Clinton Lake, a 4,300 acre lake constructed to serve as a cooling lake for a power plant, was formed by damming Salt Creek just downstream of the confluence with the North Fork of Salt Creek about six miles east of Clinton, Illinois. The lake has a narrow horseshoe shape with the original design having about 130 miles of shoreline and 74,200 acre feet of water. The dam was completed on October 12, 1977 and had filled to its normal pool elevation of 690 feet above sea level on May 17, 1978. The lake is now 28 years old.
The Clinton Lake Watershed encompasses approximately 188,000 acres of land located in DeWitt, Mclean, and Piatt Counties which eventually drain to Clinton Lake. Two main streams supply Clinton Lake: Salt Creek and North Fork Creek. Each creek has multiple smaller forks that drain to the main branches.
The predominant land use in the watershed is agriculture. Approximately 89% of the watershed is actively cultivated, with a small percentage of the land utilized for range or pasture. Urban or residential areas comprise less than 2% of land use.
New growth and development is largely concentrated roughly eight miles north east of the lake in LeRoy (pop. 3332), which has recently approved three new and/or expanded subdivisions and built a new high school. Clinton Lake itself is privately owned and leased to the Illinois Department of Natural Resources (IDNR). The 9,300 acre park has a variety of activities available such as camping, hunting, and boating, though fishing on the 4,300 acre lake is the most common recreational activity. Clinton Lake Marina is the only marina on the lake. The marina is located on the south side of the southern fork of Clinton Lake. Construction of the 4,900-acre lake began in the 1970s. The Dam was completed in October of 1977 and filled to 690 ft above sea level in May of 1978.