Illinois River Basin

The Illinois stretches for 273 miles and drains over 30,000 square miles of land.  Its basin includes 46 percent of Illinois' agricultural land and 95 percent of its urban population.

The large population in the Chicago area causes billions of gallons of treated sewage to be discharged to the Des Plaines, Fox, and other tributaries of the Illinois.  Rapid development in Chicago's sprawling suburbs is causing loss of riparian habitat and degradation of high quality streams.  Agricultural lands which dominate the majority of the watershed contribute sediment and high levels of agricultural chemicals.  The basin's streams also continue to be impacted by "legacy" problems such as sediments contaminated by metals and toxic chemicals, a result of past environmental abuses.

Nutrients are among the most important water quality issues impacting the Mississippi River basin as a whole. Studies estimate that, whereas the Illinois contributes only 7 percent of the Mississippi's flow into the Gulf of Mexico, it contributes 15 percent of the total nitrogen reaching the Gulf.  These findings are corroborated by a federal task force assembled to study the Gulf Dead Zone.

While most of this nitrogen comes from agriculture and other land use activities, the Upper Illinois River is one of only two areas in the entire Mississippi River basin where municipal pollution is a major source of nutrients.

Prairie Rivers addresses water quality problems impacting the Illinois River basin through aggressive grassroots advocacy, application of the latest scientific findings, and use of existing policies such as the Clean Water Act.