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HomeMy WebLinkAbout3325_VuongShortPlat_TIRSTORMDRAINAGE-I.EVEL2FORVI.lONGSHORTPLA1’.:REN’ION.WAS[I[NONFILENO.900-001-001PREPAREDBYTOUMAENGINEERS6632SOUTH191STPLACE,SUiTEF-I02KENT,WA.98032(425)251-0665March15,200.J4./’,ico7—25 TABLEOfCONTENTSTABLEOFCONTENTS1.PROJECTOVERVIEWH.CONDiTIONS&REQUiREMENTSSUMMARYIii.OFF-SITEANALYSISIV.FLOWCONTROL&WATERQUALITYV.CONVEYANCESYSTEMANALYSiSANDDESIGNVI.SPECIALREPORTSANDSTUDIESVII.BASiNANDOTHERCOMMUNiTYAREASN/AVIIIOTHERPERMITSIX.EROSION/SEDIMENTATIONCONTROLDESIGNX.BONDQUANTiTIESWORKSHEETN/A I.PROJECTOVERVIEWThesubjectpropertyinvolvedinthisplatcoversanareaofapproximatelyI13acres.ThepropertyissituatedinthenorthendoftheCity.ThesiteisboundedontheEastbyDuvallAvenueNE(138thAvenueSE—KingCountyStreetdesignation)andonthesouthbyNE10”Street.Itisboundedonthenorthandeastbyfairlylargesinglefamilyparcels.Accesstothepropertyismadefrominternalstreetthatwotildservetheproposedsinglelots.Theprojectareaisflatwithanaverageslopeof7,3.Theslopesareorientedfromeasttowest.Thedevelopmentfallswithinonesmallbasin.Thesurfacewaterisdirectedtothewesttowardadjacentproperty.Theflowwillbeinterceptedbynewconveyancesystemtobedesignedfortheproposedsite,anddirectstheflowsouthtoexistingundergroundstormsystemexistinginNE10thStreet.Thencetheflowisdirectedwestforapproximately170feetanddischargesintoanexistingdetentionpond.ThesoiltypeofthesiteisMderwoodAgC,glacialtill.Existinggroundcoverconsistsmainlyofforest.Theproposedplatwillhave7singlefamilylotsrangingfrom4500scluarefeettolargerlotsizeof7162squarefeet.TheplatimprovementswillbedesignedtoCityofRentonStandardsandrequirementsforstreets,storm,sewer,waterandstreetlights.Seethefiguresonfollowingpages: 62601N.1 805W W-0-23-5 RENTON ______________ -———=-—--=—::=————FZ 4-:=-.=---;;-—__=—=-— ________ ..ONE’DEWr TO’O -:---J -- I INIUM 20 UNITS 0U)U)cVjLAN\\DWJAS-z5A\nAvEr\C——_r•:gC/JT24N%1OvCT23N-4272.. .\Jt-AkUti—- -pAPCii-—•)U•—.1“:•L“—•“‘“•‘..14•l•,•U,AgCI“JA•1”I‘I:I•—II-‘.Ma’i•PykPyJ II.PRELIMINARYCONDITIONSSUMMARYCOREREQUIREMENT#1:DISCHARGEATNATURALLOCATIONTheallowableoutflowfromthesitewillbedischargedtoitsnaturallocation.TheLevel2flowcontroliscalculatedtomatchthedevelopedpeakdischargeratestotheexistingsiteconditionpeakdischargeratesforthe2-yearand10-yearreturnperiods.COREREQUIREMENTS#2:OFf-SITEANALYSISRefertooff-siteanalysisonsubsequentpages.COREREQUIREMENTS#3:FLOWCONTROLThissitewasevaluatedusing1990KCSWMEditiontodeterminethedifferencebetweenpeakflowsfora24-hr.100-yearstormforpre-devetopedandpost-developedflows.Thefollowingcalculationsindicatesnodetentionfacilityisrequired.COREREQUIREMENTS#4:CONVEYANCESYSTEMTheconveyancesystemwillbedesignedusingtherationalmethodaspresentedintheKingCounty199$SWMManual.COREREQUIREMENTS#5:EROSION/SEDIMENTATiONCONTROLPLANTheErosionlSedimentationcontrolfacilitieswillconsistoffilterfabricfencestobeplacedalongthenortheastandnorthwestboundaryofthesite.TemporaryErosionandSedimentationtrapswillbeconsideredduringconstructionofplatimprovements.COREREQUiREMENTS#6:MAINTENANCEANDOPERATIONN/ACOREREQUIREMENTS#7:FINANCIALGUARANTEESANDLIABILITYN/ACOREREQUIREMENTS#8WATERQUALITYThewaterqualityfacilityproposedforthisprojectwiltbeunderground60-inchpipeofadequatelengthtohandledwaterqualityvolume. SWMSPECIALREQUIREMENTSSpecialRequirements#1:AdoptedAreaSpecificRequirements.ThesiteislocatedwithintheHoneyCreekbasin.SpecialRequirements#2:Delineationofthe100-yrfloodPlain.NASpecialRequirements#3:floodProtectionfacilities.NASpecialRequirements#4:SourceControl.NASpecialRequirements#5:OilControlNA ifiOff-SITEANALYSISUPSTREAMThesiteisthesituatednorthofNE10thStreetwithinitsownbasinarea.ThisareafallswithintheHoneyCreekBasinArea,anditisdesignatedbytheCityofRentonasaLevel2flowControl.Thereisnosignificantoffsitecontributingtothesite.Thereisnooff-siteareatobeconsidered.DOWNSTREAMSurfacerunofffromtheproposedplatsheetflowseasttowestdirectingflowintoanopenponddetentionfacilitysituatedimmediatelywestofthesite.Upondevelopment,thesurfacerunoffwiltbepickedupbynewconveyancesystemtobeinstalledinconjunctionwithanewnorth-southhaifastreetsituatedalongtheeastsideoftheproperty.Thenewstormfacilitywillbedirectedsouthtoexistingundergroundsystemon10thStreet,andthencewestforapproximately200feetintoaregionaldetentionpond.TheoutflowfromthepondisdirectednorththroughHoneyDewEstatesandcontinuethroughWhitworthCourt,forapproximatelyhalfofamile.TheflowcontinuesnorthandconnectstoexistingundergroundfacilityinSunsetBlvd.TheflowisdirectedwesttoUnionAvenueNE,andeventuallyintoHoneyCreek,approximately1.5milesnorthfromthesite. IVFLOWCONTROLANDWATERQUALITYSBUH/SCSMETHODFORCOMPUTINGRUNOFFHYDROGRAPHSPECIFYSTORMOPTION:1S.C.S.TYPE-lARAINFALLDISTRIBUTIONENTER:FREQ(YEAR),DURATION(HOUR),PRECIP(INCHES)100,24,3.9SCSTYPE—iADISTRIBUTION**********************100-YEAR24-HOURSTORM****3.90”TOTALPRECIP.ENTER:A(PERV),CN(PERV),A(IMPERV),CN(IMPERV),TCFORBASINNO.10.96,85,0.17,98,12.69DATAPRINT-OUT:AREA(ACRES)PERVIOUSIMPERVIOUSTC(MINUTES)ACNACN1.11.085.0.298.012.7PEAK-Q(CFS)T-PEAK(HRS)VOL(CU-FT).697.8310502ENTER[d:J[path]filename[.extjFORSTORAGEOFCOMPUTEDHYDROGRAPH:c:lOOexSPECIFY:C-CONTINUE,N-NEWSTORM,P-PRINT,S-STOPCENTER:A(PERV),CN(PERV),A(IMPERV),CN(IMPERV),ICFORBASINNO.20.3,86,0.83,98,6.3DATAPRINT-OUT:AREA(ACRES)PERVIOUSIMPERVIOUSTC(MINUTES)ACNACN1.1.386.0.898.06.3PEAK-QfCFS)T-PEAKfHRS)VOLfCU-FT)1.007.6713717ENTERtd:1[path]filename[.ext]FORSTORAGEOFCOMPUTEDHYDROGRAPH:c:lOOdSPECIFY:C-CONTINUE,N-NEWSTORM,P-PRINT,S-STOPNOTE:THEDIFFERENCEBETWEENTHE24-f00YEARPRE-DEVELOPEDANDPOST-DEVELOPMENTIS1.00-0.69=0.31CFSWHICHLESSTHAN0.5CFS,THEREFORENODETENTIONISREQUIRED. STORMDRAINAGEREPORTFORVUONGSHORTPLATBASINAREAANALYSISTOTALAREA1.13ACRESONANDOFF-SITESOILTYPEA9C-ALDERWOODType“C”EXISTINGCONDITIONSPASTURE-GRASSLAND0.96ACRESGARAGE450CONCRETE1925DRIVEWAY4415HOUSE/DECK718IMPERVOUS75080.17ACRESTOTALAREA1.13POSTCONDITIONSLANDSCAPING0.3ACRESLOTAREAIMPERVIOUS145433407262114000362344000445003375571624000653944000745003375PAVEMENT8400SIDEWALKS1500TOTALIMPERVIOUS36057.25S,F,0.83ACRESTOTALAREA1.13ACRES VuongShortPlatTIMEOFCONCENTRATION-PRY-DEVELOPMENT-FOR10-YEAR,24-HOURSTORMDESIGNSHEETFLOW-OFFSITEMANNING-n0.15OVERLAND-L180FEETPRECIPITATION-P2.9INCHSLOPE-S0.0384FT/FTTi12.69MINUTESCONCENTRATEDFLOW-OFFSITETOTALTIME-PRE-DEVELOPMENT12.69MINUTESTIMEOFCONCENTRATION-POSTDEVELOPMENT-FOR10-YEAR,24-HOURSTORMDESIGNSHEETFLOW-OFFSITEMANNING-n0.011OVERLAND-L300FEETPRECIPITATION-P2.9INCHSLOPE-S0.03FT/FTTi2.61MINUTESTOTALTIME-POSTDEVELOPMENT1.74Use6.3Minutes )U)r)C’4tfEXWIREFENCEo230ND5/8”REBAR&CAPSHEDT1RETMOVEjEFENCE(0(00‘.3C)C)0)C)C)F-.zgU00I1/01)FOUND5/8”REBAR‘B&CAPELEL=420.13’417.93’—12”SL,:.H(;RAvELDR——c‘432.4E3+66.81____NE1hSTREET____CD KINf’,COuNTY,WASIIIN(’ION,StJRFACI!WA’I’ERnIsic;NMANtJAL‘rMfLE3c.2nSCSWESTERNWAStIINGTONRUNOFCURVENUMBERSSCSWESTERNWASHINGTONRUNOFFCURVENUMBERS(PublishedbySCSin1982)Runoffcurvenumbersforselectedagricultural,suburbanaridurbanlanduseforTypeIArainfalldistribution,24-hourstormduration.CURVENUMBERSBYHYDROLOGICSOILGROUPLANDUSEDESCRIPTIONABCDCultivatedIand(1):winterconditIon88919495Mountainopenareas:lowgrowingbrushandgrasslands74828992Meadoworpasture:65788589Woodorforestland:undisturbed42647681Woodorforestland:youngsecondgrowthorbrush55728186Orchard:withcovercrop81889294Openspaces,lawns,parks,golfcourses,cemeteries,landscaping.goodcondition:grasscoveron75%ormoreofthearea68808690faircondition:grasscoveron50%to75%ofthearea77859092Gravelroadsandparkinglots76858991Dirtroadsandparkinglots72828789Impervioussurfaces,pavement,roofs,etc.98989898Openwaterbodies:lakes,wetlands,ponds,etc.100100100100SingleFamilyResidential(2)-DwellingUnit/GrossAcre%Impervlotis(3)1.0DU/GA15Separatecurvenumber1.5DU/GA20shallhoselected2.0DU/GA25forperviousand2.5DU/GA30Imperviousportion3.0DU/GA34ofthesiteorbasin3.5DU/GA384.0DU/GA424.5DU/GA465.0DU/GA485.5DU/GASf)6.0DU/GA526.5DU/GA547.0DtJ/GA56Plannedunitdevelopments,%Imperviouscondominiums,apartments,must1)0computedcommercialbusinessandIndustrialareas.(1)ForamoredetaileddescriptionofagriculturallandusecurvenumbersrefertoNationalEncjlrieerinigHandbook,Section4,Hydrology,Chapter9,August1972.(2)AssumesroofariddrivewayrunoffisdirectedIntostreet/stormsystem(3)Theremainingperviousareas(lawn)areconsideredtobeingoodconditionforthesecurvenumbers-——.1.5.2-32/89 KINGCOUNTY,WASHINGTON.SURFACWATERDESIGNMANUALFIGURE3.5.111100-YEAR24-HOURISOPLUVIALS14(3100-YEAR24-HOURPRECIPITATION..-3.4—k--ISOPLUVIALSOF100-YEAR24-HOURTOTALPRECIPITATIONININCHESo1234567SMiles1:300,0003.5.1-131/90 WATERQUALITYThefollowingcalculationistodeterminewaterqualityvolume,itisbasedon1/3of2-yearstorm,whichis2/3=0.67”.The0.67”precipitationisusedforcomputingthewaterqualityvolume.SBUWSCSMETHODFORCOMPUTINGRUNOFFHYDROGRAPHSTORMOPTIONS:1-S.C.S.TYPE-lA2-7-DAYDESIGNSTORM3-STORMDATAFILESPECIFYSTORMOPTION:1S.C.S.TYPE-lARAINFALLDISTRIBUTIONENTER:FREQ(YEAR),DURATION(HOUR),PRECIP(INCHES)1,24,0.67S.C.S.TYPE-lADISTRiBUTION1-YEAR24-HOURSTORM.67hTOTALPRECIP.*********ENTER:A(PERV),CN(PERV),A(IMPERV),CN(IMPERV),TCFORBASINNO.I0.3,86,0.83,98,6.3DATAPRINT-OUT:AREA(ACRES)PERVIOUSIMPERVIOUSTC(MINUTES)ACNACN1.1.386.0.898.06.3PEAK-Q(CFS)T-PEAK(HRS)VOL(CU-FT).117.8314961496cu.ft.isrequired.Itisproposedtoconstructunderground60-inchpipetostorethecalculatedwaterqualityvolume.Cross-sectionareaof60-inchpipelessthebottomandtop6-inchesis16.02s.fRefertosketchonfollowingsheetLengthof60-inchpipeis1496/16.02=93.33IfUSE95.00ifof6Oinch 1PIPEt(60”DIACMP V.CONVEYANCESYSTEMANALYSISTheproposedstormsystemconsistsofone12-inchpipe(doublewallpipe)conveyingrunofffromthesite.The100-yeardevelopedrunofffromthesitecalbulatedat0.456cfs.All12-inchpipesproposedforthisdevelopmentexceedstheminimumof1.0percentslope.Theattachedcalculationdeterminedthattheproposedpipeataminimumof1.0percentslopecarries3.86cfs,morethan0.456cfsanticipatedfor100-yearflowsduringpostdevelopment. tmp#1.txtManningPipecalculatorGivenInputData:shapesolvingforDiameterDepthSlopeManning’snCirculatFlowrate12.0000in11.4000in0.0055ft/ft0.0120computedResults:Flowrate3.0757cfsArea0.7854ft2wettedArea0.7707ft2WettedPerimeter32.2868inPerimeter37.6991inVelocity3.9907fpsHydraulicRadius3.4374inPercentFull95.0000%FullflowFlowrate2.8624cfsFullflowvelocity3.6446fpsPage1