Jim Chapman Lake (also known as Cooper Lake) is a 19,305-acre (78.12 km2) impoundment operated by the Army Corps of Engineers and is located 75 miles (121 km) east of the Dallas/Fort Worth Metroplex in the state of Texas.The reservoir was created by the 1991 Jim Chapman Dam and impounds the South Sulphur River, a fork of the Sulphur River, and provides water supply storage for the North Texas Municipal Water District, the Sulphur River Municipal Water District.