| OCR Text |
Show Lower Provo River Flow diagrams for the reaches of Provo River below Deer Greek Reservoir are presented in Figures C- 10 through C- 12. The Bonneville Unit flows shown would not be expected to occur until about the year 2000. During the nonirrigation season, flow would be reduced 60 to 70 percent in the 5.5- mile reach of stream between Deer Creek Reservoir and Olmsted Diversion. There would be a guaranteed minimum bypass of 60 c. f. s. below the reservoir. Five miles of this section constitute Class I trout fishery. This reduction in critical winter habitat would significantly reduce the capacity of this section of stream to produce fish. The flows historically bypassing the dam would be stored in exchange for Bonneville Unit water in Utah Lake. Because of elimination of the existing power diversion, the 4- mile reach of the river from Olmsted Diversion down to Olmsted Tailrace would experience flows more than four times greater than existing flows which range from 0 to 25 second- feet. This increased volume of water would substantially improve the overwintering capability of the stream for fish. This section is presently classified as Class IV. Winter flows from Olmsted Tailrace to Utah Lake would be reduced by about 60 percent. Near the year 2000 it would probably be necessary to divert the river flow at Murdock Diversion into Jordan Aqueduct to satisfy winter water demands in Salt Lake County. As a result, the critical winter flow would be further reduced to a level about 85 percent lower than that presently occurring. Ordinarily such a severe reduction in winter flow would have a devastatingly adverse impact on a section of stream. However, in this case the impact of the winter problem would be overshadowed by a dewatering problem that occurs independently of the proposed Bonneville Unit during the late irrigation season, ( see Figure C- 12). During the early irrigation season, Unit flows in the 8.4 miles of stream from Deer Creek Reservoir to Murdock Diversion Dam would be about 100 c. f. s. or 22 percent higher than at present. This would be due to increased utilization of Provo River Project water and some Unit municipal and industrial 332 |
