Drought's long reign over in area--for now
By John Biemer
Published May 4, 2006
April showers brought something even more welcome than May flowers to Illinois this year: an apparent end to one of the worst droughts in the state's history.
The yearlong dry spell that stunted last summer's corn and left lawns and trees parched throughout the Chicago area was alleviated by above-normal rainfall this spring, Illinois State Water Survey Chief Derek Winstanley declared Wednesday.
Now experts are evaluating what was learned to better prepare for the next time--when water supplies may be even more strained under the weight of a growing population.
"Severe drought will occur in the future," Winstanley said. "We don't know exactly when, but we know it will occur again."
For now, reservoirs, rivers and lakes largely have returned to normal levels, as have moisture levels crucial for growing crops. Weather patterns also are more active, and the La Nina current in the Pacific Ocean that brings dry summers to the Midwest has weakened significantly, said state climatologist Jim Angel.
"This year is like night and day compared to last year," he said.
In March 2005, when the drought began, the state totaled 1.65 inches of precipitation. This year, March's total was 4.60 inches. In April 2005, the state got 2.59 inches of rain. This year: 4.08 inches.
And three days into May, the state already has been doused with about half the rain of the entire month in 2005. Most of the corn crop has been planted, and officials say it's in excellent shape so far.
This year's totals are not extraordinary by historical standards, nor are they enough to make up every inch of the precipitation deficit run up since last year--still almost 9 inches statewide.
But coupled with a near-term forecast of continuing rain, state experts say the indicators suggest that Illinoisans will not have to pinch water for their lawns this summer.
"...We're having month after month of normal to above-normal precipitation," Angel said. "So that tells me things are looking pretty good right now."
Last summer, the U.S. Department of Agriculture declared Illinois to be in a natural disaster. Now, the northern part of the state has been classified as merely "abnormally dry"--which reflects the overall precipitation deficit. At its peak last year, the Chicago region was in "extreme drought," just one level beneath the most desperate level.
The drought hurt a lot of farmers locally but did not devastate the overall yield.
Last year produced the state's second-largest soybean harvest on record and a surprisingly decent corn haul. Illinois Farm Bureau spokesman John Hawkins attributed that to subsoil moisture early last year before the drought kicked in and new drought-resistant corn hybrids.
"The corn plant of today is much more complex and much more robust than corn that we were planting 10, 15, 20 years ago," he said.
That's one difference between the most recent drought and previous ones, such as in 1988, which hit the farms harder, said Stan Changnon, a senior scientist at the State Water Survey and a geography professor at the University of Illinois at Urbana-Champaign.
Previous droughts also lasted longer and focused on southern Illinois--an area more dependent on surface water sources such as reservoirs and lakes, rather than underground aquifers and Lake Michigan. Those droughts forced some communities to haul water into towns by truck or lay new pipelines to distant reservoirs.
In 2005, Changnon said, the remnants of four tropical storms--including Hurricanes Rita and Katrina--brought rain relief to the southern part of the state.
That is the first time the state has been hit by so many tropical storms--and could suggest a shifting climate, he said.
"The unusualness of the drought and its shape and those storms makes the year 2005 sort of a freakish weather year for Illinois," said Changnon, the State Water Survey chief during the 1980s.
Wells running dry in Chicago's outer suburbs--beyond the reach of pipes connecting to Lake Michigan--also pointed to future problems. Some experts predict that rapid population growth and development could exhaust the water supplies provided by underground aquifers, reservoirs and rivers in some regions by 2020--and drought would exacerbate that even more.
Lake Michigan now serves 6.8 million residents through 201 public water supply systems in northeastern Illinois, but the U.S. Supreme Court and agreements with other bordering states and Canada limit Illinois to diverting 3,200 cubic feet of water per second from Lake Michigan.
That allocation is almost completely used and unlikely to be increased any time soon. Given another big drought, water could become a regional battle, Changnon said.
"It would be a real struggle between the demand and the available supplies, and the Great Lakes are the largest freshwater supply in the world," he said. "So Illinois will always turn to that as its source, at least for the area of the state that can get the water."