The Study Board concluded that: The difference in water levels between Lake Michigan-Huron and Lake Erie has declined by about 23 centimetres (cm) (9 inches) between 1963 (following the last major navigational channel dredging in the St. Clair River) and 2006. They also concluded that Three key factors contributed to this 23 cm (9 inches) change including: (1) A change in the conveyance(water-carrying capacity) of the St. Clair River accounts for an estimated 7 to 14 cm (2.8 to 5.5 inches) of the decline. (2) Glacial isostatic adjustment (the uneven shifts of the earth's crust since the last period of continental glaciations ended) accounts for about 4 to 5 cm (1.6 to 2.0 inches) of the fall. (3) Changes in climatic patterns account for 9 to 17 cm (3.5 to 6.7 inches); this factor has become even more important in recent years, accounting for an estimated 58 to 76 percent of the decline between 1996 and 2005.
The organization Georgian Bay Forever (GBF), a Canadian environmental charity which has been the leading voice in raising concerns about the impact of low water levels on the unique ecology of Georgian Bay said the IUGLSB "missed a historic opportunity to recommend environmentally sound solutions to the serious water levels situation facing the middle Great Lakes." The group is now calling on IJC Commissioners to reconsider and overrule the "do nothing' recommendations" of the IUGLSB.
Access a release from IJC with details on the meeting locations, two teleconferences and commenting procedures (click here). Access a 28-page summary report (click here). Access more background and additional information on the report and study (click here). Access a release from GBF (click here). Access the GBF website for links to a critique of the report and extensive background information (click here).