6505 MERRILL CREEK PKY 2018-01-02 MF Import

1.0 PRO,lEC7'OVEl2VIF.�V This slornt drainage narrativc rcport accompanics thc revised civil engineering plans for the proposed SNUL Archivc 13uilding dated Scptember G, 2007, preparcd by [3arghausen Consulting Gnginecrs. Wc havc rcviscd thc location of thc proposcd Archivc Duilding based on the new silc plan provided by Gary Parkinson Arcliitcct;. Gssentially, thc location of the proposcd building has shiRcd on thc SNDL cxpansion property(TL 1t28040200300500) from thc prcvious location ncar the dctention facility ro tlic soud»vcst corncr of the SNl3L expansion property adjacent ro the rcccntiy constn�ctcd westacccss road. The ncw archivc building fnNs within ll�c SNDL e�pansion property and must compiy with the approvcd drainage plan for thc SN13L facility L'xpansion Mastcr Plan. (Plcasc referencc approved Storm �rainage Rcport prepared by 13arghauscn Considting engincers,dated March l7, 2005J The proposed improveme• ';�vill include the constrnction of 4,800 square fcet(0.1 l acre) of ncw building, 7,000 squarc feet(O.I G acJ oC future building addition, 5,200 squarc fcet(0.12 ac.)of mullipur�wse sport court, 1,800 syuare �cci (0.04 ac.)of concrete pavcment,4,270 squarc feet(0.10 ac.)of asphalt pavenrent,and 5,230 square icet(0.12 acJ of landscaping. 'Clie area of work is approximatcly 0.G5 acres. The entire SNI3L �acility L�pansion projec: is localed on lhe northcasl comcr oC Merrill Creck P�rkway aud Sca��ay Boulc��ard witliin thc City of Gvcrctt and is approsimatcly 8.45 acres containcd on two largc parccls o�encd by Siiin Nippon l3iumcdical Labontorics(SNE3L), cqualing 45.G acres in iLs entirely, the western parcel is approximatcly I�.5 acres and contains the existing SN[3L rescarch and oflice facilities,d�e eastem parcel is appro�imately 29.1 acres, prcviously refcrtcd to as thc SNl3L expansion property. The SNI3L Pacility G�pansion Master Plan has recently constructed 250,000 square feet of building addition, I,000 fcct ofaccess road,d50 feet ofcovcred pedestrian walkway, approximatcly 1 S acres of temporary parking pavemcnt,and all the sronn dninagc facilitics for the master plan, including a combined pond providing 59,592 cubic fcet of detention storage and l7,I65 cubic fcct o(��et pond for watcr quality. Thc intcnt of thc azchivc building projcct is to maintain thc current drainage pattcrns and mainlain the anticipaled impervious arca as to excmpt thc projcct from providing additional dctention or watcr quality facililics or making any adjustmcnts to thc cxisling detcntion and watcr quality system. ln accordance with lhe approved Stonn Drainage rcport for die SNBL Faciliry Expansion Project, tlic reviscd archivc building location falls witiiin tl�c Powdcr Mill Crcck Sub-Dasin No. I, which is collectcd and com�eyed to thc esisting dcteniion and water quality pond located at the northeast corncr of tlic sitc. This dninage pattem is maintained undcr the proposed archivc huilding improvcmcnts. Thc following tablc compares thc assumed drainagc surfacc arca undcr thc appro��cd mastcr plan and Ihc currcnt proposcd archivc building project. hlastcr Plan Archirc Buildin New I3uildin* Acre) 0.0 �•� � Puturc DuildinG Acrc • 0.59 0.1G S ortsCourt(Acrc 0.0 �•1� As halt Pavement Acre) 0.0 0.10 Concrctc Sidc�ealk(Acrc) 0.0 0.04 Tn(a!/ni rcrninu.s Arca Acrc 0.59 0.53 7-/ C, i'