A study group blames a warmer climate, and not the St. Clair river, for low water levels on the upper Great Lakes.
The panel has been studying how dredging might have affected flow through the St. Clair River, which drains Lakes Michigan and Huron into Lake Erie.
John Nevin, spokesman for the International Upper Great Lakes Study Board, says the river's flow has increased over recent decades, but not enough to account for the fluctuating water levels in the upper lakes.
"It appears there isn't a drain hole in the Great Lakes, in the St. Clair River, but it's more like a little drip, drip," Nevin said.
Instead, he says, less ice and dryer weather has brought down levels in the upper Great Lakes.
"Because we have less ice in the wintertime and more evaporation, and because we have had a lot more precipitation down in Lake Erie than we've had up in Lake Superior, Michigan and Huron, where there's been a fair amount of drought over the past ten years," Nevin said.
The current Lake Superior water level is now close to its average for December. The study will be used by another panel considering how much of Lake Superior's water should be released through the St. Marys River.
A second panel is considering outflows from Lake Superior into Lakes Huron and Michigan. That group will take the new report into account before recommending any changes.