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H2Outlook: Water May Not be as Plentiful as Illinoisans Think

Wetlands store rainwater to keep it from running off and harbor a diversity of plants and animals.
WUIS/Illinois Issues

Everyone ?knows what happens when you withdraw more from a bank account than you deposit into it. 

And with heavy rains swelling rivers and keeping farmers on the sidelines this spring, it might be hard to believe Illinois’ bank account of fresh water could ever be in the red. But with a growing population, especially in northeastern Illinois, demand for water for residences, power generation, agriculture and other uses likely will continue to increase. Some communities already are forecasting water shortages by the year 2020.

Joyce O’Keefe, deputy director of Openlands, an urban conservation 
organization in the Chicago region, says availability of fresh water will be “one of the great issues of our time.”

Openlands collaborated on a published report looking at the future of Illinois’ water supply, Troubled Waters: Meeting Future Water Needs in Illinois. The publication points out that many of Illinois’ sources of water already are at legal or natural limits.

Over the past century and a half, people have learned some hard lessons about the limits of seemingly limitless natural resources. In Western states especially, where water is less abundant, conservation has been a visible issue for many years. But many Midwesterners only now are beginning to understand that their water supply also is exhaustible.

O’Keefe says most Americans accept that changes in behavior will be necessary to keep water flowing for everyone. But it’s not enough to simply tell people they will have to conserve water — such as to turn off the tap while brushing their teeth or cutting back on watering the lawn. They need to know why they need to conserve.

To learn why, Illinois residents need to look closely at the lakes, rivers, streams, aquifers and wetlands that move, store and filter water. To examine those pieces of the puzzle is to learn how they are interconnected. Illinois citizens draw water from all of those sources. The health of one part affects the health of the others — and the health and wealth of Illinois citizens.

Illinois, bordering on Lake Michigan, is a water-rich state. Together, the Great Lakes account for about one-fifth of the planet’s fresh water — a resource that is the envy of the world. Glaciers that advanced and retreated across the region over millennia scooped out the softest rocks and earth, leaving behind the basins that would fill to become the Great Lakes.

In the late 1800s, Chicago residents learned they could not simply abuse the seemingly endless water supply of Lake Michigan. Before 1900, when the direction of the Chicago River’s flow was reversed, sewage flowed into the lake — the same place the city got its drinking water.

Epidemics of diseases like cholera caused engineers to attempt the feat of directing the city’s sewage away from Lake Michigan.

In 1900, the Chicago River’s flow was effectively reversed, carrying the city’s sewage away from the lake and directing it toward the Illinois River basin. Since then, concerns have been voiced about how much water is diverted from the Great Lakes.

In 1967, the U.S. Supreme Court limited how much water Great Lakes states could divert. Currently, the City of Chicago’s limit is 3,200 cubic feet per second, about half of which (1 billion gallons a day) flows down the Chicago River.

“I grew up in the Chicago area, and my guess is that it would be unimaginable to most people 50 years ago that those Great Lakes might run dry,” says O’Keefe.

Retreating shorelines could have catastrophic economic and ecological results.

“The ports along the Great Lakes would find they are no longer functional,” she says. “If you think of the development along the Great Lakes, imagine what it might look like if the lake would recede half a mile.”

Rivers, streams and wetlands associated with the lakes might find their relationship changed forever. The Chicago region is considered one of the most biologically rich in the world, partly because of the diverse habitats and natural features that are part of the lake’s shoreline and beyond. 

As the last glaciers melted, the shoreline of Lake Michigan, known as Lake Chicago, was much expanded. As the shoreline retreated to its current position, it left behind an amazing array of wetlands, prairies, dunes and other habitats, some extremely rare. 

From the wetlands of the Calumet region to the shifting sands of the Indiana Dunes, the region is home to endangered species from the Karner blue butterfly to the piping plover, a tiny, plump shorebird. 

With tremendous population growth expected — at least an additional 2 million people added in northeastern Illinois alone — pressure to further tap water supplies will increase. The number of people living in the most densely populated corner of the state is expected to increase from 6.8 million to 9 million by 2020 and reach 10 million by 2030.

That’s not including outside pressure from those in arid climates who would love to pipe, truck or ship in some water from the Great Lakes.

O’Keefe says a proposal was suggested a few years back to fill ships with water and sail them to China. That idea didn’t float, but O’Keefe says that even though laws protect the Great Lakes water, pressure to share outside bordering states will continue.

“This isn’t just a ‘someday somebody will make that type of proposal’ thing,” she says.

From the observation deck of the John Hancock Center in downtown Chicago, Lake Michigan seems to go on forever. But Illinois also has vast stores of water below the surface of the ground — out of sight, but not out of mind.

Aquifers, such as the Mahomet Aquifer that stretches below much of east central Illinois, from the Illinois River near Havana east to Indiana, often are described as underground lakes or rivers. But that is not entirely accurate.

The Mahomet Aquifer is made up of vast underground deposits of sand and gravel that store water for people, farms, businesses and communities lucky enough to be located above it. The credit again goes to the glaciers that left sand and gravel deposits behind when they melted and retreated from Illinois.

Aquifers store water below the surface where it resides in the open space between grains of sand and chunks of rock.

Underground aquifers receive rainwater soaking through the ground and in turn recharge rivers, streams, lakes and wetlands with the outflow.

Gary Clark of the Illinois Department of Natural Resources Office of Water Resources compares the Mahomet Aquifer to a bathtub full of sand — especially near Havana in Mason County where sand deposits are up to 100 feet deep.

During the flood of 1993, the aquifer actually overflowed, creating surface lakes and threatening businesses, railroads and roads on the southeast side of Havana.

In Mason County, the aquifer keeps ditches and streams flowing with clear, clean water that discharges into the Illinois River.

During dry stretches, up to 40 percent of the water in the river at Beardstown can be attributed to aquifers, says Clark. And plentiful and easily accessible ground water is what allows farmers to keep growing row crops like corn in the sandy soil year after year.

But like the seemingly inexhaustible Great Lakes, underground sources also have the potential to be overtaxed, creating hardship when wells have to be sunk deeper and deeper to reach the water table. 

On average, about 200 million gallons a day is drawn from the Mahomet Aquifer by all users, according to the Illinois State Water Survey. The majority of that goes to agricultural uses, primarily irrigation in Mason and Tazewell counties, which use about 110 million gallons a day. 

The 550,000 residents in 150 communities use 60 million gallons a day; industry and commercial users draw about 30 million. 

Not all aquifers are the same. Near Havana, water permeates about 90 feet of the sand deposit, leaving water within 10 feet of the surface in most instances. But in other areas, the deposits may not be so deep and water so plentiful as in Mason County. Near Decatur, the aquifer is capped by a layer of clay and recharges much more slowly. Where less water is stored, a new municipal well can lower the water table below wells drilled for residences or farming operations, requiring them to be deepened at considerable cost.

“We want to make sure that when we do something, there is a balance in the aquifer,” says Mel Pleines, chairman of the Mahomet Aquifer Consortium, an organization working to develop options for the region’s groundwater. “It’s more like a checkbook. We want to make sure there’s enough going back into it so the aquifer is there for the future.”

He says studies on the aquifer and its use will be completed by end of next year. “It’s not just one big pool under there. It’s deeper in some places than others.”

Increased use for irrigation, residential and municipal wells and other demands can strain the equilibrium that keeps wetlands and streams supplied with clean water, too. 

Water quality also can be affected if the water table drops too low. Increased development that covers more and more land area with asphalt, concrete, homes and shopping areas prevents water from soaking in, and instead channels it directly into waterways to be carried off.

And while wetlands are not seen as a source of water, they play an important role in keeping the entire system healthy.

Illinois has lost 90 percent of its pre-settlement wetlands, most drained for farming or to build towns. About 1 million acres of wetlands remain.

People once saw wetlands as barriers to travel and places associated with diseases like malaria. Today, wetlands are viewed differently and are valued for their ability to store floodwater and because their plants can help absorb and disperse pollutants and excess nutrients like nitrogen.

“Other than preserving green space and biodiversity, probably the most important thing wetlands do in the Chicago area is floodwater or storm water storage and retention,” says Allen Plocher, a wetlands scientist with the Illinois Natural History Survey in Champaign. “You could make the point that the larger the percentage of ground that is covered with concrete or asphalt, the more important wetlands become for groundwater recharge.

“It’s a real important role, and it’s real good water.”

Clark says wetlands play more of a role in floodwater storage than in groundwater recharge because many wetlands — especially those in areas with abundant groundwater — are fed by aquifers.

In Illinois, many marsh birds are state-listed as threatened or endangered because of reduced wetlands habitat.

O’Keefe says people become less resistant to the idea of implementing conservation measures once they become more knowledgeable about the issue.

Efforts to landscape with native plants, purchasing water-efficient appliances, tuning sprinklers to water grass and not pavement and being aware that the size of the house may dictate how much water is used all are pieces in a puzzle to be solved.

“I see a tremendous change in how people view this issue in the last seven or eight years,” she says. “A few years ago these ideas — like watering golf courses with waste water — were seen as kind of out there.”

Today, this state uses about 20 billion gallons of water each day, with that expected to increase by 28 percent by 2025, according to Southern Illinois University’s Department of Geography.

And there still are problems with development coming to places where water systems already are taxed, and the population continues to grow.

“It isn’t just in northeastern Illinois; there are predicted shortages elsewhere.”

O’Keefe says planning for the future is the best way to be sure Illinois’ water resources are well protected and cared for in the future. “I think the water issue is resonating with people.”

?Chris Young is Outdoors editor for the Springfield State Journal-Register

Illinois Issues, June 2008

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