Some 30 per cent more Quebec homes to be in flood zones when new mapping takes effect

The Quebec government has announced the adoption of a modernized regulatory framework for flood zones.

The number of Quebec homes located in flood zones will likely increase by 30 per cent when new maps are introduced next year, the province’s environment minister said Thursday.

At a news conference on Quebec’s new guidelines to manage flooding, Benoit Charette said the government’s goal is to protect people and their properties, and to make sure residents understand the risk they’re exposed to. The number of homes in flood zones, he said, should rise to 35,000 from about 25,000.

“We want to make sure people have the right information about where they live,” he said. “Today that’s not the case because many of these (maps) are as old as 30 years, so they’re not up to date.”

The new maps have not been published and the new framework only comes into effect in March 2026.

Charette said that as of next year, the province will begin identifying flood risks on a categorical scale — low, moderate, high and very high. The existing system identifies risk on the probability that a certain level of flooding will happen in any given year. For instance, some areas are in a flooding recurrence zone of 0—20 years, which has a one in 20, or more than 5 per cent chance of flooding each year.

Charette said the province will create next year a fifth risk zone, associated with homes that are located behind a “flood protection structure,” such as a dike or retaining wall, that meets a set of criteria defined by the province.

The government has said the new rules are necessary due to climate change, and were conceived after major flooding in 2017 and 2019 that caused an estimated total of more than $1 billion in damages.

Some mayors have expressed concerns that the new maps will prevent some residents from being able to purchase flood insurance, and that values will plummet if homes are located in newly identified in flood zones. They also criticized the province last year for holding consultations before publishing the new maps.

Charette on Thursday struck a reassuring tone, saying most of the homes that will be added to flood zone maps will likely be in the lowest-risk categories. He said the value of homes has continued to rise, including in flood zones.

“And an important element — you’ve heard me say it a few times over the last year — we aren’t creating new flood zones through this process, we’re simply identifying them,” he said.

Quebec estimated last year that 77,000 homes could be in flood zones, but that number has since been downgraded.

The province made clear that nobody would be forced to relocate their homes under the new management plan. However, new construction will not be allowed in very high-risk zones; homes destroyed by flooding in those zones will not be permitted to be rebuilt.

Rebuilding after flood damage will be permitted in high- and moderate-risk zones, under certain conditions.

This report by The Canadian Press was first published June 12, 2025.

Stéphane Blais, The Canadian Press

— With files from Morgan Lowrie