Illinois Tollway Projects Creating Wetlands and Preserving the Environment along with Infrastructure

Pine Dunes

Illinois Tollway projects aren’t always about roads and bridges; some Tollway projects are about wetlands, woodlands and recreational trails. 

When infrastructure projects intersect with nature, however, transportation agencies are required to mitigate the impact on the local environment and in many cases restore and replace any impacted waters and wetlands affected by a project.  

The Tollway’s investment in the Lake County Forest Preserves’ Pine Dunes serves as an excellent example of how the agency approaches wetland mitigation, providing regional ecological preservation with expanded access for recreational activities to the 315-acre Pine Dunes Forest Preserve near north suburban Wadsworth. 

The Pine Dunes project successfully delivered 58 acres of new wetland creation, 32 acres of wetland enhancement and 3,300 feet of stream restoration, as well as 235 acres of woodland restoration and improvements and conversion of upland farmland to wet prairie, mesic-prairie and oak savanna areas. 

Work at Pine Dunes also included site improvements for the preserve, including nearly 3 miles of new bike and pedestrian trails, three boardwalks, overlook areas, a drinking water well, restroom facilities, parking lot and new entrance road. 

While purchasing mitigation bank credits is one way to fulfill wetland mitigation requirements, the Tollway made it a priority to go beyond its financial responsibilities to forge partnerships with local forest preserve districts, communities and environmental groups and apply its funds to creating and improving wetlands and forest preserves and to delivering additional recreational benefits to forest preserve users. 

Wetland restoration and woodland enhancements included the removal of old agricultural drain tile to re-establish the natural hydrology and water flow, removal of non-native species, control of invasive plants and the planting and seeding of diverse native prairie species. In addition, approximately 4,800 native trees and shrubs were planted in the upland areas.

It’s often ideal to perform mitigation close to the immediate project area. But for roadway projects in highly developed urban areas like construction of the Illinois Route 390 Tollway and the new I-490 Tollway, location can be a challenge – especially when construction is in and around one of the nation’s busiest airports. The Federal Aviation Administration prohibits the construction of any wetland mitigation project that might attract waterfowl and other birds near an airport. 

So, the Tollway’s goal is to find the next best location keeping environmental priorities in mind. For wetland mitigation projects, that can mean looking for a location within the larger regional watershed to maintain ecological balance and avoid disrupting natural aquatic resources that support plant and animal species within that same region. 

While the Pine Dunes Forest Preserve is in Lake County and the Tollway’s work on the new toll roads is in DuPage and Cook counties – they are all part of the Des Plaines Watershed, which stretches from southeast Wisconsin, through Northeast Illinois and as far south as Will County. 

The site was selected in coordination with federal and state regulators to mitigate construction impacts associated with construction of the Illinois Route 390 Tollway and the new I-490 Tollway. 

The Pine Dunes Forest Preserve features numerous streams, marshes, sedge meadows, ponds and other wetlands, as well as a mix of prairie, savanna and oak-hickory woodlands. These habitats have been identified by the Illinois Wildlife Action Plan, Chicago Wilderness and the Max McGraw Wildlife Foundation as critical nesting and foraging areas for a variety of birds and other wildlife species including European goldfinches, bobolinks, and sandhill cranes.

The Tollway started its work on the Pine Dunes Mitigation Project began in 2014, the same time construction was starting on the new Illinois Route 390 Tollway. 
Improvements were completed and opened to the public in 2018. 

After monitoring was completed, the overall mitigation work received sign-off from the U.S. Army Corps of Engineers in summer 2020 and now an established ecosystem, the site has been turned over to the Lake County Forest Preserve District.