Authorization: Flood Control Act approved August 18, 1941, Public Law 77-228; Project Document HD 440, 76th Congress, 1st Session.
Location: On Elk River, a tributary of the Verdigris River, at river mile 8.7, about 7 miles east of Elk City, Kansas, and about 7 miles northwest of Independence in Montgomery County, Kansas.
Purpose: Flood control, water supply, water quality, recreation, and fish and wildlife.
History of Construction: Construction began in February 1962 and the project was completed for full flood control operation in March 1966. Ultimate development was initiated on February 1, 1977; the conservation pool changed from elevation 792.0 to 796.0. A seasonal pool plan is used when requested by the State of Kansas.
Type of Structure: The dam is an earth-filled embankment 4,902.15 feet long and rises to a maximum height of 107 feet above the streambed. A rolled earth-filled dike, including the uncontrolled spillway, is 21,712 feet long and rising to a maximum height of 43 feet is located along the right rim of the reservoir south of Table Mound. It has a design rim height of 849 ft. Three rolled earth-filled levees, denoted as “A,” “B,” and “C,” are located around Elk City, Kansas. Levee A has a length of 10,286.8 ft. (STA. 1+26A to STA. 104+12.08A) and a variable top elevation of 840.0 ft. to 841.64ft (NAVD88). Levee B has a length of 695 ft. (STA. 0+95B to STA. 7+90B) and a top elevation of 840.23 ft. (NAVD88). Levee C has a length of 2,450 ft. (STA. 0+50C to STA. 25+00C) and a top elevation of 838.43 ft. (NAVD88).
Spillway & Outlet Works: The spillway, an uncontrolled, concrete-gravity, ogee weir with a net width of 400 feet, is located in a saddle southeast of the dam. Spillway discharge at maximum pool is 120,800 cubic feet per second (cfs). Outlet works consist of a gate tower; a 16-foot-diameter conduit; a stilling basin; one 24-inch-diameter low-flow pipe; and one 24-inch-diameter, valve-controlled, water supply pipe. The outlet works are located near the right abutment and are controlled by two 7- by 16-foot hoist-operated tractor gates. Discharge capacity of the outlet works at the top of the conservation pool is 9,020 cfs with minimum tailwater conditions. The low-flow pipe discharges 89 and 26 cfs at pool elevations 796.0 and 764.0, respectively. Bank-full capacity below the dam site is about 8,800 cfs and on the Verdigris River below the mouth of Elk River near Independence, Kansas, is 21,000 cfs.
Hydrologic Data: Peak flow into the reservoir was 176,000 cfs on July 3, 1976. Inflow volume for the May-June 2019 flood was 518,894 acre-feet, the equivalent of 15.3 inches of runoff from the watershed. Peak inflow for this flood was 50,100 cfs with a peak release of 10,800 cfs. Flood volume for September 29 to October 11, 1986, was 436,800 acre-feet, which is equivalent to 12.91 inches of runoff from the drainage area above the dam site.