OCR Text |
Show makes it difficult to evaluate some of the environmental changes that would result from construction and operation of the Bonneville Unit. Any interference with the natural scene would be repugnant to some individuals. Despite the obvious difficulties associated with the interpretation of esthetic values there are some reasonable conclusions, regarding the Bonneville Unit, that can be made: ( 1) Reservoirs Reservoir inundation of approximately 20,000 acres of land would substantially alter existing local landscapes. In most instances the impoundments themselves, while appearing out of natural character, would be attractive. The unattractive aspects of reservoirs would be associated ^ ith severe annual lowerings of water levels that expose extensive areas of the basin, permanent landscape scars resulting from borrow excavation and road construction, exposed power and water transmission lines, and to some observers the dams themselves. The Unit would produce 10 reservoirs of which nine of the dams would either be earthfill or rockfill. The design of the Upper Stillwater Dam has been changed to an asphalt core structure. These structures would intrude upon the natural scenery and be visually repugnant to many observers The degree of unattractivenass would be greatest at locations such as Upper Stillwater and Currant Creek where forest wilderness settings presently prevail. The esthetic problems of severe lowering of water surface would be most acute on Upper Stillwater, Hayes, and Mona Reservoirs where the water level fluctuations would occur annually. The water levels of the remaining reservoirs would either be stable or changes would occur over a period of years. Such long- term fluctuations would allow for some vegetative development along the shoreline. Some of the drawdowns would expose borrow areas and detract from esthetic quality. |