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Environmental Programs Common egret, HO....05U National Wildlife Refuge. Upper BasIn During water year 1984, Reclamation continued to study the impact of Glen Canyon Dam on the downstream environment. The Glen Canyon Environmental Studies (Studies) are a multiagency/multiobjeclive series of studies that are oriented to technically evaluate the impact of the operations of Glen Canyon Dam on the natural resources of the Grand Canyon and the Lees Ferry tailwater area. The Studies are a cooperative effort that combines the expertise and cooperative involvement of Federal, State. private, ond academic entities. Reclamation is providing the lead role In the Studies through- overall study management and funding. The main objective of the Studies is to technically evaluate the relationship between the natural resources and the complete range of flow regimes operationally feasible from Glen Canyon Dam. The resulting analysis will provide the input to the development of alternative operational scenarios thot will be evaluated for their natural resource impact and feasibility under existing physical, legal, and operational com.1raints. Four main areas of interest are being evaluated: biological, recreation, sediment transport and hydrology, and power. Representatives from four Federal agencies, two State agencies, four universities, and six private contractors currently make up the study team. The Studies ore approximately 45 percent complete with the major portion of data being collected at maximum powerplant flow levels. The remaining data collection will be oriented largely toward the relationships between fluctuating flows and the natural resources. The projected completion date for the Studies is April 1987, but is highly dependent upon the availability of specific flow levels. The cooperative nature of the Studies and the technical orientation ore a unique approach to ~ _ v!f'Y_ ~i~-=:E~e_ ~~( ~Y~C?r:!li~ _P!~b"l~~._ Fish and wildlife resources in and around CRSP reservoirs were again confronted with drastic changes to their environments during 1984. Although the levels of impact were not as severe as in 1983, the high spring release levels reduced thermal regimes, and inundation of streamside terrestrial habitat affected the propagation and growth of aquatic and terrestrial spe~ies. Impacts to these resources have not yet "been iully quantified. In some cases fisherman use and success have continued in spite of the hindrance to access caused by the high flows. Riparian areas and sandy beaches adjacent to tailwater reaches were modified or eliminated in several areas where water velocities -~>. . ,~ - . ".: ~ removed substrate materials. Deposition of much of the suspended material following the high water, however, caused new beaches to be formed and invading riparian growth is already being reestablished. "Although not accustomed to such dynamic changes in their habitats below regulated reservoirs, it appears that the fish and wildlife resources situated there have remained resilient despite the pressures placed on their environment. Management of the tailwater fisheries and investigations funded by Reclamation is focusing on balancing the needs for cold "wa_t~r_t.!"o_u! .!iR'E!.cle~ J12 tf'!e_irT!mediate tailwater reaches and on the downstream needs of warmer weter endangered species. Consultation with the Fish end Wildlife Service regarding the impacts of the CRSP reservoirs on the endangered Colorado River iishes is still ongoing. Studies designed to provide biological answers and operational options are being initiated and will help fulfill Reclamation responsibilities and requirements mandoted by the Endangered Species Act. In oddition to the native species, a recently initiated investigation of selected salmonid species and their specific habitat requirements will be completed within the next yeer. This information will elso assist Reclamation in determining flow 27