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. at Palisade, Colorado is a constant 1,100 cfs from July to Apri 1 and momentary peak flows of 8,000 cfs in May and June. The future minimum flow demand of 1,100 cfs was adopted for the purposes of this study over and above all other existing and future uses except for hydropower demands. However, it was indicated in recent discussions with the U.S. Fish and Wildlife Service that the minimum stream flow requirements are not 1 ikely to be implemented. E. FIRM WATER YIELD . After the virgin flows had been established for the Colorado River at Webster Hi 11 by adding historic upstream depletions to the recorded gaged flows adjusted to the Webster Hill site, future river flows at the site were projected by reducing the virgin flows by both past depletions and future depletions predicted under the three development scenarios. These projected inflows to the reservoir were then balanced against predicted downstream demands for the three development scenarios. Any surplus was designated as storable flow which could be retained to fill any available storage in the reservoir. The WWE report concluded that under Scenario I development conditions the reservoir would be able to capture its full 20,000 ac-ft of active storage every year. This means that under Scenario I the reservoir could be completely empty and still be entitled to fill completely, even in a critical drought year. The critical drought year is analogous to a 100 year-flood, in that it is an event which has a 1% chance of being equaled or exceeded in any given year. A 100-year drought occurred in 1977 in the Upper Colorado River Basin. . Under Scenario II development conditions, the WWE report concludes that the reservoir would be entitled to capture all of the 20,000 ac- ft of active storage in every year except the critical drought year, when only 11,000 ac-ft could be captured. This event would only 3686-a/6 II-11