Study says Upper Great Lakes not losing much water

The Associated Press ~ staff The News
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DETROIT - Lakes Huron and Michigan are not losing an unnaturally high volume of water to Lake Erie and there is no need to place barriers in the St. Clair River to stem the outflow as a Canadian group is demanding, says an engineering study released Friday.
A draft report prepared for the International Joint Commission, which advises the U.S. and Canadian governments on Great Lakes issues, acknowledges roughly 17 billion litres more than normal escaped daily from Lake Huron in the mid-to-late 1980s.
But the excess was due to natural causes, including a 1984 ice jam that was the biggest on record in the St. Clair River, instead of dredging and other man-made alterations as claimed by the Georgian Bay Association, the report says.
The problem fixed itself within a few years as equilibrium was restored between Lakes Huron and Erie, the report says.
It disputes the Canadian group's insistence that Lakes Huron and Michigan - which geographically are the same lake - still are losing billions of excess litres daily as if a giant drain hole had been punched in the St. Clair, which is part of the southerly flowing river channel that links Huron and Erie.
The recent drop in Huron water levels that led the Georgian Bay Association to commission its own study resulted largely from drought and warmer temperatures, which boost evaporation rates, the report says.
"Climate is the main driver of the lake level relationships between lakes over time," it says.
"There has been a persistent decline in net total supply of water to Lake Superior and Lake Michigan-Huron over the last two decades that has resulted in declining lake levels and a change in the relationship to Lake Erie."
The association, an environmental charity representing thousands of waterfront property owners on Lake Huron's Georgian Bay, accused the government study board of rushing to judgment and ignoring crucial information.
"They started with flawed data and they got flawed conclusions," said Bill Bialkowski, a retired engineer and member of the association's water levels committee.
"It appears that sources were carefully screened in order to support preconceived conclusions."
Eugene Stakhiv, a U.S. Army Corps of Engineers water specialist and co-chair of the team that produced the government study, defended its work.
"We had an open mind, we had no idea what the evidence was going to show us," he said in a phone interview.
"We went through all the science methodically, systematically picked up loose ends and tied them into conclusions."
The government investigation was prompted by the 2004 release of a study by Baird & Associates, a coastal engineering consulting firm hired by the Georgian Bay group.
It reported human activities on the northern end of the St. Clair River, primarily dredging in the early 1960s to enlarge the shipping channel, had caused a huge increase in outflow from Lakes Huron and Michigan. The Baird report calculated the excess loss at 45 billion litres daily - enough to fill 10,000 Olympic-sized swimming pools.
But the International Upper Great Lakes Study, part of a $15-million review of U.S. and Canadian policy on the region's water levels, concluded the Baird report had overstated the size and duration of the water loss.
The government researchers found the difference in elevation between Lakes Michigan-Huron and Erie had narrowed by about 22 centimetres between 1962 and 2006.
One reason was the ice jam of 1984, which deepened the channel by scraping the bottom and boosting water flow rates and erosion. That caused the temporary increase in outflow to Lake Erie, which lasted three to four years before the two lakes levelled off, said Jim Bruce, a Canadian member of the study team.
Other factors affecting Michigan-Huron levels include changes in climate patterns and rebound of the Earth's crust from glacial melting 10,000 years ago, which slowly is altering land levels in the region, the government study showed.
It said there had been no significant erosion of the St. Clair River bed since at least 2000.

Organizations: Georgian Bay Association, International Joint Commission, St. Clair U.S. Army Corps of Engineers Baird & Associates

Geographic location: Michigan, St. Clair River, Lake Erie U.S. Great Lakes DETROIT Lake Michigan Lake Superior

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