Authorization: Flood Control Act, Public Law 81-516a, approved 17 May 1950; Project Document HD 442, 80th Congress, 2d Session.

Location: On the Grand (Neosho) River at river mile 449.9, 1.5 miles northwest of Council Grove in Morris County, Kansas; 47 miles southwest of Topeka and 75 miles northeast of Wichita.

Status: Complete.

Purpose: Flood control, water supply, water quality control, fish and wildlife, and recreation.

History of Construction: Construction of the project began in June 1960. The project was placed in full flood control operation on 9 October 1964.

Type of Structure: The rolled earth-filled embankment is 6,500 feet long and rises 96 feet above the streambed. A roadway crosses the embankment and spillway.

Spillway and Outlet Works: The emergency, uncontrolled spillway is a 500-foot- wide open cut located in a saddle near the right abutment. Spillway capacity at maximum pool (elevation 1316.0) is 49,400 cubic feet per second (cfs). One 24-inch-diameter low-flow outlet (discharge capacity of 47 cfs at pool elevation 1240.0) and a 17-foot-diameter outlet conduit are located through the embankment near the right abutment. Outlet capacity is 8,900 cfs at pool elevation 1265.0 and 11,400 cfs at the top of the flood control pool (elevation 1289.0). Channel capacity below the dam site is 3,000 cfs. One 24-inch-diameter pipe for future water supply is provided in the structure. Outlet works have two 10.5- by 17.7-foot hoist-operated tractor gates.

Hydrologic Data: The flood of record occurred in June and July 1951 (pre-construction) with a peak discharge of 121,000 cfs and a volume of 184,200 acre-feet, which is equivalent to 14.04 inches of runoff from the drainage area above the dam site.