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native to the area wou Id also be planted, The relocation of U. S. Highway 24, required under Plans F, F.l, and F-2, would be done under the direction of the Colorado Division of Highways. D. PIPELINE CONSTRUCTION Pipelines under all plans would be buried. Generally, pipelines would be constructed in a permanent or temporary access road, Temporary roads would be obliterated and restored to satis- factory condition after the pipeline is installed. To minimize construction scars in the Homestake Valley, the gravity and pumped pipelines on or near the valley floor under Plans D, E, and F-2 would be placed in the existing Homestake Valley Road wherever possible. The pipelines in Cross Creek Valley proposed under Plan A would be founded principally upon rocky slopes which would require that most of the pipe trench be blast - excavated to achieve satisfactory progress. The pipeline to East Cross Creek also crosses several patches of talus which might be subject to sliding during construction. The pipelines on the western slope of Homestake Valley under Plans A and C are founded primarily in areas covered by fairly deep soil overburden with intermittent rock outcrops. Blasting for these pipelines would be necessary only at rock outcrops. Pipe- line rights-of-way would be restored after construction is completed to satisfactory condition as provided for roadways. E. CONSTRUCTION OF DIVERSION STRUCTURES Stream diversion structures would be constructed at designated diversion sites under the several plans. Facilities at each diversion site would include an overflow type rockfill diversion dam, a 26 gated concrete diversion structure, a measuring flume, and a buried diversion pipeline. The diversion pipeline would connect to a drop shaft into a tunnel or to a buried gravity pipeline depending upon the particular plan. 0 ~ Each diversion dam would be constructed of native rock obtalT11 ed from local talus deposits or from local project excavatio~S:- Diversion structures and measuring flumes would be constructed of concrete and would be located principally below ground to limit adverse visual impact, Facilities at each diversion site would be designed to blend with site topography and the natural envi, ron ment. I I F. DAM CONSTRUCTION ON HOMESTAKE CREEK I I I I Construction of the impounding dam on Homestake Creek under Plans E, F, F-l, and F-2 would include the following principal component items of work: (1) stripping of topsoil and unsuitable materials from the dam foundation; (2) a seepage barrier consist- ing of a cutoff trench to bedrock, backfilled with impervious compacted fill, and a pressure grout curtain into the underlying bedrock to seal water passages in the rock; (3) an outlet tunnel through an abutment to pass stream flow during dam construc- tion and to pass stored water releases through the completed dam; (4) a spillway to pass flood flows safely around the com- pleted dam; (5) a zoned dam embankment of compacted selected soil and rock materials obtained from the reservoir area upstream of the dam and tunnel muck from the tunnels constructed under the particular plan; (6) rock riprap slope protection for the embankment slopes; (7) valved outlet works to control releases of stored water; and (8) clearance of trees and vegetation from the reservoir area. I I I I I I Topsoil and other suitable materials from the dam foundation would be used to surface construction scars at the dam site or other construction sites. Trees removed from the reservoir site would be disposed of as directed by the U. S. Forest Service. Tree slash and small vegetation would be chipped and stockpiled I I