TORONTO - There's a "drain hole'' in the Great Lakes basin that's hemorrhaging almost 9.5 billion litres of water a day and must be patched up by the Canadian and American governments, environmental groups said Tuesday.

Navigation dredging, riverbed mining and shoreline alteration on the St. Clair River near Port Huron, Mich., and Sarnia, Ont., have affected the flow of the Great Lakes and is draining water into the Atlantic Ocean at a rate that's three times greater than original estimates, said Mary Muter of the Georgian Bay Association.

Muter said water levels in lakes Michigan and Huron and the Georgian Bay have fallen 60 centimetres since 1970.

The loss of water is senseless and will negatively affect water quality in the Great Lakes, as well as boating, fishing and commercial shipping, said John Jackson, program director for Great Lakes United.

"We think it's really important that the governments do some serious study to figure out the cause and to figure out what we can do,'' Jackson said.

He said the issue has been known for decades but the new research is valuable in pointing out how the problem appears to be getting worse.

"The issue is that it seems like it's increasing year by year and that's what we didn't realize before, and that's what we need to better understand,'' Jackson said.

"If that's connected to human causes - as we suspect it is - we need to figure out what we can do to correct those problems that we've created as human beings.''

The International Joint Commission is preparing a major study of Great Lakes issues, including the drain hole in the St. Clair River, but governments can't wait for that research to be done because it could take years, Muter said .

"We've spoken with federal politicians and they are totally onside and supportive of this concern and that the IJC move to address it in a timely matter,'' she said.

"But even if they come out with recommendations for what needs to be done in the St. Clair River, it will have to come back to both our federal governments for funding and approval to proceed, and if we have to wait five years we will lose another 12 centimetres of water from lakes Michigan, Huron and Georgian Bay.''

Ralph Moulton, a senior engineer for Environment Canada, said the best approach is to wait for the IJC to do its research and then react appropriately based on the best available science.

"It certainly is a concern for people around the lake and its many users, and the government is concerned about this as well, but I wouldn't characterize it as a panic situation at the present time,'' he said, adding that water levels on lakes Michigan and Huron are not at record lows.

"We're certainly looking forward to getting the results from the IJC, but I know it just started and it'll take a bit of time before we get those results.''