Wetlands in the Floodplain 101

How do they work?

Wetlands provide crucial habitats for migratory birds and are the home of some of our most beautiful and pollinator-friendly native plants like swamp milkweed, cardinal flower, and blazing star. Illinois is home to many forest wetlands and swamps.

Many wetlands in our region were created from rivers. Rivers are not static environments; they shift, grow, and shrink. The Mississippi River, for example, has shifted back and forth for thousands of years. Horseshoe Lake in Granite City is the remains of a previous course the river took at one point in its history.

The low-lying area between the bluffs and the Mississippi River from Alton to Dupo is called the American Bottom. This area is the former bed of the Mississippi River. The American Bottom once had many lakes, wetlands, and marshes borne from the curves the river has taken over time.

Wetlands provide many benefits to our communities, including wildlife habitat. However, wetlands crucially provide water storage. Wetlands, by nature, are low-lying water gatherers. During heavy rainfall, wetlands can capture much of that excess water that can cause flooding, especially in the low-lying area of the American Bottom.

Wetlands, with their unique varieties of plants and trees, are also great at capturing and holding pollution that can run off during rains in urban and rural communities. The sediment and fertilizer that may get swept off a farm field can be caught and used by a local wetland before it can get into the Mississippi river or drinking water sources.

In light of the damaging floods we experienced in Southwestern Illinois this past July, we need to take a look at all of the tools at our disposal. One tool is the restoration of wetlands in our area so that we all can protect our human habitat.