Marine shipping executives are calling on government officials to protect the St. Lawrence Seaway trade corridor to develop solutions that do not rely on one dam of limited effectiveness to solve high-water levels across the Great Lakes.

The opening of the navigation season in the Montreal-Lake Ontario (MLO) section of the St. Lawrence Seaway has been delayed to April 1 to allow more outflow from Moses-Saunders dam to lower Lake Ontario water levels, according to the Chamber of Marine Commerce (CMC), which represents the interests of shippers. The Welland Canal will open March 24.

With little ice coverage, the MLO section of the St. Lawrence Seaway could have opened as early as March 20. As many as 100 ship transits could have moved during that 12 days.

“We’re very disappointed with this delay. It’s time for politicians to start working with all the affected residents, businesses and shipping stakeholders on smart, effective solutions for high water levels. Delaying, shutting down or interrupting American, Canadian and international trade on the St. Lawrence Seaway and further damaging the economy and our nations’ global trading reputation should never be an option,” said Bruce Burrows, president of the CMC. “This dam is a very limited tool that does not solve this problem. We need to work together to develop a much broader, holistic resiliency plan that looks at every avenue including flood zoning, shoreline resiliency and infrastructure investments.”

Evidence from the International Lake Ontario-St. Lawrence River Board (ILORB) demonstrates that outflow levels at Moses-Saunders dam have little impact on the problem, lowering the Lake by centimetres only to have more water come flooding in from precipitation or Lake Erie and the other overflowing Great Lakes, Burrows says. He contends that with every outflow decision, the ILORB has to consider downstream flooding in Montreal, upstream municipal water intakes, power generation, shoreline damage and navigation safety for both commercial and recreational interests.

The CMC says that in 2019, marine shipping worked with stakeholders to ensure safe navigation at record outflow levels from Moses-Saunders dam on the St. Lawrence Seaway for five months to help lower Lake Ontario, taking on 26 mitigation measures that caused shipping delays, lost cargo business and millions of dollars of extra operating costs.

But water levels have continuously led to calls by shoreline residents to “open the floodgates” at the dam. This move would create fast-moving, unsafe currents that would stop marine shipping and cost the Canadian and American economies up to USD $193 million lost business revenues a week – impacting farmers, steel and manufacturing employees, miners and construction workers and the myriad of others whose livelihoods depend on the cargo carried on the waterway, the CMC says.