| OCR Text |
Show Vat Dam and Reservoir Vat Dam and Reservoir site, located 37 miles northwest of Duchesne on the West Fork of the Duchesne River, was investigated in the early stages of planning the Bonneville Unit as the site for a storage reservoir to regulate flows for delivery to Strawberry Aqueduct. High spring flows in May and June would be stored in this reservoir and released to the aqueduct during the fall and winter season. Costs for a dam and reservoir at various storage capacities from 2,000 acre- feet to 13,000 acre- feet were estimated. As hydrclogic studies progressed it became apparent that West Fork peak flows occurred earlier in the spring than Rock Creek flows. Eeing the major contributors to flows in the aqueduct, these two streams were studied extensively tc determine the relative economy of storage on each stream. Cost of a storage dam on West Fork could not be justified by the additional water that could be diverted to the aqueduct. A reservoir with a capacity of 8,000 to 10,000 acre- feet would maintain the minimum recommended fishery flows, if such a reservoir could be economically justified for this additional benefit. Vat Diversion Structure, with a storage capacity of kO acre- feet, was investigated and later adopted to divert West Fork water into the aqueduct in lieu of Vat Reservoir. Since publication of the August \ L96k Definite Plan Report a dam and reservoir to store 1,0^ 0 acre- feet near the mouth of " A" Hollow was investigated. " A" Hollow is located about lh miles downstream from the site of Vat Diversion Structure. This reservoir would inundate approximately kO acres of Forest Service lands primarily covered with willows. It would have a stable water surface elevation, with only UO acre- feet of active storage for maximizing fishing and recreational opportunities. Under the " A" Hollow alternative Vat Diversion Structure and Feeder Pipeline, approximately 3,000 feet of West Fork Pipeline and 100 feet of Vat Tunnel would be eliminated. About 0.8 miles of Forest Service road would require relocation. Because of greater costs , recreation and fishing opportunities are not sufficient to justify this alternative over the proposed Vat Diversion Structure. 584 |
