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Home My WebLink AboutTIR-4097 TECHNICAL INFORMATION REPORT Dalpay Short Plat 18XX Redmond Place N.E. Renton, Washington Prepared for: Dalpay Properties LLC P.O. Box 2436 Renton, WA 98056 September 24, 2019 Revised February 11, 2020 Revised September 21, 2020 Revised November 3, 2020 Our Job No. 17884 11-3-20 Stormwater adjustment 2020-4 pertaining to this TIR has been approved. DEVELOPMENT ENGINEERING Nathan Janders 11/12/2020 SURFACE WATER UTILITY jfarah 11/13/2020 Technical Information Report Dalpay Short Plat Renton, Washington Our Job No. 17884 17884.007.doc TABLE OF CONTENTS 1.0 PROJECT OVERVIEW Figure 1 – Technical Information Report (TIR) Worksheet Figure 2 – Site Location Figure 3 – Drainage Basins, Subbasins, and Site Characteristics Figure 4 – Soils 2.0 CONDITIONS AND REQUIREMENTS SUMMARY 2.1 Analysis of the Core Requirements 2.2 Analysis of the Special Requirements 3.0 OFF-SITE ANALYSIS 4.0 FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN A. Existing Site Hydrology B. Developed Site Hydrology C. Performance Standards D. Flow Control System E. Water Quality System 5.0 CONVEYANCE SYSTEM ANALYSIS AND DESIGN 6.0 SPECIAL REPORTS AND STUDIES 6.1 Geotechnical Engineering Study for Dalpay Short Plat prepared by Earth Solutions NW, LLC dated December 23, 2015 6.2 Geotechnical Addendum for Dalpay Short Plat prepared by Earth Solutions NW, LLC dated February 13, 2017 6.3 Response to Review Comments for Dalpay Short Plat prepared by Earth Solutions NW, LLC dated February 21, 2018 6.4 Response to Review Comments for Proposed Dalpay Short Plat by Earth Solutions NW, LLC dated October 8, 2019 7.0 OTHER PERMITS 8.0 CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN ANALYSIS AND DESIGN A. Erosion and Sediment Control (ESC) Plan Analysis and Design B. Stormwater Pollution Prevention Plan 9.0 BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT 10.0 OPERATIONS AND MAINTENANCE MANUAL Tab 1.0 17884.007.doc 1.0 PROJECT OVERVIEW The proposed Dalpay Short Plat is located at the intersection of N.E. 19th Street and Redmond Place N.E., in the City of Renton, King County, Washington. It is also situated within Section 4, Township 23 North, Range 5 East, Willamette Meridian. Please see Figure 2 – Vicinity Map for a more accurate depiction of the location of the site. The subject property has slopes ranging from approximately 2 to 40 percent. The northwest and southeast corners of the site are relatively flat. The remainder of the site topography consists of a "ravine" with steeper slopes down to a stream. The stream and slope are contained within an existing Native Growth Protection Easement (NGPE). On-site soils are Alderwood, which are considered to be "till" type soils and are generally not conducive to infiltration. With the exception of Lot 1, the entire site is covered with trees and brush. There are no existing structures on the site. The project consists of one parcel, containing a total area of approximately 1.66 acres. The proposal with this preliminary short plat is to create three (3) single-family lots with associated roadways, utilities, and stormwater facilities. Lot 1 will gain access from Redmond Place N.E., while Lots 2 and 3 will gain access from Redmond Court N.E. A private access tract will be constructed for the access to Lots 2 and 3, per City of Renton standards. The project will provide one drainage facility for the developed area at the southeast portion of the site (Lots 2 and 3). This facility will consist of a detention pond and will be located west of Lots 2 and 3. An 8-inch-diameter HDPE pipe is proposed to be installed to convey stormwater discharge to the natural discharge location, which is the stream located on site. This storm pipe will be installed underground and where possible it will be installed on the surface of the ground to minimize the disturbance within the existing NGPE area. The developed portion of the site located in the northwest corner of the site (Lot 1) does not require any detention since the developed conditions will only increase the 100-year peak flows from the site by 0.057 cfs as compared to the pre-developed conditions. Combined with the 0.018 cfs decrease in runoff from lots 2 and 3 after detention for the 100-year flow, the total increase in the 100-year peak from the site is approximately 0.039 cfs. This is below the threshold increase of 0.15 cfs for the 100 year from Section 1.2.3.2.E.5 of the 2017 RSWDM. Therefore, no detention is required. Please refer to section 4.0.D of this report for further analysis. Water quality facilities are not required for this project as the proposed Pollution Generating Impervious Surface (PGIS) for the entire project is less than 5,000 SF. The runoff from lot 1 will be conveyed to the drainage facilities that were designed and constructed with the original Dalpay Short Plat that was constructed about 10 years ago. The Level 1 Off-Site Drainage Analysis for the original short plat are located in Section 3.0 of this report. Figure 1 Technical Information Report (TIR) Worksheet KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 2009 Surface Water Design Manual 1/1/09 1 17884.002.doc Part 1 PROJECT OWNER AND PROJECT ENGINEER Part 2 PROJECT LOCATION AND DESCRIPTION Project Owner Dalpay Properties LLC Phone (206) 399-6302 Address P.O. Box 2436 Renton, WA 98056 Project Engineer Don E. Dawes, P.E. Company Barghausen Consulting Engineers , Inc. Phone (425) 251-6222 Project Name Dalpay Short Plat DDES Permit # Location Township 23N Range 5E Section 4 Site Address 18XX Redmond Place N.E. Part 3 TYPE OF PERMIT APPLICATION Part 4 OTHER REVIEWS AND PERMITS Landuse Services Subdivision / Short Subd. / UPD Building Services M/F / Commercial / SFR Clearing and Grading Right-of-Way Use Other DFW HPA COE 404 DOE Dam Safety FEMA Floodplain COE Wetlands Other Shoreline Management Structural Rockery/Vault/ ESA Section 7 Part 5 PLAN AND REPORT INFORMATION Technical Information Report Type of Drainage Review Full / Targeted / (circle): Large Site Date (include revision 2-11-20 dates): Date of Final: Site Improvement Plan (Engr. Plans) Type (circle one): Full / Modified / Small Site Date (include revision 2-11-20 dates): Date of Final: Part 6 ADJUSTMENT APPROVALS Type (circle one): Standard / Complex / Preapplication / Experimental / Blanket Description: (include conditions in TIR Section 2) N/A Date of Approval: KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 2009 Surface Water Design Manual 1/1/09 2 17884.002.doc Part 7 MONITORING REQUIREMENTS Monitoring Required: Yes / No Start Date: Completion Date: Describe: Part 8 SITE COMMUNITY AND DRAINAGE BASIN Community Plan : City of Renton Special District Overlays: Drainage Basin: Honey Creek Stormwater Requirements: Part 9 ONSITE AND ADJACENT SENSITIVE AREAS River/Stream Lake Wetlands Closed Depression Floodplain Other Steep Slope Erosion Hazard Landslide Hazard Coal Mine Hazard Seismic Hazard Habitat Protection Part 10 SOILS Soil Type Slopes Erosion Potential AgC (Alderwood) 8-15% Moderate AgD (Alderwood) 15-30% Moderate High Groundwater Table (within 5 feet) Sole Source Aquifer Other Seeps/Springs Additional Sheets Attached KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 2009 Surface Water Design Manual 1/1/09 3 17884.002.doc Part 11 DRAINAGE DESIGN LIMITATIONS REFERENCE LIMITATION / SITE CONSTRAINT Core 2 – Offsite Analysis Sensitive/Critical Areas SEPA Other Additional Sheets Attached Part 12 TIR SUMMARY SHEET (provide one TIR Summary Sheet per Threshold Discharge Area) Threshold Discharge Area: (name or description) Core Requirements (all 8 apply) Discharge at Natural Location Number of Natural Discharge Locations: 1 Offsite Analysis Level: 1 / 2 / 3 dated: 12/3/03 (Cramer NW, Inc.) Flow Control Level: 1 / 2 / 3 or Exemption Number (incl. facility summary sheet) Small Site BMPs Conveyance System Spill containment located at: Detention Pond Erosion and Sediment Control ESC Site Supervisor: TBD Contact Phone: After Hours Phone: Maintenance and Operation Responsibility: Private / Public If Private, Maintenance Log Required: Yes / No Financial Guarantees and Provided: Yes / No Liability Water Quality Type: Basic / Sens. Lake / Enhanced Basicm / Bog (include facility summary sheet) or Exemption No. Landscape Management Plan: Yes / No Special Requirements (as applicable) Area Specific Drainage Type: CDA / SDO / MDP / BP / LMP / Shared Fac. / None Requirements Name: Floodplain/Floodway Delineation Type: Major / Minor / Exemption / None 100-year Base Blood Elevation (or range): Datum: Flood Protection Facilities Describe: Source Control Describe landuse: (comm./industrial landuse) Describe any structural controls: KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 2009 Surface Water Design Manual 1/1/09 4 17884.002.doc Oil Control High-use Site: Yes / No Treatment BMP: Maintenance Agreement: Yes / No with whom? Other Drainage Structures Describe: Part 13 EROSION AND SEDIMENT CONTROL REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION Clearing Limits Cover Measures Perimeter Protection Traffic Area Stabilization Sediment Retention Surface Water Control Dewatering Control Dust Control Flow Control MINIMUM ESC REQUIREMENTS AFTER CONSTRUCTION Stabilize Exposed Surfaces Remove and Restore Temporary ESC Facilities Clean and Remove All Silt and Debris Ensure Operation of Permanent Facilities Flag Limits of SAO and open space preservation areas Other Part 14 STORMWATER FACILITY DESCRIPTIONS (Note: Include Facility Summary and Sketch) Flow Control Type/Description Water Quality Type/Description Detention Infiltration Regional Facility Shared Facility Flow Control BMPs Other Pond Biofiltration Wetpool Media Filtration Oil Control Spill Control Flow Control BMPs Other KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET 2009 Surface Water Design Manual 1/1/09 5 17884.002.doc Part 15 EASEMENTS/TRACTS Part 16 STRUCTURAL ANALYSIS Drainage Easement Covenant Native Growth Protection Covenant Tract Other Cast in Place Vault Retaining Wall Rockery > 4' High Structural on Steep Slope Other Part 17 SIGNATURE OF PROFESSIONAL ENGINEER I, or a civil engineer under my supervision, have visited the site. Actual site conditions as observed were incorporated into this worksheet and the attached Technical Information Report. To the best of my knowledge the information provided here is accurate. Signed/Date 2-11-20 Figure 2 Site Location Figure 3 Drainage Basins, Subbasins, and Site Characteristics Figure 4 Soils Tab 2.0 17884.007.doc 2.0 CONDITIONS AND REQUIREMENTS SUMMARY 2.1 Analysis of the Core Requirements Core Requirement No. 1: Discharge at the Natural Location. Response: All runoff from the developed site will be discharged to the on-site stream, which is the natural discharge location. Core Requirement No. 2: Off-Site Analysis. Response: The Level 1 Off-Site Drainage Analysis is provided in Section 3.0 of this report. Core Requirement No. 3: Flow Control. Response: The project will provide a detention pond in the southeast corner of the site near Lots 2 and 3. Flow control facilities for Lot 1 are provided by the original Dalpay Short Plat located just to the north of Lot 1. Detention facilities will meet duration standard matching forested conditions, as required by City of Renton. Core Requirement No. 4: Conveyance System. Response: The site development stormwater conveyance is comprised of a series of catch basins and stormwater pipe network, which will convey the runoff to the detention pond located in the Private Access Tract. The sizing of this conveyance network is based on the Rational Method delineated in the 2017 City of Renton Surface Water Design Manual (RSWDM) and sized to adequately convey the anticipated stormwater discharge based on the stormwater runoff developed from a 25-year storm event. Conveyance calculations will be provided with the final engineering plans and TIR. Spill control will be provided by a spill control tee in CB#3. See sheet C9 of the Construction plans for a detail of the oil/water separator manhole. Core Requirement No. 5: Erosion and Sediment Control. Response: Temporary erosion and sedimentation control plans will be included in the site development documents prepared for this project that meet the requirements of the City of Renton. These drawings will indicate the clearing limits, temporary and permanent erosion control measures, perimeter/off-site protection (silt fence) along the downstream edge of the site, construction traffic stabilization (rock construction entrance), and other pertinent temporary erosion and sediment control measures. Core Requirement No. 6: Maintenance and Operations. Response: In accordance with the City of Renton and the 2017 RSWDM, the stormwater facilities will be privately owned and maintained. An Operation and Maintenance Manual is included in Section 10.0 of this TIR. Core Requirement No. 7: Financial Guarantees and Liability. Response: Financial guarantees will be sufficiently instituted to cover the cost of correcting, if necessary, incomplete or substandard drainage facility construction work and to warrant for 1 year the satisfactory performance of the newly constructed drainage facilities or any facility that will be assumed by the City of Renton for maintenance operation. 17884.007.doc Core Requirement No. 8: Water Quality. Response: As dictated by the 2017 RSWDM, the Basic Water Quality Protection Menu must be followed for this project. This project is exempt from providing water quality because less than 5,000 square feet of new pollution generating impervious surface is proposed to be added to the site. Core Requirement No. 9: On-Site BMPs. Response: None of the required large lot BMPs are feasible on these lots due to soil conditions and proximity to steep slope hazard areas, landslide hazards, and erosion hazard areas. 2.2 Analysis of the Special Requirements Special Requirement No. 1: Other Adopted Area-Specific Requirements. Response: There is no known adopted area-specific requirements for this short plat. Special Requirement No. 2: Flood Hazard Area Delineation. Response: The project is not located within a floodplain or floodway. Special Requirement No. 3: Flood Protection Facilities. Response: No flood protection facilities are proposed or will be modified. Special Requirement No. 4: Source Control. Response: There are no known source controls required with this development. Special Requirement No. 5: Oil Control. Response: This project is not considered a high-use site; therefore, special oil controls are not required for this development. Special Requirement No. 6: Aquifer Protection Area. Response: This project is not located within an Aquifer Protection Area. Tab 3.0 17884.007.doc 3.0 OFF-SITE ANALYSIS Please refer to the following Level 1 Downstream Drainage Analysis from the Storm Drainage Report prepared by Cramer Northwest Inc. dated December 3, 2003. Note: Only the Level 1 Downstream Analysis from the Cramer Northwest Storm Drainage Report has been included in this section. We have reviewed the downstream analysis prepared by Cramer Northwest and it appears to be accurate for the current site conditions. CramerNorthwestInc.SurveyorsPlannersEngineersSTORMDRAINAGEREPORTAV.If•.fl’,I3LL•••‘‘—‘‘.‘--‘.\L,FORJIMDALPAY4033NESUNSETBLVD,STE3RENTON,WA98059December3,2003ecfl5tcl.iCN.I.JOBNO.2003-161PreparedbyLarryS.Krueger,RE.Phone:253.852.4880Tollfree:800.251,0189VisitCramerNorthwestonthewebathttp:t/wwv.cramemw.com.I9OFDALPAYSHORTPLATNE19THSTREETRENTON,WA94%N.CentralAveSuitei04Kent,WA98032Fax:253.852.4955 APPENDIXAOFFSITEANALYSISREPORT LEVELIDRAINAGEANALYSISOFDALPAYSHORTPLATNE19THSTREETRENTON,WASHINGTONFORJIMDALPAY4033NESUNSETBLVD,STE3RENTON,WASHINGTON98059December3,2003C.N.I.JOBNO.2003-161PreparedbyLarryS.Krueger,P.E. TABLEOFCONTENTSI.TASKISTUDYAREADEFINITIONANDMAPSII.TASK2RESOURCEREVIEWIII.TASK3FIELDINSPECTIONIV.TASK4DRAINAGESYSTEMDESCRIPTIONANDPROBLEMDESCRIPTIONSV.TASK5MITIGATIONOFEXISTINGORPOTENTIALPROBLEMS TASKISTUDYAREADEFINITIONANDMAPS TASKISTUDYAREADEFINITIONThisprojectissoutheastoftheintersectionofNE19thStreetandRedmondAveNE.ItliesalongthesouthsideofNE19thStreet.Theparcel#is042305-9032.Thesiteisapproximately2.5acres.Thenorthernportionofthesiteconsistsofmostlyofgrassandscotchbroom.ThereisalargedetentionvaultlocatedinthenortheastportionoftheprojectthatwasdesignedtodetainthestormwaterfromthissiteandtheDalpayEstatesprojectnorthwestofthisproject.Thesouthernportionoftheprojectiscompletelyforestedwithmostlyevergreensandhasaravinethatrunsthroughit.Theexistingdrainagetendstosheefflowtowardstheravine,whereitbecomesasmallstreamthatflowstowardNESunsetBoulevard.ThesmallstreamthenjoinsanotherstreamthatparallelsNESunsetBoulevard.Thesite’ssoilisanAlderwoodGravellySandyLoam(AgC)andisconsideredaTypeCsoil.MAPSAvicinitymap,sensitiveareasmap,aerial,andoffsitedrainagemapcanbefoundintheproceedingpages. jocQ3fr7F7T&WN’)A‘.tt1SSUUIJtI————rro”‘iI9£•O,C1r-°f_____•.__.5*S±JG1gHill3N1c19!________6IIL_____oz’o;[ILI.-H--w_tILt—tIV3IjLEL1d!jS0—LSH1613N______1+11Th•1rn6cI—‘mc—-L.I,;-;-;;‘LJUl/4IrI,vst0’!9‘II‘-.1.aoJII9iLhj°‘VV•jII9dSINIIiJ‘VP60t—nI\____—111i3iiFzco8IdSIII6Zj9—NU)c9-3NLlLOlZZOLIOLILOL9S?LOLZLOL6LOLIäOf.8/LC eXZ10609\,z”1soVeo9logSI79660__________________________3643_____________________________________$T\__2ISTSTU,—.7‘‘‘‘75.8/?__ ____72Z5\‘ISE85.5_1LI/2/C..2442//___ ___255I’S/4.90855__<26NEYCREEKIH85.5WIOf8-00//40-___ _ ___‘317.3—k.Lb/4283]__ __ __ ___10_____ _1k85,5ri\\28051cI_____ ___ _ ____ _ ____ _ ______ _E105ThLr31046-\___ ___/35/O\84.76I/22.26-000A14LiPL1€‘‘k‘73’cp3fr/—.GREENWAYg____ ___ __¶.\&sIAcuIN22026Tt34kI)/58Ac42‘_____s\I276V‘I3CO278.9710—68.82I55I94,JI27873097A’I226oL=278$?p/90020%TH45.245553263-SE/06/3I,I,I,I)‘IN73,0Ac__ _ _ _____\tTL260303I6Ac943270471455467I428d095ALuN.E.8Park____ _ _‘95;,50f?.?N11717kLaJ_J4Iu_ _____9!0Z‘I—<t1S‘4I3--p36_\084____g—.-st—NE17THST__ _ _ _______ _ _-7)77I8560473. ‘7Z280________ _ _ ____0484Ac/03//0910332__ _ _ ___ _ _ _ _ _ _ _ _ _ _ _ ____ _ _ ________________________ _ _ _ _ _ _ _______________ _ _________oiSo/70SC/8367___ _ _ _327/9TI3632*1836586sba08548462‘Lurt/73TI57TI4!TI/83TI40fr-’ItJii0—53J1O4,U54,1155.05164I—3-__,J55Q7TL275TI19’—’7/03SUNSETJI104..‘17ç%106‘kI’12lII207\_LuTLToi--.‘7<ji__IF1/1TI0___t%:JI\iz9i‘036AcTI2oiAQy802AcT1N35 2 7 7 2 71 4 2 ‘4’/5,7.9,ZI__ _ __ _ _ _ __ _ __ _ __\ 0r300ci0=0Ii!.-o_.‘-.pa00ci500SS(4[__/4,ViSaNo0U DALPAYSENSITIVEAREAS________1C143Jfl!M2fr:7192YX1O’1-CM-yw41r4--“<tiL35stzitti-UC_’i1kWa3’1--.iMl2jjcGrtAAaz!4*IfteiJi_--Qrnans4J{€8764difl-‘4’——1’:ae764qIè940G*J1rcd&-G4AYJ:t:.hs4r:::Ja!::-12-lI,,,c3nL-.C413359c49,_, - ----(14flL%-k4tJdLZ415°tCIL’4i-.‘(4f-e>bl95eY85cvl23D03SiJCCO1&tjaftC.tafl14?t?Wo8&)34l48OtGS&Cj‘5”__NElfl.HJT___42iaim4k-•t••a;Ma1fr<Yd134495t01d0-.CT611’3Q,1i-)asa’dosa98389ccx18*278fl(fl220c-l23OYiC:811005t30-cl2YSkkICtl589Joo32YY3gl“3t(443.k13CV..-1tSttrt1_dcv.._Vjk4lf50————--—25W&1XX0çt%32i3&72--NEJSTHST143.tS4tJYJ*30!435,a---—I--V423O59E2+c3tbi1S’°“texreo- .--VCin-411c1n14L3JSJ105‘-k)2°1lzkL4-ctøaaa4ojC)3KinC.untyL’42X5SX)-l-- --4‘ID.1O1mia3zm2jLegend,,4tSelectedFeatures--.-Jrc;t-oiSÃOEtosbnAStreetsLakesandLargeR&ers--100YearFbodplainSÃOStreamSÃOWetisridCaI[:-SÃOLandslideCus2°ccnnSÃOCoalMineSÃO/VC-o) 4 TASK2RESOURCEREVIEW TASK2RESOURCEREVIEWAdoptedBasinPlansandFinalizedDrainageStudies:ThesiteislocatedintheMayCreekBasinPlan.BasinReconnaissanceSummaryReports:Noknownreportsareknowntoexist.CriticalDrainageAreaMaps:Thesiteisnotknowntobelocatedinanycriticaldrainageareas.(FEMA)Maps:Thesiteislocatedoutsidethe100yearfloodplain.OtherOffsiteAnalysisReports:ADrainageReportwaspreparedbyDickStuthfortheDalpayEstatesprojectlocatednorthwestofthisproject.SensitiveAreasFolio:Noneofthesiteislocatedinornearanysensitivearea(seesensitiveareasmapunderTask1).DNRDrainageProblemsMaps:Notapplicable.RoadDrainageProblems:Notapplicable.KingCountySoilsSurvey:Thesite’ssoilismostlyAlderwoodGravellySandyLoam,6to15percentslopes(AgC).TheextremesouthernportionofthesitecontainsAlderwoodGravellySandyLoam,15to30percentslopes(AgD).WetlandsInventoryMaps:Therearenowetlandslocatedonornearthesite.MigratingRiverStudies:Notapplicable.DrainageComplaints:AccordingtothelistofdrainagecomplaintsprovidedbyKingCounty,therewerenocomplaintsnearthedownstreamanalysistimitsofthisprojectthatarearesultofrunofffromthisproperty. TASK3FIELDINSPECTION TASK3FIELDINSPECTIONAfieldinspectionwasconductedonDecember3,2003toinspecttheonsitedrainagesystemofthesite.Offsitedrainagesystemswerealsoinspecteddownstreamapproximately1/4mile(s)fromthedischargepointofthesite.TheinspectioninvolvedinvestigationofthetenspecificitemsofaLevel1InspectionpertheKingCountySurfaceWaterDesignManual,1990.Theinspectionyieldedthefollowingfindings:1.Therewerenoexistingorpotentialproblemsobserved.2.Theexistingdrainagesystemcapacitywasadequate.3.Therewerenoexistingorpotentialfloodingproblems.4.Therewerenoexisting/potentialovertopping,sedimentation,scouringorbanksloughingproblems.5.Nosignificantdestructionofaquatichabitatororganismswasnoticeable.6.Qualitativedatasuchaslanduse,impervioussurfaces,topography,andsoiltypeswasnotedandcanbefoundinTask4information.7.Informationwascollectedonpipes,ditches,andstructures.ThisinformationisalsoincludedintheTask4information.8.TributarybasinsdelineatedinTask1wereverified.9.Noneighborswerecontacted.10.Theweatherconditionsatthetimeoftheinspectionwerecoolandcloudy. TASK4DRAINAGESYSTEMDESCRIPTIONANDPROBLEMDESCRIPTIONS TASK4DRAINAGESYSTEMDESCRIPTIONANDPROBLEMDESCRIPTIONSSiteDrainageThisprojectissoutheastoftheintersectionofNE19thStreetandRedmondAveNE.ItliesalongthesouthsideofNE19thStreet.Theparcel#is042305-9032.Thesiteisapproximately2.5acres.Thenorthernportionofthesiteconsistsofmostlyofgrassandscotchbroom.ThereisalargedetentionvaultlocatedinthenortheastportionoftheprojectthatwasdesignedtodetainthestormwaterfromthissiteandtheDalpayEstatesprojectnorthwestofthisproject.Thesouthernportionoftheprojectiscompletelyforestedwithmostlyevergreensandhasaravinethatrunsthroughit.Theexistingdrainagetendstosheetfiowtowardstheravine,whereitbecomesasmallstreamthatflowstowardNESunsetBoulevard.ThesmallstreamthenjoinsanotherstreamthatparallelsNESunsetBoulevard.Thesite’ssoilisanAlderwoodGravellySandyLoam(AgC)andisconsideredaTypeCsofl.OffsiteDrainageAnOff-SiteAnalysisDrainageSystemTableisprovidedonthenextpagethatdescribesindetailtheoffsitedrainagecomponentsatleast1%miledownstreamfromtheprojectdischargelocation.PleaserefertotheoffsitedrainagemapinTask1becausethemapsymbolslistedinthetablecorrespondtodrainagecomponentsymbolsontheoffsitedrainagemaps. C,)Co0iCDCDml—zøzOG)OmCDrn-ICDz1%)-I--l000 TASK5MITIGATIONOFEXISTINGORPOTENTIALPROBLEMS TASK5MITIGATIONOFEXISTINGORPOTENTIALPROBLEMSAfterathoroughfieldinspectionandadetailedresourcereviewtherewerenomajororexistingproblemsidentified.Theproposedimprovementswillnotproduceasignificantimpacttotheexistingdrainagepatternsoncethesitehasbeenstabilizedandtherunoffhasbeencontrolledviatheexistingdetentionvaultandcontrolstructureonsite.Atemporaryerosionandsedimentationcontrolplanwillbecreatedtominimizethetransportofsedimentladenrunofftothedownstreamconveyancesystempriortopermitissuance. Tab 4.0 17884.007.doc 4.0 FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN A. Existing Site Hydrology The existing 1.66-acre site is primarily covered with trees. The only exception to this is Lot 1, which was cleared with the original Dalpay Short Plat. There are no existing buildings on the site. Soils are Alderwood, which are considered to be "till" type soils. Based on site reconnaissance, available topography maps, and adjacent developments, there is no upstream contributing basin area as noted in Section 3.0. The natural discharge location for the site is the existing stream that discharges along the west boundary of the site. Please refer to the enclosed Existing Basin Area Map for a graphic depiction of the site topography and characteristics. 17884.007.doc B. Developed Site Hydrology In the developed condition, the site will contain three (3) residential lots with associated houses and driveways. An underground pipe conveyance system will be installed to convey stormwater runoff from the developed site (Lots 2 and 3) to a detention pond, then to the bottom of the hill at the natural discharge point. This facility has been designed to provide the required detention for Lots 2 and 3. The developed portion of the site located in the northwest corner of the site (Lot 1) will drain to the existing storm stub installed with the original Dalpay short plat. The Site has been analyzed as a whole to determine the change in runoff from the existing conditions to the developed conditions. The pond has been sized to minimize the change in runoff. The total increase in runoff from the site in the 100-year peak storm is approximately 0.0095 cfs. This is below the threshold increase of 0.15 cfs for the 100 year from Section 1.2.3.2.E.5 of the 2017 RSWDM for an exemption from further detention requirements. A drainage adjustment will be provided per section 1.4 of the RSWDM for this project to explain how this design provides the best practicable alternative for achieving the spirit and intent of the flow control requirements. Water quality facilities are not required for this project as the proposed Pollution Generating Impervious Surface (PGIS) for the entire project is less than 5,000 SF. The on-site tributary area to the proposed detention pond is approximately 0.434 acres per the enclosed Developed Basin Area Map. All runoff routed to this facility will be detained to meet flow control duration standard matching forested site conditions before being discharged to the stream. All disturbed pervious areas will use the Soil amendment BMP as outlined in the RSWM Section C.2.13 and are thus being modeled as pasture per that section. Proposed new pervious areas will implement the Soil Amendment BMP per the 2017 RSWDM Section C.2.13. Per that section, Areas meeting the design guidelines shall be entered into approved runoff models as “Pasture” rather than “Lawn. Please refer to the enclosed basin area map for a detailed breakdown of the on-site areas and land covers, as well as the calculations for the proposed detention pond. 17884.007.doc C. Performance Standards Based on the flow control application map located in the 2017 RSWDM, this project is located within a flow control duration matching forested site conditions area. A detention pond has been proposed to meet this flow control requirement. Based on the water quality application map located in the 2017 RSWDM, this project is located within a Basic Water Quality Treatment area. This project is proposing to add less than 5,000 square feet of new pollution-generating impervious area, so it is exempt from water quality requirements. 17884.007.doc D. Flow Control System The flow control facility in this site has been designed to conform to the standards in the 2017 RSWDM. According to Core Requirement #9: On-site BMPs in Section 1.2.9, “On- site BMPs must be selected and applied according to the basic requirements, procedures, and provisions detailed in this section and the design specifications for each BMP in Appendix C, Section C.2.” Large Lot BMP Requirements: According to Section 1.2.9.2.2, the following BMPs are required for lots/sites larger than 22,000 square feet when feasible: full dispersion, full infiltration, limited infiltration, rain gardens, bioretention, permeable pavement, Basic Dispersion, Reduced Impervious Surface Credit, Native growth retention credit, Tree Retention credit, Soil Amendment, and Perforated pipe connection. Full Dispersion: According to Appendix C, Section C.2.1, “Where geotechnical evaluation and approval is required for full dispersion that proposes to discharge towards or is within described setbacks of a steep slope hazard area, erosion hazard area, landslide hazard, or slopes greater than 15%, full dispersion is considered infeasible and not required.” Since Lots 2 and 3 all drain towards a steep slope erosion hazard area (see Earth Solutions NW (ESNW) report, Section 6.1), this BMP is infeasible. Full Infiltration: According to Appendix C, Section C.2.2, “Where geotechnical evaluation and approval is required for full infiltration that proposes to discharge towards or is within described setbacks of a steep slope hazard area, erosion hazard area, landslide hazard, or slopes greater than 15%, full infiltration is considered infeasible and not required” Since Lots 2 and 3 all drain towards a steep slope erosion hazard area (see ESNW report, Section 6.1), this BMP is infeasible. In addition, the in-situ soils have extremely low permeability that will not allow for infiltration. Limited Infiltration: According to Appendix C, Section C.2.3, “Where geotechnical evaluation and approval is required for limited infiltration that proposes to discharge towards or is within described setbacks of a steep slope hazard area, erosion hazard area, landslide hazard, or slopes greater than 15%, limited infiltration is considered infeasible and not required.” Since Lots 2 and 3 all drain towards a steep slope erosion hazard area (see ESNW report, Section 6.1), this BMP is infeasible. In addition, the in-situ soils have extremely low permeability that will not allow for infiltration. Bioretention: According to Appendix C, Section C.2.6, “Where the minimum design requirements call for geotechnical evaluation and approval for bioretention that proposes to discharge towards or is within described setbacks of a steep slope hazard area, erosion hazard area, landslide hazard, or slopes greater than 15%, bioretention is considered infeasible and not required.” Since Lots 2 and 3 all drain towards a steep slope erosion hazard area (see ESNW report, Section 6.1), this BMP is infeasible. In addition, the in-situ soils have extremely low permeability that will not allow for infiltration. Permeable Pavement: According to Appendix C, Section C.2.7, “Where the minimum design requirements call for geotechnical evaluation and approval for permeable pavement that proposes to discharge towards or is within described setbacks of a steep slope hazard area, erosion hazard area, landslide hazard, or slopes greater than 15%, permeable pavement is considered infeasible and not required.” Since Lots 2 and 3 all drain towards a steep slope erosion hazard area (see ESNW report, Section 6.1), this BMP is infeasible. Rain Gardens: Rain gardens have the same infeasibility criteria as bioretention according to Appendix C, Section C.2.12, so they are also infeasible. 17884.007.doc Basic Dispersion: According to Appendix C, Section C.2.4, “Where geotechnical evaluation and approval is required for basic dispersion that proposes to discharge towards or is within described setbacks of a steep slope hazard area, erosion hazard area, landslide hazard, or slopes greater than 15%, full dispersion is considered infeasible and not required.” Since Lots 2 and 3 all drain towards a steep slope erosion hazard area (see Earth Solutions NW (ESNW) report, Section 6.1), this BMP is infeasible. Reduced Impervious surface credit: This project will implement the Reduced Impervious Surface Credit according to the guidelines listed in Appendix C, Section C.2.9. The technique to be used for the Reduced Impervious Surface Credit will be Restricted Footprint, according to Section C.2.9.2. The maximum impervious surface allowed on each lot will be reduced from 70% to 50% in order to meet the minimum BMP implementation of 20% of the site as required in Section C.1.3.1.5. The roof downspouts will be connected to the storm system via perforated stub-out connections. Soil Amendment: This project will implement the Soil amendment BMP according to the guidelines listed in Appendix C, Section C.2.13. Implementation Options: The soil quality design guidelines listed in Section C.2.13.1 can be met by using one of the methods listed below: 1. Leave undisturbed native vegetation and soil, and protect from compaction during construction. 2. Amend existing site topsoil or subsoil either at default “pre-approved” rates, or at custom calculated rates based on tests of the soil and amendment. 3. Stockpile existing topsoil during grading, and replace it prior to planting. 4. Stockpiled topsoil must also be amended if needed to meet the organic matter or depth requirements, either at a default “pre-approved” rate or at a custom calculated rate. 5. Import topsoil mix of sufficient organic content and depth to meet the requirements. More than one method may be used on different portions of the same site. Soil that already meets the depth and organic matter quality standards, and is not compacted does not need to be amended. A detention pond has been proposed to provide flow control for this site. The stormwater will then be discharged to the existing on-site stream. Please refer to the enclosed WWHM calculations for further details on the sizing of this facility. As previously noted, the drainage facilities for the original Dalpay Short Plat located north of Lot 1 were sized to accommodate Lot 1. Therefore, no new facilities are proposed to accommodate the runoff from Lot 1. The Site has been analyzed as a whole to determine the change in runoff from the existing conditions to the developed conditions. The pond has been sized to minimize the change in runoff. The total increase in runoff from the site in the 100-year peak storm is approximately 0.0095 cfs. This is below the threshold increase of 0.15 cfs for the 100 year from Section 1.2.3.2.E.5 of the 2017 RSWDM for an exemption from further detention requirements. A drainage adjustment will be provided per section 1.4 of the RSWDM for this project to explain how this design provides the best practicable alternative for achieving the spirit and intent of the flow control requirements. WWHM2012 PROJECT REPORT STORMWATER CALCULATIONS BCE #17884 NOVEMBER 3, 2020 DALPAY SHORT PLAT 17884-Full Site Analysis-2020-11-03 11/3/2020 4:27:52 PM Page 2 General Model Information Project Name:17884-Full Site Analysis-2020-11-03 Site Name: Site Address: City: Report Date:11/3/2020 Gage:Seatac Data Start:1948/10/01 Data End:2009/09/30 Timestep:15 Minute Precip Scale:1.167 Version Date:2019/09/13 Version:4.2.17 POC Thresholds Low Flow Threshold for POC1:50 Percent of the 2 Year High Flow Threshold for POC1:50 Year 17884-Full Site Analysis-2020-11-03 11/3/2020 4:27:52 PM Page 3 Landuse Basin Data Predeveloped Land Use Basin 1 Bypass:No GroundWater:No Pervious Land Use acre C, Forest, Flat 0.434 Pervious Total 0.434 Impervious Land Use acre Impervious Total 0 Basin Total 0.434 Element Flows To: Surface Interflow Groundwater 17884-Full Site Analysis-2020-11-03 11/3/2020 4:27:52 PM Page 4 Basin 2 Bypass:No GroundWater:No Pervious Land Use acre C, Forest, Flat 0.177 Pervious Total 0.177 Impervious Land Use acre Impervious Total 0 Basin Total 0.177 Element Flows To: Surface Interflow Groundwater 17884-Full Site Analysis-2020-11-03 11/3/2020 4:27:52 PM Page 5 Basin 3 Bypass:No GroundWater:No Pervious Land Use acre C, Forest, Steep 1.049 Pervious Total 1.049 Impervious Land Use acre Impervious Total 0 Basin Total 1.049 Element Flows To: Surface Interflow Groundwater 17884-Full Site Analysis-2020-11-03 11/3/2020 4:27:52 PM Page 6 Mitigated Land Use Basin 1 Bypass:No GroundWater:No Pervious Land Use acre C, Pasture, Flat 0.282 Pervious Total 0.282 Impervious Land Use acre ROADS FLAT 0.05 ROADS MOD 0.01 ROOF TOPS FLAT 0.092 Impervious Total 0.152 Basin Total 0.434 Element Flows To: Surface Interflow Groundwater Trapezoidal Pond 1 Trapezoidal Pond 1 17884-Full Site Analysis-2020-11-03 11/3/2020 4:27:52 PM Page 7 Basin 2 Bypass:Yes GroundWater:No Pervious Land Use acre C, Pasture, Flat 0.1033 Pervious Total 0.1033 Impervious Land Use acre ROOF TOPS FLAT 0.0459 DRIVEWAYS FLAT 0.0278 Impervious Total 0.0737 Basin Total 0.177 Element Flows To: Surface Interflow Groundwater 17884-Full Site Analysis-2020-11-03 11/3/2020 4:27:52 PM Page 8 Basin 3 Bypass:Yes GroundWater:No Pervious Land Use acre C, Forest, Steep 1.049 Pervious Total 1.049 Impervious Land Use acre Impervious Total 0 Basin Total 1.049 Element Flows To: Surface Interflow Groundwater 17884-Full Site Analysis-2020-11-03 11/3/2020 4:27:52 PM Page 9 Routing Elements Predeveloped Routing 17884-Full Site Analysis-2020-11-03 11/3/2020 4:27:52 PM Page 10 Mitigated Routing Trapezoidal Pond 1 Bottom Length:25.00 ft. Bottom Width:25.00 ft. Depth:4.5 ft. Volume at riser head:0.1042 acre-feet. Side slope 1:3 To 1 Side slope 2:3 To 1 Side slope 3:3 To 1 Side slope 4:3 To 1 Discharge Structure Riser Height:3.5 ft. Riser Diameter:12 in. Orifice 1 Diameter:0.45 in.Elevation:0 ft. Orifice 2 Diameter:1.1 in.Elevation:2.5 ft. Element Flows To: Outlet 1 Outlet 2 Pond Hydraulic Table Stage(feet)Area(ac.)Volume(ac-ft.)Discharge(cfs)Infilt(cfs) 0.0000 0.014 0.000 0.000 0.000 0.0500 0.014 0.000 0.001 0.000 0.1000 0.015 0.001 0.001 0.000 0.1500 0.015 0.002 0.002 0.000 0.2000 0.015 0.003 0.002 0.000 0.2500 0.016 0.003 0.002 0.000 0.3000 0.016 0.004 0.003 0.000 0.3500 0.016 0.005 0.003 0.000 0.4000 0.017 0.006 0.003 0.000 0.4500 0.017 0.007 0.003 0.000 0.5000 0.018 0.008 0.003 0.000 0.5500 0.018 0.009 0.004 0.000 0.6000 0.018 0.009 0.004 0.000 0.6500 0.019 0.010 0.004 0.000 0.7000 0.019 0.011 0.004 0.000 0.7500 0.020 0.012 0.004 0.000 0.8000 0.020 0.013 0.004 0.000 0.8500 0.020 0.014 0.005 0.000 0.9000 0.021 0.015 0.005 0.000 0.9500 0.021 0.017 0.005 0.000 1.0000 0.022 0.018 0.005 0.000 1.0500 0.022 0.019 0.005 0.000 1.1000 0.022 0.020 0.005 0.000 1.1500 0.023 0.021 0.005 0.000 1.2000 0.023 0.022 0.006 0.000 1.2500 0.024 0.023 0.006 0.000 1.3000 0.024 0.025 0.006 0.000 1.3500 0.025 0.026 0.006 0.000 1.4000 0.025 0.027 0.006 0.000 1.4500 0.026 0.028 0.006 0.000 1.5000 0.026 0.030 0.006 0.000 1.5500 0.027 0.031 0.006 0.000 1.6000 0.027 0.032 0.007 0.000 1.6500 0.028 0.034 0.007 0.000 17884-Full Site Analysis-2020-11-03 11/3/2020 4:27:52 PM Page 11 1.7000 0.028 0.035 0.007 0.000 1.7500 0.028 0.037 0.007 0.000 1.8000 0.029 0.038 0.007 0.000 1.8500 0.029 0.040 0.007 0.000 1.9000 0.030 0.041 0.007 0.000 1.9500 0.030 0.043 0.007 0.000 2.0000 0.031 0.044 0.007 0.000 2.0500 0.031 0.046 0.007 0.000 2.1000 0.032 0.047 0.008 0.000 2.1500 0.033 0.049 0.008 0.000 2.2000 0.033 0.051 0.008 0.000 2.2500 0.034 0.052 0.008 0.000 2.3000 0.034 0.054 0.008 0.000 2.3500 0.035 0.056 0.008 0.000 2.4000 0.035 0.058 0.008 0.000 2.4500 0.036 0.059 0.008 0.000 2.5000 0.036 0.061 0.008 0.000 2.5500 0.037 0.063 0.016 0.000 2.6000 0.037 0.065 0.019 0.000 2.6500 0.038 0.067 0.021 0.000 2.7000 0.039 0.069 0.023 0.000 2.7500 0.039 0.071 0.025 0.000 2.8000 0.040 0.073 0.027 0.000 2.8500 0.040 0.075 0.028 0.000 2.9000 0.041 0.077 0.030 0.000 2.9500 0.041 0.079 0.031 0.000 3.0000 0.042 0.081 0.032 0.000 3.0500 0.043 0.083 0.033 0.000 3.1000 0.043 0.085 0.035 0.000 3.1500 0.044 0.088 0.036 0.000 3.2000 0.044 0.090 0.037 0.000 3.2500 0.045 0.092 0.038 0.000 3.3000 0.046 0.094 0.039 0.000 3.3500 0.046 0.097 0.040 0.000 3.4000 0.047 0.099 0.041 0.000 3.4500 0.047 0.101 0.042 0.000 3.5000 0.048 0.104 0.043 0.000 3.5500 0.049 0.106 0.162 0.000 3.6000 0.049 0.109 0.378 0.000 3.6500 0.050 0.111 0.650 0.000 3.7000 0.051 0.114 0.954 0.000 3.7500 0.051 0.116 1.264 0.000 3.8000 0.052 0.119 1.557 0.000 3.8500 0.053 0.122 1.811 0.000 3.9000 0.053 0.124 2.009 0.000 3.9500 0.054 0.127 2.151 0.000 4.0000 0.055 0.130 2.254 0.000 4.0500 0.055 0.132 2.387 0.000 4.1000 0.056 0.135 2.492 0.000 4.1500 0.057 0.138 2.592 0.000 4.2000 0.057 0.141 2.689 0.000 4.2500 0.058 0.144 2.782 0.000 4.3000 0.059 0.147 2.872 0.000 4.3500 0.059 0.150 2.959 0.000 4.4000 0.060 0.153 3.044 0.000 4.4500 0.061 0.156 3.127 0.000 4.5000 0.062 0.159 3.207 0.000 4.5500 0.062 0.162 3.286 0.000 17884-Full Site Analysis-2020-11-03 11/3/2020 4:27:52 PM Page 12 17884-Full Site Analysis-2020-11-03 11/3/2020 4:27:52 PM Page 13 Analysis Results POC 1 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area:1.66 Total Impervious Area:0 Mitigated Landuse Totals for POC #1 Total Pervious Area:1.4343 Total Impervious Area:0.2257 Flow Frequency Method:Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.087679 5 year 0.143626 10 year 0.185896 25 year 0.244763 50 year 0.292366 100 year 0.343044 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.100488 5 year 0.154157 10 year 0.19555 25 year 0.254772 50 year 0.304095 100 year 0.358038 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 0.113 0.140 1950 0.128 0.142 1951 0.162 0.170 1952 0.060 0.071 1953 0.048 0.056 1954 0.064 0.075 1955 0.116 0.113 1956 0.093 0.101 1957 0.089 0.112 1958 0.081 0.083 17884-Full Site Analysis-2020-11-03 11/3/2020 4:28:25 PM Page 14 1959 0.067 0.070 1960 0.135 0.154 1961 0.066 0.083 1962 0.048 0.055 1963 0.065 0.079 1964 0.084 0.092 1965 0.065 0.089 1966 0.053 0.069 1967 0.147 0.163 1968 0.074 0.091 1969 0.076 0.088 1970 0.065 0.089 1971 0.078 0.099 1972 0.130 0.136 1973 0.064 0.069 1974 0.075 0.096 1975 0.110 0.129 1976 0.075 0.092 1977 0.035 0.050 1978 0.067 0.078 1979 0.036 0.051 1980 0.206 0.216 1981 0.053 0.084 1982 0.144 0.172 1983 0.091 0.094 1984 0.059 0.069 1985 0.035 0.056 1986 0.144 0.138 1987 0.133 0.138 1988 0.057 0.062 1989 0.035 0.046 1990 0.366 0.361 1991 0.184 0.206 1992 0.073 0.086 1993 0.066 0.070 1994 0.027 0.040 1995 0.083 0.090 1996 0.202 0.212 1997 0.164 0.166 1998 0.066 0.088 1999 0.207 0.211 2000 0.066 0.083 2001 0.019 0.042 2002 0.099 0.121 2003 0.127 0.142 2004 0.165 0.186 2005 0.103 0.114 2006 0.096 0.102 2007 0.274 0.284 2008 0.300 0.303 2009 0.133 0.145 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.3660 0.3614 2 0.3001 0.3026 3 0.2737 0.2840 17884-Full Site Analysis-2020-11-03 11/3/2020 4:28:25 PM Page 15 4 0.2068 0.2160 5 0.2055 0.2121 6 0.2016 0.2107 7 0.1838 0.2055 8 0.1648 0.1857 9 0.1638 0.1720 10 0.1617 0.1700 11 0.1469 0.1655 12 0.1444 0.1627 13 0.1436 0.1544 14 0.1346 0.1453 15 0.1330 0.1423 16 0.1329 0.1419 17 0.1300 0.1405 18 0.1277 0.1382 19 0.1271 0.1377 20 0.1157 0.1365 21 0.1128 0.1289 22 0.1101 0.1214 23 0.1026 0.1137 24 0.0989 0.1134 25 0.0960 0.1122 26 0.0926 0.1017 27 0.0906 0.1014 28 0.0895 0.0987 29 0.0842 0.0957 30 0.0830 0.0943 31 0.0808 0.0924 32 0.0776 0.0916 33 0.0764 0.0914 34 0.0755 0.0905 35 0.0748 0.0891 36 0.0741 0.0887 37 0.0729 0.0884 38 0.0667 0.0876 39 0.0665 0.0861 40 0.0664 0.0843 41 0.0662 0.0830 42 0.0661 0.0827 43 0.0660 0.0827 44 0.0651 0.0794 45 0.0649 0.0779 46 0.0646 0.0751 47 0.0644 0.0715 48 0.0641 0.0698 49 0.0603 0.0695 50 0.0595 0.0693 51 0.0571 0.0693 52 0.0530 0.0685 53 0.0528 0.0619 54 0.0479 0.0560 55 0.0476 0.0557 56 0.0364 0.0548 57 0.0352 0.0512 58 0.0351 0.0502 59 0.0349 0.0456 60 0.0265 0.0421 61 0.0185 0.0397 17884-Full Site Analysis-2020-11-03 11/3/2020 4:28:25 PM Page 16 17884-Full Site Analysis-2020-11-03 11/3/2020 4:28:25 PM Page 17 Duration Flows Flow(cfs)Predev Mit Percentage Pass/Fail 0.0438 12339 12414 100 Pass 0.0463 10812 10797 99 Pass 0.0489 9567 9430 98 Pass 0.0514 8425 8305 98 Pass 0.0539 7463 7313 97 Pass 0.0564 6675 6470 96 Pass 0.0589 5987 5736 95 Pass 0.0614 5366 5155 96 Pass 0.0639 4800 4605 95 Pass 0.0664 4299 4179 97 Pass 0.0689 3953 3788 95 Pass 0.0715 3610 3429 94 Pass 0.0740 3302 3125 94 Pass 0.0765 3018 2832 93 Pass 0.0790 2748 2558 93 Pass 0.0815 2481 2304 92 Pass 0.0840 2231 2117 94 Pass 0.0865 1986 1906 95 Pass 0.0890 1796 1713 95 Pass 0.0915 1630 1554 95 Pass 0.0940 1474 1414 95 Pass 0.0966 1353 1288 95 Pass 0.0991 1229 1188 96 Pass 0.1016 1110 1081 97 Pass 0.1041 1021 1002 98 Pass 0.1066 937 943 100 Pass 0.1091 878 870 99 Pass 0.1116 816 806 98 Pass 0.1141 748 738 98 Pass 0.1166 698 676 96 Pass 0.1192 639 621 97 Pass 0.1217 591 566 95 Pass 0.1242 544 528 97 Pass 0.1267 495 474 95 Pass 0.1292 439 416 94 Pass 0.1317 386 369 95 Pass 0.1342 338 326 96 Pass 0.1367 288 294 102 Pass 0.1392 246 264 107 Pass 0.1417 210 237 112 Fail 0.1443 175 208 118 Fail 0.1468 159 184 115 Fail 0.1493 131 164 125 Fail 0.1518 112 149 133 Fail 0.1543 96 132 137 Fail 0.1568 76 114 150 Fail 0.1593 64 94 146 Fail 0.1618 55 79 143 Fail 0.1643 53 66 124 Fail 0.1668 49 56 114 Fail 0.1694 47 52 110 Pass 0.1719 46 48 104 Pass 0.1744 45 44 97 Pass 0.1769 41 43 104 Pass 17884-Full Site Analysis-2020-11-03 11/3/2020 4:28:25 PM Page 18 0.1794 38 43 113 Fail 0.1819 33 40 121 Fail 0.1844 31 36 116 Fail 0.1869 28 28 100 Pass 0.1894 23 24 104 Pass 0.1920 20 24 120 Fail 0.1945 18 22 122 Fail 0.1970 16 19 118 Fail 0.1995 14 17 121 Fail 0.2020 9 15 166 Fail 0.2045 9 12 133 Fail 0.2070 6 11 183 Fail 0.2095 6 10 166 Fail 0.2120 6 9 150 Fail 0.2145 6 8 133 Fail 0.2171 6 7 116 Fail 0.2196 6 6 100 Pass 0.2221 6 6 100 Pass 0.2246 6 6 100 Pass 0.2271 6 6 100 Pass 0.2296 6 6 100 Pass 0.2321 6 6 100 Pass 0.2346 6 6 100 Pass 0.2371 5 6 120 Fail 0.2396 5 6 120 Fail 0.2422 5 5 100 Pass 0.2447 4 5 125 Fail 0.2472 4 5 125 Fail 0.2497 4 5 125 Fail 0.2522 4 4 100 Pass 0.2547 4 4 100 Pass 0.2572 4 4 100 Pass 0.2597 4 4 100 Pass 0.2622 4 4 100 Pass 0.2648 4 4 100 Pass 0.2673 4 4 100 Pass 0.2698 4 4 100 Pass 0.2723 4 4 100 Pass 0.2748 3 4 133 Fail 0.2773 3 4 133 Fail 0.2798 3 4 133 Fail 0.2823 3 4 133 Fail 0.2848 3 3 100 Pass 0.2873 2 2 100 Pass 0.2899 2 2 100 Pass 0.2924 2 2 100 Pass The development has an increase in flow durations from 1/2 Predeveloped 2 year flow to the 2 year flow or more than a 10% increase from the 2 year to the 50 year flow. 17884-Full Site Analysis-2020-11-03 11/3/2020 4:28:25 PM Page 19 Water Quality Water Quality BMP Flow and Volume for POC #1 On-line facility volume:0 acre-feet On-line facility target flow:0 cfs. Adjusted for 15 min:0 cfs. Off-line facility target flow:0 cfs. Adjusted for 15 min:0 cfs. 17884-Full Site Analysis-2020-11-03 11/3/2020 4:28:25 PM Page 20 LID Report 17884-Full Site Analysis-2020-11-03 11/3/2020 4:28:49 PM Page 21 Model Default Modifications Total of 0 changes have been made. PERLND Changes No PERLND changes have been made. IMPLND Changes No IMPLND changes have been made. 17884-Full Site Analysis-2020-11-03 11/3/2020 4:28:49 PM Page 22 Appendix Predeveloped Schematic 17884-Full Site Analysis-2020-11-03 11/3/2020 4:28:49 PM Page 23 Mitigated Schematic 17884-Full Site Analysis-2020-11-03 11/3/2020 4:28:50 PM Page 24 Predeveloped UCI File 17884-Full Site Analysis-2020-11-03 11/3/2020 4:28:50 PM Page 25 Mitigated UCI File 17884-Full Site Analysis-2020-11-03 11/3/2020 4:28:50 PM Page 26 Predeveloped HSPF Message File 17884-Full Site Analysis-2020-11-03 11/3/2020 4:28:50 PM Page 27 Mitigated HSPF Message File 17884-Full Site Analysis-2020-11-03 11/3/2020 4:28:50 PM Page 28 Disclaimer Legal Notice This program and accompanying documentation are provided 'as-is' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by End User. Clear Creek Solutions Inc. and the governmental licensee or sublicensees disclaim all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions Inc. be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions Inc. or their authorized representatives have been advised of the possibility of such damages. Software Copyright © by : Clear Creek Solutions, Inc. 2005-2020; All Rights Reserved. Clear Creek Solutions, Inc. 6200 Capitol Blvd. Ste F Olympia, WA. 98501 Toll Free 1(866)943-0304 Local (360)943-0304 www.clearcreeksolutions.com Tab 5.0 17884.007.doc 5.0 CONVEYANCE SYSTEM ANALYSIS AND DESIGN This section contains the typical calculations necessary for the sizing of the pipe facilities proposed on this project. The Rational Method and Manning's Formula will be used for sizing purposes. Conveyance pipes were sized to accommodate the 100-year storm event at a flowing full condition. 17884-100-year-conv.xlsBARGHAUSEN CONSULTING ENGINEERS - PIPE FLOW CALCULATORusing the Rational Method & Manning FormulaKING COUNTY DESIGN FOR 100YEAR STORMJOB NAME:Dalpay Short Plat NOTE: ENTER DEFAULTS AND STORM DATA BEFORE BEGINNING JOB#:17884 DEFAULTS C=0.6n=0.012FILE NO.:17884-100-year-conv d=12Tc=6.3A= Contributing Area (Ac)Qd= Design Flow (cfs)COEFFICIENTS FOR THE RATIONAL METHOD "Ir"-EQUATIONC= Runoff Coefficient Qf= Full Capacity Flow (cfs)STORMAr BrTc= Time of Concentration (min)Vd= Velocity at Design Flow (fps)2YR1.580.58I= Intensity at Tc (in/hr) Vf= Velocity at Full Flow (fps)10YR 2.44 0.64PRECIP=4d= Diameter of Pipe (in) s= Slope of pipe (%)25YR 2.66 0.65Ar=2.61L= Length of Pipe (ft)n= Manning Roughness Coefficient50YR2.750.65Br=0.63D= Water Depth at Qd (in)Tt= Travel Time at Vd (min)100YR2.610.63FROM TO A s Ld Tc n CSUM AA*CSUM A*C I Qd QfQd/QfD/d D Vf VdTt====== ====== ====== ====== ================== ====== ============ ===================== ====== ====== ====== ====== ====== ====== ====== ======CB4 CB3 0.43 11.19 418 6.3 0.012 0.60.4340.260.26 3.27 0.85 4.380.1950.296 2.37 12.55 9.660.07CB3 POND 0.00 4.56 228 6.4 0.012 0.60.4340.000.26 3.25 0.85 2.790.3030.376 3.01 8.01 7.010.05POND CB2 0.00 0.50 118 6.4 0.012 0.60.4340.000.26 3.23 0.84 0.930.9100.743 5.95 2.65 3.000.06CB2 CB1 0.00 0.50 98 6.5 0.012 0.60.4340.000.26 3.22 0.84 0.930.9050.740 5.92 2.65 3.000.05CB1 DAYLIGHT 0.00 0.50 648 6.5 0.012 0.60.4340.000.26 3.20 0.83 0.930.9000.737 5.90 2.65 3.000.36DAYLIGHT 0.00 33.00 158 6.9 0.012 0.60.4340.000.26 3.09 0.81 7.520.1070.222 1.78 21.55 13.970.020.00 45.00 108 6.9 0.012 0.60.4340.000.26 3.09 0.80 8.780.0920.202 1.62 25.17 15.340.01OUTLET 0.00 57.00 158 6.9 0.012 0.60.4340.000.26 3.09 0.80 9.880.0810.191 1.53 28.33 16.150.02Page 1 SECTION 5.1 DETENTION FACILITIES Riser Overflow The nomograph in Figure 5.1.4.H may be used to determine the head (in feet) above a riser of given diameter and for a given flow (usually the 100-year peak flow for developed conditions). FIGURE 5.1.4.H RISER INFLOW CURVES 1 10 100 0.1 1 10HEAD IN FEET (measured from crest of riser) Qweir=9.739 DH3/2 Qorifice=3.782 D2H1/2 Q in cfs, D and H in feet Slope change occurs at weir-orifice transition Q (cubic feet per second)18 21 24 27 30 42 487254 10 12 15 33 36 RISER DIAMETER (inches) 4/24/2016 2016 Surface Water Design Manual 5-34 Developed 100yr Peak Flow to Tract B=0.19 CFS DALPAY SHORT PLAT - BCE # 17884 CB#1A - 12" RISER OVERFLOW CALCULATIONS 0.35' Head SECTION 5.1 DETENTION FACILITIES Riser Overflow The nomograph in Figure 5.1.4.H may be used to determine the head (in feet) above a riser of given diameter and for a given flow (usually the 100-year peak flow for developed conditions). FIGURE 5.1.4.H RISER INFLOW CURVES 1 10 100 0.1 1 10HEAD IN FEET (measured from crest of riser) Qweir=9.739 DH3/2 Qorifice=3.782 D2H1/2 Q in cfs, D and H in feet Slope change occurs at weir-orifice transition Q (cubic feet per second)18 21 24 27 30 42 487254 10 12 15 33 36 RISER DIAMETER (inches) 4/24/2016 2016 Surface Water Design Manual 5-34 Developed 100yr Peak Flow to Tract B=0.19 CFS DALPAY SHORT PLAT - BCE # 17884 CB#1 - RISER OVERFLOW CALCULATIONS 0.13' Head Tab 6.0 17884.007.doc 6.0 SPECIAL REPORTS AND STUDIES The following special reports and studies are included: 6.1 Geotechnical Engineering Study for Dalpay Short Plat prepared by Earth Solutions NW, LLC dated December 23, 2015 6.2 Geotechnical Addendum for Dalpay Short Plat prepared by Earth Solutions NW, LLC dated February 13, 2017 6.3 Response to Review Comments for Dalpay Short Plat prepared by Earth Solutions NW, LLC dated February 21, 2018 6.4 Response to Review Comments for Proposed Dalpay Short Plat by Earth Solutions NW, LLC dated October 8, 2019 Geotechnical Engineering Study by Earth Solutions NW, LLC dated December 13, 2015 6.1 EarthSolutionsNWLLC EarthSolutionsNWLLC Geotechnical Engineering Geology Environmental Scientists Construction Monitoring 1805 -136th Place N.E.,Suite 201 Bellevue,WA 98005 (425)449-4704 Fax (425)449-4711 www.earthsolutionsnw.com GEOTECHNICAL ENGINEERING STUDY DALPAY SHORT PLAT REDMOND COURT NORTHEAST RENTON,WASHINGTON ES-4208 2005 2015 Drwn. Checked Date Date Proj.No. Plate Earth Solutions NWLLC Geotechnical Engineering,Construction Monitoring EarthSolutionsNWLLC EarthSolutionsNWLLC and Environmental Sciences Vicinity Map Dalpay Short Plat Renton,Washington MRS TJM 12/09/2015 Dec.2015 4208 1 NORTH NOTE:This plate may contain areas of color.ESNW cannot be responsible for any subsequent misinterpretation of the information resulting from black &white reproductions of this plate. Reference: King County,Washington Map 626 By The Thomas Guide Rand McNally 32nd Edition SITE Plate Proj.No. Date Checked By Drwn.ByEarthSolutionsNWLLCGeotechnicalEngineering,ConstructionMonitoringandEnvironmentalSciencesEarthSolutionsNWLLCEarthSolutionsNWLLCTestPitLocationPlanDalpayShortPlatRenton,WashingtonMRS TJM 12/09/2015 4208 2NORTH03060120 Scale in Feet1"=60' NOTE:This plate may contain areas of color.ESNW cannot be responsible for any subsequent misinterpretation of the information resulting from black &white reproductions of this plate. NOTE:The graphics shown on this plate are not intended for design purposes or precise scale measurements,but only to illustrate the approximate test locations relative to the approximate locations of existing and /or proposed site features.The information illustrated is largely based on data provided by the client at the time of our study.ESNW cannot be responsible for subsequent design changes or interpretation of the data by others. LEGEND Approximate Location of ESNW Test Pit,Proj.No. ES-4208,Nov.2015 Subject Site REDMOND COURT N.E. TP-1 TP-2 TP-3 TP-4 RE DMOND PLACE N.E.N.E.19THSTREETVeldyke II Short Plat Lot 1 Lot 2 Lot 3 Lot 4 380 390 400 410 420 380390 400 410 420 390 390 410 410 Rockery TP-1 Drwn. Checked Date Date Proj.No. Plate Earth Solutions NWLLC Geotechnical Engineering,Construction MonitoringandEnvironmentalSciences EarthSolutionsNWLLC EarthSolutionsNWLLC RETAINING WALL DRAINAGE DETAIL Dalpay Short Plat Renton,Washington MRS TJM 12/10/2015 Dec.2015 4208 3 NOTES: Free Draining Backfill should consist of soil having less than 5 percent fines. Percent passing #4 should be 25 to 75 percent. Sheet Drain may be feasible in lieu of Free Draining Backfill,per ESNW recommendations. Drain Pipe should consist of perforated, rigid PVC Pipe surrounded with 1" Drain Rock. LEGEND: Free Draining Structural Backfill 1 inch Drain Rock 18"Min. Structural Fill Perforated Drain Pipe (Surround In Drain Rock) SCHEMATIC ONLY -NOT TO SCALE NOT A CONSTRUCTION DRAWING Drwn. Checked Date Date Proj.No. Plate Earth Solutions NWLLC Geotechnical Engineering,Construction Monitoring and Environmental Sciences EarthSolutionsNWLLC EarthSolutionsNWLLC FOOTING DRAIN DETAIL Slope Perforated Rigid Drain Pipe (Surround with 1"Rock) 18"(Min.) NOTES: Do NOT tie roof downspouts to Footing Drain. Surface Seal to consist of 12"of less permeable,suitable soil.Slope away from building. LEGEND: Surface Seal;native soil or other low permeability material. 1"Drain Rock SCHEMATIC ONLY -NOT TO SCALE NOT A CONSTRUCTION DRAWING Dalpay Short Plat Renton,Washington MRS TJM 12/10/2015 Dec.2015 4208 4 Geotechnical Addendum by Earth Solutions NW, LLC dated February 13, 2017 6.2 Response to Review Comments by Earth Solutions NW, LLC dated February 21, 2018 6.3 Response to Review Comments by Earth Solutions NW, LLC dated October 8, 2018 6.4 Tab 7.0 17884.007.doc 7.0 OTHER PERMITS The City of Renton will be the governing body for the roadway, grading, and storm drainage construction of the project. A building permit and grading permit will be required for the construction of the proposed improvements. Other anticipated permits and information that will be required for the project are listed below: Postmaster / Mailbox Location Approval Fire Marshal / Fire Hydrant Location Approval Water Availability Certificate Sewer Availability Certificate Construction Stormwater General Permit (Department of Ecology) Forest Practices Permit (Department of Natural Resources) Tab 8.0 17884.007.doc 8.0 CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN ANALYSIS AND DESIGN A. Erosion and Sediment Control (ESC) Plan Analysis and Design The erosion and sediment control plans for the Dalpay Short Plat were prepared in accordance with the 2017 RSWDM and will comply with standard industry practices throughout the construction process to limit the amount of sediment traveling into the downstream storm drainage systems. Temporary sediment traps will be constructed to provide sediment retention on site before discharging into the ground. The site's runoff will be conveyed from the roads and lot areas via temporary V-ditches with rock checkdams or sheet flow to the temporary sediment traps. Additional BMPs will be proposed as necessary and will include rocked construction entrances, silt fencing where needed, straw mulch for the areas that reach final grade in the lot areas, and hydroseeding. Clearing limits will be established per the final construction plans. The temporary sediment traps will trap sediment prior to any discharge off site. Due to site topography and soil type, there is a risk for erosion. Standard erosion control measures noted in this section should be sufficient to control erosion and prevent sediment from leaving the site. Silt fence will be installed at all locations where sediment-laden runoff may potentially leave the site. Cover measures shall be provided by the contractor when necessary on stockpiled material and all disturbed areas. Temporary cover shall be installed if an area is to remain unworked for more than seven (7) days during the dry season (May 1 to September 30) or for more than two (2) days during the wet season (October 1 to April 30). During the wet season the contractor shall stockpile material necessary to cover all disturbed areas. Slopes and stockpiles 3H:1V or steeper with more than 10 feet of vertical relief shall be covered if they are to remain unworked for more than 12 hours. All disturbed areas will be paved, covered with a house, or landscaped with grass, shrubbery, or trees pursuant to the development plans to provide permanent erosion control. 17884.007.doc B. Stormwater Pollution Prevention and Spill Control (SWPPS) Plan The Temporary Erosion and Sedimentation Control (TESC) analysis and design complies with the 2017 RSWDM. The TESC elements are addressed as follows: Clearing Limits: The clearing limits will be shown on the final engineering plans and will be flagged in the field. The project is proposing to save existing trees where possible on the site. Cover Measures: Cover measures will be added in the TESC notes and on the final engineering plans. Perimeter Protection: Perimeter protection will be shown on the engineering plans (silt fencing). Traffic Area Stabilization: A stabilized gravel construction entrance will be shown on the engineering plans. Sediment Retention: Temporary sediment ponds will be proposed on the final construction plans to retain sediment on site. Surface Water Control: Interceptor ditches will be shown on the final engineering plans and will be implemented if needed. Dust Control: Dust will be controlled by water trucks if necessary. Wet Season Construction: Construction will be conducted according to the City of Renton standards during the wet season. Construction within Sensitive Areas and Buffers: There is an existing Native Growth Protection Easement (NGPE) on the site for steep slopes and a creek. The project is not proposing any construction in this area. Maintenance: Maintenance requirements will be detailed in the TESC notes on the final engineering plans. Final Stabilization: Upon completion of the project, all disturbed areas will be stabilized and Best Management Practices removed if appropriate. IN COMPLIANCE WITH CITY OF RENTON STANDARDSDALPAY SHORT PLATDALPAY PROPERTIES, LLC.4033 N.E. SUNSET BOULEVARDRENTON, WA 98059DALPAY SHORT PLAT DALPAY SHORT PLAT DALPAY SHORT PLATTED-40-4097 TESC AND SWPPS PLANC3 “” “” R-409703 Tab 9.0 17884.007.doc 9.0 BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT This section contains the following items: 9.1 Bond Quantity Worksheet 9.2 Stormwater Facility Summary Sheet 9.3 Declaration of Covenant for Inspection and Maintenance of Drainage Facilities and On- Site BMPs Bond Quantity Worksheet9.1 Planning Division |1055 South Grady Way – 6th Floor | Renton, WA 98057 (425) 430-7200••Section I: Project Information•••Section II: Bond Quantities Worksheets••Section II.a EROSION CONTROL (Stabilization/Erosion Sediment Control (ESC))•Section II.b TRANSPORTATION (Street and Site Improvements)•Section II.c DRAINAGE (Drainage and Stormwater Facilities): •Section II.d WATER - ONLY APPLICABLE IF WATER SERVICE IS PROVIDED BY CITY OF RENTON•Section II.e SANITARY SEWER - ONLY APPLICABLE IF SEWER SERVICE IS PROVIDED BY CITY OF RENTON••••••Section III. Bond Worksheet• This section calculates the required Permit Bond for construction permit issuance as well as the required Maintenance Bond for project close-out submittals to release the permit bond on a project. All unit prices include labor, equipment, materials, overhead and profit. Complete the 'Quantity' columns for each of the appropriate section(s). Include existing Right-of-Way (ROW), Future Public Improvements and Private Improvements.The 'Quantity Remaining' column is only to be used when a project is under construction. The City allows one (1) bond reduction during the life of the project with the exception of the maintenance period reduction.Excel will auto-calculate and auto-populate the relevant fields and subtotals throughout the document. Only the 'Quantity' columns should need completing.Additional items not included in the lists can be added under the "write-in" sections. Provide a complete description, cost estimate and unit of measure for each write-in item. Note: Private improvements, with the exception of stormwater facilities, are not included in the bond amount calculation, but must be entered on the form. Stormwater facilities (public and private) are required to be included in the bond amount.BOND QUANTITY WORKSHEET INSTRUCTIONSThis worksheet is intended to be a "working" copy of the bond quantity worksheet, which will be used throughout all phases of the project, from initial submittal to project close-out approval. Submit this workbook, in its entirety, as follows:The following forms are to be completed by the engineer/developer/applicant as applicable to the project: The Bond Worksheet form will auto-calculate and auto-populate from the information provided in Section I and Section II.This section includes all pertinent information for the projectSection II contains a separate spreadsheet TAB for each of the following specialties: (1) electronic copy (.xlsx format) and (1) hard copy of the entire workbook for civil construction permit submittal. Hard copies are to be included as part of the Technical Information Report (TIR).(1) electronic copy (.xlsx format) and (1) hard copy of the entire workbook for final close-out submittal.This section must be completed in its entiretyInformation from this section auto-populates to all other relevant areas of the workbookPage 1 of 14Ref 8-H Bond Quantity WorksheetINSTRUCTIONSUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 2/11/2020 Planning Division |1055 South Grady Way – 6th Floor | Renton, WA 98057 (425) 430-7200Date Prepared: Name:PE Registration No:Firm Name:Firm Address:Phone No.Email Address:Project Name: Project Owner:CED Plan # (LUA):Phone:CED Permit # (U):Address: Site Address:Street Intersection:Addt'l Project Owner:Parcel #(s):Phone:Address: Clearing and grading greater than or equal to 5,000 board feet of timber? Yes/No:NOWater Service Provided by:If Yes, Provide Forest Practice Permit #:Sewer Service Provided by: SITE IMPROVEMENT BOND QUANTITY WORKSHEETPROJECT INFORMATIONCITY OF RENTONCITY OF RENTON1 Select the current project status/phase from the following options: For Approval - Preliminary Data Enclosed, pending approval from the City; For Construction - Estimated Data Enclosed, Plans have been approved for contruction by the City; Project Closeout - Final Costs and Quantities Enclosed for Project Close-out SubmittalEngineer Stamp Required (all cost estimates must have original wet stamp Clearing and GradingUtility ProvidersN/AProject Location and DescriptionProject Owner InformationDalpay Short PlatRenton, WA 98056042305-9032Dalpay and AssociatesLUA-17000234206-399-6302Date 2-11-20Prepared by:FOR APPROVALProject Phase 1ddawes@barghausen.comDon E. Dawes, P.E, Senior Project EngineerPE Registration No. 42009Barghausen Consulting Engineers, Inc.18215 72nd Avenue South, Kent, WA 98032425-251-622218XX Redmond Place N.E.PO Box 2436N.E. 19th StreetAbbreviated Legal Description:A portion of the NE quarter of the SE 1/4 of Section 4, Township 23 North, Range 5 East, Willamette Meridian, City of Renton, King County, Washington.Page 2 of 14Ref 8-H Bond Quantity WorksheetSECTION I PROJECT INFORMATIONUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 2/11/20202-11-20 CED Permit #:UnitReference #PriceUnitQuantity CostBackfill & compaction-embankmentESC-16.50$ CY Check dams, 4" minus rockESC-2SWDM 5.4.6.380.00$ Each7560.00Catch Basin ProtectionESC-335.50$ Each271.00Crushed surfacing 1 1/4" minusESC-4WSDOT 9-03.9(3)95.00$ CY DitchingESC-59.00$ CY Excavation-bulkESC-62.00$ CY Fence, siltESC-7SWDM 5.4.3.11.50$ LF450675.00Fence, Temporary (NGPE)ESC-81.50$ LF500750.00Geotextile FabricESC-92.50$ SY Hay Bale Silt TrapESC-100.50$ Each HydroseedingESC-11SWDM 5.4.2.40.80$ SY19911,592.80Interceptor Swale / DikeESC-121.00$ LF230230.00Jute MeshESC-13SWDM 5.4.2.23.50$ SY Level SpreaderESC-141.75$ LF Mulch, by hand, straw, 3" deepESC-15SWDM 5.4.2.12.50$ SY Mulch, by machine, straw, 2" deepESC-16SWDM 5.4.2.12.00$ SY19913,982.00Piping, temporary, CPP, 6"ESC-1712.00$ LF Piping, temporary, CPP, 8"ESC-1814.00$ LF Piping, temporary, CPP, 12"ESC-1918.00$ LF Plastic covering, 6mm thick, sandbaggedESC-20SWDM 5.4.2.34.00$ SY Rip Rap, machine placed; slopesESC-21WSDOT 9-13.1(2)45.00$ CY Rock Construction Entrance, 50'x15'x1'ESC-22SWDM 5.4.4.11,800.00$ Each11,800.00Rock Construction Entrance, 100'x15'x1'ESC-23SWDM 5.4.4.13,200.00$ Each Sediment pond riser assemblyESC-24SWDM 5.4.5.22,200.00$ Each Sediment trap, 5' high berm ESC-25SWDM 5.4.5.119.00$ LF Sed. trap, 5' high, riprapped spillway berm section ESC-26SWDM 5.4.5.170.00$ LF Seeding, by handESC-27SWDM 5.4.2.41.00$ SY Sodding, 1" deep, level groundESC-28SWDM 5.4.2.58.00$ SY Sodding, 1" deep, sloped groundESC-29SWDM 5.4.2.510.00$ SY TESC SupervisorESC-30110.00$ HR8880.00Water truck, dust controlESC-31SWDM 5.4.7140.00$ HR81,120.00UnitReference #PriceUnitQuantity Cost EROSION/SEDIMENT SUBTOTAL:11,660.80SALES TAX @ 10%1,166.08EROSION/SEDIMENT TOTAL:12,826.88(A)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR EROSION & SEDIMENT CONTROLDescription No.(A)WRITE-IN-ITEMS Page 3 of 14Ref 8-H Bond Quantity WorksheetSECTION II.a EROSION_CONTROLUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 2/11/2020 CED Permit #:ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostGENERAL ITEMS Backfill & Compaction- embankmentGI-16.00$ CY80480.00Backfill & Compaction- trenchGI-29.00$ CYClear/Remove Brush, by hand (SY)GI-31.00$ SYBollards - fixedGI-4240.74$ EachBollards - removableGI-5452.34$ EachClearing/Grubbing/Tree RemovalGI-610,000.00$ AcreExcavation - bulkGI-72.00$ CY13002,600.00Excavation - TrenchGI-85.00$ CYFencing, cedar, 6' highGI-920.00$ LFFencing, chain link, 4'GI-1038.31$ LF2509,577.50Fencing, chain link, vinyl coated, 6' highGI-1120.00$ LFFencing, chain link, gate, vinyl coated, 20' GI-121,400.00$ EachFill & compact - common barrowGI-1325.00$ CYFill & compact - gravel baseGI-1427.00$ CYFill & compact - screened topsoilGI-1539.00$ CYGabion, 12" deep, stone filled mesh GI-1665.00$ SYGabion, 18" deep, stone filled mesh GI-1790.00$ SYGabion, 36" deep, stone filled meshGI-18150.00$ SYGrading, fine, by handGI-192.50$ SYGrading, fine, with graderGI-202.00$ SY320640.00Monuments, 3' LongGI-21250.00$ EachSensitive Areas SignGI-227.00$ EachSodding, 1" deep, sloped groundGI-238.00$ SYSurveying, line & gradeGI-24850.00$ DaySurveying, lot location/linesGI-251,800.00$ AcreTopsoil Type A (imported)GI-2628.50$ CYTraffic control crew ( 2 flaggers )GI-27120.00$ HRTrail, 4" chipped woodGI-288.00$ SYTrail, 4" crushed cinderGI-299.00$ SYTrail, 4" top courseGI-3012.00$ SYConduit, 2"GI-315.00$ LFWall, retaining, concreteGI-3255.00$ SFWall, rockeryGI-3315.00$ SFSUBTOTAL THIS PAGE:13,297.50(B)(C)(D)(E)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR STREET AND SITE IMPROVEMENTSQuantity Remaining (Bond Reduction) (B) (C)Page 4 of 14Ref 8-H Bond Quantity WorksheetSECTION II.b TRANSPORTATIONUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 2/11/2020 CED Permit #:ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostSITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR STREET AND SITE IMPROVEMENTSQuantity Remaining (Bond Reduction) (B) (C)ROAD IMPROVEMENT/PAVEMENT/SURFACINGAC Grinding, 4' wide machine < 1000syRI-130.00$ SYAC Grinding, 4' wide machine 1000-2000syRI-216.00$ SYAC Grinding, 4' wide machine > 2000syRI-310.00$ SYAC Removal/DisposalRI-435.00$ SY10350.00Barricade, Type III ( Permanent )RI-556.00$ LFGuard RailRI-630.00$ LFCurb & Gutter, rolledRI-717.00$ LFCurb & Gutter, verticalRI-812.50$ LFCurb and Gutter, demolition and disposalRI-918.00$ LFCurb, extruded asphaltRI-105.50$ LFCurb, extruded concreteRI-117.00$ LFSawcut, asphalt, 3" depthRI-121.85$ LF2037.00Sawcut, concrete, per 1" depthRI-133.00$ LFSealant, asphaltRI-142.00$ LF2040.00Shoulder, gravel, 4" thickRI-1515.00$ SYSidewalk, 4" thickRI-1638.00$ SYSidewalk, 4" thick, demolition and disposalRI-1732.00$ SYSidewalk, 5" thickRI-1841.00$ SYSidewalk, 5" thick, demolition and disposalRI-1940.00$ SYSign, Handicap RI-2085.00$ EachStriping, per stallRI-217.00$ EachStriping, thermoplastic, ( for crosswalk )RI-223.00$ SFStriping, 4" reflectorized lineRI-230.50$ LFAdditional 2.5" Crushed SurfacingRI-243.60$ SYHMA 1/2" Overlay 1.5" RI-2514.00$ SYHMA 1/2" Overlay 2"RI-2618.00$ SYHMA Road, 2", 4" rock, First 2500 SYRI-2728.00$ SY3208,960.00HMA Road, 2", 4" rock, Qty. over 2500SYRI-2821.00$ SYHMA Road, 4", 6" rock, First 2500 SYRI-2945.00$ SYHMA Road, 4", 6" rock, Qty. over 2500 SYRI-3037.00$ SYHMA Road, 4", 4.5" ATBRI-3138.00$ SYGravel Road, 4" rock, First 2500 SYRI-3215.00$ SYGravel Road, 4" rock, Qty. over 2500 SYRI-3310.00$ SYThickened EdgeRI-348.60$ LF50430.00SUBTOTAL THIS PAGE:9,817.00(B)(C)(D)(E)Page 5 of 14Ref 8-H Bond Quantity WorksheetSECTION II.b TRANSPORTATIONUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 2/11/2020 CED Permit #:ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostSITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR STREET AND SITE IMPROVEMENTSQuantity Remaining (Bond Reduction) (B) (C)PARKING LOT SURFACINGNo.2" AC, 2" top course rock & 4" borrowPL-121.00$ SY2" AC, 1.5" top course & 2.5" base coursePL-228.00$ SY4" select borrowPL-35.00$ SY1.5" top course rock & 2.5" base coursePL-414.00$ SYSUBTOTAL PARKING LOT SURFACING:(B)(C)(D)(E)LANDSCAPING & VEGETATIONNo.Street TreesLA-1Median LandscapingLA-2Right-of-Way LandscapingLA-3Wetland LandscapingLA-4SUBTOTAL LANDSCAPING & VEGETATION:(B)(C)(D)(E)TRAFFIC & LIGHTINGNo.SignsTR-1Street Light System ( # of Poles)TR-2Traffic SignalTR-3Traffic Signal ModificationTR-4SUBTOTAL TRAFFIC & LIGHTING:(B)(C)(D)(E)WRITE-IN-ITEMSSUBTOTAL WRITE-IN ITEMS:STREET AND SITE IMPROVEMENTS SUBTOTAL:23,114.50SALES TAX @ 10%2,311.45STREET AND SITE IMPROVEMENTS TOTAL:25,425.95(B)(C)(D)(E)Page 6 of 14Ref 8-H Bond Quantity WorksheetSECTION II.b TRANSPORTATIONUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 2/11/2020 CED Permit #:ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostDRAINAGE (CPE = Corrugated Polyethylene Pipe, N12 or Equivalent) For Culvert prices, Average of 4' cover was assumed. Assume perforated PVC is same price as solid pipe.) Access Road, R/DD-126.00$ SY1303,380.00* (CBs include frame and lid)BeehiveD-290.00$ Each190.00Through-curb Inlet FrameworkD-3400.00$ EachCB Type ID-41,500.00$ Each11,500.00CB Type ILD-51,750.00$ EachCB Type II, 48" diameterD-62,300.00$ Each36,900.00 for additional depth over 4' D-7480.00$ FTCB Type II, 54" diameterD-82,500.00$ Each for additional depth over 4'D-9495.00$ FTCB Type II, 60" diameterD-102,800.00$ Each for additional depth over 4'D-11600.00$ FTCB Type II, 72" diameterD-126,000.00$ Each for additional depth over 4'D-13850.00$ FTCB Type II, 96" diameterD-1414,000.00$ Each for additional depth over 4'D-15925.00$ FTTrash Rack, 12"D-16350.00$ EachTrash Rack, 15"D-17410.00$ EachTrash Rack, 18"D-18480.00$ EachTrash Rack, 21"D-19550.00$ EachCleanout, PVC, 4"D-20150.00$ EachCleanout, PVC, 6"D-21170.00$ EachCleanout, PVC, 8"D-22200.00$ EachCulvert, PVC, 4" D-2310.00$ LFCulvert, PVC, 6" D-2413.00$ LF42546.00Culvert, PVC, 8" D-2515.00$ LF721,080.00Culvert, PVC, 12" D-2623.00$ LFCulvert, PVC, 15" D-2735.00$ LFCulvert, PVC, 18" D-2841.00$ LFCulvert, PVC, 24"D-2956.00$ LFCulvert, PVC, 30" D-3078.00$ LFCulvert, PVC, 36" D-31130.00$ LFCulvert, CMP, 8"D-3219.00$ LFCulvert, CMP, 12"D-3329.00$ LFSUBTOTAL THIS PAGE:13,496.00(B)(C)(D)(E)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESQuantity Remaining (Bond Reduction) (B)(C)Page 7 of 14Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 2/11/2020 CED Permit #:ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostSITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESQuantity Remaining (Bond Reduction) (B)(C)DRAINAGE (Continued)Culvert, CMP, 15"D-3435.00$ LFCulvert, CMP, 18"D-3541.00$ LFCulvert, CMP, 24"D-3656.00$ LFCulvert, CMP, 30"D-3778.00$ LFCulvert, CMP, 36"D-38130.00$ LFCulvert, CMP, 48"D-39190.00$ LFCulvert, CMP, 60"D-40270.00$ LFCulvert, CMP, 72"D-41350.00$ LFCulvert, Concrete, 8"D-4242.00$ LFCulvert, Concrete, 12"D-4348.00$ LFCulvert, Concrete, 15"D-4478.00$ LFCulvert, Concrete, 18"D-4548.00$ LFCulvert, Concrete, 24"D-4678.00$ LFCulvert, Concrete, 30"D-47125.00$ LFCulvert, Concrete, 36"D-48150.00$ LFCulvert, Concrete, 42"D-49175.00$ LFCulvert, Concrete, 48"D-50205.00$ LFCulvert, CPE Triple Wall, 6" D-5114.00$ LFCulvert, CPE Triple Wall, 8" D-5216.00$ LFCulvert, CPE Triple Wall, 12" D-5324.00$ LFCulvert, CPE Triple Wall, 15" D-5435.00$ LFCulvert, CPE Triple Wall, 18" D-5541.00$ LFCulvert, CPE Triple Wall, 24" D-5656.00$ LFCulvert, CPE Triple Wall, 30" D-5778.00$ LFCulvert, CPE Triple Wall, 36" D-58130.00$ LFCulvert, LCPE, 6"D-5960.00$ LFCulvert, LCPE, 8"D-6072.00$ LFCulvert, LCPE, 12"D-6184.00$ LFCulvert, LCPE, 15"D-6296.00$ LFCulvert, LCPE, 18"D-63108.00$ LFCulvert, LCPE, 24"D-64120.00$ LFCulvert, LCPE, 30"D-65132.00$ LFCulvert, LCPE, 36"D-66144.00$ LFCulvert, LCPE, 48"D-67156.00$ LFCulvert, LCPE, 54"D-68168.00$ LFSUBTOTAL THIS PAGE:(B)(C)(D)(E)Page 8 of 14Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 2/11/2020 CED Permit #:ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostSITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESQuantity Remaining (Bond Reduction) (B)(C)DRAINAGE (Continued)Culvert, LCPE, 60"D-69180.00$ LFCulvert, LCPE, 72"D-70192.00$ LFCulvert, HDPE, 6"D-7142.00$ LFCulvert, HDPE, 8"D-7242.00$ LF1024,284.00Culvert, HDPE, 12"D-7374.00$ LFCulvert, HDPE, 15"D-74106.00$ LFCulvert, HDPE, 18"D-75138.00$ LFCulvert, HDPE, 24"D-76221.00$ LFCulvert, HDPE, 30"D-77276.00$ LFCulvert, HDPE, 36"D-78331.00$ LFCulvert, HDPE, 48"D-79386.00$ LFCulvert, HDPE, 54"D-80441.00$ LFCulvert, HDPE, 60"D-81496.00$ LFCulvert, HDPE, 72"D-82551.00$ LFPipe, Polypropylene, 6"D-8384.00$ LFPipe, Polypropylene, 8"D-8489.00$ LFPipe, Polypropylene, 12"D-8595.00$ LFPipe, Polypropylene, 15"D-86100.00$ LFPipe, Polypropylene, 18"D-87106.00$ LFPipe, Polypropylene, 24"D-88111.00$ LFPipe, Polypropylene, 30"D-89119.00$ LFPipe, Polypropylene, 36"D-90154.00$ LFPipe, Polypropylene, 48"D-91226.00$ LFPipe, Polypropylene, 54"D-92332.00$ LFPipe, Polypropylene, 60"D-93439.00$ LFPipe, Polypropylene, 72"D-94545.00$ LFCulvert, DI, 6"D-9561.00$ LFCulvert, DI, 8"D-9684.00$ LFCulvert, DI, 12"D-97106.00$ LFCulvert, DI, 15"D-98129.00$ LFCulvert, DI, 18"D-99152.00$ LFCulvert, DI, 24"D-100175.00$ LFCulvert, DI, 30"D-101198.00$ LFCulvert, DI, 36"D-102220.00$ LFCulvert, DI, 48"D-103243.00$ LFCulvert, DI, 54"D-104266.00$ LFCulvert, DI, 60"D-105289.00$ LFCulvert, DI, 72"D-106311.00$ LFSUBTOTAL THIS PAGE:4,284.00(B)(C)(D)(E)Page 9 of 14Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 2/11/2020 CED Permit #:ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostSITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESQuantity Remaining (Bond Reduction) (B)(C)Specialty Drainage ItemsDitching SD-19.50$ CYFlow Dispersal Trench (1,436 base+)SD-328.00$ LF French Drain (3' depth)SD-426.00$ LFGeotextile, laid in trench, polypropyleneSD-53.00$ SYMid-tank Access Riser, 48" dia, 6' deepSD-62,000.00$ EachPond Overflow SpillwaySD-716.00$ SYRestrictor/Oil Separator, 12"SD-81,150.00$ Each11,150.00Restrictor/Oil Separator, 15"SD-91,350.00$ EachRestrictor/Oil Separator, 18"SD-101,700.00$ EachRiprap, placedSD-1142.00$ CY10420.00Tank End Reducer (36" diameter)SD-121,200.00$ EachInfiltration pond testingSD-13125.00$ HRPermeable PavementSD-14Permeable Concrete SidewalkSD-15Culvert, Box __ ft x __ ftSD-16SUBTOTAL SPECIALTY DRAINAGE ITEMS:1,570.00(B)(C)(D)(E)STORMWATER FACILITIES (Include Flow Control and Water Quality Facility Summary Sheet and Sketch)Detention PondSF-120,000.00$ Each 120,000.00Detention TankSF-2Each Detention VaultSF-3Each Infiltration PondSF-4Each Infiltration TankSF-5Each Infiltration VaultSF-6Each Infiltration TrenchesSF-7Each Basic Biofiltration SwaleSF-8Each Wet Biofiltration SwaleSF-9Each WetpondSF-10Each WetvaultSF-11Each Sand FilterSF-12Each Sand Filter VaultSF-13Each Linear Sand FilterSF-14Each Proprietary FacilitySF-15Each Bioretention FacilitySF-16Each SUBTOTAL STORMWATER FACILITIES:20,000.00(B)(C)(D)(E)Page 10 of 14Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 2/11/2020 CED Permit #:ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostSITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESQuantity Remaining (Bond Reduction) (B)(C)WRITE-IN-ITEMS (INCLUDE ON-SITE BMPs)WI-1WI-2WI-3WI-4WI-5WI-6WI-7WI-8WI-9WI-10WI-11WI-12WI-13WI-14WI-15SUBTOTAL WRITE-IN ITEMS:DRAINAGE AND STORMWATER FACILITIES SUBTOTAL:39,350.00SALES TAX @ 10%3,935.00DRAINAGE AND STORMWATER FACILITIES TOTAL:43,285.00(B) (C) (D) (E)Page 11 of 14Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 2/11/2020 CED Permit #:ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostConnection to Existing WatermainW-12,000.00$ Each12,000.00Ductile Iron Watermain, CL 52, 4 Inch DiameterW-250.00$ LFDuctile Iron Watermain, CL 52, 6 Inch DiameterW-356.00$ LFDuctile Iron Watermain, CL 52, 8 Inch DiameterW-460.00$ LF10600.00Ductile Iron Watermain, CL 52, 10 Inch DiameterW-570.00$ LFDuctile Iron Watermain, CL 52, 12 Inch DiameterW-680.00$ LFGate Valve, 4 inch DiameterW-7500.00$ EachGate Valve, 6 inch DiameterW-8700.00$ EachGate Valve, 8 Inch DiameterW-9800.00$ EachGate Valve, 10 Inch DiameterW-101,000.00$ EachGate Valve, 12 Inch DiameterW-111,200.00$ EachFire Hydrant AssemblyW-124,000.00$ EachPermanent Blow-Off AssemblyW-131,800.00$ Each11,800.00Air-Vac Assembly, 2-Inch DiameterW-142,000.00$ EachAir-Vac Assembly, 1-Inch DiameterW-151,500.00$ EachCompound Meter Assembly 3-inch DiameterW-168,000.00$ EachCompound Meter Assembly 4-inch DiameterW-179,000.00$ EachCompound Meter Assembly 6-inch DiameterW-1810,000.00$ EachPressure Reducing Valve Station 8-inch to 10-inchW-1920,000.00$ EachWATER SUBTOTAL:4,400.00SALES TAX @ 10%440.00WATER TOTAL:4,840.00(B) (C) (D) (E)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR WATERQuantity Remaining (Bond Reduction) (B)(C)Page 12 of 14Ref 8-H Bond Quantity WorksheetSECTION II.d WATERUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 2/11/2020 CED Permit #:ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostClean OutsSS-11,000.00$ EachGrease Interceptor, 500 gallonSS-28,000.00$ EachGrease Interceptor, 1000 gallonSS-310,000.00$ EachGrease Interceptor, 1500 gallonSS-415,000.00$ EachSide Sewer Pipe, PVC. 4 Inch DiameterSS-580.00$ LFSide Sewer Pipe, PVC. 6 Inch DiameterSS-695.00$ LF464,370.00Sewer Pipe, PVC, 8 inch DiameterSS-7105.00$ LF222,310.00Sewer Pipe, PVC, 12 Inch DiameterSS-8120.00$ LFSewer Pipe, DI, 8 inch DiameterSS-9115.00$ LFSewer Pipe, DI, 12 Inch DiameterSS-10130.00$ LFManhole, 48 Inch DiameterSS-116,000.00$ Each16,000.00Manhole, 54 Inch DiameterSS-136,500.00$ EachManhole, 60 Inch DiameterSS-157,500.00$ EachManhole, 72 Inch DiameterSS-178,500.00$ EachManhole, 96 Inch DiameterSS-1914,000.00$ EachPipe, C-900, 12 Inch DiameterSS-21180.00$ LFOutside DropSS-241,500.00$ LSInside DropSS-251,000.00$ LSSewer Pipe, PVC, ____ Inch DiameterSS-26Lift Station (Entire System)SS-27LSSANITARY SEWER SUBTOTAL:8,310.004,370.00SALES TAX @ 10%831.00437.00SANITARY SEWER TOTAL:9,141.004,807.00(B) (C) (D) (E)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR SANITARY SEWERQuantity Remaining (Bond Reduction) (B)(C)Page 13 of 14Ref 8-H Bond Quantity WorksheetSECTION II.e SANITARY SEWERUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 2/11/2020 Planning Division |1055 South Grady Way – 6th Floor | Renton, WA 98057 (425) 430-7200Date:Name:Project Name: PE Registration No:CED Plan # (LUA):Firm Name:CED Permit # (U):Firm Address:Site Address:Phone No.Parcel #(s):Email Address:Project Phase: Site Restoration/Erosion Sediment Control Subtotal (a)Existing Right-of-Way Improvements Subtotal (b)(b)-$ Future Public Improvements Subtotal(c)13,981.00$ Stormwater & Drainage Facilities (Public & Private) Subtotal(d)(d)43,285.00$ (e)(f)Site RestorationCivil Construction PermitMaintenance Bond11,453.20$ Bond Reduction2Construction Permit Bond Amount 3Minimum Bond Amount is $10,000.001 Estimate Only - May involve multiple and variable components, which will be established on an individual basis by Development Engineering.2 The City of Renton allows one request only for bond reduction prior to the maintenance period. Reduction of not more than 70% of the original bond amount, provided that the remaining 30% willcover all remaining items to be constructed. 3 Required Bond Amounts are subject to review and modification by Development Engineering.* Note: The word BOND as used in this document means any financial guarantee acceptable to the City of Renton.** Note: All prices include labor, equipment, materials, overhead and profit. 425-251-6222ddawes@barghausen.comDalpay Short PlatLUA-1700023418XX Redmond Place N.E.042305-9032FOR APPROVAL 18215 72nd Avenue South, Kent, WA 9803256,111.88$ P (a) x 100%SITE IMPROVEMENT BOND QUANTITY WORKSHEET BOND CALCULATIONSDate 2-11-20Don E. Dawes, P.E, Senior Project EngineerPE Registration No. 42009Barghausen Consulting Engineers, Inc.R((b x 150%) + (d x 100%))S(e) x 150% + (f) x 100%Bond Reduction: Existing Right-of-Way Improvements (Quantity Remaining)2Bond Reduction: Stormwater & Drainage Facilities (Quantity Remaining)2T(P +R - S)Prepared by:Project InformationCONSTRUCTION BOND AMOUNT */**(prior to permit issuance)EST1((b) + (c) + (d)) x 20%-$ MAINTENANCE BOND */**(after final acceptance of construction)12,826.88$ -$ 43,285.00$ 12,826.88$ -$ 43,285.00$ -$ Page 14 of 14Ref 8-H Bond Quantity WorksheetSECTION III. BOND WORKSHEETUnit Prices Updated: 06/14/2016Version: 04/26/2017Printed 2/11/2020 Stormwater Facility Summary Sheet 9.2 2016 KING COUNTY SURFACE WATER DESIGN MANUAL, REFERENCE D 4/24/2016 Page 1 STORMWATER FACILITY SUMMARY SHEET DPER Permit No.___________________ (provide one Stormwater Facility Summary Sheet per Natural Discharge Location)Date ___________________ OVERVIEW:NPDES Permit No.___________________ Project Name Parcel No.____________________________ Project Location Retired Parcel No.____________________________ Downstream Drainage Basins:Project includes Landscape Management Plan?yes Major Basin Name ______________________________________________(include copy with TIR as Appendix)no Immediate Basin Name ______________________________________________ GENERAL FACILITY INFORMATION: Leachable Metals Infiltration Impervious Surface Limit Type # of Type # of Type # of facilities Flow Control BMPs Ponds ______ Ponds ______ Ponds ______ Basic Clearing Limit Vaults ______ Tanks ______ Vaults ______ Conservation Drainage Facility Tanks ______ Trenches _____ Tanks ______ Flood Problem Landscape Management Plan If no flow control facility, check one: Project qualifies for KCSWDM Exemption (KCSWDM 1.2.3): Basic Exemption (Applies to Commercial parcels only)Area % of Total Redevelopment projects Cost Exemption for Parcel Redevelopment projects Direct Discharge Exemption Other _____________________ Total impervious surface served by Project qualifies for 0.1 cfs Exception per KCSWDM 1.2.3 flow control facility(ies) (sq ft) Impervious surface served by flow KCSWDM Adjustment No. ___________________control facility(ies) designed 1990 or later (sq ft) approved KCSWDM Adjustment No. __________________ Impervious surface served by Shared Facility Name/Location: _________________________ pervious surface absorption (sq ft) No flow control required (other, provide justification): Impervious surface served by approved ____________________________________________________ water quality facility(ies) (sq ft) Flow Control Performance Std Declarations of Covenant Recording No. Water QualityDetention TREATMENT SUMMARY FOR TOTAL IMPERVIOUS SURFACES ----- Total Impervious Acreage (ac) No flow control required per approved Flow control provided in regional/shared facility per approved PROVIDE FACILITY DETAILS AND FACILITY SKETCH FOR EACH FACILITY ON REVERSE. USE ADDITIONAL SHEETS AS NEEDED FOR ADDITIONAL FACILITIES Impervious Surface Exemption for Transportation Total Acreage (ac) Dalpay Short Plat 18XX Redmond Place NE, Renton, WA 1 x 042305-9032 N/A Cedar River/Lake Washington May Creek x 2016 KING COUNTY SURFACE WATER DESIGN MANUAL, REFERENCE D 4/24/2016 Page 2 STORMWATER FACILITY SUMMARY SHEET DPER Permit No.___________________ (provide one Stormwater Facility Summary Sheet per Natural Discharge Location) Project Name Downstream Drainage Basins: Major Basin Name _______________________________ Project Location Immediate Basin Name ___________________________ FLOW CONTROL FACILITY:Basin: Facility Name/Number _______________________________________ New Facility Project Impervious Facility Location ____________________________________________ Existing Facility Acres Served ________ UIC? □ yes □ no UIC Site ID:% of Total Project Impervious cu.ft.Volume Factor Acres Served ________ _____________ ac.ft.____________of Safety _______No. of Lots Served ________ Control Structure location: _______________________________________________ Type of Control Structure:No. of Orifices/Restrictions __________ Riser in vault Size of Orifice/Restriction (in.) No.1 ______ cu.ft. Riser in Type II CB (numbered starting with lowest No.2 ______ ac.ft. Weir in Type II CB orifice): No.3 ______ (inches in decimal format)No.4 ______ WATER QUALITY FACILITIES Design Information Indicate no. of water quality facilities/BMPs for each type:Water Quality design flow (cfs) _______Flow dispersion Water Quality treated volume (sandfilter) (cu.ft.) _______Filter strip Water Quality storage volume (wetpool) (cu.ft.) _______Biofiltration swale regular, wet or Landscape management plan Farm management plan continuous inflow _______Wetvault combined w/detention ______High flow bypass structure (e.g., flow-splitter catch basin) _______Wetpond basic large combined w/detention ______Oil/water separator baffle coalescing plate _______Pre-settling pond ______Storm filter _______Stormwater wetland ______Pre-settling structure (Manufacturer:______________________) _______Sand filter basic large Sand bed depth ______Catch basin inserts (Manufacturer:________________________) regular linear vault (inches)______________Source controls _________________________________________ ● Is facility lined? yes no If so, what marker is used above liner?_____________________________________________________ Facility Summary Sheet Sketch: All detention, infiltration and water quality facilities must include a detailed sketch (11"x17" reduced size plan sheets preferred). Dam Safety Regulations (WA State Dept of Ecology): Reservoir Volume above natural grade Depth of Reservoir above natural grade (ft) Live Storage Volume Live Storage Depth (ft) x 6,202 x 3.5 Dalpay Short Plat 18XX Redmond Place NE, Renton, WA Cedar River/Lake Washington May Creek 1Pond Pond Tract A x 2 0.15 Tract A 1.37 0.67 0 0 2 0.40 1.00 IN COMPLIANCE WITH CITY OF RENTON STANDARDSDALPAY SHORT PLATDALPAY PROPERTIES, LLC.4033 N.E. SUNSET BOULEVARDRENTON, WA 98059DALPAY SHORT PLAT DALPAY SHORT PLAT DALPAY SHORT PLATTED-40-4097 DETENTION POND PLAN AND SECTIONSC7 R-409707 Declaration of Covenant 9.3 Tab 10.0 17884.007.doc 10.0 OPERATIONS AND MAINTENANCE MANUAL The drainage facilities on this project will be private facilities owned and maintained by the Homeowners Association. Therefore, an Operation and Maintenance Manual is included in this section. KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL, APPENDIX A APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WATER QUALITY FACILITIES This appendix contains the maintenance requirements for the following typical stormwater control and water quality facilities and components (ctrl/click ► to follow the link): ► No. 1 – Detention Ponds (p. A-2) ► No. 2 – Infiltration Facilities (p. A-3) ► No. 3 – Detention Tanks and Vaults (p. A-5) ► No. 4 – Control Structure/Flow Restrictor (p. A-7) ► No. 5 – Catch Basins and Manholes (p. A-9) ► No. 6 – Conveyance Pipes and Ditches (p. A-11) ► No. 7 – Debris Barriers (e.g., Trash Racks) (p. A-12) ► No. 8 – Energy Dissipaters (p. A- 13) ► No. 9 – Fencing (p. A-14) ► No. 10 – Gates/Bollards/Access Barriers (p. A-15) ► No. 11 – Grounds (Landscaping) (p. A-16) ► No. 12 – Access Roads (p. A-17) ► No. 13 – Basic Bioswale (grass) (p. A-18) ► No. 14 – Wet Bioswale (p. A-19) ► No. 15 – Filter Strip (p. A-20) ► No. 16 – Wetpond (p. A-21) ► No. 17 – Wetvault (p. A-23) ► No. 18 – Stormwater Wetland (p. A-24) ► No. 19 – Sand Filter Pond (p. A-26) ► No. 20 – Sand Filter Vault (p. A-28) ► No. 21 – Stormfilter (Cartridge Type) (p. A-30) ► No. 22 – Baffle Oil/Water Separator (p. A-32) ► No. 23 – Coalescing Plate Oil/Water Separator (p. A-33) ► No. 24 – Catch Basin Insert (p. A-34) ► No. 25 – Drywell BMP (p. A-35) ► No. 26 – Gravel Filled Infiltration Trench BMP (p. A-35) ► No. 27 – Gravel Filled Dispersion Trench BMP (p. A-36) ► No. 28 – Native Vegetated Surface / Native Vegetated Landscape BMP (p. A-37) ► No. 29 – Perforated Pipe Connections BMP (p. A-37) ► No. 30 – Permeable Pavement BMP (p. A-38) ► No. 31 – Bioretention BMP (p. A-39) ► No. 32 – RainWater Harvesting BMP (p. A- 40) ► No. 33 – Rock Pad BMP (p. A-40) ► No. 34 – Sheet Flow BMP (p. A-40) ► No. 35 – Splash Block BMP (p. A-41) ► No. 36 – Vegetated Roof BMP (p. A-42) 2016 Surface Water Design Manual – Appendix A 4/24/2016 A-1 APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO. 1 – DETENTION PONDS Maintenance Component Defect or Problem Conditions When Maintenance Is Needed Results Expected When Maintenance Is Performed Site Trash and debris Any trash and debris which exceed 1 cubic foot 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. Trash and debris cleared from site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to County personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where County personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Top or Side Slopes of Dam, Berm or Embankment Rodent holes Any evidence of rodent holes if facility is acting as a dam or berm, or any evidence of water piping through dam or berm via rodent holes. Rodents removed or destroyed and dam or berm repaired. Tree growth Tree growth threatens integrity of slopes, does not allow maintenance access, or interferes with maintenance activity. If trees are not a threat or not interfering with access or maintenance, they do not need to be removed. Trees do not hinder facility performance or maintenance activities. Erosion Eroded damage over 2 inches deep where cause of damage is still present or where there is potential for continued erosion. Any erosion observed on a compacted slope. Slopes stabilized using appropriate erosion control measures. If erosion is occurring on compacted slope, a licensed civil engineer should be consulted to resolve source of erosion. Settlement Any part of a dam, berm or embankment that has settled 4 inches lower than the design elevation. Top or side slope restored to design dimensions. If settlement is significant, a licensed civil engineer should be consulted to determine the cause of the settlement. Storage Area Sediment accumulation Accumulated sediment that exceeds 10% of the designed pond depth. Sediment cleaned out to designed pond shape and depth; pond reseeded if necessary to control erosion. Liner damaged (If Applicable) Liner is visible or pond does not hold water as designed. Liner repaired or replaced. Inlet/Outlet Pipe. Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Emergency Overflow/Spillway Tree growth Tree growth impedes flow or threatens stability of spillway. Trees removed. Rock missing Only one layer of rock exists above native soil in area five square feet or larger or any exposure of native soil on the spillway. Spillway restored to design standards. 4/24/2016 2016 Surface Water Design Manual – Appendix A A-2 APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO. 4 – CONTROL STRUCTURE/FLOW RESTRICTOR Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed Structure Trash and debris Trash or debris of more than ½ cubic foot which is located immediately in front of the structure opening or is blocking capacity of the structure by more than 10%. No Trash or debris blocking or potentially blocking entrance to structure. Trash or debris in the structure that exceeds 1/3 the depth from the bottom of basin to invert the lowest pipe into or out of the basin. No trash or debris in the structure. Deposits of garbage exceeding 1 cubic foot in volume. No condition present which would attract or support the breeding of insects or rodents. Sediment Sediment exceeds 60% of the depth from the bottom of the structure to the invert of the lowest pipe into or out of the structure or the bottom of the FROP-T section or is within 6 inches of the invert of the lowest pipe into or out of the structure or the bottom of the FROP-T section. Sump of structure contains no sediment. Damage to frame and/or top slab Corner of frame extends more than ¾ inch past curb face into the street (If applicable). Frame is even with curb. Top slab has holes larger than 2 square inches or cracks wider than ¼ inch. Top slab is free of holes and cracks. Frame not sitting flush on top slab, i.e., separation of more than ¾ inch of the frame from the top slab. Frame is sitting flush on top slab. Cracks in walls or bottom Cracks wider than ½ inch and longer than 3 feet, any evidence of soil particles entering structure through cracks, or maintenance person judges that structure is unsound. Structure is sealed and structurally sound. Cracks wider than ½ inch and longer than 1 foot at the joint of any inlet/outlet pipe or any evidence of soil particles entering structure through cracks. No cracks more than 1/4 inch wide at the joint of inlet/outlet pipe. Settlement/ misalignment Structure has settled more than 1 inch or has rotated more than 2 inches out of alignment. Basin replaced or repaired to design standards. Damaged pipe joints Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering the structure at the joint of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of inlet/outlet pipes. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Ladder rungs missing or unsafe Ladder is unsafe due to missing rungs, misalignment, rust, cracks, or sharp edges. Ladder meets design standards and allows maintenance person safe access. FROP-T Section Damage T section is not securely attached to structure wall and outlet pipe structure should support at least 1,000 lbs of up or down pressure. T section securely attached to wall and outlet pipe. Structure is not in upright position (allow up to 10% from plumb). Structure in correct position. Connections to outlet pipe are not watertight or show signs of deteriorated grout. Connections to outlet pipe are water tight; structure repaired or replaced and works as designed. Any holes—other than designed holes—in the structure. Structure has no holes other than designed holes. 2016 Surface Water Design Manual – Appendix A 4/24/2016 A-7 APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO. 4 – CONTROL STRUCTURE/FLOW RESTRICTOR Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed Cleanout Gate Damaged or missing Cleanout gate is missing. Replace cleanout gate. Cleanout gate is not watertight. Gate is watertight and works as designed. Gate cannot be moved up and down by one maintenance person. Gate moves up and down easily and is watertight. Chain/rod leading to gate is missing or damaged. Chain is in place and works as designed. Orifice Plate Damaged or missing Control device is not working properly due to missing, out of place, or bent orifice plate. Plate is in place and works as designed. Obstructions Any trash, debris, sediment, or vegetation blocking the plate. Plate is free of all obstructions and works as designed. Overflow Pipe Obstructions Any trash or debris blocking (or having the potential of blocking) the overflow pipe. Pipe is free of all obstructions and works as designed. Deformed or damaged lip Lip of overflow pipe is bent or deformed. Overflow pipe does not allow overflow at an elevation lower than design Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Metal Grates (If Applicable) Unsafe grate opening Grate with opening wider than 7/8 inch. Grate opening meets design standards. Trash and debris Trash and debris that is blocking more than 20% of grate surface. Grate free of trash and debris. footnote to guidelines for disposal Damaged or missing Grate missing or broken member(s) of the grate. Grate is in place and meets design standards. Manhole Cover/Lid Cover/lid not in place Cover/lid is missing or only partially in place. Any open structure requires urgent maintenance. Cover/lid protects opening to structure. Locking mechanism Not Working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to Remove One maintenance person cannot remove cover/lid after applying 80 lbs. of lift. Cover/lid can be removed and reinstalled by one maintenance person. 4/24/2016 2016 Surface Water Design Manual – Appendix A A-8 APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO. 5 – CATCH BASINS AND MANHOLES Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed Structure Sediment Sediment exceeds 60% of the depth from the bottom of the catch basin to the invert of the lowest pipe into or out of the catch basin or is within 6 inches of the invert of the lowest pipe into or out of the catch basin. Sump of catch basin contains no sediment. Trash and debris Trash or debris of more than ½ cubic foot which is located immediately in front of the catch basin opening or is blocking capacity of the catch basin by more than 10%. No Trash or debris blocking or potentially blocking entrance to catch basin. Trash or debris in the catch basin that exceeds 1/3 the depth from the bottom of basin to invert the lowest pipe into or out of the basin. No trash or debris in the catch basin. Dead animals or vegetation that could generate odors that could cause complaints or dangerous gases (e.g., methane). No dead animals or vegetation present within catch basin. Deposits of garbage exceeding 1 cubic foot in volume. No condition present which would attract or support the breeding of insects or rodents. Damage to frame and/or top slab Corner of frame extends more than ¾ inch past curb face into the street (If applicable). Frame is even with curb. Top slab has holes larger than 2 square inches or cracks wider than ¼ inch. Top slab is free of holes and cracks. Frame not sitting flush on top slab, i.e., separation of more than ¾ inch of the frame from the top slab. Frame is sitting flush on top slab. Cracks in walls or bottom Cracks wider than ½ inch and longer than 3 feet, any evidence of soil particles entering catch basin through cracks, or maintenance person judges that catch basin is unsound. Catch basin is sealed and is structurally sound. Cracks wider than ½ inch and longer than 1 foot at the joint of any inlet/outlet pipe or any evidence of soil particles entering catch basin through cracks. No cracks more than 1/4 inch wide at the joint of inlet/outlet pipe. Settlement/ misalignment Catch basin has settled more than 1 inch or has rotated more than 2 inches out of alignment. Basin replaced or repaired to design standards. Damaged pipe joints Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering the catch basin at the joint of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of inlet/outlet pipes. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. 2016 Surface Water Design Manual – Appendix A 4/24/2016 A-9 APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO. 5 – CATCH BASINS AND MANHOLES Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed Metal Grates (Catch Basins) Unsafe grate opening Grate with opening wider than 7/8 inch. Grate opening meets design standards. Trash and debris Trash and debris that is blocking more than 20% of grate surface. Grate free of trash and debris. footnote to guidelines for disposal Damaged or missing Grate missing or broken member(s) of the grate. Any open structure requires urgent maintenance. Grate is in place and meets design standards. Manhole Cover/Lid Cover/lid not in place Cover/lid is missing or only partially in place. Any open structure requires urgent maintenance. Cover/lid protects opening to structure. Locking mechanism Not Working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to Remove One maintenance person cannot remove cover/lid after applying 80 lbs. of lift. Cover/lid can be removed and reinstalled by one maintenance person. 4/24/2016 2016 Surface Water Design Manual – Appendix A A-10 APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO. 6 – CONVEYANCE PIPES AND DITCHES Maintenance Component Defect or Problem Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Pipes Sediment & debris accumulation Accumulated sediment or debris that exceeds 20% of the diameter of the pipe. Water flows freely through pipes. Vegetation/roots Vegetation/roots that reduce free movement of water through pipes. Water flows freely through pipes. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Damage to protective coating or corrosion Protective coating is damaged; rust or corrosion is weakening the structural integrity of any part of pipe. Pipe repaired or replaced. Damaged Any dent that decreases the cross section area of pipe by more than 20% or is determined to have weakened structural integrity of the pipe. Pipe repaired or replaced. Ditches Trash and debris Trash and debris exceeds 1 cubic foot per 1,000 square feet of ditch and slopes. Trash and debris cleared from ditches. Sediment accumulation Accumulated sediment that exceeds 20% of the design depth. Ditch cleaned/flushed of all sediment and debris so that it matches design. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to County personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where County personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Vegetation Vegetation that reduces free movement of water through ditches. Water flows freely through ditches. Erosion damage to slopes Any erosion observed on a ditch slope. Slopes are not eroding. Rock lining out of place or missing (If Applicable) One layer or less of rock exists above native soil area 5 square feet or more, any exposed native soil. Replace rocks to design standards. 2016 Surface Water Design Manual – Appendix A 4/24/2016 A-11 APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO. 7 – DEBRIS BARRIERS (E.G., TRASH RACKS) Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed. Site Trash and debris Trash or debris plugging more than 20% of the area of the barrier. Barrier clear to receive capacity flow. Sediment accumulation Sediment accumulation of greater than 20% of the area of the barrier Barrier clear to receive capacity flow. Structure Cracked broken or loose Structure which bars attached to is damaged - pipe is loose or cracked or concrete structure is cracked, broken of loose. Structure barrier attached to is sound. Bars Bar spacing Bar spacing exceeds 6 inches. Bars have at most 6 inches spacing. Damaged or missing bars Bars are bent out of shape more than 3 inches. Bars in place with no bends more than ¾ inch. Bars are missing or entire barrier missing. Bars in place according to design. Bars are loose and rust is causing 50% deterioration to any part of barrier. Repair or replace barrier to design standards. 4/24/2016 2016 Surface Water Design Manual – Appendix A A-12 APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO. 8 – ENERGY DISSIPATERS Maintenance Component Defect or Problem Conditions When Maintenance is Needed Results Expected When Maintenance is Performed. Site Trash and debris Trash and/or debris accumulation. Dissipater clear of trash and/or debris. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Rock Pad Missing or moved Rock Only one layer of rock exists above native soil in area five square feet or larger or any exposure of native soil. Rock pad prevents erosion. Dispersion Trench Pipe plugged with sediment Accumulated sediment that exceeds 20% of the design depth. Pipe cleaned/flushed so that it matches design. Not discharging water properly Visual evidence of water discharging at concentrated points along trench (normal condition is a “sheet flow” of water along trench). Water discharges from feature by sheet flow. Perforations plugged. Over 1/4 of perforations in pipe are plugged with debris or sediment. Perforations freely discharge flow. Water flows out top of “distributor” catch basin. Water flows out of distributor catch basin during any storm less than the design storm. No flow discharges from distributor catch basin. Receiving area over- saturated Water in receiving area is causing or has potential of causing landslide problems. No danger of landslides. Gabions Damaged mesh Mesh of gabion broken, twisted or deformed so structure is weakened or rock may fall out. Mesh is intact, no rock missing. Corrosion Gabion mesh shows corrosion through more than ¼ of its gage. All gabion mesh capable of containing rock and retaining designed form. Collapsed or deformed baskets Gabion basket shape deformed due to any cause. All gabion baskets intact, structure stands as designed. Missing rock Any rock missing that could cause gabion to loose structural integrity. No rock missing. Manhole/Chamber Worn or damaged post, baffles or side of chamber Structure dissipating flow deteriorates to ½ or original size or any concentrated worn spot exceeding one square foot which would make structure unsound. Structure is in no danger of failing. Damage to wall, frame, bottom, and/or top slab Cracks wider than ½-inch or any evidence of soil entering the structure through cracks, or maintenance inspection personnel determines that the structure is not structurally sound. Manhole/chamber is sealed and structurally sound. Damaged pipe joints Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering the structure at the joint of the inlet/outlet pipes. No soil or water enters and no water discharges at the joint of inlet/outlet pipes. 2016 Surface Water Design Manual – Appendix A 4/24/2016 A-13 APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO. 9 – FENCING Maintenance Component Defect or Problem Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Site Erosion or holes under fence Erosion or holes more than 4 inches high and 12-18 inches wide permitting access through an opening under a fence. No access under the fence. Wood Posts, Boards and Cross Members Missing or damaged parts Missing or broken boards, post out of plumb by more than 6 inches or cross members broken No gaps on fence due to missing or broken boards, post plumb to within 1½ inches, cross members sound. Weakened by rotting or insects Any part showing structural deterioration due to rotting or insect damage All parts of fence are structurally sound. Damaged or failed post foundation Concrete or metal attachments deteriorated or unable to support posts. Post foundation capable of supporting posts even in strong wind. Metal Posts, Rails and Fabric Damaged parts Post out of plumb more than 6 inches. Post plumb to within 1½ inches. Top rails bent more than 6 inches. Top rail free of bends greater than 1 inch. Any part of fence (including post, top rails, and fabric) more than 1 foot out of design alignment. Fence is aligned and meets design standards. Missing or loose tension wire. Tension wire in place and holding fabric. Deteriorated paint or protective coating Part or parts that have a rusting or scaling condition that has affected structural adequacy. Structurally adequate posts or parts with a uniform protective coating. Openings in fabric Openings in fabric are such that an 8-inch diameter ball could fit through. Fabric mesh openings within 50% of grid size. 4/24/2016 2016 Surface Water Design Manual – Appendix A A-14 APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO. 10 – GATES/BOLLARDS/ACCESS BARRIERS Maintenance Component Defect or Problem Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Chain Link Fencing Gate Damaged or missing members Missing gate. Gates in place. Broken or missing hinges such that gate cannot be easily opened and closed by a maintenance person. Hinges intact and lubed. Gate is working freely. Gate is out of plumb more than 6 inches and more than 1 foot out of design alignment. Gate is aligned and vertical. Missing stretcher bar, stretcher bands, and ties. Stretcher bar, bands, and ties in place. Locking mechanism does not lock gate Locking device missing, no-functioning or does not link to all parts. Locking mechanism prevents opening of gate. Openings in fabric Openings in fabric are such that an 8-inch diameter ball could fit through. Fabric mesh openings within 50% of grid size. Bar Gate Damaged or missing cross bar Cross bar does not swing open or closed, is missing or is bent to where it does not prevent vehicle access. Cross bar swings fully open and closed and prevents vehicle access. Locking mechanism does not lock gate Locking device missing, no-functioning or does not link to all parts. Locking mechanism prevents opening of gate. Support post damaged Support post does not hold cross bar up. Cross bar held up preventing vehicle access into facility. Bollards Damaged or missing Bollard broken, missing, does not fit into support hole or hinge broken or missing. No access for motorized vehicles to get into facility. Does not lock Locking assembly or lock missing or cannot be attached to lock bollard in place. No access for motorized vehicles to get into facility. Boulders Dislodged Boulders not located to prevent motorized vehicle access. No access for motorized vehicles to get into facility. Circumvented Motorized vehicles going around or between boulders. No access for motorized vehicles to get into facility. 2016 Surface Water Design Manual – Appendix A 4/24/2016 A-15 APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO. 11 – GROUNDS (LANDSCAPING) Maintenance Component Defect or Problem Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Site Trash or litter Any trash and debris which exceed 1 cubic foot 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. Trash and debris cleared from site. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to County personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where County personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches. Trees and Shrubs Hazard Any tree or limb of a tree identified as having a potential to fall and cause property damage or threaten human life. A hazard tree identified by a qualified arborist must be removed as soon as possible. No hazard trees in facility. Damaged Limbs or parts of trees or shrubs that are split or broken which affect more than 25% of the total foliage of the tree or shrub. Trees and shrubs with less than 5% of total foliage with split or broken limbs. Trees or shrubs that have been blown down or knocked over. No blown down vegetation or knocked over vegetation. Trees or shrubs free of injury. Trees or shrubs which are not adequately supported or are leaning over, causing exposure of the roots. Tree or shrub in place and adequately supported; dead or diseased trees removed. 4/24/2016 2016 Surface Water Design Manual – Appendix A A-16 APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO. 12 – ACCESS ROADS Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed Site Trash and debris Trash and debris exceeds 1 cubic foot per 1,000 square feet (i.e., trash and debris would fill up one standards size garbage can). Roadway drivable by maintenance vehicles. Debris which could damage vehicle tires or prohibit use of road. Roadway drivable by maintenance vehicles. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Blocked roadway Any obstruction which reduces clearance above road surface to less than 14 feet. Roadway overhead clear to 14 feet high. Any obstruction restricting the access to a 10- to 12 foot width for a distance of more than 12 feet or any point restricting access to less than a 10 foot width. At least 12-foot of width on access road. Road Surface Erosion, settlement, potholes, soft spots, ruts Any surface defect which hinders or prevents maintenance access. Road drivable by maintenance vehicles. Vegetation on road surface Trees or other vegetation prevent access to facility by maintenance vehicles. Maintenance vehicles can access facility. Shoulders and Ditches Erosion Erosion within 1 foot of the roadway more than 8 inches wide and 6 inches deep. Shoulder free of erosion and matching the surrounding road. Weeds and brush Weeds and brush exceed 18 inches in height or hinder maintenance access. Weeds and brush cut to 2 inches in height or cleared in such a way as to allow maintenance access. Modular Grid Pavement Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Damaged or missing Access surface compacted because of broken on missing modular block. Access road surface restored so road infiltrates. 2016 Surface Water Design Manual – Appendix A 4/24/2016 A-17 APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO. 22 – BAFFLE OIL/WATER SEPARATOR Maintenance Component Defect Condition When Maintenance is Needed Results Expected When Maintenance is Performed Site Trash and debris Any trash or debris which impairs the function of the facility. Trash and debris removed from facility. Contaminants and pollution Floating oil in excess of 1 inch in first chamber, any oil in other chambers or other contaminants of any type in any chamber. No contaminants present other than a surface oil film. Vault Treatment Area Sediment accumulation Sediment accumulates exceeds 6 inches in the vault. No sediment in the vault. Discharge water not clear Inspection of discharge water shows obvious signs of poor water quality- effluent discharge from vault shows thick visible sheen. Effluent discharge is clear. Trash or debris accumulation Any trash and debris accumulation in vault (floatables and non-floatables). Vault is clear of trash and debris. Oil accumulation Oil accumulations that exceed 1 inch, at the surface of the water in the oil/water separator chamber. No visible oil depth on water. Vault Structure Damage to Wall, Frame, Bottom, and/or Top Slab Cracks wider than ½-inch or evidence of soil particles entering the structure through the cracks, or maintenance/inspection personnel determines that the vault is not structurally sound. Vault replaced or repaired to design specifications. Baffles damaged Baffles corroding, cracking, warping and/or showing signs of failure as determined by maintenance inspection personnel. Repair or replace baffles to specifications. Gravity Drain Inoperable valve Valve will not open and close. Valve opens and closes normally. Valve won’t seal Valve does not seal completely. Valve completely seals closed. Inlet/Outlet Pipe Sediment accumulation Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. Trash and debris Trash and debris accumulated in inlet/outlet pipes (includes floatables and non-floatables). No trash or debris in pipes. Damaged Cracks wider than ½-inch at the joint of the inlet/outlet pipes or any evidence of soil entering at the joints of the inlet/outlet pipes. No cracks more than ¼-inch wide at the joint of the inlet/outlet pipe. Access Manhole Cover/lid not in place Cover/lid is missing or only partially in place. Any open manhole requires immediate maintenance. Manhole access covered. Locking mechanism not working Mechanism cannot be opened by one maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Mechanism opens with proper tools. Cover/lid difficult to remove One maintenance person cannot remove cover/lid after applying 80 lbs of lift. Cover/lid can be removed and reinstalled by one maintenance person. Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. Large access doors/plate Damaged or difficult to open Large access doors or plates cannot be opened/removed using normal equipment. Replace or repair access door so it can opened as designed. Gaps, doesn't cover completely Large access doors not flat and/or access opening not completely covered. Doors close flat and cover access opening completely. Lifting Rings missing, rusted Lifting rings not capable of lifting weight of door or cover/lid. Lifting rings sufficient to lift or remove cover/lid. 4/24/2016 2016 Surface Water Design Manual – Appendix A A-32 APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO. 23 – COALESCING PLATE OIL/WATER SEPARATOR Maintenance Component Defect Condition When Maintenance is Needed Results Expected When Maintenance is Performed Large access doors/plate Damaged or difficult to open Large access doors or plates cannot be opened/removed using normal equipment. Replace or repair access door so it can opened as designed. Gaps, doesn't cover completely Large access doors not flat and/or access opening not completely covered. Doors close flat and cover access opening completely. Lifting Rings missing, rusted Lifting rings not capable of lifting weight of door or plate. Lifting rings sufficient to lift or remove door or plate. NO. 24 – CATCH BASIN INSERT Maintenance Component Defect or Problem Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Media Insert Visible Oil Visible oil sheen passing through media Media inset replaced. Insert does not fit catch basin properly Flow gets into catch basin without going through media. All flow goes through media. Filter media plugged Filter media plugged. Flow through filter media is normal. Oil absorbent media saturated Media oil saturated. Oil absorbent media replaced. Water saturated Catch basin insert is saturated with water, which no longer has the capacity to absorb. Insert replaced. Service life exceeded Regular interval replacement due to typical average life of media insert product, typically one month. Media replaced at manufacturer’s recommended interval. Seasonal maintenance When storms occur and during the wet season. Remove, clean and replace or install new insert after major storms, monthly during the wet season or at manufacturer’s recommended interval. 4/24/2016 2016 Surface Water Design Manual – Appendix A A-34 APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO. 28 – NATIVE VEGETATED SURFACE / NATIVE VEGETATED LANDSCAPE BMP Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance Is Performed Site Trash and debris Trash and debris accumulated on the native vegetated surface/native vegetated landscape site. Native vegetated surface site free of any trash or debris. Vegetation Native vegetation type Less than two species each of native trees, shrubs, and groundcover occur in the design area. A minimum of two species each of native trees, shrubs, and groundcover is established and healthy. Native vegetated area Less than 90% if the required vegetated area has healthy growth. A minimum of 90% of the required vegetated area has healthy growth. Undesirable vegetation Weeds, blackberry, and other undesirable plants are invading more than 10% of vegetated area. Less than 10% undesirable vegetation occurs in the required native vegetated surface area. Vegetated Area Soil compaction Soil in the native vegetation area compacted. Less than 8% of native vegetation area is compacted. Insufficient area Less than 3.5 square feet of native vegetation area for every 1 square foot of impervious surface. A minimum of 3.5 square feet of native vegetation area for every 1 square foot of impervious surface. Excess slope Slope of native vegetation area greater than 15%. Slope of native growth area does not exceed 15%. Inspection Frequency Annually Inspect native vegetation area for any defects of deficiencies NO. 29 – PERFORATED PIPE CONNECTIONS BMP Maintenance Component Defect or Problem Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Preventative Blocking, obstructions Debris or trash limiting flow into perforated pipe system or outfall of BMP is plugged or otherwise nonfunctioning. Outfall of BMP is receiving designed flows from perforated pipe connection. Inflow Inflow impeded Inflow into the perforated pipe is partially or fully blocked or altered to prevent flow from getting into the pipe. Inflow to the perforated pipe is unimpeded. Pipe Trench Area Surface compacted Ground surface over the perforated pipe trench is compacted or covered with impermeable material. Ground surface over the perforated pipe is not compacted and free of any impervious cover. Outflow Outflow impeded Outflow from the perforated pipe into the public drainage system is blocked. Outflow to the public drainage system is unimpeded. Outfall Area Erosion or landslides Existence of the perforated pipe is causing or exasperating erosion or landslides. Perforated pipe system is sealed off and an alternative BMP is implemented. Inspection Frequency Annually and prior to and following significant storms. Perforated pipe system is operating as designed. 2016 Surface Water Design Manual – Appendix A 4/24/2016 A-37 APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO. 32 – RAINWATER HARVESTING BMP Maintenance Component Defect or Problem Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Preventative Storage volume No rain water in storage unit at the beginning of the rain season. Maximum storage available at the beginning of the rain season (Oct. 1st). Collection Area Trash and debris Trash of debris on collection area may plug filter system Collection area clear of trash and debris. Filter Restricted or plugged Filter is partially or fully plugged preventing water from getting in to the storage unit. Filter is allowing collection water into storage unit. Inspection Frequency Annually and after large storms Rain harvesting equipment is functioning normally. Maintenance log A Maintenance log must be kept and available for review by KC staff. Maintenance log is kept and is available to KC staff. NO. 33 – ROCK PAD BMP Maintenance Component Defect or Problem Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Site Trash and debris Trash and debris accumulated on rock pad site. Rock pad site free of any trash or debris. Rock Pad Area Rock pad size Rock pad is not 2 feet by 3 feet by 6 inches thick or as designed. Rock pad is 2 feet by 3 feet by 6 inches thick or as designed. Vegetation Vegetation is seen growing in or through rock pad. No vegetation within rock pad area. Rock Exposed soil Soil can be seen through the rock pad. Full thickness of the rock pad is in place, no soil visible through rock pad. Inspection Frequency Annually and after large storms Rock pad is functioning normally. NO. 34 – SHEET FLOW BMP Maintenance Component Defect or Problem Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Site Trash and debris Trash and debris accumulated on the sheet flow site. Sheet flow site free of any trash or debris. Sheet flow area Erosion Soil erosion occurring in sheet flow zone. Soil erosion is not occurring and rills and channels have been repaired. Concentrated flow Sheet flow is not occurring in the sheet flow zone. Sheet flow area is regraded to provide sheet flow. Inspection Frequency Annually and after large storms Rain harvesting equipment is functioning normally. 4/24/2016 2016 Surface Water Design Manual – Appendix A A-40