Sunday, May 24, 2009

Droughts drain northern lakes

Milwaukee Journal-Sentinel Online: Scientists and property owners say they are worried about the long-term effects of a prolonged drought on fishing and water quality in northern Wisconsin as they've watched some lakes drop to their lowest point in 70 years. As people flock to the north this weekend, drought conditions also are evident in tinder-dry forests that experienced a surge in fires last week.

Many lakefront property owners are being forced to push out docks and motor around new shallows as water levels have dropped, in some cases, as much as 8 feet from their highs. Levels are likely to drop even more in some reservoirs controlled by dams, and utilities say that they're generating less hydropower than in the past. The main culprit: less rainfall over the last four years.

But a University of Wisconsin-Madison scientist says the problem goes back much further than the last couple of years. Using statistical modeling, Chris Kucharik found that the northern quarter of the state has received 15% to 20% less rain from the decade of the 1950s to the decade ending in 2006.

"This doesn't even include the drought years after 2006," said Kucharik, an assistant professor of agronomy and environmental sciences. "You continue to run a deficit of rain, and the response to the system is the lakes," he said.

Some lakes are at their lowest levels in seven decades. Those most affected are seepage lakes that rely on groundwater and runoff for recharging themselves instead of streams and rivers….

Balsam Lake, Wisconsin, shot by peterrieke, Wikimedia Commons via Flickr, under Creative Commons Attribution 2.0 License

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