New Brunswick

Tantramar dikes feel pressure of rising sea levels

The Tantramar dikes have been protecting the Sackville, New Brunswick area for hundreds of years, but as sea levels slowly rise, the dikes will need to be heightened.

The barriers made of earth were first built by the Acadians to turn swampland into pastures and hayfields

Evidence indicates that water from the Bay of Fundy will overcome or destroy the Tantramar dykes, causing flooding in Sackville. (Mount Alison Geospatial Modelling Lab)

The Tantramar dikes have been protecting the Sackville, New Brunswick area for hundreds of years, but as sea levels slowly rise, the dikes will need to be heightened.

Engineer Claude Robichaud is constantly surveying the dikes, looking for damage or weakened areas.

"High, high tide that we get a couple times a year, it'll go almost to the top of the dike, you know like a foot, on a calm day," he said.

The barriers made of earth were first built by the Acadians to turn swampland into pastures and hayfields.

Robichaud says the dikes were only meant to expand agricultural lands, but as towns like Sackville started to grow, they were used to protect homes and businesses.

"So now the community relies on the protection of the dikes and that occurred in other places in the province too," Robichaud said.

Area residents are concerned about another major flood. The last one was in 1962 when low lying areas were a metre deep in water.

Studies are showing another major flood isn't a matter of if, but when. A map developed by a geography professor at Mount Allison estimates which neighbourhoods in Sackville could be underwater when the next major flood hits.

Both Heather Patterson's home and workplace are on the flood plain.

"It's a little bit unnerving," she said, but she has also made an effort to educate herself.

"I said 'oh my heavens we should get a plan' and so we've started planning and getting things together for 72 hours survival because it could come down to that," she said.

The barriers made of earth were first built by the Acadians to turn swampland into pastures and hayfields. (www.virtualmuseum.ca)

Sackville fire Chief Craig Bowser says the town has gone to great lengths to prepare for a major flood, including starting a boat registry.

"Canoe, flat bottom boat, anything we can utilize to get people to safety, that's what we're looking to hear from," he said.

Robichaud says there's never been a barrier breach, but he does not underestimate the power of the tides.

"Well, it can throw boulders over you know, 50 feet, the wave action just pounding so you'd get there and you'd see these big one foot rocks just fly up and over the dike, just the pounding of the waves," he said.

If the water were to rise one metre in the next hundred years, Robichaud predicts the dikes won't be high enough to hold it back.

"I feel like it's inevitable, but I'm not really afraid because I understand that there is planning going on," he said. "There is work being done on the dikes and most of this is happening without most of us knowing about it."