OCR Text |
Show Fisheries and Aquatic Habitat Bonneville Unit construction and operation would cause an irretrievable loss of about 39 miles of stream ecosystem through inundation. Under the proposed plan of diversion, there would be reduced flows in approximately 205 miles of stream. This resource commitment would be irretrievable and the adverse impacts irreversible only to the degree that the proposed plan would be followed. Unit features would be capable of passing most of the natural flows downstream. If the proposed diversions would be carried out, much of the resulting habitat losses incurred could be recovered by increasing minimum releases. In the 67 miles of Class I through Class III streams scheduled to have flows reduced below recommended minimum flows, the recovery of the aquatic ecosystem to its existing state would likely occur over a long period of time. The 20,000 surface acres of reservoir area that would be produced by the Unit would generate a substantially increased demand upon the State's capacity to provide adequate numbers of hatchery fish. An indication of the magnitude of the demand can be obtained by projecting the numbers of fish presently required for three Bureau of Reclamation reservoirs to include the proposed acreage. Deer Creek ( 2,681 acres), Starvation Reservoir ( 3,495 acres), and the existing Strawberry Reservoir ( 8,400 acres) currently receive about 2.65 million, trout annually. The average planting rate is approximately 180 fish per acre. On this basis, Bonneville Unit reservoirs would require about 3.6 million fish each year. The trend towards increased fishing demands indicates that a supply of hatchery fish would be a necessary commitment of resources. Wildlife Habitat Table D- l summarizes the commitment of wildlife habitat required to permit development of the proposed Bonneville Unit. There would be an irretrievable production loss within 810 acres of beaver habitat; 810 acres of moose habitat; 15,500 acres of sage grouse habitat; 16,500 acres of deer habitat; 8,000 acres of pheasant winter habitat; and 28,000 acres of waterfowl habitat. Some of this loss of production would be mitigated with development of replacement lands. In addition to habitat losses for game species, populations of non- game birds, mammals, reptiles, and amphibians would be irreversibly affected in an adverse manner. The habitat losses would be primarily associated with inundation of streamside and terrestrial ecosystems, reduction of streamflow, and drainage of marshlands. Some of the impacts on nongame species would be more specifically covered in additional detailed environmental statements « It would be expected that the inundation of about 20,000 acres of land, the diking of about 7,000 acres of Provo Bay, and allowing about 484 |