... 1.00 ...................................................................... . .. 0.21 411.36 0.84 . 409.51 . ...................... .. . .. 0.22 . . ................ 90 1.32 . ......................... 0.29 ............................ 0.00 0.00 411.44 . 413.42 .................. CB3 CB4 4.63 90 .. 15 ..... ... 0.012 .... 408.46 408.91 .................................................. 1.227 3.77 0.22 411.44 0.39 411.83 0.50 0.11 1.00 0.22 412.16 0.85 409.98 0.09 0 0.02 0.00 2.75 0.38 0.03 412.10 .. 413.69 ........................................................................... CB4 CB5 1.88 105 ......... 12 ............................................. 0.012 408.91 409.44 0.785 .................... 2.39 ............................................................................................................................................................................................................................................................................................................................. . 0.09 412.10 0.25 412.35 0.50 0.04 1.00 0.09 412.48 . 0.70 410.14 0.02 0 0.02 0.00 0.93 0.33 0.01 412.47 ...................... 413.05 .. ........ ........................................................... CB5 CB6 0.95 124 12 0.012 .... ..... 409.44 ........... 410.06 0.785 1.21 0.02 ........................................... 412.47 0.07 ... 412.54 . ........... 0.50 . 0.01 .. 1.00 . . 0 02 . . 412.58 . . 0.51 . .................... 410.57 ... . .. ......................... 0.02 . 90 ........................ . 1.32 . 0.02 0.11 0.09 . . 0.00 . 412.58 414.90 ............................................. C66 C67 ..................................................................................................... 0.84 79 12 0.012 410.06 410.45 ......................................... 0.785 ............................... 1.07 ......................................................................................................................................................................................................... 0.02 412.58 0.04 412.62 0.50 0.01 1.00 0.02 412.65 0.48 410.93 ......................................................................................................................... 0.00 0 0.02 0.00 0.46 0.36 0.00 ..... 412.65 . .... ............... 413.83 . ................................................... CB7 C68 ....................................................................................................... 0.38 150 12 0.012 410.45 411.20 0.785 0.48 ............................................................................................................................................................................................................................................................................................................................................... 0.00 412.65 0.01 412.66 0.50 0.00 1.00 0.00 412.67 0.34 411.54 0.06 0 0.02 0.00 0.38 0.55 0.03 412.64 ............. 414.48 .........................................................................................._.................................................._................................................................................................ 0.000 2.00 0.06 ... .... ................. ..... ............... ...... ....... .... ...... .... .................. .... ................... .... .................. .... ................... .... ........... ..... ....... ...... ........ ..... ................ .... ...... .... ..... .. ............. . . ................. NOTES: 1. All pipe material is assumed to be LCPE. 2. Flow rates (Q) are based on Rational Method. 3. Entrance loss coefficients are from Table 4.3.1.E for LCPE pipe, headwall with square edge entrance. 4. Exit loss coefficients are based on Figure 4.2.1.1, Column (14) and ASCE Manual "Design and Construction of Sanitary and Storm Sewers". 1970, page 107. site Conveyance Improvements: CB4 to C1310 1 2 4 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Pipe Segment Q cfs Length ft Pipe Size in "n" Value Outlet Elev (ft) Inlet Elev (ft Barrel Area sf Barrel Velocity (fps) Barrel Vel Head ft TW Elev ft Friction Loss ft Entrance HGL Elev ft Entrance HL Coef Entrance HL- (ft) : -' `= Exit HL (ft I Outlet Cntrl. Elev ft Inlet Control HW/D Inlet Cntrl. Elev (ft) Approach Vel. Head (ft Benc Defl. de L Bend HL Coef Bend HL ft Junctions HW Elev. ft Top Upstream 'Structure `. ,��,, • KI HL ft CB . #o . ;,CB CB4 ........................................................................................................................................................................................................ CB9 ............................................. .................... CB9 CB10 .......................... 2.59 0.73 ......................._......................................................................................................... ............. 118 32 ................ 12 12 0.012 0.012 I .............. 408.29 409.50 i 409.50 409.66 ..................... 0.785 0.785 t....000 0... 3.30 0.93 2.00 0.17 0.01 0.061 412.10 ...... 412.89 ........................ .............. . ... 0.53 .............................................................................................................................................................. 0 01 ...... .................. 412.63 412.90 ................. I ...................... . 0.50 0.50 ................ .................... 0.08 . 0.01 ............... F... 1.00 1.00 ....... 0.17 0.01 ...... 412.88 412.92 .................. i 0.84 .. .. 0.45 _ .................. ....................... 410.34 410.11 .. .... .................. .................... 0.01 ... .. ............................... 0.06 .... ................... ....................... ..90 ............ 90 ..... ........... ............... 1.32 ............................................................................ . 1.32 ....... ..... I ............. 0.02 0.08 ........ ..... I ............. 1.87 0.73 ............... ...................... r 0.44 0.55 ..... .... ..... ......... 0.01 ..... . 0.03 .......... 412.89 ........................ 412.98 . ................. .. ............. 413.11 413.07 ................. ...................... Onsite Conveyance Improvements: CB5 to CB 11 1 2 3 4 . 6 7 8 9 10 it 12 13 14 15 16 17 18 19 20 Pipe Segment Q cfs Length ft Pipe Size in "n" Value Outlet Elev ft Inlet Elev ft Barrel Area sf Barrel Velocity (fps) Barrel Vel Head ft TW Elev ft Friction Loss ft Entrance HGL Elev ft Entrance , HL Coef Entrance HL (ft) Exit j HL (ft Outlet Cntrl. Elev ft Inlet Control HW/D Inlet Cntrl. Elev (ft) Approach Vel. Head (ft Bend: Defl. d) Bend HL Coef Bend HL ft Junctions HW Elev. ft Top Upstream Structure Added Q %" Q3 I KI HL ft ,CB to CB CB5 ..................................................................................................................................................................................................................................................................... CB11 0.42 32 12 0.012 409.44 409.60 0.785 0.000 0.53 2.00 0.00 0.06 412.47 0.00 412.47 0.50 ..... 0.00 ................ 1.00 ....... 0.00 ...... 412.48 .................. 0.36 .................. 409.96 .................. 0.06 ................... 0 ........... 0.02 ....... 0.00 ........ 0.42 ................ 0.55 ...... 0.03 ..... 412.45 ............. 413.05 ................. 7/24/2002 Honey Crest HGL v1.xls Page 1 6:04 PM A71- U) c �0 W cc 00 LL L z un an z v z I OO N Table C.1.1. Flow Rate Calculations Using the Rational Method Design Storm = 25 Year 24 Hr Precip = 3.4 in Sub Upstrm Downstrm SubArea Forest Lawn Impervious Total Cumul. Tc it I Q Pipe Pipe Upstrm Downstrm Slope n Veloc Travel Basin Node Node Subtotal C=0.10 C=0.25 C=0.90 Area C C*A C*A Unit Peak Diam. Length Invert El Invert El Time (SF) (AC) (AC) (AC) (AC) (MIN) (IN/HR) (CFS) in ft % fps min F CB8 CB7 11,146 0.00 0.14 0.12 0.26 0.55 0.140 0.140 6.3 0.80 2.73 0.38 12 150 411.20 410.45 0.50% 0.012 2.37 1.1 E C137 CB6 15,950 0.00 0.20 0.17 0.37 0.55 0.201 0.341 7.4 0.73 2.47 0.84 12 79 410.45 410.06 0.49% 0.012 3.09 0.4 D C86 C135 4,653 0.00 0.06 0.05 0.11 0.55 0.059 0.400 7.8 0.70 2.38 0.95 12 124 4%06 409.44 0.50% 0.012 3.24 0.6 C* CB11 C135 11,132 0.00 0.12 0.14 0.26 0.61 0.155 0.155 6.3 0.80 2.73 0.42 12 32 409.60 409.44 0.50% 0.012 2.44 0.2 B CB5 CB4 19,801 0.00 0.20 0.25 0.45 0.61 0.276 0.832 8.4 0.67 2.26 1.88 12 105 409.44 408.29 1.10% 0.012 5.20 0.3 H* CB10 C139 19,242 0.00 0.20 0.24 0.44 0.61 0.268 0.268 6.3 0.80 2.73 0.73 12 32 409.66 409.5 0.50% 0.012 2.95 0.2 G* C139 CB4 57,249 0.00 0.75 0.57 1.31 0.53 0.696 0.965 6.5 0.79 2.68 2.59 12 118 409.50 408.29 1.03% 0.012 5.31 0.4 A C84 CB3 23,861 0.00 0.30 0.25 0.55 0.55 0.301 2.097 8.8 0.65 2.21 4.63 12 90 408.91 408.46 0.50% 0.012 5.89 0.3 CB3 C132 2.097 9.0 0.64 2.17 4.54 12 92 408.46 408.00 0.50% 0.012 5.79 0.3 C132 C131 2.097 9.3 0.63 2.13 4.46 12 57 408.00 407.08 1.61 % 0.012 7.04 0.1 CB1 Pond 2.097 9.4 0.62 2.11 4.42 18 92 407.08 402.50 4.98% 0.012 10.43 0.1 Note: * denotes branch in storm system. Church Property K CBEX3 CBEX2 21,344 0.13 0.36 0.00 0.49 0.21 0.103 0.103 6.3 0.80 2.73 0.28 12 264 409.54 409.18 0.14% 0.024 0.88 5.0 J CBEX3 CBEX2 54,796 0.00 0.19 1.07 1.26 0.80 1.009 1.112 6.3 0.80 2.73 3.04 12 264 409.64 409.18 0.14% 0.024 3.87 1.1 I CBEX2 CBEX1 50,330 0.00 0.17 0.98 1.16 0.80 0.927 2.040 7.4 0.72 2.45 5.01 12 96 408.59 407.16 1.49% 0.024 6.37 0.3 Table C.1.2. Time of Concentration Calculations Lawn Grassed Waterway Pavement Basin Kr 7.0 15.0 20.0 Segment 1 Segment 2 Length Height Slope Kr Tc Length Height Slope Kr Tc F F (FT/FT) (M I N) FT F (FT/FT) (M I N) F 60 0.005 7.0 2.0 60 G 300 0.020 7.0 5.1 110 K 241 0.020 7.0 4.1 70 Note: All onsite Time of Concentrations were calculated to be < 6.3 minutes. 0.010 20.0 0.5 0.010 20.0 0.9 0.010 20.0 0.6 TOTAL Tc (MIN) 2.5 6.0 4.6 Appendix C.2 KCRTS Time Series Calculations 1-Hour Times Series: KCRTS Command ------------- CREATE a new Time Series ------------------------ Production of Runoff Time Series Project Location Sea-Tac Computing Series siteex.tsf Regional Scale Factor 1.00 Data Type Reduced Creating Hourly Time Series File Loading Time Series File:C:\KC_SWDM\KC_DATA\STTF60R.rnf Till Forest 1.78 acres Loading Time Series File:C:\KC_SWDM\KC_DATA\STTG60R.rnf Till Grass 1.03 acres Loading Time Series File:C:\KC_SWDM\KC_DATA\STEI60R.rnf Impervious 0.29 acres -------------- Total Area 3.10 acres Peak Discharge: 0.482 CFS at 6:00 on Jan 9 in Year 8 Storing Time Series File:siteex.tsf Time Series Computed KCRTS Command ------------- Enter the Analysis TOOLS Module ------------------------------- Analysis Tools Command ---------------------- Compute PEAKS and Flow Frequencies ---------------------------------- Loading Stage/Discharge curve:siteex.tsf Flow Frequency Analysis -------------------------------------------------------- Time Series File:siteex.tsf Project Location:Sea-Tac Frequencies & Peaks saved to File:siteex.pks Analysis Tools Command ---------------------- Compute Flow DURATION and Exceedence ------------------------------------ Loading Time Series File:siteex.tsf Computing Interval Locations Computing Flow Durations Durations & Exceedence Probabilities to File:siteex.dur Analysis Tools Command ---------------------- RETURN to Previous Menu ----------------------- KCRTS Command ------------- Haney Crest TLR -July 2002 CREATE a new Time Series ------------------------ Production of Runoff Time Series Project Location Sea-Tac Computing Series sitede.tsf Regional Scale Factor 1.00 Data Type Reduced Creating Hourly Time Series File Loading Time Series File:C:\KC_SWDM\KC_DATA\STTG60R.rnf Till Grass 1.43 acres Loading Time Series File:C:\KC_SWDM\KC_DATA\STEI60R.rnf Impervious 1.67 acres -------------- Total Area 3.10 acres Peak Discharge: 1.09 CFS at 6:00 on Jan 9 in Year 8 Storing Time Series File:sitede.tsf Time Series Computed KCRTS Command ------------- Enter the Analysis TOOLS Module ------------------------------- Analysis Tools Command ---------------------- Compute PEAKS and Flow Frequencies ---------------------------------- Loading Stage/Discharge curve:sitede.tsf Flow Frequency Analysis -------------------------------------------------------- Time Series File:sitede.tsf Project Location:Sea-Tac Frequencies & Peaks saved to File:sitede.pks Analysis Tools Command ---------------------- Compute Flow DURATION and Exceedence ------------------------------------ Loading Time Series File:sitede.tsf Computing Interval Locations Computing Flow Durations Durations & Exceedence Probabilities to File:sitede.dur Analysis Tools Command ---------------------- RETURN to Previous Menu ----------------------- KCRTS Command ------------- CREATE a new Time Series ------------------------ Production of Runoff Time Series Project Location Sea-Tac Computing Series trib.tsf Regional Scale Factor 1.00 Data Type Reduced Creating Hourly Time Series File Loading Time Series File:C:\KC_SWDM\KC_DATA\STTF60R.rnf Honey Crest TIR-July 2002 Till Forest 0.13 acres Loading Time Series File:C:\KC_SWDM\KC_DATA\STTG60R.rnf Till Grass 0.85 acres Loading Time Series File:C:\KC_SWDM\KC_DATA\STEI60R.rnf Impervious 0.15 acres -------------- Total Area 1.13 acres Peak Discharge: 0.260 CFS at 6:00 on Jan 9 in Year 8 Storing Time Series File:trib.tsf Time Series Computed KCRTS Command ------------- Enter the Analysis TOOLS Module ------------------------------- Analysis Tools Command ---------------------- Compute PEAKS and Flow Frequencies ---------------------------------- Loading Stage/Discharge curve:trib.tsf Flow Frequency Analysis -------------------------------------------------------- Time Series File:trib.tsf Project Location:Sea-Tac Frequencies & Peaks saved to File:trib.pks Analysis Tools Command ---------------------- Compute Flow DURATION and Exceedence ------------------------------------ Loading Time Series File:trib.tsf Computing Interval Locations Computing Flow Durations Durations & Exceedence Probabilities to File:trib.dur Analysis Tools Command ---------------------- RETURN to Previous Menu ----------------------- KCRTS Command ------------- CREATE a new Time Series ------------------------ Production of Runoff Time Series Project Location Sea-Tac Computing Series churchex.tsf Regional Scale Factor 1.00 Data Type Reduced Creating Hourly Time Series File Loading Time Series File:C:\KC_SWDM\KC_DATA\STTG60R.rnf Till Grass 2.69 acres Loading Time Series File:C:\KC_SWDM\KC_DATA\STEI60R.rnf Impervious 1.50 acres -------------- Total Area 4.19 acres Peak Discharge: 1.28 CFS at 6:00 on Jan 9 in Year 8 Storing Time Series File:churchex.tsf Honey C,esr 777? —July 2002 Time Series Computed KCRTS Command ------------- Enter the Analysis TOOLS Module ------------------------------- Analysis Tools Command ---------------------- Compute PEAKS and Flow Frequencies ---------------------------------- Loading Stage/Discharge curve:churchex.tsf Flow Frequency Analysis -------------------------------------------------------- Time Series File:churchex.tsf Project Location:Sea-Tac Frequencies & Peaks saved to File:churchex.pks Analysis Tools Command ---------------------- Compute Flow DURATION and Exceedence ------------------------------------ Loading Time Series File:churchex.tsf Computing Interval Locations Computing Flow Durations Durations & Exceedence Probabilities to File:churchex.dur Analysis Tools Command ---------------------- RETURN to Previous Menu ----------------------- KCRTS Command ------------- CREATE a new Time Series ------------------------ Production of Runoff Time Series Project Location Sea-Tac Computing Series churchde.tsf Regional Scale Factor 1.00 Data Type Reduced Creating Hourly Time Series File Loading Time Series File:C:\KC_SWDM\KC_DATA\STTG60R.rnf Till Grass 2.28 acres Loading Time Series File:C:\KC_SWDM\KC_DATA\STEI60R.rnf Impervious 1.91 acres -------------- Total Area 4.19 acres Peak Discharge: 1.38 CFS at 6:00 on Jan 9 in Year 8 Storing Time Series File:churchde.tsf Time Series Computed KCRTS Command ------------- Enter the Analysis TOOLS Module ------------------------------- Analysis Tools Command ---------------------- Haley Crest TOR -July 2002 Compute PEAKS and Flow Frequencies Loading Stage/Discharge curve:churchde.tsf Flow Frequency Analysis -------------------------------------------------------- Time Series File:churchde.tsf Project Location:Sea-Tac Frequencies & Peaks saved to File:churchde.pks Analysis Tools Command ---------------------- Compute Flow DURATION and Exceedence ------------------------------------ Loading Time Series File:churchde.tsf Computing Interval Locations Computing Flow Durations Durations & Exceedence Probabilities to File:churchde.dur Analysis Tools Command ---------------------- RETURN to Previous Menu ----------------------- KCRTS Command ------------- ADD Time Series --------------- Adding Time Series Computing Series:totex.tsf Loading Time Series File:siteex.tsf Peak Flow Rate: 0.482 CFS at 6:00 on Jan 9 in Year 8 Lag= 0.00 Factor: 1.00 Loading Time Series File:trib.tsf Peak Flow Rate: 0.260 CFS at 6:00 on Jan 9 in Year 8 Lag= 0.00 Factor: 1.00 Loading Time Series File:churchex.tsf Peak Flow Rate: 1.28 CFS at 6:00 on Jan 9 in Year 8 Lag= 0.00 Factor: 1.00 Peak Flow Rate: 2.02 CFS at 6:00 on Jan 9 in Year 8 Storing Time Series File:totex.tsf Time Series addition complete KCRTS Command ------------- Enter the Analysis TOOLS Module ------------------------------- Analysis Tools Command ---------------------- Compute PEAKS and Flow Frequencies ---------------------------------- Loading Stage/Discharge curve:totex.tsf Flow Frequency Analysis -------------------------------------------------------- Time Series File:totex.tsf Project Location:Sea-Tac Frequencies & Peaks saved to File:totex.pks Analysis Tools Command Honey Crest TIR-.hdy 2002 ---------------------- Compute Flow DURATION and Exceedence Loading Time Series File:totex.tsf Computing Interval Locations Computing Flow Durations Durations & Exceedence Probabilities to File:totex.dur Analysis Tools Command ---------------------- RETURN to Previous Menu ----------------------- KCRTS Command ------------- ADD Time Series --------------- Adding Time Series Computing Series:totdev.tsf Loading Time Series File:sitede.tsf Peak Flow Rate: 1.09 CFS at 6:00 on Jan 9 in Year 8 Lag= 0.00 Factor: 1.00 Loading Time Series File:trib.tsf Peak Flow Rate: 0.260 CFS at 6:00 on Jan 9 in Year 8 Lag= 0.00 Factor: 1.00 Loading Time Series File:churchde.tsf Peak Flow Rate: 1.38 CFS at 6:00 on Jan 9 in Year 8 Lag= 0.00 Factor: 1.00 Peak Flow Rate: 2.74 CFS at 6:00 on Jan 9 in Year 8 Storing Time Series File:totdev.tsf Time Series addition complete KCRTS Command ------------- Enter the Analysis TOOLS Module ------------------------------- Analysis Tools Command ---------------------- Compute PEAKS and Flow Frequencies ---------------------------------- Loading Stage/Discharge curve:totdev.tsf Flow Frequency Analysis -------------------------------------------------------- Time Series File:totdev.tsf Project Location:Sea-Tac Frequencies & Peaks saved to File:totdev.pks Analysis Tools Command ---------------------- Compute Flow DURATION and Exceedence ------------------------------------ Loading Time Series File:totdev.tsf Computing Interval Locations Computing Flow Durations Durations & Exceedence Probabilities to File:totdev.dur Analysis Tools Command ---------------------- Honey Crest TIR-J*2002 RETURN to Previous Menu ----------------------- KCRTS Command ------------- eXit KCRTS Program ------------------ Ha+ey Cmm 7YR - July 2002 15-Minute Times Series: KCRTS Command ------------- CREATE a new Time Series ------------------------ Production of Runoff Time Series Project Location Sea-Tac Computing Series sitedel5.tsf Regional Scale Factor 1.00 Data Type Reduced Creating 15-minute Time Series File Loading Time Series File:C:\KC_SWDM\KC_DATA\STTG15R.rnf Till Grass 1.43 acres Loading Time Series File:C:\KC_SWDM\KC_DATA\STEI15R.rnf Impervious 1.67 acres -------------- Total Area 3.10 acres Peak Discharge: 2.69 CFS at 6:30 on Jan 9 in Year 8 Storing Time Series File:sitedel5.tsf Time Series Computed KCRTS Command ------------- Enter the Analysis TOOLS Module ------------------------------- Analysis Tools Command ---------------------- Compute PEAKS and Flow Frequencies ---------------------------------- Loading Stage/Discharge curve:sitedel5.tsf Flow Frequency Analysis -------------------------------------------------------- Time Series File:sitedel5.tsf Project Location:Sea-Tac Frequencies & Peaks saved to File:sitedel5.pks Analysis Tools Command ---------------------- RETURN to Previous Menu ----------------------- KCRTS Command ------------- CREATE a new Time Series ------------------------ Production of Runoff Time Series Project Location Sea-Tac Computing Series tribl5.tsf Regional Scale Factor 1.00 Data Type Reduced Creating 15-minute Time Series File Loading Time Series File:C:\KC_SWDM\KC_DATA\STTF15R.rnf Till Forest 0.13 acres Loading Time Series File:C:\KC_SWDM\KC_DATA\STTG15R.rnf Till Grass 0.85 acres Loading Time Series File:C:\KC_SWDM\KC_DATA\STEI15R.rnf HarleyCmV TIR-July2002 Impervious 0.15 acres -------------- Total Area 1.13 acres Peak Discharge: 0.616 CFS at 6:30 on Jan 9 in Year 8 Storing Time Series File:tribl5.tsf Time Series Computed KCRTS Command ------------- Enter the Analysis TOOLS Module ------------------------------- Analysis Tools Command ---------------------- Compute PEAKS and Flow Frequencies ---------------------------------- Loading Stage/Discharge curve:tribl5.tsf Flow Frequency Analysis -------------------------------------------------------- Time Series File:tribl5.tsf Project Location:Sea-Tac Frequencies & Peaks saved to File:tribl5.pks Analysis Tools Command ---------------------- RETURN to Previous Menu ----------------------- KCRTS Command ------------- CREATE a new Time Series ------------------------ Production of Runoff Time Series Project Location Sea-Tac Computing Series chdel5.tsf Regional Scale Factor 1.00 Data Type Reduced Creating 15-minute Time Series File Loading Time Series File:C:\KC_SWDM\KC_DATA\STTG15R.rnf Till Grass 2.08 acres Loading Time Series File:C:\KC_SWDM\KC_DATA\STEI15R.rnf Impervious 2.11 acres -------------- Total Area 4.19 acres Peak Discharge: 3.54 CFS at 6:30 on Jan 9 in Year 8 Storing Time Series File:chdel5.tsf Time Series Computed , KCRTS Command ------------- Enter the Analysis TOOLS Module ------------------------------- Analysis Tools Command ---------------------- Compute PEAKS and Flow Frequencies ---------------------------------- Loading Stage/Discharge curve:chdel5.tsf Flow Frequency Analysis Honey Crest 77R—J*2002 -------------------------------------------------------- Time Series File:chdel5.tsf Project Location:Sea-Tac Frequencies & Peaks saved to File:chdel5.pks Analysis Tools Command ---------------------- RETURN to Previous Menu ----------------------- KCRTS Command ------------- ADD Time Series --------------- Adding Time Series Computing Series:totdevl5.tsf Loading Time Series File:sitedel5.tsf Peak Flow Rate: 2.69 CFS at 6:30 on Jan 9 in Year 8 Lag= 0.00 Factor: 1.00 Loading Time Series File:tribl5.tsf Peak Flow Rate: 0.616 CFS at 6:30 on Jan 9 in Year 8 Lag= 0.00 Factor: 1.00 Loading Time Series File:chdel5.tsf Peak Flow Rate: 3.54 CFS at 6:30 on Jan 9 in Year 8 Lag= 0.00 Factor: 1.00 Peak Flow Rate: 6.85 CFS at 6:30 on Jan 9 in Year 8 Storing Time Series File:totdevl5.tsf Time Series addition complete KCRTS Command ------------- Enter the Analysis TOOLS Module ------------------------------- Analysis Tools Command ---------------------- Compute PEAKS and Flow Frequencies ---------------------------------- Loading Stage/Discharge curve:totdevl5.tsf Flow Frequency Analysis -------------------------------------------------------- Time Series File:totdevl5.tsf Project Location:Sea-Tac Frequencies & Peaks saved to File:totdevl5.pks Analysis Tools Command ---------------------- RETURN to Previous Menu ----------------------- KCRTS Command ------------- eXit KCRTS Program ------------------ Honey Cmst TIR—A*2002 Flow Frequency Analysis Time Series File:siteex.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- FlowRate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period 0.249 3 2/09/01 15:00 0.482 1 100.00 0.990 0.138 7 1/05/02 16:00 0.273 2 25.00 0.960 0.273 2 2/27/03 7:00 0.249 3 10.00 0.900 0.092 8 8/26/04 2:00 0.249 4 5.00 0.800 0.146 6 1/05/05 8:00 0.224 5 3.00 0.667 0.249 4 1/18/06 16:00 0.146 6 2.00 0.500 0.224 5 11/24/06 3:00 0.138 7 1.30 0.231 0.482 1 1/09/08 6:00 0.092 8 1.10 0.091 Computed Peaks 0.412 50.00 0.980 Flow Frequency Analysis Time Series File:trib.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- FlowRate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period 0.117 4 2/09/01 2:00 0.260 1 100.00 0.990 0.073 6 1/05/02 16:00 0.145 2 25.00 0.960 0.145 2 2/27/03 7:00 0.123 3 10.00 0.900 0.053 8 8/26/04 2:00 0.117 4 5.00 0.800 0.069 7 10/28/04 16:00 0.112 5 3.00 0.667 0.123 3 1/18/06 16:00 0.073 6 2.00 0.500 0.112 5 11/24/06 3:00 0.069 7 1.30 0.231 0.260 1 1/09/08 6:00 0.053 8 1.10 0.091 Computed Peaks 0.222 50.00 0.980 Flow Frequency Analysis Time Series File:churchex.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- FlowRate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period 0.604 5 2/09/01 2:00 1.28 1 100.00 0.990 0.443 7 1/05/02 16:00 0.737 2 25.00 0.960 0.737 2 2/27/03 7:00 0.636 3 10.00 0.900 0.424 8 8/26/04 2:00 0.614 4 5.00 0.800 0.524 6 10/28/04 16:00 0.604 5 3.00 0.667 0.636 3 1/18/06 16:00 0.524 6 2.00 0.500 0.614 4 10/26/06 0:00 0.443 7 1.30 0.231 1.28 1 1/09/08 6:00 0.424 8 1.10 0.091 Computed Peaks 1.10 50.00 0.980 Honey Crest TIR-J* 2002 Flow Frequency Analysis Time Series File:totex.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- FlowRate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period 0.954 4 2/09/01 2:00 2.02 1 100.00 0.990 0.654 7 1/05/02 16:00 1.16 2 25.00 0.960 1.16 2 2/27/03 7:00 1.01 3 10.00 0.900 0.570 8 8/26/04 2:00 0.954 4 5.00 0.800 0.710 6 10/28/04 16:00 0.931 5 3.00 0.667 1.01 3 1/18/06 16:00 0.710 6 2.00 0.500 0.931 5 11/24/06 3:00 0.654 7 1.30 0.231 2.02 1 1/09/08 6:00 0.570 8 1.10 0.091 Computed Peaks 1.73 50.00 0.980 Flow Frequency Analysis Time Series File:sitede.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- FlowRate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period 0.533 6 2/09/01 2:00 1.09 1 100.00 0.990 0.422 8 1/05/02 16:00 0.644 2 25.00 0.960 0.643 3 2/27/03 7:00 0.643 3 10.00 0.900 0.443 7 8/26/04 2:00 0.564 4 5.00 0.800 0.536 5 10/28/04 16:00 0.536 5 3.00 0.667 0.564 4 1/18/06 16:00 0.533 6 2.00 0.500 0.644 2 10/26/06 0:00 0.443 7 1.30 0.231 1.09 1 1/09/08 6:00 0.422 8 1.10 0.091 Computed Peaks 0.943 50.00 0.980 Flow Frequency Analysis Time Series File:churchde.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- FlowRate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period 0.667 5 2/09/01 2:00 1.38 1 100.00 0.990 0.512 8 1/05/02 16:00 0.809 2 25.00 0.960 0.809 2 2/27/03 7:00 0.752 3 10.00 0.900 0.518 7 8/26/04 2:00 0.704 4 5.00 0.800 0.633 6 10/28/04 16:00 0.667 5 3.00 0.667 0.704 4 1/18/06 16:00 0.633 6 2.00 0.500 0.752 3 10/26/06 0:00 0.518 7 1.30 0.231 1.38 1 1/09/08 6:00 0.512 8 1.10 0.091 Computed Peaks 1.19 50.00 0.980 Haney Crest TIR - July 2002 Flow Frequency Analysis Time Series File:totdev.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- FlowRate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period 1.32 5 2/09/01 2:00 2.74 1 100.00 0.990 1.01 8 1/05/02 16:00 1.60 2 25.00 0.960 1.60 2 2/27/03 7:00 1.47 3 10.00 0.900 1.01 7 8/26/04 2:00 1.39 4 5.00 0.800 1.24 6 10/28/04 16:00 1.32 5 3.00 0.667 1.39 4 1/18/06 16:00 1.24 6 2.00 0.500 1.47 3 10/26/06 0:00 1.01 7 1.30 0.231 2.74 1 1/09/08 6:00 1.01 8 1.10 0.091 Computed Peaks 2.36 50.00 0.980 Flow Frequency Analysis Time Series File:rdout.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- FlowRate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) (ft) Period 0.988 3 2/09/01 16:00 2.32 3.09 1 100.00 0.990 0.297 7 1/05/02 18:00 1.14 2.80 2 25.00 0.960 0.577 5 3/06/03 20:00 0.988 2.74 3 10.00 0.900 0.271 8 8/23/04 23:00 0.927 2.71 4 5.00 0.800 0.475 6 1/05/05 10:00 0.577 2.46 5 3.00 0.667 0.927 4 1/18/06 21:00 0.475 1.89 6 2.00 0.500 1.14 2 11/24/06 5:00 0.297 1.22 7 1.30 0.231 2.32 1 1/09/08 9:00 0.271 1.01 8 1.10 0.091 Computed Peaks 1.92 3.03 50.00 0.980 Flow Frequency Analysis Time Series File:sitede15.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates --- Flow Rate Rank Time of Peak (CFS) 0.796 6 0.589 8 1.82 2 0.641 7 1.13 3 0.983 5 1.13 4 2.69 1 Computed Peaks Honey Cho& T!R-Ady 2002 8/27/01 18:00 1/05/02 15:00 12/08/02 17:15 8/23/04 14:30 11/17/04 5:00 10/27/05 10:45 10/25/06 22:45 1/09/08 6:30 -----Flow Frequency Analysis------- - - Peaks - - Rank Return Prob (CFS) Period 2.69 1 100.00 0.990 1.82 2 25.00 0.960 1.13 3 10.00 0.900 1.13 4 5.00 0.800 0.983 5 3.00 0.667 0.796 6 2.00 0.500 0.641 7 1.30 0.231 0.589 8 1.10 0.091 2.40 50.00 0.980 Flow Frequency Analysis Time Series File:tribl5.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- FlowRate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period 0.151 4 2/09/01 12:45 0.616 1 100.00 0.990 0.094 7 1/06/02 1:00 0.328 2 25.00 0.960 0.326 3 12/08/02 17:15 0.326 3 10.00 0.900 0.070 8 8/26/04 1:00 0.151 4 5.00 0.800 0.328 2 11/17/04 5:00 0.137 5 3.00 0.667 0.136 6 10/27/05 10:45 0.136 6 2.00 0.500 0.137 5 11/24/06 1:00 0.094 7 1.30 0.231 0.616 1 1/09/08 6:30 0.070 8 1.10 0.091 Computed Peaks 0.520 50.00 0.980 Flow Frequency Analysis Time Series File:chdel5.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- FlowRate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period 1.00 6 8/27/01 18:00 3.54 1 100.00 0.990 0.757 8 1/05/02 15:00 2.36 2 25.00 0.960 2.36 2 12/08/02 17:15 1.51 3 10.00 0.900 0.809 7 8/23/04 14:30 1.43 4 5.00 0.800 1.51 3 11/17/04 5:00 1.26 5 3.00 0.667 1.26 5 10/27/05 10:45 1.00 6 2.00 0.500 1.43 4 10/25/06 22:45 0.809 7 1.30 0.231 3.54 1 1/09/08 6:30 0.757 8 1.10 0.091 Computed Peaks 3.15 50.00 0.980 Flow Frequency Analysis Time Series File:totdevl5.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- FlowRate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period 1.87 6 8/27/01 18:00 6.85 1 100.00 0.990 1.44 8 1/05/02 15:00 4.50 2 25.00 0.960 4.50 2 12/08/02 17:15 2.97 3 10.00 0.900 1.51 7 8/23/04 14:30 2.68 4 5.00 0.800 2.97 3 11/17/04 5:00 2.38 5 3.00 0.667 2.38 5 10/27/05 10:45 1.87 6 2.00 0.500 2.68 4 10/25/06 22:45 1.51 7 1.30 0.231 6.85 1 1/09/08 6:30 1.44 8 1.10 0.091 Computed Peaks 6.07 50.00 0.980 Honey Crv& TIR - July 2002 The following is a description of KCRTS input and output files used in designing the R/D facilities and conducting the downstream drainage analysis for Honey Crest. EXECUTABLE FILES basins.exc: This executable file creates time series for all contributing areas to the downstream system for both existing and developed conditions. Based on 1-hour peak flow rates. Basinsl5.exc: This executable file creates time series for all contributing areas to the downstream system for developed conditions. Based on 15-minute peak flow rates. tar.exc: This executable creates target duration files for R/D design. TIME SERIES FILES R/D Design siteex.tsf: The Honey Crest site under existing conditions. trib.tsf: Offsite tributary basin draining to the Honey Crest site and the church property. churchex.tsf: The neighboring church property under existing conditions. sitede.tsf: The Honey Crest site under proposed developed conditions. churchde.tsf: The neighboring church under future potential developed conditions. This includes the church property with up to 0.82 acre of new impervious area. rdout.tsf: Time series out of proposed R/D system for site (lev2.rdf). totex.tsf: Total project area draining to the proposed pond under existing conditions. This time series was used to develop the target duration curve for the proposed R/D system design. Based on the following Hbney Crest TIR —July 2002 times series: siteex.tsf + trib.tsf + churchex.tsf. tar.tsf: Target duration curve for the proposed R/D system design. Based on the following times series: siteex.tsf + trib.tsf + churchex.tsf. totdev.tsf: Total project area draining to the proposed pond under proposed developed conditions. Based on the following times series: sitede.tsf + trib.tsf + churchde.tsf. 15-minute time series: The following 15-minute time series were calculated for pond overflow design: sitedel5.tsf + tribl5.tsf + chdel5.tsf = totdevl5.tsf RESERVOIRS Lev2.rdf: Honey Crest R/D facility managing stormwater from the entire developed site as well as from 0.82 acre of new impervious on the church property. GENERAL NOTES 1. Seatac regional rainfall runoff files with a scale factor of 1.0 were used in the hydrologic simulations. 2. R/D facilities were designed with the 8-year data set. 1-hour peak flow rates were used for detention calculations. 3. 15-minute peak flow rates were used for conveyance calculations. 4. Gravel areas were modeled in KCRTS by assuming that 50 percent of the area is impervious and the remaining 50 percent are the same cover type as that surrounding the gravel area. Honey Crest TM —.Tiny 2002 Appendix E. Proposed Site Plan Honey Crest 77R—July 2002 SCALE: 1" = 50' Figure E.I. Honey Crest Plat Haozous Engineering, P.S. PAGE DATE 7/24/02