The Saint Clair River is a major trunk line for commercial navigation. But, is it also possible that it's draining the Great Lakes?
The river partially connects Lake Michigan and Lake Huron to Lake Erie.
International Joint Commission Public Affairs Advisor John Nevin said Erie??s lower elevation makes the Saint Clair River act as a drain.
??If the Saint Clair River erodes or is dredged, that makes that drain bigger?|more water runs out of the Lake Michigan-Lake Huron bathtub into the Lake Erie bathtub,?? Nevin said.
Nevin has spent part of his career studying the impact degrading in the Saint Clair River has had on the Great Lakes.
He said dredging first began in 1850.
The largest dredging activity occurred between 1933 and 1936, when 11 million cubic yards of material was excavated from the river. The most recent major project occurred between 1960 and 1962, when 2 million cubic yards of material was removed. Since 1962, dredging has been confined to upkeep projects.
Over time, there has been erosion in the river, and experts said all this activity in the river has had a direct impact on lake levels.
??If you look at the period between 1962 and currently, erosion in the river is believed to account for three to five inches of lowering. If you go back into history, that's another 16 inches of lowering in Michigan and Huron. So if you add those together, you are looking at about 20 inches of difference because of changes in the Saint Clair River.
A bi-national Study Board directed by 100 scientists and engineers from governments, academia and the private sector in both the United States and Canada agree that 20 inches of permanent lowering is a fair estimate.
The group also agreed that weather still has the biggest influence on lakes levels, but since we can't control the weather the debate is fixed on the river.
Should we try to reverse the impact dredging has had? Or should we let nature run its course?
Roger Gauthier, with Restore Our Water International, said something should to be done.
??A do nothing alternative is always an alternative. But it always costs more to society over time,?? Gauthier said.
Gauthier was a senior hydrologist for the U.S. Corps of Engineers for 30 years.
??The design work the Corps of Engineers did in the 1960s showed they could put in a series of speed bumps, essentially underwater sills, which the freighters go right over top of," said Gauthier. "There are also a couple spots, a couple islands in the river, which have non-navigable channels. These are areas where the freighters don't go, that a gated structure could be put in that would hold back water in Michigan and Huron.??
The cost of these projects is estimated to run between $30 million and $180 million.
The International Joint Commission worries that creating a manmade barrier would come with an even greater cost.
??People remember 1986. You had people who were flooded. Grand Traverse Bay, South Haven?|houses in Grand Haven were falling into Lake Michigan," Nevin said. "You don't want to go back to that and that is what the climatologists tell us?|that in the future we will see higher water and lower water again, so any kind of recommendation to change the levels of the lakes though human activity needs to take that into consideration.??
At the end of April, the International Joint Commission made a formal recommendation to the United States and Canadian federal governments.
They suggested a thorough cost-benefit analyses be done weighing the pros and cons of decreasing water displacement though the Saint Clair River. Nevin said such a complex study could take more than 5 years.
In the meantime, low lake levels are taking a tool on the boating and fishing industry.
There is also a broader impact. Commercial freighters are forced to carry lighter loads, which means northern Michigan is getting shipped a lower quantity of goods, like gasoline.