Large area of Montreal under boil-water advisory after 'enormous' water main erupts

About 150,000 homes are under a boil-water advisory and multiple roads were closed after a massive water main break Friday morning in Montreal's Ville-Marie borough sent water spewing several metres into the air, flooding streets and basements.

Montreal Mayor Valerie Plante told reporters that it would likely take hours to repair the pipe, which she described as "enormous" at around a metre wide. 

The city has put a boil-water advisory in place for three boroughs: Mercier–Hochelaga-Maisonneuve, Riviere-des-Prairies–Pointe-aux-Trembles and the City of Montreal-East. A map of affected residences is available here.

The City of Montreal's website says residents should boil their water for at least a minute before consuming it.

Officials say a drop in water pressure within the distribution network triggered the advisory, which they called "preventative."

The City of Montreal issued a precautionary boil-water advisory in several boroughs after a major watermain break in the downtown area on Friday, Aug. 16, 2024. (Source: City of Montreal)

The water main broke around 6 a.m. on René-Lévesque Boulevard at De Lorimier Avenue, causing water to spill into the streets. About a half hour later, a massive geyser about 20 metres high had erupted. 

Ankle-deep water spread through a significant portion of the neighbourhood as fast-moving floods washed across Notre-Dame Street to the south, and Ste. Catherine Street to the north, Papineau to the west, and through the neighbourhoods within.

The pipeline supplies water to the city's east end. The cause of the water main break is currently unknown.

By 10 a.m., the geyser had shrunk to about six feet high as the water started to recede. Plante said the situation was "under control" shortly before noon. 

"Firefighters are going door-to-door, and they have ordered some to evacuate their homes and workplaces," said Plante. "The Red Cross is here to help people who need to relocate."

Firefighters say about 100 homes have been affected by the flooding.

Chantal Morrisette, who's responsible for the city's water services, says the pipe was transporting drinking water only, and that the water in the street does not pose a danger to residents.

Maxime Carignan Chagnon told The Canadian Press a "giant wall of water" gushed for about two hours. The rushing water was "very, very strong," he said, splashing as it crashed against lamp posts and trees. "It was truly impressive."

He said about two feet of water collected in his basement. "I heard some people had much, much more," he said.

A large water spout is seen in Montreal after a massive water main break flooded streets.

Residents were forced to vacate their homes to allow firefighters to assess any damage and pump out water from their basements. 

"It's not only people who live in basements. It's people in buildings," said Plante, referring to apartment buildings in the area. Electricity has also been cut to several residences but most of the outages were over by the early evening hours. 

A massive water main break sent water billowing into the streets near the Jacques Cartier Bridge on Aug. 16, 2024. (Daniel J. Rowe, CTV News)

Plan travel ahead

The STM said Friday it was rerouting bus lines and that service was still ongoing.

"Since the beginning of this situation, obviously, the bus network in this area was impacted. We're talking about lines number 10, 15, 34, 45, 150, 410, 430. Those lines do circulate in the perimeter of the actual situation," said Isabelle A. Tremblay, an STM spokesperson.

"We have the personnel on site. We have operational chiefs, as well as drivers, where our bus control center is coordinating everything. An hour ago, we stopped doing the shuttle with the 769 to go to La Ronde, and that's for an indeterminate period."

A person stands on cracked asphalt next to a geyser caused by a broken watermain on a street in Montreal, Friday, August 16, 2024, causing flooding in several streets of the area. THE CANADIAN PRESS/Graham Hughes

Trembaly urged all commuters to plan their trips ahead of time and to take the metro, which is not affected. The nearby Papineau metro station is still operational.

Drivers heading east through the Ville-Marie tunnel on Route 136 will have to leave at the Saint-Laurent Boulevard exit, and De Lorimier Avenue, Rene-Levesque Boulevard, Notre-Dame Street and Papineau Avenue all have closures due to flooding.

People are asked to avoid the area until the survey is complete, which could take "all day," said Plante.

Some offices, including CTV News Montreal, have instructed workers to stay home. 

Plante said in a post on social media that the Red Cross has assisted some residents. 

"If you have any questions or require resources related to this morning's event, please do not hesitate to contact our 311 agents. They are there to help you," said Plante. 

- With files from The Canadian Press.