Where is the Water?
The drought affecting the Upper Midwest has taken its toll on the lakes, and scientists say low levels are part of a long-term weather cycle that probably won't end soon.
A U.S. Army Corps of Engineers survey comparing monthly water levels for April to long-term April levels (1918 to 2006) shows that Lake Superior is 17 inches below average and Lakes Michigan and Huron are 15 inches below average. Lakes Erie and Ontario were 4 and 5 inches above average, respectively. Lake St. Clair, which is part of the Great Lakes system, is 3 inches below average.
When there's too little precipitation in the form of melting snow and rain, and too much evaporation off the lakes during the fall and winter months, levels go down. Are the lake levels lower as part of a long-term weather cycle? Or are they lower as a result of global warming? Unusually low lake levels, whether they're permanent or temporary, are a problem for the Great Lakes economy.
Changes in the lakes impact many water-dependent industries such as recreational boating, sport fishing and shipping. Low lake levels translate into shallower harbors and marinas for recreational boaters, forcing dredging. The result is often higher slip fees at marinas. Shallower waters could permanently raise the temperature of the lakes, making it more difficult for cold-water fish such as lake trout to survive.
May 29, 2007 6:46 AM | Category: Drought, Great Lakes