Proposal for Lake Ontario and St. Lawrence River Regulation


"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..."
IJC Mission Statement 

The need for a new plan for regulating water levels and flows


Reducing environmental impacts

Lake Ontario is recognized as the most environmentally stressed of the Great Lakes due a variety of factors, including degraded habitat.  Extensive research shows the regulation criteria developed in the 1950s, and regulation practices since then have compressed the range of water levels to the point of causing widespread degradation of the coastal wetlands on Lake Ontario and the upper St. Lawrence River. Coastal wetlands provide habitat for most of the birds, fish and other animals living in this ecosystem. Allowing more natural variations in water levels, while moderating extreme levels, can improve the wetland ecosystem on the lake and upper river.

A plan for current and future conditions

The 1950s plan is based on the limited range of water supplies to Lake Ontario that were recorded from the 1860s to the 1950s. Criteria adopted in the 1950s created an unrealistic expectation that Lake Ontario water levels could be maintained within a four-foot range (approx. 1.2 meters). Over 50 years of experience, including the low levels of 1965 and the high levels in the mid-1970s, 1993 and 1998 have shown that it is not possible to keep the lake within this range under more wide-ranging water supply conditions. Loss of ice cover, increased storm intensity and warmer temperatures all influence how water levels and flows impact coastal communities, recreational boating and commercial navigation, drinking water, hydropower production, and the system’s ecological health.