OCR Text |
Show gains accruing below Unit dams and diversion structures would produce a significant amount of fish habitat in Uinta Basin streams under proposed operating conditions. The impact of stream gains for the Uinta Basin streams is illustrated in Table C- 20. Of the 106.8 miles of Class II and III habitat scheduled to experience reduced flows, it is anticipated that stream gains would substantially reduce the severity of impact in 60.5 miles of stream. Without considering the influence of stream gains, the Bonneville Unit would reduce the quality of fishing in 8.1 percent of the State's Class I fishing waters, 10.5 percent of the Class II waters, and 2.9 percent of the Class III waters ( refer to Table C- 20). The adverse impact upon Class II streams within the Uinta Basin would be substantial even when considering the benefits of stream gains. Of the 47.6 miles of Class II stream habitat that would be damaged by the Unit, the impact on 31.1 miles or 65 percent would be very severe„ Much of this existing habitat would be eliminated. The recreation boating potential on about 200 miles of stream would be curtailed by about 50 percent0 Sudden flow changes and excessive flows sufficient to create a significant public safety hazard and cause serious channel erosion would occur in 5 miles of Class III stream on Diamond . Fork above Hayes Reservoir. The intensity of this impact would be lessened or eliminated if alternative feature design, presently under consideration, were to be implemented0 b. Utah Lake The diking of Utah Lake would reduce the surface area of the lake by about 35 percent. The draining of Provo and Goshen Bays would destroy a significant amount of fish habitat. Spawning and feeding areas, " with the exception of the unique rocky shoal area of Goshen Bay , have not been delineated. However, it is known that a considerable amount of catfish spawning occurs in Provo Bay. The actual extent of the unavoidable adverse impacts upon Utah Lake would not be known until planned studies were completed. There would be considerable potential to enhance desirable aquatic production within the lake through creation of rocky shoal areas along the dike faces. Existing studies suggest that lack of such substrate may be limiting production of some species of game fish. Wildlife Habitat A summary of potential nonmitigated Unit impacts on game and fur- bearers of the Uinta and Bonneville Basins is presented in Table 470 • |