The North Loup Project was authorized as a multi-purpose flood control and irrigation project by the Flood Control Act of 1944. The Twin Loups Irrigation District, organized in November 1958, were created to promote the Project's construction. The U.S. Congress reauthorized the Project on October 20, 1972.
The major feature of the North Loup Project is the Calamus Dam and Reservoir, completed in 1986 at a cost of eighty-two million dollars. The Dam is 7,295 feet long and rises 89 feet above the streambed. The Reservoir has storage capacity of 103,600 acre feet of water covering 5,127 surface acres at the top of the active conservation pool. The Reservoir is approximately 10 miles long and one and one-half miles wide, with 36 miles of shoreline.
Through a system of canals, pumping plants, and diversion structures, water from the Calamus and Davis Creek Reservoirs irrigates 53,000 acres in Valley, Greeley, Howard, Merrick, and Nance Counties. The North Loup Project was dedicated on July 4, 1986.