No one reason for lower lake levels

[Spiel]

No one reason for lower lake levels

 

 

August 13, 2008

SCOTT DUNN / owensoundsuntimes.com

 

 

Changes to the St. Clair River bed are responsible for a 13-centimetre drop in lakes Huron and Michigan and in Georgian Bay, according to preliminary finding of an extensive binational scientific examination.

 

The preliminary results were discussed Tuesday night at a public meeting attended by some 75 people at the Harry Lumley Bayshore Community Centre and hosted by the International Upper Great Lakes Study group's public interest advisory committee.

 

Several local politicians, including Bruce-Grey-Owen Sound MP Larry Miller, Bruce County Warden Milt McIver and Owen Sound Mayor Ruth Lovell attended.

 

Those in the audience raised dozens of concerns, including the loss of pike and lake trout spawning areas due to dropping lake levels and a suggestion that hot water from the nuclear plant near Kincardine may be increasing the temperature and evaporation rate of Lake Huron.

 

One man asked what lowering Lake Superior by one inch would do to the levels of the other Great Lakes, while another raised the notion of diverting rivers in northern Ontario away from James Bay and into Superior.

 

A Lion's Head boater complained he can't get his sailboat to his dock now and a Mallory Beach homeowner said the shoreline has widened by 40 feet over the last 10 years.

 

Paradoxically, this summer's unusually wet weather has resulted in Lake Huron and Lake Michigan levels 22 centimetres higher than a year ago, the meeting was told. Huron, however, is still 36 centimetres below its 1918- 2007 average for early July.

 

Ted Yuzykj, the Canadian co-chair of the study group, suggested at the meeting it doesn't appear the dredging of the northerly mouth of the St. Clair River is the main concern as some suspected.

 

"There is something going on there," he said. "Almost 90 per cent" of the area responsible for increased flow is at the south end of the river, he said.

 

Exactly what is responsible for the five per cent increase in the river flow -- which occurred sometime between 1972 and 2000, the two dates when data are available -- remains to be studied, he said. But scientists are considering whether any of the 12 ships which sank in the river changed the flow and affected the riverbed.

 

He also said the riverbed has stabilized.

 

Yuzyk said there appears not to be "one smoking gun" but rather a number of possible causes which have combined to reduce the levels of the upper Great Lakes.

 

A key one appears to be increased evaporation, largely due to the increasingly infrequent ice cover on the lakes in winter when most of lake evaporation occurs, said Jim Bruce, a noted Canadian meteorologist and study advisor.

 

He's a founding member of the International Panel on Climate Change, which shared the Nobel Prize with former U. S. vice-president Al Gore last December.

 

The study's preliminary findings also suggest less precipitation has fallen in the upper Great Lakes than the lower lakes and glacial rebound, or tilt of the lakebeds, which is viewed as a relatively minor factor, are all factors at play.

 

The International Upper Great Lakes Study, which began in March 2007, is looking into whether dredging in the St. Clair River in 1962 is contributing to low levels in the upper Great Lakes today.

 

It's also examining whether regulation of outflows from Lake Superior might be improved to take into consideration climate change, interests of property owners, ecosystems, local governments, the shipping sector, hydro power and the recreation/ tourism industry.

 

While the overall project has a five-year timeline, a final report regarding the St. Clair River is due in June 2009.

 

If the International Upper Great Lakes Study confirms more water is escaping the upper Great Lakes because of dredging and erosion of the river, the study will look at solutions, possibly underwater walls to slow the flow or a submerged turbine which would generate power while slowing the flow, the meeting learned.

 

The Georgian Bay Association cottager group has organized to focus attention on the role it believes dredging of the St. Clair River has had on declining water levels in the bay.

 

It paid for a $250,000 study by Baird & Associates Coastal Engineers in 2004 which, along with other voices, led to inclusion of the St. Clair River issue in the overall study and moved it to the top of the agenda.

 

That study found that dredging a shipping channel in the river in 1962 "effectively opened a bigger drain hole in the Great Lakes," the association's president said when the study results were announced.

[fishindevil]

Wow we can send little machines to mars,and other planets,and yet we cant figure out where all the water is going??????