Owned by the City of Mattoon, Lake Mattoon is located in the counties of Coles, Shelby and Cumberland.

Having a maximum depth of 35 feet, the average depth is only 10.5 feet. The capacity is 2.6 billion gallons with a surface area of 765 acres. 53% of the 55.5 mile shoreline is owned by the City of Mattoon, along with 348.5 acres of surrounding property.

Lake Mattoon is fed by the Little Wabash River and is a popular recreation spot for boating, fishing, and camping. Approximately 1,042 boat permits are issued every year and 360 two day permits. The primary use of Lake Mattoon is supplying water to the City of Mattoon, Illinois.