Following the agricultural devastation of the Dust Bowl during the 1930s, local residents and state officials advocated for construction of a dam in the Solomon River basin to create a reservoir for irrigation. The U.S. Bureau of Reclamation began investigating potential sites in 1939. The Flood Control Act of 1944 authorized construction of Kirwin Dam and Reservoir as part of the Pick-Sloan Missouri Basin Program, but World War II and its aftermath delayed the effort. Kirwin Irrigation District No. 1 organized in 1950. A massive flood of the entire Kansas River basin stoked public demand for flood control infrastructure. In response, the U.S. Congress passed an appropriation act directing the immediate construction of Kirwin Dam and Reservoir for flood control, but allowing for further study before starting irrigation operations. Construction of Kirwin Dam began in March 1952 and lasted until completion of the project in August 1955. Storage of water in the reservoir began in October 1955. The next month, contractors started building Kirwin Canal and its extensions east of the dam, finishing construction in January 1958. Kirwin National Wildlife Refuge was established in 1954 as an overlay project on the flood control and irrigation efforts at the site. The first such national refuge in Kansas, it was created to conserve and manage local wildlife, specifically migratory birds.
Geography
Kirwin Reservoir is located at at an elevation of. It lies in northern Kansas in the Smoky Hills region of the Great Plains. The reservoir is located entirely within Phillips County. The reservoir is impounded at its eastern end by Kirwin Dam. The dam is located at at an elevation of. The North Fork Solomon River and Bow Creek are the reservoir's primary inflows; the North Fork Solomon is also its primary outflow. Kansas Highway 9 runs generally east-west north of the reservoir. East 1100 Road, a paved county road, runs generally north-south immediately east of the reservoir. There is one settlement at the reservoir: Kirwin, Kansas, located immediately below the dam.
Hydrography
The surface area, surface elevation, and water volume of the reservoir fluctuate based on inflow and local climatic conditions. In terms of capacity, the Bureau of Reclamation vertically divides the reservoir into a set of pools based on volume and water level, and it considers the reservoir full when filled to the capacity of its active conservation pool. When full, Kirwin Reservoir has a surface area of, a surface elevation of, and a volume of. When filled to maximum capacity, it has a surface area of, a surface elevation of, and a volume of. The streambed underlying the reservoir has an elevation of. Since the reservoir's initial flooding, sedimentation has gradually accumulated on the reservoir bottom thus raising its elevation.
Infrastructure
Kirwin Dam is a rolled earth-fill embankment dam with a structural height of and a length of. At its crest, the dam has an elevation of. A concrete spillway controlled by 15 gated sluiceways is located at the south end of the dam. It empties into a short channel which joins the North Fork Solomon River east of the dam. Outlet works through the dam, including a stilling well, empty directly into the river and the Kirwin Main Canal. When the reservoir is at maximum water surface elevation, the spillway has a discharge capacity of. The canal outlet has a discharge capacity of, and the river outlet has a capacity of. The Kirwin Main Canal extends east from the dam for on the north side of the river. It then branches into the Kirwin North Canal, which continues for another, and the Kirwin South Canal, which crosses the river in a siphon and continues along its south side for another. of lateral canals extend outward from all three central canals. The entire network provides irrigation to of land.
Management
The U.S. Bureau of Reclamation operates and maintains Kirwin Dam and Reservoir. The local irrigation authority, Kirwin Irrigation District No. 1, operates and maintains the canals, laterals, and drains. The U.S. Fish and Wildlife Service administers the reservoir surface and most of the surrounding land as the Kirwin National Wildlife Refuge.
Recreation
Kirwin Reservoir is open for sport fishing year-round. The Fish and Wildlife Service permits hunting for waterfowl and upland game during appropriate seasons.
