Water levels in Lake Michigan and Lake Huron, although constantly in flux, are showing a steady decrease, experts say.
Lake levels can rise or drop as much as 6 feet in only a matter of years. However, concern is increasing that the overall level of the lakes is on a decline, the Milwaukee Journal-Sentinel reported.
Much of the decline is blamed on the Army Corps of Engineer's 1960s dredging of a shipping channel in the St. Clair River. Ongoing erosion in the St. Clair River may be the cause of a deeper lakebed and expanding drain holes.
The St. Clair River is the main outflow for Lake Michigan and Lake Huron.
The Georgian Bay Association, a Canadian property owners' group -- contends that the lake levels are dropping at a rate of about one inch per year. However, since levels are constantly in flux, it is hard to determine exactly what "normal" levels should be.
The U.S. and Canadian governments are planning to launch a $14.7 million study of water levels on the upper Great Lakes.
Copyright 2006 by United Press International
Explore further: Five anthropogenic factors that will radically alter northern forests in 50 years