615 ILCS 10/7.3

To use or to lease, or permit the use of, in whole or in part, the surplus waters of such waterway, for a period not to exceed 50 years, and to sell, use, lease or permit the use of, in whole or in part, any land, rights in land or property interests for hydropower development, or the power developed therefrom, for a period not to exceed 50 years.