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<br />June 7,2000
<br />
<br />Mr, Ben Urbona~, PE.
<br />ChicfMasterPlarmins
<br />Urban Drainage and Flood Control Districl
<br />2480W. 28th Avenllc, Suile156-B
<br />Denver. Colorado 80211
<br />
<br />Rf:F: 9n2A. Outfall Systrms Planning
<br />Alternate E\'aluation Report
<br />[rie and Adjacent BOllldu and Weld County Area~
<br />
<br />DearBcn
<br />
<br />Enc1o>~d, please find Outfa/! .<'}'.\Iem.~ Plwlllmg Alternare };mhwtio/l Report f;ri~ <IIld AJ;un'fll
<br />HOIdJer <llId Wdd Coullty Ar~u.' The study area encompasses approximately 17.3 sq. mi. and is
<br />~mnd by Mineral Road 10 the north, Co~l Creek Of the Weld.rnouldcr County bOllrldary line to lh~
<br />cast, B;:sehne Road to the south, and Highway 287 to the we~l The rtp"n j, ,;ubmittcd In
<br />completion of the first phase of Urban Drainage and Flood Control District Agreement 99-04.09
<br />
<br />The report rcpre~cnts a significant contribution to the exi~ting hydrologic and hydraulic data hase
<br />required for s!ormwater management in the stl.ldy area It contains recent topographic and
<br />hydrologic information, discusses historic and current f1oodinj!. problems, dcfmcscurrellt and future
<br />ful1ydeyeloped hydrology, and idemifiesthe impact of roads, railroads, and irrigation ditches on
<br />stormwater t1llw~ in th.. study area The allah'si, of existing SlOrmwater convcy~nce fadlitie~ within
<br />the study area "how llmt these facilities do not have the eapacit~, to transport the 100-year event
<br />when proposed nUlIte de,elopment of the area i> wmplete and. in wille en"..,. under current
<br />tlev,'lopme"teolldition"
<br />
<br />The final altemate analysis was preceded by drainage design guidelines developed individually for the
<br />various jurisdictions in the study area to reflect the needs of the communities in the slUdy area The
<br />drainage design guidelines also allowed the Advisory Board overseeing our work to focus on the most
<br />practical and cost effective solutions to SlOrmwater conveyance Two alternate outfall systems were
<br />produced d<.lring this process. The first alternate analyz:ed existing conveyance systems to determine how
<br />they could be improved to safely convey flood flows through Ihe study area The results of the first
<br />alternate was examined by the Advisory Board, and concerns were raised and changes to the alternate
<br />suggested by the members Alternate 2 resulted from these communications
<br />
<br />The recommended outfall system cost indudes approximately $25,600,000 for regional detention facilities,
<br />S33,350,000 for conveyance facilities, $5,600,000 for road and railr oaderossings, and $550,000 for
<br />improvement' to irrigatiun facilities The total estimated cost for drainage Improvements for the
<br />recommended alternate is $65.100,000, The majority of these costs should be borne by future development.
<br />
<br />Love & Ass.ociates, Inc. wishes to thank you and all members of the Advisory Board for the practical
<br />approach represented by tbis report to improve slormwaterconveyan ceefficiency, reduce flood hantrds, and
<br />improve water quality within the sludy area We look fOTVo'ard to working with you on the ~uceessful
<br />completionoftheprclimir,arydl'signofthe~electedoutfallsystem,
<br />
<br />
<br />Sincerely.
<br />
<br />LOVE & ASSOCIATES, 1i\C.
<br />
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<br />DavidJ. Love, PL,
<br />preSident//?;
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