Recently retired as a Program Director for the Great Lakes Commission after 8 years of service, Roger Gauthier gave this terrific presentation at our Great Lakes Symposium (April 8, 2011 in Port Huron, Michigan). The title of the presentation is: Great Lakes Levels and Flows.
The material included is wholistic as to patterns & influences on the Great Lakes water levels. Gauthier's conclusions are hard-hitting: the sustained low lake levels in lakes Michigan, Huron & Georgian Bay are neither natural nor inevitable. And the choice to keep these lakes low is having negative economic and environmental effects.