Council Grove Lake is a reservoir on the Neosho River in east-central Kansas. Built and managed by the U.S. Army Corps of Engineers, it is used for flood control, recreation, and water supply. The Flood Control Act of 1950 authorized the building of Council Grove Dam and Lake, named after the nearby community of Council Grove, Kansas. The effects of …Council Grove Lake is a reservoir on the Neosho River in east-central Kansas. Built and managed by the U.S. Army Corps of Engineers, it is used for flood control, recreation, and water supply. The Flood Control Act of 1950 authorized the building of Council Grove Dam and Lake, named after the nearby community of Council Grove, Kansas. The effects of the Great Flood of 1951 further demonstrated the need for the project, and the Tulsa District of the U.S. Army Corps of Engineers began construction in June 1960. The reservoir was completed at a total cost of $11.5 million and became operational for flood control on October 9, 1964.