Bond, Champaign, Clinton, Coles, Douglas, Effingham, Fayette, Macoupin, Madison, Montgomery, Marion, Monroe, Moultrie, Piatt, Randolph, Shelby, St. Clair, Washington Counties

5,746 square miles (10% of the State)

Drains to: Mississippi River

Impairments: In 2006 and 2007, a comprehensive water quality assessment was conducted for the Kaskaskia River watershed by Dr. Karl Williard (SIU-Carbondale) in partnership with HeartLands Conservancy. The findings of this analysis were shared in a series of workshops throughout the watershed, alongside descriptions of Best Management Practices (BMPs) to address the pollution issues identified.

Ten years on, Dr. Williard conducted an update to this water quality assessment with support from the Illinois Council on Best Management Practices and the Illinois Soybean Association. Pollutants assessed include nitrogen, phosphorus, turbidity, and fecal coliform. Reviewing changes from the previous assessment revealed whether water quality trends have improved, declined, or remained the same at 14 monitoring gauges throughout the watershed.

HeartLands Conservancy presented the findings of this assessment to stakeholders in the Upper Reach of the watershed at the Lake Shelbyville Visitors Center on June 15, 2016, and to stakeholders in the Lower Reach of the watershed at St. Pancratius Church in Fayetteville to the Lower Kaskaskia Stakeholders, Inc. (LKSI) group on July 27, 2016.

The report summarizing the water quality assessment is available for download here.

About This Watershed

The Kaskaskia River has been an important and prominent natural feature in Central and Southwestern Illinois throughout recorded history.  It is the second largest river system within Illinois, rising along farm ditches in Champaign County and flowing in a southwesterly direction for approximately 292 miles, where it unites with the Mississippi River, in Randolph County. 

The Kaskaskia River Watershed covers all, or parts, of twenty-two counties and encompasses an area of 5,746 square miles (3,677,787 acres) or 10.2% of the entire state.  There are 8,680 miles of tributary streams, including the main river channel, (33% of the state stream-miles), and 843 lakes or ponds covering 79,037 acres.  Two large reservoirs, Carlyle Lake and Lake Shelbyville, add another 37,000+ acres of surface water.  The elevation at the Kaskaskia River headwaters is 740 feet NVGD and drops to 368 feet NVGD at the Kaskaskia Lock and Dam near the confluence with the Mississippi River.

The watershed has many ecologically rich resources.  The largest bottomland, hardwood forest within Illinois, at 43,000 acres, is located along the Kaskaskia River between Carlyle Lake and Fayetteville.  One tract within this forest is the single largest contiguous tract in Illinois (7,300 acres) and is approximately two miles wide at certain points.  In addition, the vast majority of the state’s high quality southern flatwoods forest occurs within this corridor.

The river is an important habitat for waterfowl, migratory birds, and plants associated with wetland habitats.  

Funding Opportunities

None currently available.