OCR Text |
Show Suggested Modifications to Provide Recommended Minimum Stream Flows The Bureau has weighed carefully the environmental impacts projected for the Bonneville Unit and on balance cannot modify the project further to meet the demands for guaranteed higher minimum flows in the streams effected by the collection system. It must be understood that the availability of water in the Uinta Basin is limited and a decision had to be made as to how to allocate the supply. Reformulation of the plan beyond the present framework would require additional financing of great magnitude in order to substantially increase minimum streamflows in the Uinta Basin as requested. The current plan calls for an increase in storage in Upper Stillwater Reservoir above project requirements to gurantee 6,500 acre- feet minumum flows for Rock Creek and Strawberry River. To further enlarge Upper Stillwater Reservoir, as an example, to provide 15,000 acre- feet more carryover capacity, would yield about 7,500 acre- feet annually. Such enlargement would necessitate raising the proposed 200 foot high dam by 42 feet and would inundate a longer reach of Rock Creek and require backing waters into the High Uinta Primitive Area. Coupled with this added environmental impact would be high costs. A 150 second- feet enlargement of Vat Tunnel, with an enlargement of the Currant Creek Reservoir by 4,000 acre- feet, would yield about 2,800 acre- feet annually from Currant Creek and West Fork of Duchesne. Such enlargements would also be costly. These two modifications would yield about 10,300 acre- feet annually. Development of a 17,000 acre- foot reservoir at the Hanna damsite on the Duchesne River would regulate another 14,000 acre- feet for fishery flows for delivery to the aqueduct through a 1,320 foot pump lift. The projected by- passes for downstream irrigation rights are 6,200 acre- feet. All of the above added to the present guarantee of 6,500 acre- feet of minimum streamflows would provide the full 37,000 acre- feet requested. However, as the following tabulation indicates, costs are projected near or exceeding $ 80 million. 627a |