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<br />Environmental Programs <br /> <br /> <br />I <br />Upper Basin <br />During water year 1985, Reclamation <br />:ontinued 10 study the impact at Glen <br />i:;anyon Dam on the downstream environ. <br />ment. The Glen Canyon Environmental <br />Studies are a multiagency/multiobjective <br />series of studies that are oriented to <br />technically evaluate the impact of the <br />operations of Glen Canyon Dam on the <br />natural resources at the Grand Canyon <br />and the Lees Ferry tailwater area. The <br />studies are a cooperative efforf that com. <br />bines the expertise and cooperative <br />involvement of Federal, State, private, <br />and academic entities. Reclamation is <br />providing the lead role in the studies <br />through overall study management and <br />funding. The main objective of the studies <br />is to technically evaluate the relationship <br />belween the natural resources and the <br />complete range of flow regimes opera- <br />tionally feasible from Glen Canyon Dam. <br /> <br />The resulting analysis will provide the <br />input to the development of alternative <br />operational scenarios that will be evalu- <br />ated as to their natural resource impact <br />and feasibility under existing physical, <br />legal, and operational constraints. <br /> <br />Four main areas of interest are being <br />evaluated: biologicat, recreation, sediment <br />transport and hydrology, and power. <br />Representatives from four Federal <br />agencies, two State agencies, four univer- <br />sities, and six private contractors currently <br />make up the study leam. <br /> <br />The studies are approximately 67 percent <br />complete with the major portion of data <br />being collected at maximum powerplant <br />flow levels. The remaining data collection <br />will be oriented largely toward the rela- <br />tionships between fluctuating flows and <br />the natural resources. The projected <br /> <br />completion date for the studies is April <br />1987, but is highly dependent upon the <br />availability of specific \low levels. The <br />cooperative nature of the studies and the <br />technical orientation are a unique <br />approach to a very diverse and dynamic <br />problem. <br /> <br />Fish and wildlife resources in and around <br />CRSP reservoirs were again confronted <br />with drastic changes to their environ. <br />ments during 1985. Although the levels of <br />impact were not as severe as in 1983 <br />and 1984, the high spring release levels <br />reduced thermal regimes, and Inundation <br />of streamside terrestrial habitat affected <br />the propagation and growth of aquatic <br />and terrestrial species. <br /> <br />Impacts to these resources have not yet <br />been fully quantified. In some cases <br />fisherman use and success have con. <br />tinued in spite of the hindrance to access <br />caused by the high flows. Riparian areas <br />and sandy beaches adjacent to tailwater <br />reaches were modified or eliminated In <br />several areas where water velocities <br />removed substrate materials. Deposition <br />of much of fhe suspended material <br />following the high water, however, <br />caused new beaches to be formed and <br />invading riparian growth is already being <br />reestablished. Although not accustomed <br />to such dynamic changes in their habitats <br />below regulated reservoirs, it appears <br />that the fish and wildlife resources <br />situated there have remained resilient <br />despite the pressures placed on their <br />environment. <br /> <br />Management of the tailwater fisheries <br />and investigations funded by Reclamation <br />is focusing on balancing the needs for <br />cold water trouf species in the immediate <br />tailwater reaches and on the downstream <br />needs of warmer water endangered <br />species. <br /> <br />Consultation with the Fish and Wildlife <br />Service regarding the impacts of the. <br />CRSP reservoirs on the endangered <br />Colorado River fishes is slill ongoing. <br />Studies designed to provide biological <br />answers and operational oat ions are <br />being initiated and will help fulfill Recla- <br />mation responsibilities and requirements <br />mandated by tile Endangered Species <br />Act. <br /> <br />In addition to the native species, Investi. <br />gatlons of selected salmonld species and <br />their specific habifat requirements are <br />progressing. This inlormatlon will also <br />assist Reclamation in determining Ilow <br />requirements and habitat preferences 01 <br />economically and recreatlonally important <br />trout species. <br /> <br />Information gained from both aquatic <br />studies will be incorporated into the <br />overall operation of the reservoirs to <br />insure continued protection at Important <br />environmental values while maintaining <br />many other project purposes. <br /> <br /> <br />... <br />::~r ! <br />J'!,i. <br />f$i.'l-' ''', <br /> <br />~ii!i~J;&\g&;i;~~~ <br /> <br />Preparing lor Fish Sluclles Flaming Gorge <br /> <br />27 <br />