Illinois Water Supply Planning




Welcome to the State of Illinois' Water Supply Planning web site.

Executive Order     On January 9, 2006, Governor Blagojevich issued Executive Order 2006-01 (pdf ~90kb) calling for the development of State and regional water-supply plans. That Order, and a subsequent 3-year funding commitment to carry out its mandates, are the culmination of years of discussions among scientists at the Illinois State Water Survey (ISWS), the Illinois State Geological Survey (ISGS), the Office of Water Resources (OWR), and other agencies and concerned stakeholders on the need for comprehensive water-supply planning in Illinois. Reports reflecting those discussions and needs are in the Water Planning History and Water Law areas of this site.

Water Use and Demand     Almost 16 billion gallons of water are used in Illinois each day by industry, agriculture, domestic consumption, commerce, and energy production. About 85 percent of that water is used in electric power production, and most of that is recycled. But more than 2 billion gallons are consumed each day, being withdrawn and not returned to the source. Each Illinois resident, on average, uses 150 gallons of water daily from public water supplies.

In addition to the water used by Illinois residents and the economy, large amounts of water also are needed to sustain healthy populations of fish, aquatic wildlife and wetlands, and to support recreation and navigation in rivers, streams, lakes, and reservoirs.

As the population and economy grow, the demand for water grows. Although water demands can be reduced through conservation and reuse, we anticipate that 20 to 50 percent more water will be required in the decades ahead to meet the needs of Illinois’ residents and economy.

Planning     Planning (pdf ~6.7mb) ) is essential to ensure adequate, reliable supplies of clean water at reasonable costs. It is important to know which water resources are subject to rising demand and which ones are most sensitive to drought and climate change. Factors to consider include water availability (including the effects of drought and possible climate change), water demand, use, and cost. It also is important to evaluate potential impacts of new withdrawals as part of the planning process.

Other states plan and manage their water supplies on a regional scale. Illinois is also developing a regional planning framework that will allow greater coordination and collaboration among communities, counties, and other entities within a region for groundwater and surface water supplies that extend beyond community and county boundaries.

Historically, groundwater and surface water have been managed separately despite being interconnected with each other. The potential for future climate change to impact our surface water and groundwater resources also must be considered. Thus, it is reasonable for planners and managers of water supplies at the community and county level to consider the entire water cycle, including groundwater withdrawals from shared aquifers, surface water withdrawals from rivers, streams, lakes and reservoirs, and climate variability through precipitation, evaporation, runoff, and groundwater recharge. Plans need to address all of these aspects of the water cycle.

Priority Areas     Planning work has been completed three priority areas where water demand is increasing rapidly: northeast and east-central Illinois, and the Kaskaskia River region.

The Northeast Illinois area covers the eleven counties of Boone, Cook, DeKalb, DuPage, Grundy, Kane, Kankakee, Kendall, Lake, McHenry, and Will. For that planning area, the focus is on the deep bedrock aquifer system that underlies the entire region and all water resources within and beneath the Fox River basin.

The East-Central Illinois area covers the fifteen counties of Cass, Champaign, DeWitt, Ford, Iroquois, Logan, Macon, Mason, McLean, Menard, Piatt, Sangamon, Tazewell, Vermilion, and Woodford. For that area, the focus is on the Mahomet aquifer system and the Sangamon River.

The Kaskaskia River Region includes the entire Illinois counties of Bond, Christian, Clay, Clinton, Coles, Cumberland, Douglas, Effingham, Fayette, Jasper, Marion, Montgomery, Moultrie, Randolph, Richland, Shelby, Washington, and Wayne and the portions of Macoupin, Madison, Monroe, and St. Clair counties that are located within the Kaskaskia River watershed. The study effort highlights the surface-water resources of the region, with particular interest on the two federal reservoirs, Lake Shelbyville and Carlyle Lake, and water supply allocations from these two reservoirs.

The Chicago Metropolitan Agency for Planning and the Mahomet Aquifer Consortium are the lead agencies in northeast and east central Illinois, respectively; setting up locally based regional planning groups. With the completion of the Kaskaskia planning effort, the Kaskaskia Watershed Association has assumed the lead agency role for that region. A priority for these groups has been to develop water demand scenarios to the year 2050. A brochure (pdf ~700kb) is available explaining these planning activities, as is the charge (pdf ~30kb) to the planning groups.

The Office of Water Resources in the Department of Natural Resources is working with the Scientific Surveys and others in establishing an administrative framework and packages of financial and technical support for locally-based regional water-supply groups.

Based in Science     The ISWS and the ISGS, working cooperatively with other agencies, established a scientific basis for water-supply planning using all relevant existing data, gathering new data, and developing new analytical tools. As appropriate, water quality issues will be considered, but the initial focus is on water quantity.

Scientific information and mathematical computer models were developed for each priority area, and water supply management options were evaluated based on comparisons of water supply to water demand to 2050. Relevant historical reports and information have been placed on this web site for easy access by planning group members and the public. Products from the current planning efforts also will be accessible from this web site as they are completed.

This site is intended primarily as a resource for regional water supply planning. Resources for individuals seeking more information and assistance with domestic water well supplies are encouraged to visit the Illinois State Water Survey’s Domestic Well Information site. Additional information regarding Illinois geology and online well data are available from the ISGS.

It is expected that much will be learned from these two priority areas in the first three years. This experience subsequently will be used to update regional plans, make them more comprehensive, develop similar plans for other regions of Illinois, and develop a statewide strategic plan. The goal is to make regional water supply planning and management a permanent consideration in the way Illinois conducts business.

Illinois State Water Survey

2204 Griffith Dr
Champaign, IL 61820-7463

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