Illinois Statutes Chapter 615. Waterways § 5/6. Data; report

§ 6. The Department of Natural Resources shall obtain all possible data with reference to all of the waters of the State of Illinois, including original surveys, meander notes, maps, plats, river gauges, high and low water marks, and all and every source of information which will tend to disclose or establish the rights of the People of the State of Illinois with reference to each body of water in the State, and shall from time to time make public report of its findings.