Two proposed class-action lawsuits have been filed in Quebec Superior Court following the June 20 flooding on Montreal's West Island, alleging the City of Montreal, the borough of Pierrefonds-Roxboro and the City of Dollard-des-Ormeaux failed to mitigate known flood risks.
The lawsuits followed a series of "near-stationary thunderstorms" that Environment Canada said dumped between 100 and 170 mm of rain on southern Quebec on June 20, flooding more than 300 homes across Pierrefonds-Roxboro and Dollard-des-Orneaux.
Jeff Orenstein, a lawyer with Consumer Law Group, which filed the actions, said the municipalities "failed to take proper action to address the risk of flooding by installing adequate systems that absorb, detain and slowly release rainwater such as sponge parks." He also said that about 625 people have signed on to the class action.
Dollard-des-Ormeaux resident Mike Silverman, whose home flooded for the second time since 2024, put the damage at $100,000 and said he's unsure how his insurer will respond next time.
"I don't even know what my insurance is going to do for the next time if they're going to cover me and I may have to find new insurance and, again, pay more money out of my pocket," he said.
Pierrefonds-Roxboro resident Myriam Guadelli, who also filed a claim, told CBC she hadn't heard back from her insurer two weeks after the flood: "If we can stop this from happening again in the future, then that's a huge win for me. But that change is not going to be made if we don't force it. And I think the class action lawsuit is what's needed to force the city to change."
Quebec has been hit by repeated major flooding in recent years. The 2024 floods, driven by the remnants of tropical storm Debby, were ranked by the Insurance Bureau of Canada as the costliest severe weather event in the province's history, with CatIQ later putting insured damage at nearly $2.5 billion.
The IBC has recorded an average of 25,000 flood-related claims a year in Quebec over the past five years.
Standard home insurance in Canada doesn't automatically include overland flood or sewer backup protection; both are separate, optional endorsements. The IBC's Rob de Pruis has urged homeowners to check policies before a flood, not after. Standard home insurance does not automatically include overland flood or sewer backup protection, he said, and homeowners need to contact their insurance provider to confirm whether those optional coverages have been added.
"That can literally help and save you thousands of dollars in the future if you do experience that damage," de Pruis said.
Even homeowners with that coverage aren't necessarily made whole: limits set years ago can fall short of current repair costs, and in high-risk areas with a flooding history, overland coverage can be capped, subject to steep deductibles, or declined. The IBC estimated roughly 1.5 million high-risk Canadian households cannot obtain affordable flood insurance.
The Montreal flooding fits a broader pattern. CatIQ data showed severe weather cost Canadian insurers over $2.4 billion in 2025, the tenth-costliest year on record, after 2024 became the first year insured catastrophe losses topped $8 billion nationally.
IBC figures show annual insured losses from catastrophic weather averaged $14 billion a decade between 2006 and 2015, nearly tripling to $37 billion between 2016 and 2025, pushing the IBC to lobby for updated building codes, stronger hazard mapping and stormwater systems built for extreme rainfall, echoing the lawsuits' core allegation: that municipalities failed to invest in adequate stormwater absorption despite known, repeated risk.
The structural fix the industry wants remains unresolved: Ottawa committed to a national flood program in the 2023 and 2024 budgets, and the IBC has proposed a federal reinsurance entity for the highest-risk households, but Budget 2025 gave no update and no timeline is confirmed.
For insurers, the litigation adds a new dimension to a familiar problem -- municipal liability claims over stormwater infrastructure are emerging alongside private disputes over what policies cover.
With repeat flooding a documented pattern in the West Island, and national catastrophe losses trending sharply upward, insurers may face pressure to clarify overland flood and sewer backup coverage at the point of sale and price accordingly where flood risk has become recurring.
A successful municipal claim could also reshape how insurers view subrogation against local governments in flood-prone areas. Until a national backstop materializes, that pressure will likely keep falling on private carriers and policyholders.
