Authorization: Flood Control Act approved August 18, 1941, Public Law 77-228; Project Document HD 440, 76th Congress, 1st Session.
Location: On Fall River, a tributary of the Verdigris River, at river mile 54.2, about 4 miles northwest of Fall River in Greenwood County, Kansas, and about 17 miles southeast of Eureka, Kansas.
Purpose: Flood control, water quality, recreation, fish and wildlife, and supplemental water supply.
History of Construction: Construction of the dam was started on May 9, 1946. The embankment closure was completed on August 12, 1948, and the conservation pool was filled on June 9, 1949. The project was completed for full flood control operation in April 1949.
Type of Structure: The dam consists of a rolled impervious and random earth-filled embankment with rock-protected slopes. The Length of the dam, including the spillway is 6,512.35 ft. This spans from the right non-overflow start at STA. 0+5+45A, to the Left Abutment Access Road at STA. 64+57.35A, and the Left Abutment Access Road at STA. 0+00L to the end of the embankment riprap at STA. 6+00L. The maximum height of the embankment is 94 feet above the streambed. A 28-foot-wide access road extends across the top of the dam and spillway.
Spillway & Outlet Works: The spillway is a gate-controlled, concrete-gravity, ogee weir having a net overflow width of 400 feet. The structure is located across the existing stream channel between the embankment and the right abutment of the dam. Spillway discharges are controlled by eight 50- by 25-foot tainter gates. The concrete slab stilling basin has two rows of baffles and a 7-foot-high stepped-end sill. Spillway discharge at maximum pool is 280,640 cubic feet per second (cfs). Operating capacity of the channel below and at Fredonia, Kansas, is 6,500 cfs. The outlet works consist of seven 5- by 8.5-foot rectangular sluices at invert elevation 915.0, with a discharge at maximum pool of 17,357 cfs. These sluices pass through the intermediate piers of the spillway. The sluices are controlled by hydraulically-operated slide gates. A 30-inch cast iron pipe passes through the weir with an invert elevation of 929.0 for low-flow releases. A 12-inch pipe is also located through the structure for future water supply.
Hydrologic Data: Maximum peak inflow (June 1951) was 105,000 cfs, and flood volume (June and July 1951) was 368,000 acre-feet, which is equivalent to 11.8 inches of runoff. The May flood of 2019 produced a flood volume of 443,104 acre-feet, and an equivalent of 14.2 inches of runoff from the drainage area, with an inflow of 65,200 cfs.