By CHENQI GUO
Capital News Service
LANSING – Gerogian Bay Association, a Canadian environmental group, is blaming navigational dredging in the St. Clair River decades ago for lower water levels in Lake Michigan and Lake Huron decades later.
Not everyone agrees.
For example, the International Joint Commission says the argument is bogus. The commission assists governments in solving water-related problems across the border between the United States and Canada.
Lynn Duerod, public affairs officer for the U.S. Army Corps of Engineers said, “Navigational dredging doesn’t have an impact on the lakes. It just affects shores that are in the harbors.”
The dredging has occurred at various times since the 1960s. The last major dredging was in 1962 and lowered lakes Michigan and Huron, according to Frank Bevacqua, public information officer at the Commission.
But that wouldn’t affect water levels today, he said. “The lakes are not continuing to drop because of that. Since 2000, the St. Clair River bed appears to be stable.”
St. Clair River affects the Great Lakes because they’re all in one system. Water flows from Lake Superior to lakes Michigan and Huron. Then it flows through the St. Clair River and to Lake Erie.
Meetings about lake levels were held in Muskegon and Toronto in late March.
People in Muskegon were concerned about the shoreline and what might happen during high water. In Toronto the concerns were about low water and wetlands, Bevacqua said.
“In Muskegon, some of the people said they were concerned that there were some work in places in the St. Clair River during the high water cycle that might make the water level higher than they would have been otherwise.
“Other people thought that if you regulate the flows, you could reduce some of the highs and some of the lows to have a nice range of fluctuation,” Bevacqua said.
He said that the major reason for the change in lake levels is climate, such as drier weather over the upper lakes.
Another factor is called glacial isostatic adjustment.
“Portions of the earth’s crust in the basin are still rising and falling. The land in the northern parts of Lake Huron and Lake Superior is rising, and in the southern parts of the Lake Michigan in Chicago the land is actually falling. That has an effect on water levels on the shore,” Bevacqua said.
James Clift, policy director for the Michigan Environmental Council said, “Lake levels impact those people who live on the lake shore when levels are high.”
Sometimes property owners have erosion problems when high water eats away at their land, he said. In some extreme cases, houses become unstable and fall off their foundations.
“Lake levels are Mother Nature. Lake levels have historically gone up and down so we try to educate people about what that pattern looks like,” Clift said.
“Actually the beneficial thing that has happened on the lakeshore is making a healthier ecosystem,” he said.
© 2010, Capital News Service, Michigan State University School of Journalism. Not to be reproduced without permission.