Laserfiche WebLink
-�---'---�_ _ <br /> BE�C <br /> ENGINEERS <br /> "'1 <br /> � EXISTING CONDITIONS <br /> Drainage at the proJect slte goes to c,ne of two baslns, Powder <br /> Mill Gulch or Japanese Gulch. The divldtng line between these <br /> baslns runs north/south thru the proJect slte. <br /> The portfon of the stte tn the Powder M(11 Gulch Basin Is <br /> currently paved and impervious. A network of exlstlng storm <br /> draln plpes up to 66 lnches in dlameter conveys runoff from <br /> thls basln northerly thru the plant. On the Powder Mill Gulch <br /> Bastn at the northerly end ot the North Complex, there is an <br /> extstlng sedttrientaUon pond and adJacent reglonal detentlon <br /> storage pond. These ponds are downstream of the site. Any <br /> increase in peak tlow w111 be controlled to the allowable release <br /> rate and storage is avatlable tn these ponds. <br /> For the portion of the project site In the Japanese Gulch Bastn <br /> there are no exlsting storm water control facillttes downstream <br /> of the site. <br /> Japanese Gulch Creek runs northerly in a low area along the <br /> westerly boundary of the Boeing property and west of West <br /> , , Perlmeter Road. <br /> Extsting areas of the site, both paved and unpaved, draln <br /> westerly and southerly to the creek in a combtnation of dttches <br /> and ptpes. <br /> For a further descripUon of the extsting or pre-development <br /> topography, ground cover, and conveyance pipes and swales <br /> see the EX7STING DRAINAGE PLAN IN SECTION D of these <br /> calculaUons. <br /> � <br /> •�. ._J <br /> mJc:326•91239-CALC-1 <br /> 12/!0/91 <br />