International Great Lakes Study Board Releases Report on St. Clair River

ALEXANDRIA, VA – December 29, 2009. The International Great Lakes Study Board has released a report on the St. Clair River. Drs. Eugene Stakhiv and Tony Eberhardt of IWR are the U.S. Study Director and Study Manager, respectively. The panel found that the St. Clair River is stable and that there is no need for remedial measures. In its report, the Board found that:

• There has been no significant erosion of the channel in the upper reach of the St. Clair River bed since at least 2000.
• While there has been an increase in the river's conveyance capacity that accounts for part of the decline in head difference between Lake Michigan-Huron and Lake Erie from 1963 to 2006, the change is not ongoing and there has been a slight decrease in conveyance capacity since 2000.
• Climate is the main driver of lake level relationships over time. In particular, hydroclimatic change contributed to a substantial decline in net water supplies to Lake Michigan-Huron in the most recent decade.

The Board also reviewed past proposed remedial works and new innovative approaches to modifying flows in the St. Clair River and identified a range of options that might be employed if remediation were deemed necessary, which it found it was not. The Board also recommended that the U.S. and Canada work cooperatively to improve monitoring and analysis of Great Lakes water supplies and connecting channel flows.

This examination of the St. Clair River was part of a broader evaluation that is expected to produce recommendations in 2012 regarding improvements to the control orders for the international compensating works and power dams on the St. Marys River in Sault Ste. Marie. The Board is recommending that the next phase of the Study examine whether mitigative measures in the St. Clair River might be necessary based on its assessment of the potential future impacts of climate change on upper Great Lakes levels.

More about the International Great Lakes Study

Pursuant to the Boundary Waters Treaty of 1909, the International Joint Commission has an ongoing responsibility for assuring that projects it has approved continue to operate in a manner that is consistent with the provisions of the Treaty as interpreted by the Commission and the governments of Canada and the United States. In December 2005, a directive established the International Upper Great Lakes Study Board. The Board's mandate is to undertake the studies required to provide the Commission with the information it needs to evaluate options for regulating levels and flows in the Upper Great Lakes system in order to benefit affected interests and the system as a whole in a manner that conforms to the requirements of the Treaty. One of those studies is to examine physical processes and possible ongoing St. Clair River changes and its impacts on levels of Lakes Michigan and Huron and, additionally, depending on the nature and extent of St. Clair River changes and impacts, recommend and evaluate potential remedial options.

Learn more:

• International Great Lakes Study
• Press Release (pdf, 156 KB)
• Report: Impacts on Upper Great Lakes Water Levels: St. Clair River (pdf, 11.66 MB)