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Show C- 21. Table D- l shows the extent to which proposed mitigation measures would compensate for Unit- caused losses. Under the proposed plan, unavoidable habitat losses would occur as follows: beaver - 540 acres; sage grouse - 15,500 acres; deer - 15,500 acres; and waterfowl - 18,000 acres„ While these adverse impacts would be serious at the local level their significance at the Statewide level would not be so great. It is difficult to adequately evaluate the broad effects of the Unit upon the various habitat types in Utah because, except for big game, a total analysis of available habitat is not currently available. •'• 20,122 jn a\\ instances, reservoirs would cause displacement of fauna,. To the greatest extent feasible, facilities to permit natural migration of big game animals to continue through Unit features would be constructed. However, it is recognized that these facilities would not fully eliminate interference with existing migration patterns and that a presently unquantified adverse impact upon big game populations would be unavoidable. Despite the beneficial impact of fencing there would also be some unavoidable losses of big game associated with open canals. The Unit would have adverse impacts upon nongame birds and animals as well as amphibians and reptiles0 These losses have been described qualitatively but inadequately quantified because such organisms do not receive the attention given to game birds and animals. Thus, the relationships of Unit- caused losses to mitigation measures to unavoidable adverse impacts is poorly understood. Because most of the organisms to be affected are known to be adaptable and widespread in distribution and the Unit would create new habitats, it would not be expected that the unavoidable adverse impacts would be severe. One known exception to this situation would be Provo Bay. This unique ecosystem has been studied sufficiently to show that mitigation measures would likely be inadequate and that the environmental loss would be severe. Information gained from completion of planned research projects is expected to reduce the magnitude of this and other types of presently unavoidable adverse impacts. The unavoidable adverse impacts attributable to reduced streamflows would not be limited to fish and other strictly aquatic organisms. There would also be unavoidable adverse impacts on all small mammals, birds, amphibians, and reptiles that inhabit streamside habitat. Recreation The potential relationships of the Bonneville Unit to fish and hunting have been shown in Tables C- 23, C- 24, and C- 26. Sufficient information to discuss other forms of outdoor recreation, in detail, is not available. 471 |