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a0 ANALYSIS AND UI�:SIGN OF REQUIRI:D RUNOIT CON'fKOL [3�tPs <br /> l hc si�c is loc.ucd �vithin ih� hfcrrill and Ring Creck and Glcm�ood Crcek druinagc hasins. This <br /> �,rojcci will maintain �hc appruximatc equi��alcnt areas to cach basin. Por purposcs of convcyancc <br /> und collcclion of stormwaicr runoff on thc proposcd project site, a 25-Year stonn bascd on a <br /> i,r.:cipi�ation valuc uf 2.G inehcs and thc hqdrograph mcdiod utiliring Ihe Sanla 13arbara Urban <br /> i lydrorraph with n T'YPr. IA rain(.ill di:at�ibution was a mcthodology for sizing thc convcyancc <br /> sysiem on site. Ylease see ihe calculaticns within �he appendix of tLis report for meihodology and <br /> design of cuncey+mce on site. This i� consisten� wiih Ihe nppro�ed (ur �he Se:n�ay I3usiness <br /> Ccnicr Ovcr;ill Storin Drainagr ('onrcpi.�al 1'lan ;md S�orm Dr.iinagc Rep�m. <br /> �9crrill K Kin� Crcek Urainacc If:�sin: <br /> Thc dcvclopcd area (ha� will hc collccled and conccycd Iu �hc csi�ting dctcnron und �entcr <br /> qu,dity tr�atmcnt pond luc:Ucd in"Cract 501.and ultimmcly discharging to Mcrrill and I:ing Crcck <br /> is approsim:ucly IU.S acres. The existing punJ was dcsigncd to accommodate this devclopmcni <br /> and h�is suflicicnt detcn�ion sturage and �c,uer yu�dity trcatment capaciq�. '1'he IO.S acre are;� will <br /> consist of parking lot p:ivcmcnt .md landscapc and uuck loading dock pavemcnt arca. 'I'hc to�al <br /> impervious pavcment :uca is 7.52 acres and the total pervious landscape arca is .ipproxim,uely <br /> 3._'S acres. �vhich is consistcm �vi�h thc 70Sb impervious arca assumcd in ihc originul pond siring <br /> r,ilculation fix thc cxis[ing pond. �A cup�� of the dcirntion �alculaiions tix thc c�isting pond is <br /> included in the appendix of this repuri. <br /> Gkmcood Crcek Urain:�ec I3asiu: <br /> � I�hc dcvclope� ure:i that will hc cullectcd detained prior lo rcicising Gom thc cxisling �low <br /> cuntrol svuc�ure located at thc northeasl corner of the projec� si�e, and ultimutely discharges lo <br /> Glcmvood ('rcck is :ipproximalcly 7.2 acres. Thc cxisting (lo�a control structur� �aus dcsigncd <br /> assuming thai inlihration �vould bc allowcd up to thc 2-)'car design s[ortn c�'ent and tha� dctcntion <br /> ��ould be provided (or the 10-ycar ;md IUO-year design slorm. Infiltr.uion will be providcd irom <br /> Pund 13 und 760 linem� luot hy fi foot ���ide infiltr;uion trench. The existing cor.lrol structure will <br /> not 1� nwdificd and �lic proposed system will comply �e:ih ihe original hydraulic design, sec �hc <br /> approved calculaiions ior the esisling control strucWre included in the:ippendix of this rcport. <br /> 'I'hc pond and infiltration was sized :issuming full build aut of Ihc projcct. Thc futwc cxpansion <br /> arcas an� assumed to Im impervious. Thc 7.2 acre arca will consist of building roof, fumrc <br /> huilding expansiun are:� and designatcd I:mdscupe area. There is upprosimatcly 2I.SG0 squarc <br /> fcct (0.45 acres) of fuhirc building cxpansion that is currcntly asphalt pavcmcnt �hat will bc: <br /> collected ;md treated lor ���ater yu+dily prior to discharge lo the infiltraiion ponJ. The treaunent <br /> �cill bc providcd with a Irc;umcN train consisting of a Stornucptor manholc followcd by a <br /> Stonnwatcr Inc. stonnfilier��atdt. 'I'hc intcn� of Ihc �rcaimcnt irain is to procidc trc;dmcnt for this <br /> na�emcnt scction untii such timc ihat thc south h�iildin� cspansiun is construc�cd and thc �'cl�idc <br /> tr;i��cled pa��cmen� seciian dr,iining to pond is rcmu��ed. <br /> \II futurc building arca has hccn mod�lcd as impen iuu. ;u�a lor thc dc�cntion calculations. but <br /> ��ill bc grass co�crcd in thc intcrim. "fhc toial impervious pnccmuu arca at full dc�clapment per <br /> � ih�� currcnl sitc pl:m is 5.92 acres and ihc tolal pervious landscapc arca is approxitnatcly 13U <br /> � ;irrrs. ���hich is appmximaltly S2C„ sit� im�cn�iuus co��u. <br /> I W 70.0(}l.Juc �1 PJ/by l <br />