January 31, 2013

Lake Michigan in February 2010. Without an ice cover the water evaporates more rapidly through winter.

Earlier this month WBEZ reported that Lake Michigan water levels are at a record low. Today the lake levels are still dropping, putting the livelihoods of shippers, boaters and whole coastal towns at risk.

That news is not getting old, either: As of Jan. 28, the lake was two inches below the previous record set in 1965 (down from just one inch in early January). It was more than five feet below the record high of 1987. A person of an average height can stand on dry land today in spots where 26 years ago she would have been up to her neck in water.

A few commenters on this story asked about the reasons for today’s low levels in Lake Michigan. The short answer is that there is no short-term answer. Lake levels are subject to long-term fluctuations caused by weather and precipitation patterns.

The U.S. Army Corps of Engineers tests the lake levels in all five Great Lakes daily, and they havedata on lake levels going back to 1860. That data shows relatively consistent fluctuations of several feet of depth, usually over the space of a decade or more. In one instance, the water in Lake Michigan went up three whole feet in only three years (1926-1929). Between 1965 and 1987, the levels went up five feet. Now they’re back down, but our environmental concerns are drastically different than they were fifty years ago. As Greg Buckley, the City Manager of Two Rivers, Wis. put it, “In ‘64 nobody talked about climate change.”



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