‘Wall of water’ in Montreal after underground pipe breaks, floods streets and homes

MONTREAL — Nearly 150,000 Montreal homes were put under a boil water advisory on Friday after a broken water main erupted into a “geyser” that transformed streets into streams, paralyzed traffic and forced people to evacuate from flooded buildings.

Montreal Mayor Valérie Plante said many residents east of downtown woke up around 6 a.m. to firefighters urging them to get out of their homes because of flooding risks from the underground water main that broke near the Jacques Cartier Bridge.

Witnesses said that at its peak, a “wall of water” 10 metres high had burst through the ground, flooding the densely populated neighbourhood. Residents donned rubber boots and waded through the water that streamed down the streets and puddled in intersections during the approximately five and a half hours it took to fully stem the flow.

By 11:45 a.m. the situation was “under control,” Plante said, and the city’s director of water services said workers had managed to close a valve so the pressure in the water main was dropping. However, the city issued a boil-water advisory that covered a large swath of the northeastern part of the island.

“The good news is that everything is under control,” Plante said. “We will have to repair the pipe, but we no longer have the same quantity of water (on the street) that we had this morning … and as a precaution, there will be a preventive boil-water advisory.”

Earlier in the day, officials said that thanks to redundancies in the city’s network of 4,000 kilometres of pipes, there were no safety issues with drinking water in the flooded district. But about an hour later, they said they had noticed a drop in water pressure in part of the network and they wanted to test water samples to be certain there were no problems.

The source of the flooding was a pipe more than two metres in diameter installed in 1985, said officials, who explained the asphalt and concrete above the broken section of pipe would need to be excavated before they know how serious the problem is.

Lyman Zhu said he woke up to what sounded like “heavy rain” and when he looked out his window saw a “wall of water” that was about 10 metres high and the width of the street. “It was insane,” he said.

Maxime Carignan Chagnon said the “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 noted.

Martin Guilbault, division chief of the Montreal fire department, said people should stay away from the flooded area until authorities give the green light to return.

“Just because there is less water doesn’t mean the work is done,” he said, explaining that parts of streets could be damaged and give way from all the water that poured over them.

Fire officials didn’t give a precise number of people evacuated, telling reporters that crews visited all the buildings affected and ensured everyone was safe. Guilbault said just before noon that firefighters were still going door to door, pumping out basements. He said they had visited 100 addresses with water infiltration at that point, but in some cases the water was in parking garages rather than apartments.

City officials said the Red Cross was meeting with affected residents and offering resources to those who couldn’t immediately return home.

Quebec’s hydro utility cut power to the affected area as a precaution, leaving about 14,000 clients without electricity.

The water main break comes as many people in Montreal and across Quebec are still cleaning out flooded basements after parts of the province were battered by up to 200 millimetres of rain last Friday.

Premier François Legault confirmed Friday the province would enlarge its financial assistance program for disaster victims to include people whose homes were flooded when their sewers backed up during the storm, rather than limiting eligibility to damage caused by overland flooding.

Public Security Minister François Bonnardel told reporters in Montreal that the situation was improving after last week’s flooding, but 20 roads still had to be repaired and 36 people remained evacuated from their homes.

This report by The Canadian Press was first published Aug. 16, 2024.

Morgan Lowrie, The Canadian Press