Corporate municipal authorities are granted broad authority to protect and maintain watercourses, pursuant to 65 ILL. COMP. STAT. 5/11-104-1 (2004). Municipal authorities may “deepen, widen, dock, cover, wall, or alter channels of watercourses.” Furthermore, municipal authorities may construct and repair canals and slips to accommodate commercial interests, 65 ILL. COMP. STAT. 5/11-104-2 (2004), and water-related landing facilities. 65 ILL. COMP. STAT. 5/11-104-3 (2004). Municipal authorities may also relocate existing water courses within municipal limits to accommodate plans to establish or improve roadways and sidewalks. 65 ILL. COMP. STAT. 5/11-87-1 (2004).