The finding has been included as an emerging issue in the U.S. Environmental Protection Agency's 2006 management plan for Lake Erie. University of Windsor aquatic ecologist Jan Ciborowski, who authored the section, admits an exact prediction is difficult. But Ciborowski says new climate change models show the Great Lakes could lose up to 15% of their water by 2050. That's a drop of nearly three feet overall.
Jan Ciborowski: It's not taking the extreme necessarily, it's saying this is the maximum, this is the minimum limit we expect and the realistic results are going to be somewhere in that envelope. Having said that, I think of nine different models that are out there, seven of them predict that water levels are going to decline and that they'll keep on going down as time goes on.
Great Lakes shippers are already having to lighten their loads in order to avoid grounding in shallower ports, locks and channels. Glenn Nekvasil, a spokesman for the Lake Carriers Association, says this year the biggest lake freighters are carrying an average of 4,000 tons less than a few years ago. That's a loss of between $6,000 and $12,000 a voyage.
Glenn Nekvasil: To lose three feet without compensating dredging... I'm not entirely certain that shipping would be economically viable.
Dredging is key to keeping ports and harbors deep enough for Great Lakes ships. But for the last decade and more, Nekvasil says Army Corps dredging in the Great Lakes has been severely underfunded. Mike Asquith, who heads the Buffalo District's dredging program, concedes that to save money the Corps has been dredging ports to the authorized depth, but not the authorized width. He says a major drop in lake levels probably won't change the Corps' practices.
Mike Asquith: No matter what we always dredge to the same depth - it's like an elevation. So that wouldn't affect our work, per se, but it would affect how much the vessels could carry. So in other words, we would be dredging like we always do, but there would be less water above that point for the ships to use.
Rich Thomas, chief of Great Lakes water maintenance for the Corps, says there would also be less water for other uses, such as hydroelectric dams and power plants.
Rich Thomas: How can you modify a power plant - it's set up to use current conditions to supply water to the plant - without re-doing the whole plant? And water intakes for cities. There could be some major problems in these areas.
It's also a consideration for future shoreline projects, like plans for new lakefront development in Cleveland and the Port Authority's plans to consolidate its docks and storage facilities on the west side of the Cuyahoga River. Local planners say they don't think their projects will be affected, but environmental engineer Benjamin Hobbs of Johns Hopkins University says they'd be well-advised to take a closer look.
Benjamin Hobbs: The first thing you should ask is whether this is potentially going to be a problem. And that would arise if you're spending a lot of money now, making a big investment that's going to be around for decades and decades. And once you've poured the concrete it's going to be difficult to modify.
Cleveland port officials say their harbor is deep enough now to remain in use if lake levels drop, although the river may not be. But Hobbs says that may not matter if shipping is no longer viable. He suggests building any major shoreline project in stages, so that if conditions change, major investments won't be lost. And while it's considerably less expensive to dredge marinas or move private docks, recreational boaters and private landowners may also want to plan for change. Karen Schaefer, 90.3.