Addressing Climate Change in the International Upper Great Lakes Study

Rachel M. Gregg
Posted on: 2/06/2013 - Updated on: 3/02/2020

Posted by

Rachel Gregg

Project Summary

The International Upper Great Lakes Study (IUGLS) is a project of the International Joint Commission (IJC). The IUGLS was established to identify and evaluate potential improvements to outflow regulation of Lake Superior to better address changing interests and climate, and resulting impacts on water flows, water levels, and associated resources in the Great Lakes region.


The IJC is responsible for managing the cooperative use and protection of the lakes and rivers that span the U.S.-Canadian border under the 1909 Boundary Waters Treaty. The IJC created the International Upper Great Lakes Study Board (Study Board) to improve research and information exchange that could enhance decision making regarding the regulation of regional water levels and flows. The Study Board provides recommendations to the IJC and the IJC is in turn responsible for making decisions on regulations and advising the Canadian and U.S. governments on management strategies.

The IUGLS, which is funded equally by the U.S. and Canadian governments, was created in order to evaluate potential improvements to outflow regulation of Lake Superior and identify possible effects on water flows, water levels, and associated resources in the region. The IUGLS identified the possible impacts of climate change on Great Lakes water levels, including increased temperatures, changes in frequency and intensity of weather events, and altered precipitation patterns that will likely cause a decrease in water supply to the region, in its 2005 report, Upper Lakes Plan of Study for the Review of the Regulation of Outflows from Lake Superior.


The Study Board hosted a workshop in June 2009 to discuss how adaptive management could be applied to the IUGLS. One recommendation from participants was the creation of an adaptive management strategy and a committee that could identify and organize climate change adaptation efforts relevant to the study’s directive. In October 2009, the Study Board requested that the IJC expand the IUGLS scope to include the assessment of climate change impacts on water levels and identification of possible adaptation measures; on April 5, 2010, the governments of the United States and Canada agreed that the IUGLS could expand its scope and also consider structural and non-structural options to regulate water levels in a changing climate.

Outcomes and Conclusions

Barriers to evaluating projected climate change impacts in the IUGLS include limited availability of climate and other ecosystem data and inherent uncertainty. Advancing adaptive management through the IUGLS requires enhanced monitoring and modeling of precipitation and runoff, improved monitoring of human alterations to the lakes and connecting waterways, and increased dissemination of up-to-date information to planners and managers so that they can plan for changing water levels. These recommendations are made by the Study Board to the IJC in the report Lake Superior Regulation: Addressing Uncertainty in Upper Great Lakes Water Levels.

The uncertainty about climate-induced lake level changes in the Great Lakes motivated the Study Board to create an Adaptive Management Working Group to assess vulnerabilities to extreme water levels, identify and address uncertainty, encourage flexible decision making, and seek support for a post-study, long-term monitoring program. The Working Group, chaired by Environment Canada and the Great Lakes Observing System, is developing a two-pronged strategy that will (1) allow for regulation changes as conditions change, and (2) provide information on climate change and water levels to related stakeholders and interest groups so that they may adapt their own practices.


Gregg, R. M. (2012). Addressing Climate Change in the International Upper Great Lakes Study [Case study on a project of the International Joint Commission]. Product of EcoAdapt's State of Adaptation Program. Retrieved from CAKE:… (Last updated October 2012)

Project Contact

Ted Yuzyk
[email protected]

Affiliated Organizations

The International Joint Commission prevents and resolves disputes between the United States of America and Canada under the 1909 Boundary Waters Treaty and pursues the common good of both countries as an independent and objective advisor to the two governments.

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