| OCR Text |
Show of stream support a fishery of negligible value. A more detailed discussion of post- operation stream flows is presented in paragraph C4c ( 3). A summary of the affected streams and an idea of the potential adverse impact of fisheries is presented in Table C- l. The Bureau of Sport Fisheries and Wildlife has estimated that the reduced stream flows caused by proposed diversion structures and feeder pipeline would result in the annual loss of 7,800 man- days of fishing. Of this amount, 5,600 man- days were attributed to losses that would occur on the West Fork of the Duchesne. The reduced stream flows would have other impacts besides eliminating physical habitat for fish. Production and drift of terrestrial and aquatic invertebrate food items for fish may be reduced. Strearnside habitats of some species of amphibians, reptiles, birds, and animals would either be depleted or eliminated entirely. The dewatering of the West Fork of the Duchesne, Layout Creek, and Water Hollow Creek could dry up about 200 acres of willow community presently being utilized by beaver. Construction of the diversions and associated pipelines, access roads, and powerlines would result in additional ecological and esthetic impacts that would be both temporary and permanent. Many of these impacts would be adverse. The temporary adverse impacts would be connected with the clearing away of natural plant communities and the disturbance of stream channels in the vicinity of diversion works. Such disturbances would produce unattractive views and cause erosion of soil into streams rendering them turbid. A small amount of erosion would be expected to occur even after these areas had been riprapped and restored. The removal of vegetation and the excavation work carried out along pipeline, power- line, and road alinements would also produce landscape disturbances conducive to soil erosion, some of which would be long- term. Other temporary adverse impacts would include undesirable noise and dust levels and problems associated with accommodating construction personnel at the construction sites. Permanent esthetic impacts would be visual and would consist of the completed structures and the landscape scars remaining after restoration measures have been carried out. The Forest Service, in its comments on the Bonneville Unit Draft Environmental Statement, 102 pointed out that construction of pipelines and access roads at the proposed Docs and Hades Diversions would 232 |
