The Prairie Parkway

Potential Threat to Sensitive Areas in the Fox Watershed

By Tom Schrader
Vice President, Friends of the Fox River

Various routing alternatives for the proposed Prairie Parkway connecting I-88 and I-80 are currently under consideration by the Illinois Department of Transportation (IDOT). The Friends of the Fox River has a vested interest in evaluating the potential impact that construction of such a freeway may have on the streams in the Fox watershed on or near the proposed routes under consideration. While IDOT maintains that no specific route has yet been identified, the Illinois Natural History Survey (INHS) has been commissioned to conduct biological surveys of fish and mussels at various sites along a potential route (mainly in the Big Rock Creek sub-watershed and at potential Fox River crossing sites near Silver Springs State Park and between Yorkville and Oswego). These surveys are part of the Environmental Impact Evaluation phase of the Prairie Parkway project.

The route along which stream sites are being surveyed by the INHS roughly parallels Dauberman Road from around near the village of Kaneville to just east of the village of Big Rock, crosses Big Rock Creek proper just east of the intersection of Granart and Jericho Roads, continues south paralleling Big Rock Creek until crossing it again just northeast of the city of Plano, crosses the Fox River just upstream from Silver Springs State Park and then continues southeast into the Aux Sable Creek watershed before joining I-80 near Minooka.

The northern portion of this route is almost wholly contained within the Big Rock Creek sub-watershed while the southern end of the route impacts the Aux Sable Creek watershed. This factor is significant in that Big Rock and Aux Sable Creeks are northeastern Illinois’s only “A” rated streams designated as “Unique Aquatic Resources” by the Biological Stream Characterization (BSC) ratings calculated by the Illinois Department of Natural Resources. These two streams are also home to the state endangered greater redhorse. This particular route is also acknowledged to be the most impactful to the region’s streams by IDOT on their website devoted to the project (

While stream crossings (bridges) are perhaps the most visible of a freeway’s impacts on streams, other factors associated with the construction of a freeway have detrimental impacts that are at least as severe to the streams’ ecological health. Runoff from the construction process can contribute to stream siltation, burying habitat and raising water temperatures. Deforestation of riparian areas near stream banks can contribute to erosion and eliminate cooling shade, again resulting in higher stream water temperatures. The added hard surface of the roadway itself contributes to additional runoff resulting in flashier (more prone to flooding) streams. Finally, the inevitable development a freeway attracts will exacerbate the effects of runoff and contribute to increases in treated wastewater inputs into the affected streams. The combination of these effects (increased siltation, increased water temperatures, and more nutrients added from wastewater) will result in degradation of some of the best stream habitat in northern Illinois.

What can we do, As citizens of the Fox River watershed and members of Friends of the Fox River, what can we do to help protect our unique resources? Stay informed. Visit the Prairie Parkway website (see link above). Make your thoughts and concerns known to IDOT and your local legislators. Public opposition to routing the Prairie Parkway through our most pristine watersheds will result in a better chance that an alternative transportation solution will be selected.

The Board of the Friends of the Fox River Board will continue to monitor the progress of the Prairie Parkway project and will keep you informed of any new developments that may require action on our part. In subsequent newsletters, we will be examining in more detail some of the natural features of the Big Rock Creek watershed and the Fox River that lie within the footprint of the Prairie Parkway. This area is rich in beautiful and diverse natural resources. Our best efforts are needed to preserve and protect them.