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CALCULATIONS <br />llRAIIVAGF. CAI.CULATIONS <br />Uctcntion nnd wntcr qualily will trc providcd by mcans of n�actvault & wct�nd simd according to currcnt <br />Ciry of 8vcrett Slandards ��ilh a 2R% corrcction factor and watcr yuality by mcans o( dcad srnrn�c si:ed rn <br />ntalch �he 6-nionlh .storm �•uhimr (3.d3? cQ utilizin�; u ce�,�ernird treatmen! crl! jor 15% of �his ti�olu�ne c� <br />wen�utd� jor !he o�her 85%. <br />MF.TIIODOLOGY AND ASSUMPTIONS <br />• SIiUH MBTIIOD AND SCS CN NUMUC:RS Wf:RF: USGD FOR HYDROGRAPII (�FN[NAlInN <br />• nir ��LGVGL PWL ROU1'ING" T'GCIINIQUG WAS USED FOR PONU DFiSIGN <br />• Sl'ORMSI113D SOPTWARE (SBUII) WAS USF:D POR HYDRO(iRAPII GHNGRATION AND I'OND D[SIGN <br />• 24-IIOUR DIiSIGN S'1'ORMS WI:RI�. USGD A7' l'llti VARIOU$ R[CURRCNCG INTIiRVALS I.ISTGD l31iLOW <br />WI'I'll RAINFALL DF.PTIIS 1'OR 1'HIi AREA IN'1'IIRPOLATBD PROM ISOPLUVIAL MAPS OF 24-IIR STORMS <br />• "t'llli SCS ti011. SURVIiY INDICATGS AI.UIiRW(�D-URBAN I.AND COMPI.IIX AS TUG SOIL TYPE. 1liUti <br />HYDROLOCiIC SOII. GROUP "C" WAS IISGD POR COMPUTA7'IONS <br />I'he intcresl nrcas Imve heen mexicled using �hc SCS hydrogrnph mcthcxl with TyFx lA minfall distribution. 1'hc computer <br />program IPutenl'urk� Srormahe�i wns iued for annlysis nnd design. <br />1'he fulluwing slnnJarJs fiom the 1992 Stnrm�varer hlanu}�rment AlanualJnr thr P��gr! Snrnvl /lusm wcre used for sturmwater <br />R/D cnlculn�ions� ll�c sitc was enulymd as bcing 0.15 ac imp, 1.33 nc brush, OAS ac pasturc. 7his (acilily shall be siycd to <br />IH)li standards and detnin the 2, 10 nnJ 100 ycar stomis. "I'he dischargc Gom this tecilily will be designcd �o mlease nt hnl(of <br />the existing 2-ycnr raic, nt ihe cxisling 10•ycar ntc nnd 100-ycar rnte for tlie dcveloprJ 2. 10 nnd 100•year s�omi events. <br />I. Ihc incrcasc in ilows genernted from �he devclo�nd site vs. the Oows currently genern�ed from the site under existing <br />cunJitions(O.I S oc imp = nousc � mnhilc+ uay), 1 J3 ac bnish, 0.95 nc pnswrc) werc nnalyzed end �he rcsults arc as follows: <br />Pro��scJ rcicasc rotcs (i <br />Iw/ 2N°�6 vnult correction <br />RAINFALL INTF;NtiITY TAI3LE <br />(6mo) 0.896 in <br />j2 yrj 1.40 in <br />�10 yrj 2.00 in <br />� 100 yr] 3 00 in <br />0.14 <br />✓ UK <br />11 <br />