Tuesday March 26: Great Lakes water levels – Midland

email from Robert Bowles March 18 2013

We have observed drastic changes with lower water levels in the Great Lakes especially in Lake Superior, Lake Michigan, Lake Huron and Georgian Bay. 

The Great Lakes Basin was formed by the thick blanket of ice of the Wisconsin Glacier that once covered the area. As the ice cap melted it formed melt water lakes at the different stages as the ice disappeared. Ontario’s first land mass called Ontario Island around the Dundalk Highlands emerged in Southern Ontario 14,000 years ago. Lakes formed as the ice melted and the melt waters at first drained to the south through Lake Chicago and the Chicago outlet up to about 12,000 years ago. Lake Algonquin first drained through the Chicago outlet but as the earth rebounded with the disappearance of the ice it blocked the outlet forcing the melt waters to drain through different outlets to the east by what is now the St. Lawrence River. The drainage then again returned to the Chicago outlet as more ice melted in the east and the land rebounded about 10,000 years ago. 

The Penetanguishene Peninsula including the islands of Christian, Hope and Beckwith were covered with a thick blanket of ice of the Wisconsin Glacier like the rest of Ontario, 14,000 years ago then flooded with the water of Lake Algonquin 11,000 years ago. They finally emerged from the waters of Lake Stanley 10,500 years ago.  They were again flooded with the rising waters of Lake Nipissing 5,500 years ago then emerged again from the waters of Lake Algoma 3,000 years ago. The Midland Peninsula has native relics carbon dating back to 10,400 years ago. Indigenous people would have moved from the islands which were exposed 10,500 years ago when they were flooded again 5,500 years ago. Water levels dropped again to expose the islands in the waters of Lake Algoma about 3,000 years ago. Water levels then dropped slightly about 2,000 years ago to the present-day Lake Huron level. Recently, water levels are again dropping in some of the Great Lakes. 

We will discuss these changes in the Couchiching Conservation on Tuesday, March 26, 2013 at the Midland library starting at 7:00 p.m. and how they affect both indigenous and non-indigenous people.  Are these changes due to climate change, the melting of the polar ice caps to the north, the connection of the Mississippi River to the Great Lakes Basin at Chicago which caused a reverse flow out of the Great Lakes to the Mississippi, dredging of the St. Clair River, or some other reason? Discussions will focus on the reasons for these lower water levels, who should do something about them and how we can either adapt to or prevent these lower water levels in the future. Join Bob Bowles, renowned Simcoe County naturalist and Brian Charles, a Native community liaison for Anishnabe Education who will lead the discussion from an indigenous and non-indigenous perspective in a conversation on this important subject by all attendees. 

For more information on this conversation see the web site for the Couchiching Institute