OCR Text |
Show Some existing flora would be eliminated. The disruption caused by actual construction would be temporary. Specific development plans have not yet been formulated. However, a feasibility study accompanied by an environmental assessment is scheduled for 1973. Cumulative and Specific Unit Effects The previous portion of Section C has discussed environmental impacts resulting from the individual systems and features of the Bonneville Unit. Much of the remaining portion of this section is devoted to discussing the impacts of actions that frequently occur and exert a cumulative affect on the Unit and adjacent areas or those impacts that cannot reasonably be considered as resulting from a specific system or feature and should be treated as cumulative Unit impacts. a• Road Cons true t ion Present Unit planning includes the improvement of about 45 miles of existing road, relocation of about 60 miles of road and construction of about 23 miles of new road. Table C- 2 summarizes the construction according to location and type. The Forest Service estimates that on the average it requires 10 to 15 acres of land disturbance for each mile QO of road to be constructed. 00 This means that Unit road construction would remove about 1,000 acres of existing vegetative cover. The adverse environmental impacts of this construction would depend upon the physiography of the land upon which the road would be constructed. Usually the more rugged the terrain the more clearing required to build the road to necessary width and grade. In general, the higher the elevation the more fragile are the existing ecosystems and the more susceptible they are to degradation from disturbance. In this respect the roads along the Strawberry Aqueduct and in the Diamond Fork area would be expected to produce the most permanent scarring of the existing landscape. Construction disturbances in these areas would sometimes not be susceptible to restoration and revegetation. Road work in other Unit areas would not be expected to be harsh on the local landscape. Some of the potential adverse environmental impacts that could result from road construction, particularly on steeper forested lands, are described below with an excerpt from a 70 Forest Service report concerning forest roads in general: |