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<br />00253~ <br /> <br />Proposal to Develop a Research Plan to Analyze the Response of Natural <br />Resources below Glen. Canyon Dam to a Beach Habitat Building Flow Greater <br />than 45,000 d's and Fluctuations During Periods of High Powerplaut <br />Releases. <br /> <br />May 19, 1,998 <br /> <br />The objectives of a Beacll Habitat Building Flow delaibed in !be Glen Canyon Dam EIS are to <br />.....rebuild high e1evalion sandbars,provide WlI1er for vegetation, deposit nulrienfs, restore <br />backwa1er cbannels, and provide some of the dynamics of a naI:Ux3l syslmL w (GCDEIS) <br />Specific r . d1 questions addl : S l e II by the test flow included (BHBFBA): <br /> <br />1) ~lofllOlHlll1ivefisb, <br />2) Rejuvenate backwaler habitats for native fish, <br />3) IncRase lleigbt and areaof emting ~ followed by erosion al rates that deaclse <br />with time, . <br />4) Reduce ...,...llhulC vegetalion. <br />5) Preserve and restore camping beaches, <br />6) Promct cultuml RlSOUl't'.es from erosioIl, <br />7) Result in more navigable rapids, and <br />8) Not cause significant advel'se effi:ds on the aquatic food base, trout fishing, endangered <br />species, cultmal IeSOII1'ceS, and economics.. <br /> <br />~v ~{.\t <br />~,cA ~\ <br />'\''' ~, <br /> <br />While bene'.fi1ir1g many ""h....'. cultural, and recreatiooal resources, the e",pe. ;"'...."', Beach <br />Habitat Rm'mflg Flow (BHBF) conducted in 1996 fiIiled to achieve several of these objec:lives <br />(GCMRc, 1997). Following that test flow, many IeSeaId1en suggested that a BHBF oftbcse <br />""'wmtde and shom:c duratioo could achieve ~ sedimeoI: dcposiliuu and :>Miflooal <br />ICjuvma/ion ofbackwatec habitats witholll oigl'ifiNmt; advuse impacts (GCMRC, 1997). In <br />addi.tioo, ~ steady high powelpJam rd~ ~ tOaccelelare beach erosioa <br />(Moody. 1998). Resea.ch.:...i hyp04~re that lIlOdela1e flnmt2tinus may deaclsethisralcof <br />erosion al bigh flows (Kaplinski, 1998) while increased ability for tile hydropower resoun:e to <br />fuJIow e1ectricaJ.loads has economic value (Palmer. 1998). <br /> <br />This paper proposes a process fur detecmin.ing the pm>~ for flows that would beua <br />adrieve the ~ oCtile BeachlHabitat-Builtli'lg Flow, delc..wiaea =earc.b stmtegy to <br />assess these test flows, and evaluate the potential impacts of implel1~"I;..g such a tesClbis <br />inf....tlldtlon will be used by The lWG and AMWG in dtocitling whether to carry out the <br />proposed rcsc.....J1. <br /> <br />(. The Pl'oposa.(: <br />The Grand Canyon MoniTOring and Research Center (GCMRC), in consullal:ion with the <br />lWG, is to: <br />A.. Reoommend the 1lIlIgD.ilude, liming, dwation, and pm and post flow regimes for a test flow <br />' between January and July That best meets the ob.iectiws of a BHBF. This should include <br />flows grcws than 45,000 cis. <br />B. Define a test flow regime to redu<:e beach erosion rates during periods of high powerplant <br />reT""""S (>1.5 maflmo). Th~ should include fluctuating floWS, (wilhincurtenl daily, <br />upramp, and ~~p limits) ~e 25,000 cfs up to powerplant capacity. <br />c. ~ the advisability of conducting research on A and B sequentially and/or sepaxatcIy, <br /> <br />D. Evaluare, based on best current knowledge, the positive and negative impacts of . <br />implementing the proposed test flows.. <br />