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

Witnesses said that at its peak, a “wall of water” 10 metres high had burst through the ground, flooding the densely populated neighbourhood near the bridge.

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, Plante added, the city was issuing a boil-water advisory that covered about 150,000 residences in the eastern part of the city.

People will have to boil their water for one minute before consuming it if they live below Sherbrooke Street in the boroughs of Mercier—Hochelaga-Maisonneuve and Rivière-des-Prairies — Pointe-aux-Trembles, and the on-island suburb of Montréal-Est.

“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 one 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 is 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 will 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 lampposts and trees. “It was truly impressive.” He said about two feet of water collected in his basement, but “I heard some people had much, much more.”

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. They said crews still need to evaluate the danger before residents can return home.

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

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