A homeowner stood in his Pierrefonds driveway surrounded by the wreckage of a flooded basement. “Thirty-five years of stuff — gone,” he told reporters.
He is far from alone. On the evening of June 20, near-stationary thunderstorms dumped up to 170 millimeters of rain on Montreal’s West Island in a matter of hours on a landscape of asphalt and concrete. Around 300 basements flooded the West Island and over 20,000 homes lost power.
No stormwater system can handle 170 millimeters in a few hours. June 20 was a collision between a changing climate and a city built for the weather of the past. These storms form within a day or two, cannot be forecast precisely, and will return.
Risa Weigersberg throws a bag of garbage onto the growing pile of flood-damaged items outside her Dauphin St. home in Dollard-des-Ormeaux on June 21, 2026. Tim Snow / Montreal Gazette
Since 2017, Pierrefonds-Roxboro alone has seen four major flood episodes. The Insurance Bureau of Canada reports that Quebec flood claim costs rose nearly 128 per cent between 2014 and 2024. This is no longer an exceptional event. It is the new normal and future storms are only going to get worse.
And yet, homeowners have more tools to fight back than many realize. They can start now before another storm arrives.
Here is the catch, though: many already tried. One Dollard-des-Ormeaux resident told reporters she had installed a sump pump after flooding in 2024. On June 20, her basement filled with three feet of water anyway.
A Pierrefonds homeowner told The Gazette her home had a pump, too, but when the power went out, it stopped.
These stories are not arguments against taking action. They are arguments for taking a combination of action, because a single measure, installed in isolation, is rarely enough.
Start with the free steps:
Clear the storm drain in front of the house.
Extend downspouts two meters from the foundation onto permeable soil.
Make sure the ground slopes away from the house.
When ready to invest more, solution exists:
A backwater valve stops sewage from surging back through floor drains when the city’s sewer system is overwhelmed.
A sump pump with a battery backup and an external generator actively removes groundwater before it rises — and the external generator matters because severe storms also knock out power.
Homes with below-grade garage entries face a specific risk: a watertight garage door or a removable flood barrier, called a batardeau, can stop surface water before it ever enters.
None of these is cheap, but subsidies exist:
Quebec’s new Rénoclimat-Adaptation program offers up to $1,000 for basic measures and covers up to 75 per cent of costs for major structural work in recognized flood zones.
Écohabitation’s program JeRénovÉco also offers free advisory service, guiding homeowners through exactly which combination their building needs.
In parallel, the city has obligations of its own. The core idea is simple: A city built mainly of asphalt and concrete gives rainwater nowhere to go but down, fast, and all at once into pipes that were never designed to handle such deluges.
Montreal has a climate adaptation plan. Now it must give it the resources and urgency it deserves to implement rain gardens and bioswales along streets, include permeable pavement in parking lots, and build more retention structures so that water is slowed, absorbed and held before it ever reaches the sewer network.
The Quebec government also has a responsibility and must accelerate the publication of official flood-zone maps. Homeowners cannot make informed decisions about their own properties without them.
Individual action and public investment work best in combination, but individual action can start today. One Montrealer who went through the full flood-proofing process told La Presse said she no longer feels stressed when it rains.
The time for a full-blown action to protect your home is now.
Allison Reynaud is managing director of climate resilience for Quebec at the Intact Centre on Climate Adaptation, an applied research institute at the University of Waterloo.
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