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Lake Superior Results

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Experts Recommend New Regulation Plan for Lake Superior Outflows Improved Plan More Robust, Provides Additional Benefits to Environment

The International Upper Great Study (IUGLS) announced they have recommended an improved regulation plan for outflows from Lake Superior.  The new plan - Lake Superior Regulation Plan 2012 - is more robust than the existing plan and provides important benefits, especially to the environment.  Made up of a panel of experts from Canada and the U.S., the recommendation is the highlight of their final, peer-reviewed report to the International Joint Commission (IJC), marking the end of the $14.6 million ($17.6 million Cdn.) five-year study.

State-of-the-art climate research.  The report provides cutting edge scientific information regarding the impacts of climate change on the upper Great Lakes.  In particular, the Study found that changes in lake levels may not be as extreme over the next 30 years as previous studies have predicted.  This finding reflects a trend of increasing evaporation, likely due to lack of ice cover, and increasing water temperatures and wind speeds, with the resulting reduction in water supplies largely offset by increased precipitation.  Projections suggest that lake levels will remain within a relatively narrow historical range with lower levels likely though higher levels are possible at times.

Improved protections for fish habitat.  Based on a shared vision planning process, the Study identified a regulation plan that is superior to the current plan, which has been in place since 1990, especially under conditions of lower water supplies.  For example, if conditions are significantly drier, the new plan does a better job of preserving Lake Superior water levels while taking into account downstream lakes.   In addition, under dry conditions, the new plan avoids the serious adverse effects on the spawning habitat of lake sturgeon in the St. Marys River. 

More natural river flows.  Compared to the existing plan, month-to-month changes will generally be smaller under the new plan, giving the St. Marys River a more natural flow relationship to Lake Superior levels.  This is an important factor in sustaining ecosystem health in the river.  

Benefits to other key interests.  Lake Superior Regulation Plan 2012 will provide modest additional benefits for commercial navigation, hydroelectric generation and coastal interests, under both wetter and drier water supply conditions.  Most importantly, under very dry conditions, commercial navigation through the Soo Locks and power generation would be threatened with closure under the current plan but not under the improved plan.

Less complex, more adaptable.   The rules for operating Lake Superior Regulation Plan 2012 will be much less complex than rules for the existing plan, making it easier to manage, maintain and adapt to a changing climate.

Restoration and multi-lake regulation.  Researchers found that restoration structures (such as "speed bumps" in the St. Clair River) designed to raise Lake Michigan-Huron water levels would result in adverse effects on certain key interests.  Moreover, the potential for multi-lake regulation (additional control points on the St. Clair and Niagara rivers) to address extreme water levels is limited by uncertainty of future water supplies, environmental concerns and institutional requirements.

Public concerns about water levels.  Not surprisingly, public concerns about water levels in the upper Great Lakes differ considerably depending on geographic location.  For example, many residents of the Georgian Bay region of Ontario supported construction of new structures to provide for restoration or multi-lake regulation.  In contrast, many residents of Lake Michigan (and other areas) expressed concern about potential damages of higher water levels and those living on the St. Clair River and downstream opposed new structures because of the possibility of negative environmental impacts, among other reasons.

The Study Board made the following key recommendations:

  • the IJC should approve Lake Superior Regulation Plan 2012 as the new plan for regulating Lake Superior outflow;
  • the IJC should seek to improve scientific understanding of hydroclimatic processes and impacts on future Great Lakes water levels as part of a continuous, coordinated bi-national effort that includes strengthened modeling and enhanced data collection;
  • an adaptive management strategy should be applied to address future extreme water levels and a Great Lakes-St. Lawrence River Levels Advisory Board should be established to help administer the strategy; and,
  • further study of multi-lake regulation in the Great Lakes-St. Lawrence system should not be pursued at this time.

The study was launched by the IJC in 2007 to review the regulation of Lake Superior outflows and to assess the need for improvements to address both changing needs and a changing climate.  Lake Superior Regulation Plan 2012 will determine the operation of the power dams and other control structures in the St. Marys River at Sault Ste. Marie (MI and ON).   The final report was unanimously endorsed by the 10-member binational Study Board, includes the work of more than 200 scientists and engineers, and reflects extensive, independent peer review.  The Study also benefited from the advice of a 20-member Public Interest Advisory Group and input provided by the public at meetings held throughout the upper Great Lakes basin.  Prior to taking action, the IJC plans to hold public hearings in July.