70 ILCS 1565/1
Any park commission, park board or board of park commissioners which has heretofore acquired the title to any land adjacent to or adjoining upon or penetrating into any public waters in this State or to the submerged lands and bed of such public waters or any part thereof or to any riparian or other rights in relation to such public waters, may grant, convey or lease any of such lands or rights to any city having a population of 500,000 or more and owning and operating its waterworks and waterworks system, to be used as a site or sites for buildings and other structures for the purpose of improving and extending such system and for the construction of water purification plants, intakes, tunnels, breakwaters and other structures and appurtenances connected with such waterworks and waterworks system.
70 ILCS 1565/1