ANN ARBOR, Mich. (AP) — Great Lakes levels will continue rising and falling in often unpredictable ways and people should learn to deal with the changes instead of trying to tame nature with costly engineering projects, experts said Thursday.
Donald Scavia, director of the University of Michigan's Graham Sustainability Institute, announced a wide-ranging study of ways to adapt to up-and-down water levels during a seminar at which about 50 Great Lakes policymakers, scientists and advocates debated whether further efforts to control the inland seas would be worth the trouble.
"Lake levels are varying and they're going to continue to vary," Scavia said. "The question we should be focusing on is, how do you live with the variability instead of where do you put the next dam."
The five lakes are in constant flux, rising during spring and summer, then dropping in fall and winter. Levels also experience periods above and below their long-term averages that can last for years or decades. They were unusually low during the 1960s, but by the 1980s were so high that shoreline cottages were swept away.
One of the lengthiest sustained slumps began in the late 1990s and bottomed out in January 2013, when Lakes Huron and Michigan hit their lowest point on record. Since then, heavy snow and abundant rainfall have fueled such a rapid comeback that Lakes Superior, Erie and Ontario are forecast to return to normal this year. Even Huron and Michigan, which suffered most, have risen substantially.
But the recovery was produced by a 15-month wet period and winter's bitter cold, which froze most of the lakes' surface area and blocked evaporation. Whether the improvement will continue or is a momentary blip in a downward spiral resulting from climate change remains to be seen, analysts said at the conference.