MILWAUKEE (AP) - Low water levels in the Great Lakes are causing problems for shippers, who must shed cargo to avoid running aground in shallower waters.
The lower levels also mean wooden harbor structures that have been underwater are now exposed to air, hastening their deterioration.
The official depth of the Great Lakes' navigable waters is supposed to be 27.5 feet. But in some areas this spring it was closer to 25 feet.
An ore boat leaves Marquette’s Upper Harbor after depositing coal at the Presque isle Power Plant. The lake Carriers Association said low water levels in the Great Lakes have been hurting the shipping industry because shallow harbors requires boats to carry lighter loads, thus increasing costs. (Journal file photo)
That's a problem for the shipping industry. For every inch below that a 1,000-foot ship has to sail light, it has to shed about 270 tons of cargo to avoid hitting the bottom, which can account for millions of dollars of losses.
There's not much hope on the horizon, either. Jim Weakley, the president of the Lake Carriers Association, said he's stopped using the word "cyclical" to describe water levels because the term implies the water will return to its former level.
"If you're 14 years below the long-term average, that's not cyclical," he said.
The low water levels are compounded with a backlog in harbor dredging, in with the U.S. Army Corp of Engineers clear out sediment that accumulates on the bottom. The federal government generally funds the work through taxes on the value of shipped cargo, but even though it has collected about $1.6 billion per year, it's only spending about half that, according to the Great Lakes Commission.
Weakley said he sees the overall problem as more political than natural - the money is there to do the dredging, but Congress just isn't spending it.
The lack of navigation depth means that some large freighters are sailing about 10 percent under capacity.
But it's not just shippers who stand to lose money. Because of the low water, ports across the Great Lakes are beginning to crumble and rot because of exposure to air.
"As water drops, wood that's been preserved underwater for a long time is now is being exposed to decay," said David Wright, the chief of operations for the Army Corps' Detroit district. "And if you get a failure of foundations, you get a failure of structures."