615 ILCS 105/5
The Department of Natural Resources is authorized to lease, in whole or in part, to the City of Rock Falls or its successors or assigns, for a period not to exceed 60 years, the Rock Falls Dam at Sterling Rock Falls, Illinois, and the necessary State owned land, surplus waters and appurtenances for hydropower development. All such leased property shall be deemed a part of the electric system of the City of Rock Falls, Illinois, and the City is hereby expressly authorized in connection therewith to acquire, construct, own, operate and maintain without its corporate limits electric generating facilities and appurtenances at or near the Rock Falls Dam. All revenue received from such leases shall be deposited in the State Treasury in the special fund known as the State Parks Fund and shall be used only for those purposes described in Section 8.11 of the State Finance Act.
615 ILCS 105/5