Chicago's thirst for water will escalate a whopping 30 percent over the next 20 years--and the rest of Illinois will demand 28 percent more water than it soaked up in 2000, according to a new report by SIUC water-use experts.

By 2025, thermoelectric power plants will suck up 17 billion gallons per day--nearly 85 percent of the state's projected water use, says Benedykt "Ben" Dziegielewski, an SIUC geography professor and lead author of a comprehensive report predicting future water needs in Illinois, Indiana, Michigan, Minnesota, Ohio, and Wisconsin.

The first such study of its kind, it was a joint project by researchers from SIUC's Department of Geography and Environmental Resources and the Illinois State Water Survey (ISWS).

The study projects a 7.3 percent increase in combined publicly supplied water use for the six-state region over the next 20 years, despite an overall decline in per-capita water use. Illinois and Ohio account for the majority of the projected increase.

Study totals show Illinois will need to pump about 20 billion gallons of water a day in 2025, up from the daily total in 2000 of 15.8 billion gallons. The state's population is expected to grow to nearly 14 million residents in 2025, and its per-capita water demand is predicted to jump 14 percent, to 1,450 gallons a day--a 178-gallon increase over 2000 usage.

About 16.9 billion gallons of water a day will be needed in 2025 to cool Illinois' power plants, the report predicts. (Although thermoelectric use declined between 1995 and 2000, it has since rebounded and is growing rapidly.) Another 3.3 billion gallons will be needed to meet the remaining needs of the public, commercial and industrial entities, irrigation, mining, and livestock.

Cook County alone will demand 2.4 billion gallons of water daily, half of which will go to cool power plants. And the burgeoning metro areas southwest of Chicago and east of St. Louis will be under tremendous pressure to provide water.

"Although we live in a water-rich state, with Lake Michigan and the major rivers, we should not take our present and future water supply for granted," says Dziegielewski, who also directs the International Water Resources Association, based at SIUC. "Local water shortages are likely to happen in Illinois, especially in the heavily urbanized parts of the state."

The research team predicts that 70 of Illinois' 102 counties will need more water in the future.

For instance, daily water demands in Cook, DuPage, Will, Lake, and Kane Counties are projected to climb by more than an additional 25 million gallons above their 2000 totals. Obtaining more water for these counties from Lake Michigan would require permission from the International Joint Commission, which monitors water withdrawals from the Great Lakes. Will, Grundy, and Madison Counties also will experience acute water needs, due to increasing thermoelectric demands.

"There will be areas where additional water supplies will not be readily available and their development may be costly and controversial," Dziegielewski says. "On the up side, new water supplies may be easier to obtain in the McHenry County area and some east-central parts of the state where there is abundant groundwater."

The report is broken into two documents: "County-Level Forecasts of Water Use in Illinois: 2005-2025," available at www.sws.uiuc.edu/hilites.asp, and "Countywide Projections of Community Water Supply Needs in the Midwest," available at mtac.sws.uiuc.edu.

Dziegielewski urges that developers and planners take the projections into consideration in order to avert future water shortages. Conservation and careful management will be key. For example, he says, power plants could construct cooling towers that recycle water (called closed-loop cooling), which reduces a plant's water needs by 95 percent.

"We have to act on this information and draw appropriate plans," he says, "to ensure that future water needs are met without undue pressures on the environment."

--by Paula Davenport, Media & Communication Resources