Illinois River Basin Environmental Problems and Solutions: Illinois Rivers 2020 State of Illinois Cooperative Project with the U.S. Army Corps of Engineers

Abstract

The Illinois River Basin encompasses some 30,000 square miles, covering 44 percent of the land area of the state. The basin (contained in 55 counties) includes 46 percent of the state’s agricultural land, 28 percent of its forests, 37 percent of its surface waters and streams, and 95 percent of its urban areas. Over the years, the diversion of water from Lake Michigan, combined with the discharge of domestic and industrial waste into the Illinois River, improved drainage, construction of levees, urbanization, and the introduction of navigation structures, dramatically altered the river's hydraulic characteristics. Today, the Illinois River, its tributaries, sidechannels and backwater areas are choked with sediment and in need of environmental restoration. Much of the water in off-main channel areas and backwater areas is less than 1 foot deep at normal pool elevation. Populations of many types of economically important fish, waterfowl, and mussels, as well as numerous other species of flora and fauna are annually declining from the increasing sediment load and deposition of silt in highly productive habitats found in backwater, side and main channel areas in the Illinois River. The Illinois Rivers 2020 Program will provide a full toolbox to federal, state, and local governments, non-governmental organizations, and the public to implement a sound and successful basin wide restoration effort. This project builds upon and is complementary to the existing Peoria Lake Restoration and Kankakee River Basin Restoration projects with the Corps and numerous farm bill programs implemented through the Farm Services Agency and the Natural Resource Conservation Service. About 2 million tons of sediment reach Peoria Pool annually. The Kankakee and Fox River Basins represent about 20 percent of the total sediment load to Peoria Lake. The direct tributaries to Peoria Lake represent about 50 percent of the annual sediment load. Reducing the sedimentation from the direct tributaries into Peoria Lake and the Kankakee and Vermilion watersheds will significantly reduce the total annual sediment load to Peoria Lake. The Illinois River Basin project will provide for implementation of ecosystem based watershed management projects within the entire Illinois River Basin under the leadership of the U.S. Army Corps and other federal agencies including the U.S. Department of Agriculture and the State of Illinois under the guidance provided by the Integrated Plan for the Illinois River Basin. The framework for restoration included the following target areas on the main stem as well as tributaries of the Illinois River: