For Release: February 7, 1997
Lake Ontario-St. Lawrence River Flows Increased
After Stable Ice Cover Forms
Outflows from Lake Ontario have increased steadily since January 31, 1997, when formation of a
stable ice cover on the St. Lawrence River was nearing completion. Under the winter operations
provision of the International Joint Commission's Orders of Approval, the outflows will be as
as possible without causing downstream flooding.
Formation of an ice cover, as complete and stable as possible, helps to prevent underwater ice
blockages that can restrict flows.
The Commission's International St. Lawrence River Board of Control had reduced flows to allow
ice cover formation. As recently as January 28, 1997, flows were reduced to 6,500 cubic meters
per second or cms (230,000 cubic feet per second or cfs) to aid ice cover formation above
Iroquois Dam, the last critical section of the St. Lawrence River to form ice.
Since January 31, 1997, the Board of Control has increased Lake Ontario outflows by
approximately 300 cms (10,600 cfs) per day. The present outflow is 8,100 cms (286,000 cfs).
The Board of Control will carefully monitor conditions that affect levels and flows on Lake
Ontario and the St. Lawrence River, including the condition of the ice cover.
On January 17, 1997, the Commission invoked criterion (k) of its Orders of Approval to provide
all possible relief to shoreline property on Lake Ontario and the St. Lawrence River from the
Thousand Islands to past Montreal. Criterion (k) will provide the authority to continue higher
outflows, which will likely still be needed once winter operations are over.
The International Joint Commission was created under the Boundary Waters Treaty of 1909 to
help prevent and resolve disputes over the use of waters along the Canada-United States
boundary. Its responsibilities include approving certain projects that would change water levels
the other side of the boundary, such as the hydropower project near Cornwall, Ontario and
Massena, New York. The Commission established the International St. Lawrence River Board of
Control to ensure that outflows from Lake Ontario meet the requirements of the Commission's
Orders. The Board also develops regulation plans and conducts special studies as requested by