Heavy rain causes two flooding events in Moncton within a week

Monday night’s storm came hard and fast, bringing loud thunder, bright lightning and pooling water to Moncton, N.B.

It was the second time in a week the downtown streets were submerged in water.

“It’s what we call short duration, high intensity,” said René Lagace, director of engineering for the City of Moncton.

“The first event last week, we received about 50 mm of rain in a short period of time and last night 15 mm in 15 minutes.”

Social media posts showed vehicles of all sizes driving through completely flooded streets. By Tuesday, only puddles remained.

Lagace says while flooded streets aren’t ideal, the sewer systems are actually designed to hold water during heavy rain.

“The water’s meant to stay on the ground, on the street, and it’s actually to prevent some underground flooding. So, if you can imagine, all that water would have been pushed through our systems, then you have a higher chance of people backing up from their sewers,” he said.

Legace says the city’s systems are designed to handle a lot of water during a longer duration, noting the Petitcodiac River and high tide also play a role.

“When we have a storm event that coincides with a high tide, it’s definitely more difficult for the water to push its way through and that’s actually what happened on the first event last week,” he said.

The Moncton Fire Department said despite the two incidents on Oct. 8 and 14, they haven’t seen an increase in flood-related calls.

The city says plans and renewal work are underway to help prevent flooding in the future.

“We’re adding these storm sewer basins,” said Legace. “People might have noticed them in the east end and also south of Lewisville. Those are great examples of adding capacity to our system. We’re also redoing a lot of our older streets that have combined sewer systems, so it’s just one pipe that’s handling all the flows and what we’re doing is installing separated sewers so dedicated sanitary and a dedicated storm sewer.”

He says while the improvements throughout the city are helping, climate change means high-intensity storms are happening more often.

“The intensity and the frequency of these storm events is getting more and more,” he said. “We just had the event last week and we’re kind of just scrambling to get some numbers and do some statements and here we are again talking about it, so we’re definitely seeing the impacts of climate change.” 

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