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<br />Glen Canyon Dam Environmental Studies <br /> <br />TIle Glen Canyon Environmental <br />Studies (GeES) program provides a <br />substantial portion of the <br />information base for the Glen <br />Canyon D..rn Environmental <br />Impact Statement (GCD-EIS). The <br />program to d~termlne the effects of <br />operation of the dam on <br />downstream existing conditiollS, <br />has bet>n expanded to meet the <br />additionClI demands of nn EJs while <br />Cldd ressing scientific questions. <br /> <br />All pr€'vious GeES activities have <br />focused around the collection of <br />d:ltil during .normill~ flow <br />opt.'C<\tions of the dam <md several <br />short duration special flows. <br />Starting in June 1990, and <br />continuing through July 1991, the <br />emphasis changed to research <br />specifically oriented towards <br />specific flow scenarios. <br /> <br />The question man}' ask is -Why the <br />need to have special flow releases <br />for scientific resE'arch?- In order to <br />flSsess the impacts of specific <br />operations on the natuml and <br />ft'CreationaJ resources of the Grand <br />Canyun, it is necessaI)' to develop <br />flow response relationships. In <br /> <br />order to maximize useable research <br />dilta in time for the EIS, a specific set <br />of releases is necessary. <br /> <br />The specific research nO\\ls are built <br />arowld the concept of identification <br />of impacts associated with <br />fluctuating flow relea.<>es, induding <br />ramping rates, and con."tant flow <br />releases. Ramping rates are the rate <br />at which flows change. Fourt{>('n <br />separate fesenrch flow scenarios <br />have been designed by GCES <br />Senior Scientist Of. Duncan Patten <br />and the GeES Scientific Core Team. <br />Two of t},e flow scenMios will be <br />replicated to id('ntifr that the <br />original ml:'asuremPllts were valid. <br />Prior to, and following each <br />research flow scenario, a research <br />evaluation flow will be scheduled <br />to allow the researchers to mea';ure <br />initial and resulting conditions of <br />each flow scenario. The research <br />evaluation flows will run for a <br />duration of three days at a level of <br />5,000 cfs. <br /> <br />A stiUldard operilting prOCt"dure to <br />maintain each research flow is <br />being established between <br />Reclamation and Western Area <br /> <br /> <br />Power Administr<ttion. This is <br />important to Western since it hilS <br />certain contractual power deliver)' <br />obligations to meet. along with <br />concerns for protecting the power <br />deliv(>rr grid s)'Mem. R(>scarc}, <br />flO\..,s have a significant effect on <br />Western's daily pow(>r marketinp; <br />operations. In many cases pO\....er <br />peaking forgone due to rt':'learch <br />flows must be repl<tced from other <br />sources. <br /> <br />To make efficient use of the <br />research flows, the GCEs Team is <br />preparing an integrated study plem. <br />The plan is the result of the' <br />combined efforts of the scientists, <br />technical reviewers, and feedback <br />provided by the National Academy <br />of Sciences. Thl:' plan will be made <br />available to interested persons. <br />Specific areas covered by the plan <br />include: sediment transport, <br />hydrology, archeology, <br />geomorphology, water quality, <br />limnology, nquatic studies, <br />endangered species, trout, <br />recreation, il.Cld economics. <br /> <br />J <br />, <br /> <br />Seining for Humpback <br />chub down the Little <br />Colorado River, This Is <br />one of the endangered <br />fish species being <br />studied. The humpback <br />chub population Is <br />heaviest In this area. <br /> <br />5 <br />