Illinois Department of Transportation

LaGrange Wetland Bank

Prairie upland buffer and wetland site. (Illinois DOT)

Wetland area adjacent to a backwater lake. (Illinois DOT)

In Brown County, Illinois, where the Illinois and LaMoine Rivers converge, what used to be a floodplain wetland before it was drained for farmland will be returned to its natural state, thanks to the Illinois Department of Transportation (IDOT).

The IDOT has purchased the 1,645-acre property to restore as LaGrange Wetland Mitigation Bank. In return for restoring the property to what it used to be, IDOT will receive credits offsetting unavoidable highway impacts to wetlands and natural resources in the region.

In its original state, the LaGrange site held floodwaters from both the Illinois and LaMoine Rivers, protecting other watersheds downstream. Before the 1940s, when the site was converted to agriculture, flooding was controlled by a combination of approximately 5 miles of levees, 9 miles of ditches, 15 miles of drain pipes, and a 12,000 gallon-per-minute diesel-powered pump. High water from the Illinois and LaMoine Rivers was "leveed-out" and channeled downstream.

After purchasing the LaGrange property, IDOT "deactivated" the ditches, drain pipes, and pump and left a breached levee unrepaired. Now the site provides floodwater and sediment storage for the watersheds of both rivers.

Restoring the flood-control function of the wetland banking site is just the beginning. Full restoration will involve returning the site to a multi-habitat system with open water (backwater lakes), marsh, shrub wetlands, grasslands, and upland and floodplain forest. It will mean planting trees and other vegetation . . . removing non-native invasive plant species . . . preserving existing wetlands . . . even "doing nothing" in some areas, letting nature take its course.

Once restoration is complete, the site will provide habitat for the federally-threatened decurrent false aster, which grows only on the floodplains and prairie wetlands along the Illinois River, and the State and federally-threatened bald eagle, which nests downstream at Meredosia National Wildlife Refuge and which has been seen hunting over the LaGrange site. Three State-listed birds--Wilson's phalarope, least bittern, and common snipe--will gain habitat at the LaGrange site.

Eventually, humans too will benefit from the mitigation bank site after paths are constructed for biking, birding, and walk-in fishing.

The IDOT's restoration work and commitment to long-term management will benefit all or part of 39 Illinois counties (see map). What's more, the site's prime location at the confluence of the Illinois and LaMoine Rivers will enable IDOT to enhance its involvement in ongoing efforts to restore the Illinois River system-efforts involving IDOT, The Nature Conservancy, Wetlands Initiatives, U.S. Fish & Wildlife Service, and numerous private individuals and clubs.

For more information, contact Denny O'Connell at O'ConnellDM@nt.dot.state.il.us.