The International Joint Commission confirmed late this week that it does not intend to raise Moses-Saunders Dam outflow levels to rates that would force an early closure of the St. Lawrence Seaway in 2019.
A IJC spokesperson told an Ontario newspaper that it would be difficult to remove more water before next spring than it is already doing. A season of intense flooding around the easternmost Great Lake, Lake Ontario, precipitated the idea to open the dam. But shipping industry leaders decried the plan for the hit the shipping economy would incur.
“The options for increasing the flow would provide limited additional relief — on the order of 2 to 4 centimeters — and would have considerable negative impacts on other interests, including flooding downstream,” said an IJC email shared by the Duluth Seaway Port Authority on Friday.
Industry and U.S. congressional leaders opposed opening the dam as a remedy to relieve flooding on Lake Ontario because of the way it risked closing the shipping campaign early by raising outflow above a safe navigation limit.
Closing the St. Lawrence Seaway that connects the Great Lakes with the Atlantic Ocean in December to accommodate higher water outflow at the Moses-Saunders dam would have cost the Canadian and U.S. economies $193 million per week, the Chamber of Marine Commerce said Monday. Deborah DeLuca, Duluth Seaway Port Authority executive director, called the impact of increased outflow at the dam "negligible."
A future solution could still impact the start of the 2020 campaign in March.
“The IJC continues to review options for higher flows, including those that would result in Seaway navigation opening later than it otherwise would in 2020,” an IJC spokesperson wrote.
The shipping campaign ends Jan. 15 for an eight-week offseason that lifts in March.