Report of the Secretary of the Army
on Civil Works Activities for Fiscal Year 1996
Department of the Army Corps of Engineers
Extract Report of the Walla Walla District
Jackson Hole, Wyoming
Existing project. On the Snake River, approximately 23.5 miles of Federally constructed levees consisting of the following: 1) on the right bank - a series of levees, off-set levees, and bank protection structures, all with full riprap protection from 10 miles upstream of the Jackson-Wilson Bridge to 3.5 miles below the bridge for a total of 13.5 miles; and 2) the left bank - a series of Federally-constructed levees and bank protection structures, all with full riprap protection, extending from 10 miles upstream of the Jackson-Wilson Bridge to 5 miles upstream and extending 1.5 miles immediately upstream of the same bridge to 3.5 miles below the bridge for a total of 10 miles. In addition, a series of Federal and non-Federal constructed levees, with a total length of approximately 5 miles, most having some or full riprap protection, are interspersed along both banks of the Snake River from Highway 26 Bridge to 4 miles downstream of the Jackson-Wilson Bridge.
On the Gros Ventre River, approximately 2 miles of riprap protected levees on the left bank from 1.5 miles west of Cattlemen's Bridge and extending to 0.5 miles east of the same bridge. On the right bank, a series of levees extending from 0.5 miles west of Cattlemen's Bridge to approximately 0.3 miles east of the same bridge.
Project authorized by PL 516, Flood Control Act of 1950, for flood control protection by channel improvements consisting of channel rectification, levees, and revetments along the Snake River in the vicinity of Wilson, Wyoming. The PL 99-662 modified the original PL 516 to ensure the operation, maintenance, modifications, and additions to the project become Federal responsibility.
Local cooperation. Non-Federal sponsors shall pay the initial $35,000 in cash or materials of any such costs expended in any one year, plus inflation as of the date of enactment of the Water Resources Development Act of 1986.
Since 1978, $40,849,000 (adjusted to October 1996 Price Index) in potential flood damage has been prevented by the levees.
Operations during fiscal year. Teton County, under their Local Cooperative Agreement, worked with the Corps during spring runoff performing emergency levee maintenance. Average daily flows exceeded 24,000 cubic feet per second, which is approximately a 1:25-year frequency. After the flows receded, an inspection of the project was made, and maintenance contracts were awarded. Fiscal year costs were $732,877.