Annual Report of the Chief of Engineers
on Civil Works Activities
Fiscal Year 1977
Department of the Army Corps of Engineers
Extract Report of Walla Walla District
Ririe Lake, Idaho
Location. On Willow Creek, a tributary of Snake River, in Bonneville County, Idaho. The channel improvement extends from junction of Sand and Willow Creeks to a point on Snake River about 4 miles upstream from city of Idaho Falls, Idaho. (See Geological Survey quadrangle map, Ucon, Idaho.) Dam is about 5 miles below confluence of Willow Creek and Meadow Creek and about 15 miles northeast of city of Idaho Falls, Idaho. (See Geological Survey quadrangle map, Poplar, Idaho.)
Existing project. See table 39-B for authorizing legislation. A rockfill dam about 840 feet long at the crest and about 184 feet high above streambed and downstream channel construction. Spillway has a concrete-lined channel in right abutment. Outlet works utilize a reinforced concrete conduit leading from an intake tower upstream to a stilling basin downstream at the toe of left abutment. Lake has gross storage capacity of 100,000 acre-feet; 90,000 acre-feet of active space for flood control, irrigation, and recreation; and 10,000 acre-feet of space for sediment storage and conservation. Floodway channel is about 8.0 miles long, with a capacity of 900 cubic feet per second. Authorization specified that the project shall be constructed by the Corps of Engineers and operated and maintained by the Water and Power Resources Service. Estimated Federal cost of new work (October 1976) is $38,230,000, including $30,000 for value of public-owned lands.
Local cooperation. Complete except for irrigation contracts.
Operations and results during fiscal year. Main dam construction is 100 percent complete. Two contracts for recreation and buildings and grounds have been awarded, and work is underway. All construction work will be completed by 30 September 1978. A Project Transfer Agreement with the Bureau of Reclamation was signed on October 14, 976 for transfer of the project for flood control and recreation use only until the irrigation water rights and space allocation issues are resolved.
Condition as of September 30. Construction began June 1967 and was completed in September 1980. All necessary real estate has been acquired. Entire project is about 95 percent complete. The final Environmental Impact Statement was filed with the Council on Environmental Quality February 13, 1973.