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5 . Storage of the spring runoff in Idylwi1.de Reservoir for power regulation would coincide, to some extent, with the unit's storage of the present1.y unappropriated flows, municipal supplies, and plains reservoir transfer. Since a large portion of the water stored in Idylwilde would normally be appropriated for other uses, Grey Mountain Reservoir releases would replace the water which is stored out of priority in ICly1.wi1.de. ......... H.w .;.,;' '~'i;/;,I/;>/"l /' Minimum storage leve1.s are proposed in each of the project reservoirs for the combined purposes of providing space for sediment encroachment, furnishing additionaJ. power head, and providing minimum pools for fishery and recreation. . IdYlwilde Reservoir Idylwilde Reservoir would have an active capacity of 169,000 acre-feet and an inactive capacity of lltOOO acre-feet. The top of active conservation water surface elevation would be 7,860 feet and the top of the inactive storage would be e1.evation 7,695 feet. The water surface areas at these elevations would be 1,700 and 330 acres respectively. An earth and rock-fill dam with a crest length of about 1,250 feet and a height above stream bed of about 290 feet would be required. A dike containing a spillway structure with a capacity of 27,000 cfs would be 1.ocated in a saddle to the right of the dam.. The spillway channel below the structure would be unlined. State Highway No. 14 and the existing power line would be relocated to the north of the reservoir. The State Fish Hatchery would also be re1.ocated if a suitable site is available; otherwise, the state would be reimbursed for the loss. Idylwilde Powerplant Releases from Idylwi1.de Reservoir would be made through a peaking p01rerp1.ant located about one-fourth mi1.e downstream from the toe of the dam. The downstream location and the excavation made for the tailrace would f'urnish additional head for the power- plant. The powerplant would consist of two units haVing a totaJ. capacity of 24,000 KW. The average head would be 278 feet and the maximum flow would be 1,250 cfs. AnnuaJ. generation would be 39,700,000 kilowatt-hours of saJ.able energy. The plant factor on an annuaJ. basis would be 20.4 percent and on a 5-1/2-day per week basis 26 percent. Operation of this plant would be by remote control from the Cache la Poudre Powerplant which would be 1.ocated further downstream. .