Great Lakes water levels.(Canada-U.S. Relations)(Report)

Issue Definition

Great Lakes water levels have been decreasing steadily since 1997, with Lake Superior setting a record low for September in 2007, and Lakes Michigan and Huron near their record lows for December in 2007. In 2008, water levels initially rose for all Lakes, due to above average snowfalls in the northern Great Lakes. The latest water level forecast predicts higher water levels on Lake Superior and Lake Michigan-Huron when compared with 2008. The remaining lakes are expected to have lower water levels than 2008.

Low water levels disrupt shipping, alter coastal and aquatic ecosystems, reduce recreational boating and fishing, and adversely affect water quality. Water levels are directly related to precipitation, runoff, evapotranspiration, and outflows (e.g., through the St. Lawrence River and diversions). Climate change and new precipitation patterns are cited as a possible causes for low water levels. Some also contend that dredging in Lake St. Clair in the 1960s might have led to widening the channel in the St. Clair River and increasing outflows from the …