Madison County | 43,245 Acres

Drains to: Mississippi River

Communities: Brooklyn, Edwardsville, Fairmont City, Granite City, Hartford, Madison, Pontoon Beach, Venice

Townships and Districts: Chouteau, Venice, Nameoki, Collinsville, Granite City

Impairments: Total suspended solids, phosphorus, manganese, iron, barium, polychlorinated biphenyls (PCBs), low dissolved oxygen, aquatic algae

Watershed Plan Completed: 2020 – Pending IEPA Approval

About This Watershed

The American Bottom Watershed is an area in Madison Country that is part of a larger watershed known as Judy’s Branch-Mississippi River (the name given by the U.S. Geological Survey). In this area water generally flows east to west into the Mississippi River. The watershed includes parts of 16 municipalities, including Granite City, Pontoon Beach, Brooklyn, Madison, and Venice.

Notable features in the watershed include Monks Mound (in the Cahokia Mounds complex), Chouteau Island, Horseshoe Lake, and Arlington Wetlands.