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" " ~,...., t~ ,t . ~ 1 t 0039 2.11 flows (November through March) were augmented to the 90 cfs level. This pro- vided a year-round minimum release from Ruedi Dam of 90 cfs. ,The maximum augmentation required for hydropower in any year was 9,900 acre-feet with the average annual augmentation being 8,500 acre-feet. Impacts resulting from Alternative 10 are most similar to those of Alternatives 6/9 and 8, because the volume of water to be sold is the same as Alternative 6/9, the only difference being the augmentation of winter stream flows to support hydropower generation. The resulting difference in impacts is fewer months of altered stream flows and slightly lower reservoir volumes on September 1 of an average year. Trout habitat is much less degraded than with Alternative 6/9 or 8. Again, the primary reason for not selecting this alternative was the full supply delivery schedule. 2.2 Alternatives Eliminated from Detailed Studr 2.2.1 Peaking Hydropower One alternative use of water from the reservoir was considered and elimi- nated from further study, i.e., the construction of a peak load hydroelectric power generating system. The facilities would be designed to produce a maxi- mum amount of power during thepe~k demand hours of each day, normally 1-1/2 to 2 hours each afternoon. A peaking power facility would be designedrto accept the entire daily outflow from the reservoir at a rate equal to the capacityof'the outlet" works. This is equivalent to 1600 cfs when Ruedi is full (Sheaffer & Roland, Inc., 1982). This alternative would also require the construction of an afterbay dam designed to provide storage and flow equalization for each day's releases from Ruedi. The size and capacity of the afterbay would be dictated by the daily volume of water passing through the hydropower facilities. An afterbay would have to be large enough to contain (as a minimum) minimum stream flows below the dam (currently the minimum fishery release 100 cfs in' the summer, or 200 AF per day). Water would flow through the powerhouse during the peak power production periods into the afterbay and would then be subSequently released to the Fryingpan River at a constant rate on a twenty-four hour per day basis. In order to avoid flooding the powerhouse, the base of the existing dam, the existing spillway, the existing outlet works, and the existing Rocky Fork bypass, it would be necessary to locate the afterbay dam several thousand feet