WSP04033 - Laserfiche WebLink

Home Browse Search

, . . . .>. .,) :'~ . new game management area recommended by the Bureau of Sport Fisheries and Wildlife. Turkey and grouse losses also would occur due to the irrigation development of the mesa and no feasible means of mitiga- tion is known. Resting areas for migrant waterfowl would be provided at Ridgway Reservoir and, to a slight extent, at Dallas Divide Reser- voir. As recommended by the Bureau a waterfowl production area would be provid.ed. at the upper end of Ridgway Reservoir. The Corps of Engineers concluded that the control of floods on the Uncompahgre River provided by Ridgway Reservoir would be an important aspect of project development. The reservoir would be valuable in controlling snowmelt floods on the river if, as provided in the proj- ect plan, conservation storage were evacuated from the floodflows as the need was indicated by forecasts. Benefits from control of snow- melt were estimated by the Corps at $17,000 annually, based on 1963 prices and average conditions over a 100-year period in the future. Intangible benefits were not evaluated but would include saving of lives and curtailment of sickness and destitution which could accompany flood devastations. The Corps commented that inviolate storage space for flood control at Ridgway Reservoir would prevent a minor portion of the damages caused by rainfall and would not be economically justified. Although no inviolate storage space is provided, the Bureau of Reclamation antici- pates that the rain floods would be largely controlled by Ridgway Reservoir since the reservoir would be drawn down to only partial capacity late in the irrigation season when the rainstorms normally occur. Benefits from control of rain floods have not been evaluated monetarily. The Corps concluded that Dallas Divide Reservoir would. have no effects on flood control. It made no evaluation of the effects of the small Sneva Reservoir on flood control but undoubtedly they would be inconsequential. The Public Health Service concluded that additional storage capacity in Ridgway Reservoir for water quality control on the Uncompahgre River would not be justified and therefore no monetary value was assigned. It antieipates, however, that heavy metals previously precipitated in the streambed at the Ridgway Reservoir site may go back into solution when inundated, and therefore it recommends a two- level municipal water supply intake at the reservoir to provide greater flexibility in operation and to permit drawing off the better quality of water from the upper portion of the reservoir. We believe that the 35,750 aere-feet of-inactive storage capacity presently proposed below the reservoir outlet would provide an adequate ponding basin for preeipitation of the metals. Further study, however, will be given to this problem during detailed planning of the p~oject after authorization. At that time, and during the development of the project, consideration , 1 ~ ! 'I 1 5 .1