Great Lakes Water Level Update

Back in December the International Joint Commission studying the impacts on water levels in the Great Lakes issued their summary report. For anyone with concerns regarding the low water levels in Georgian Bay, the summary recommendations or lack thereof were somewhat disappointing.

In summary, the report found that the water level in Lakes Michigan and Huron which includes Georgian Bay have declined approximately 9" from 1963 to 2006. Erosion of the St. Clair River bottom whose increased flow rate has long been felt as one of the major contributors to these low water levels has in fact been relatively stable now for a number of years. In total, the change in water carrying capacity of the St. Clair River is the estimated cause for 2.8" to 5.5" of the aforementioned 9" decline.

The second component of the decline is allegedly caused by a phenomena known as glacial isostatic adjustment. In layman's terms, the earth's crust is expanding (rising) which gives the impression that the water level is decreasing. Glacial isostatic adjustment is particularly pronounced in the area around Georgian Bay and accounts for 1.6" to 2" of the 9" water level decrease.

Lastly and most importantly is the change we are experiencing in climatic patterns ie: global warming. These changes have become more significant in recent years and is said to represent up to 76% of the decline in water levels between 1996 and 2005. Overall. the affect is 3.5" to as much as 6.7" of the total 9" decline that has taken place.

For the time being, no remedial actions of any significance are going to be implemented. Additional studies are ongoing and we can expect these to examine such issues as the St. Clair River, water flow from Lake Superior into Lakes Michigan and Huron as well as other factors.
For those interested copies of the report are available at the following link:

http://www.iugls.org/en/Publications_StudyReports.htm

The next public meeting scheduled for our area is: March 22, 2010 at 7:00pm. North Simcoe Sports and Recreation Centre 527 Len Self Blvd, Midland.