The Illinois River forms about 50 miles southwest of Chicago and then flows 273 miles across the state of Illinois before emptying into the Mississippi River. The Illinois and its 30,000-square-mile watershed once supported an exceptionally productive freshwater fishery and abundant mussel populations.
This natural wealth of resources eventually brought commercial harvesting of waterfowl, fish and mussels. As development of the Illinois River Valley intensified, other changes occurred. Dams were built to help barges ferry regional products to the world, while levees constructed for flood protection also provided more acreage for the farms needed to feed a growing nation. As time passed, the river's health and diversity declined as the waters of the Illinois became isolated from its floodplain wetlands.
Wetlands are essential to the healthy functioning of streams with which they are associated and to the well-being of many plants and animals. They protect water quality by filtering sediments and contaminants from run-off and help control floods by reducing water levels and velocities in streams. Wetlands also provide safe breeding grounds for fish and serve as critical habitat for migrating waterfowl.
Strategies and Progress
At The Nature Conservancy's 1,195-acre Merwin Preserve at Spunky Bottoms and an adjacent 833 acres owned by the Illinois Department of Natural Resources, the two organizations are cooperating to demonstrate the benefits of restoring the river's floodplain habitat. Other project partners include the USDA Natural Resources Conservation Service, U.S. Fish and Wildlife Service, National Fish and Wildlife Foundation, U.S. Army Corps of Engineers, The Wetlands Initiative, Illinois Natural History Survey and several universities and colleges.
At the project site on the west side of the Illinois River in west-central Illinois, the Conservancy is seeking to promote and sustain native species and communities by restoring natural ecological processes and habitats on 800 acres of uplands and more than 1,200 acres of floodplain. More than 7,500 hardwood trees and hundreds of pounds of prairie seed have been planted, prairie cordgrass and sedges have been transplanted and control of non-native, invasive species is underway.
The replanted species are thriving, as are other wetland plant species that have re-emerged from seeds that remained viable despite decades of farming. In addition, the re-establishment of wetlands and open water habitats is being promoted by reducing the amount of water being pumped out of the area.
Since the Conservancy began its work, the formerly drained landscape has been transformed into a thriving wetland where thousands of American lotus bloom each summer. It is now home to one of the state's largest populations of northern cricket frogs and has attracted several species rarely seen locally, including river otters and American and least bitterns. Each spring and fall, more than 16,000 migrating waterfowl use the area.
The Spunky Bottoms project offers a glimpse at a new future for the Illinois River, for the Mississippi River and ultimately for other large floodplain rivers around the planet. The restoration efforts are being guided by solid science and their effects are thoroughly evaluated so that successful techniques can be promoted elsewhere through the Conservancy's Great Rivers Partnership, which seeks to protect the Earth's critically important freshwater resources.