What one region’s water level woes reveal about climate change and the St. Lawrence River

Strolling along the shore of his home on Ault Island, about 30 minutes west of Cornwall, Ont., Cliff Steinburg points to the end of his dock. He says this summer there was less than a foot of water there, making it impossible to launch a boat. While the river has since stabilized, Steinburg worries what next year will bring to a region known for its fishing, beaches, and boating.

“This area cannot go through another season like we did,” Steinburg said. 

“It’s going to have a major effect on tourism. It’s going to have a major effect on all of us living here.”

The St. Lawrence Seaway is an economic powerhouse; not only the lifeblood of local life and tourism in the many towns that overlook its shores, but a major trade artery relied on for commercial shipping between Montreal and Lake Ontario.

But the river is changing.

Steinburg lives in a particular section of the river known as the Lake St. Lawrence. The region was flooded in the late 1950s so that commercial ships could bring their cargo further upriver and inland.

Located directly upstream of the international Moses-Saunders Power Dam, the Lake St. Lawrence’s water levels drop when the dam opens, so that water can flow from Lake Ontario downstream to Montreal. 

While the area has always been vulnerable to some water level fluctuations for that reason, Steinburg said that in his two decades living there he has never seen levels as low as they were in the summer of 2022. 

According to public data from the International Lake Ontario-St. Lawrence River Board, the Lake St. Lawrence dropped below the lowest minimums ever recorded multiple times over the last few years, in May 2020, May 2021, and July, August, September and October 2022. 

What climate change means for the Great Lakes

Those seesawing water levels may get worse. Engineers and scientists are warning communities around the Great Lakes to prepare for a future with more extreme water level fluctuations. 

A report published this year by Natural Resources Canada warns that “climate change may affect net water supplies” to the Great Lakes and the St. Lawrence River over the next few decades.

“We’re likely to see higher highs and lower lows on both ends of the scale,” said Frank Seglenieks, Canadian co-secretary of the Lake Ontario — St. Lawrence River Board, which regulates the flow of water through the Moses-Saunders Power Dam.

“We have about 100 years of water level data in the Great Lakes and over the past 10 years, some of the lakes have seen both their lowest levels and their highest level just within the last 10 years,” he said.

In a recent analysis, Seglenieks found that if the global average temperature increased by more than 2.5 C, the range between the average monthly minimum and maximum levels in Lake Ontario could grow by as much as a metre — from about two metres to three. Those fluctuations would trickle down to the St. Lawrence River as well.

Jeff Ridal, a research scientist and the executive director of The River Institute in Cornwall, Ont, said the Lake St. Lawrence region may be a “canary in the coal mine.”

“This is the reality that we have to accept … at the end communities will have to adapt,” Ridal said.

A disappearing bay prompts concerns over fish

Acceptance is hard to come by, especially among residents who are seeing beloved local ecosystems change.

Avid fisher John Sliter, who is the president of The Friends of Hoople Creek Society, is especially concerned about the walleye population. 

He said the basin of Hoople Bay has been drying up, but it’s a part of the annual spawning route taken by fish who swim from the St. Lawrence River upstream to Hoople Creek.

“When I was a young child growing up on Hoople Creek … there were thousands of fish that used to go up the creek to spawn,” Sliter said. 

“When I went back [to the bay] this past summer, it was nothing more than a field. As far as you could see it’s dry land, and I found a few remnants of dead fish.”

He fears many fish aren’t making it up the creek to spawn before it dries out in the spring. As for those that do make it in time, Sliter said he has seen some of their eggs rotting in the sun.

“It’s quite devastating,” he said. 

Potential ecological impacts are being studied by The River Institute. Ridal said they are especially concerned about the fact that the river levels are dropping earlier and earlier in the summer. 

While so far research hasn’t shown any significant differences in fish populations, Ridal said it may take time for the data to catch up with what is a relatively new phenomenon.

‘Sacrificial lambs’ in a balancing act

Steinburg and many other locals believe it’s the responsibility of the board that manages the Moses-Saunders dam to adjust its operation to make water levels more consistant.

“I think it can be better managed, if you want my honest opinion,” said Steinburg, who is a member of the public advisory group that suggests improvements to the dam’s operation.

South Stormont Mayor Bryan McGillis agrees more needs to be done. He’s concerned about economic fallout in his community, not to mention impacts on home values.

“We don’t need to be the sacrificial lambs here,” he said.

“We really need our water where it is, because this is a tourist area and it’s important that the people still come to this community for our businesses.”

The Moses-Saunders Power Dam management plan — and how it can be adapted for climate change — is currently under review. 

While there is hope that some adjustments can be made for a future with more extreme weather patterns, Seglenieks warned there are limits to what can be done.

“The water that comes into the system, that’s determined by Mother Nature. All we can do is change the regulation plan a little bit to try to balance it,” he said. 

That balancing act is a challenge, because releasing less water from the dam during a dry spell may keep water levels higher for residents upstream, it has consequences downstream. 

“It could reduce the water level at the Port of Montreal so low that the container ships couldn’t actually come in, and that would shut down the shipping industry, which is billions of dollars a day,” he said. 

Ridal agrees there is no easy answer.

“We need a whole gamut of possible ways of dealing with these issues … hopefully improvements on water level management plans, but at the same time I think communities will have to take steps to better protect shorelines … and even adapt so they ensure that they can get their boats in the water.”

Some of those adaptations are already underway. The St. Lawrence Parks Commission is investing millions in adapting local marinas and campgrounds to the new reality. 

Mike Pratt, park operations assistant manager with the St. Lawrence Parks Commission, said that by building breakwalls, dredging and building new boat ramps designed for more extreme water fluctuations, they hope to be better prepared for whatever the future holds. 

“Nobody has a crystal ball, but we’re doing our best and we’re listening to the experts,” he said.

But residents like Sliter and Steinburg worry if water fluctuations get worse, their region will get the short end of the stick, as dam authorities try to balance the needs of towns upriver and downriver, along with the pressures of the shipping industry. 

“We’re the weakest link if you will, or the link that can be sacrificed,” Sliter said. 

“We want to fight for the protection of our area and we want to fight for the protection of the fish and the wildlife.”