20 ILCS 805/805-120

The Department has the power to exercise all rights, powers, and duties conferred by law and to take measures that are necessary for the prevention of pollution of and engendering of sanitary and wholesome conditions in rivers, lakes, streams, and other waters in this State that will promote, protect, and conserve fauna and flora and to work in conjunction with any other department of State government that is proceeding to prevent stream and water pollution.