Outflow Strategy
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Copyrights : International St. Lawrence River Board of Control

Lake Ontario Outflow Strategy
(March 12, 2003)

The dry spell on the Great Lakes basin continues. Water supplies to all of the Great Lakes were below average in January and February. Lake Ontario water supplies have been below average for the past eight consecutive months. Montreal Harbour levels set new record lows for January and February.

Water levels of all the Great Lakes are below their respective March averages and all are lower than one year ago. On March 5, Lake Ontario was at elevation 74.29 m (243.73 feet), which was 35 cm (14 inches) below the average for this time of the year, and 47 cm (19 inches) below the level of one year ago. The water levels in Lac St. Louis and Montreal Harbour were about 20.47 m (67.2 feet) and 5.47 m (17.95 feet), respectively. These were 50 cm (20 inches) and 77 cm (26 inches) below their respective averages.

The Board discussed these and other conditions in its meeting on March 5-6 and decided to update the outflow regulation strategy announced on January 13. In light of continued low basin supplies, the long-term strategy is to conserve water on Lake Ontario, as opportunities arise, for use later in the year. Through the first week of April outflows will generally be as determined by the Regulation Plan 1958-D except for the following deviations:

a. Flow reductions during spring runoff , when the level of Lake St. Louis is above 20.6 m, and, once the Seaway opens (anticipated March 31) the level of Lake St. Francis at Summerstown is above 46.50 m.

b. Flow increases to maintain Lake St. Louis levels above 20.45 m (67.1 ft) until the Seaway opens, and thereafter, maintain Lake St. Louis above 20.52 m and the level of Lake St. Francis at Summerstown above 46.50 m.

c. Flow increases to meet critical hydropower needs and to raise levels at the Port of Montreal to meet critical navigation needs, with a maximum daily over-discharge of 300 cms (10,600 cfs) above the Plan flow.

The outflow increases for the purposes mentioned above may use the equivalent of a maximum of 8 cm (3 inches) of water from Lake Ontario relative to Regulation Plan 1958-D. As of March 5, the accumulated over-discharges were at 4.1 cm (1.6 inches).

The Board intends to review this strategy in April at its next Board meeting, or before if conditions require. The Board continues to closely monitor the conditions on the Lake Ontario-St. Lawrence River System and will intervene as required.

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 on the other side of the boundary, such as the international hydropower project at Massena, New York and Cornwall, Ontario. When it approves a project, the Commissionís Orders of Approval may require that flows through the project meet certain conditions to protect interests in both countries. For more information, visit the Commissionís website at www.ijc.org.

The International St. Lawrence River Board of Control was established by the International Joint Commission, mainly to ensure that outflows from Lake Ontario meet the requirements of the Commissionís Orders of Approval. For more information, visit the Boardís website at www.islrbc.org.

For Release: March 12, 2003


Reg Golding, Ottawa, Ontario (613) 998-1408

John Kangas, Chicago, Illinois (312) 353-4333