Quebec flood zone map: where to consult it, how to read the four intensity classes and the mobility zones

Flood zone · Map

The portal, the four colours, what each class allows, and how to check an address when the new map is not yet published.

The Government of Quebec's interactive map of flood zones and river mobility zones (zonesinondables.mrnf.gouv.qc.ca) has been publishing new-generation maps progressively since spring 2026. Every zone is classed as low, moderate, high or very high intensity by probability of flooding over 25 years and water depth: very high, more than 70% with more than 30 cm; high, between 70% and 20% with 30 to 60 cm; moderate, between 20% and 7% with more than 60 cm; low, between 20% and 7% with 0 to 30 cm. Added are river mobility zones, short term (50 years) and long term (100 years and more). Where the new map is not published, the map in force at the municipality or the MRC applies, with its high-current (0-20 year) and low-current (20-100 year) zones. Maps are reviewed at least every 10 years.

Where to consult the map

The official portal is the interactive map of flood zones and river mobility zones, at zonesinondables.mrnf.gouv.qc.ca. New-generation maps are published there progressively since spring 2026, territory by territory; in their absence, the maps in force are those of your municipality or MRC. In Greater Montreal, the CMM released a preliminary map, with no legal value, for the first batch (Rivière des Mille Îles and Rivière des Prairies, Lac des Deux Montagnes, Lac Saint-Louis, the river). Several cities also have their own tool: the Géoportail urbanisme in Gatineau, Géo-inondations in Saint-Jean-sur-Richelieu, the interactive map of Vaudreuil-Dorion.

The four intensity classes

The class combines two things the old maps did not distinguish: frequency and water height. A zone can be flooded often but shallowly (high class by frequency) or rarely but deeply (moderate class by depth). It is the class, not the colour alone, that sets what the law allows: see renovating or rebuilding in a flood zone.

Mobility zones

The new map adds river mobility zones, short term (50-year horizon) and long term (100 years and more): the space in which a watercourse can move by eroding its banks. New construction is prohibited in the short-term mobility zone and permitted under conditions in the long-term one.

The old maps, still in force in places

Until the new generation is published for a territory, you still read the high-current zone (0-20 year recurrence) and the low-current zone (20-100 years), and the modernized framework provides rules for those territories. The Haut-Richelieu, for example, does not expect its new map before 2027. And a dike recognized as a protection structure lowers the exposure class of the sectors it protects: 11 CMM municipalities have protection structures on their territory and 24 months to have them recognized.

Checking an address, in order

1. The government portal, with the exact address and the legend.
2. The municipality or the MRC, for the map in force and the written class.
3. The certificate of location (in French), which mentions the zone when the surveyor records it.
4. The seller's declaration, for the real history of the house, map or no map.

Frequently asked questions

Where do I find my city's flood zone map?

On zonesinondables.mrnf.gouv.qc.ca if the new-generation map is published; otherwise at the municipality or the MRC, or on the city's mapping tool when it has one.

What does “low intensity class” mean?

Between 20% and 7% probability of being flooded at least once in 25 years, with 0 to 30 cm of water. It is the only class where a new residence remains permitted, under conditions.

Will the maps change again?

Yes: they are reviewed at least every 10 years, and the recognition of a protection structure can change a sector's class.

Sources read on 15 September 2026: Québec.ca (regulatory framework for water environments in force 1 March 2026, interpretation of new-generation maps, work in flood zones, disaster financial assistance and immunisation), the zonesinondables.mrnf.gouv.qc.ca portal, Insurance Bureau of Canada (spring floods and insurance), OACIQ (transaction on a flooded property), Communauté métropolitaine de Montréal, Radio-Canada (Desjardins, February 2024), La Presse (insurance guide, 5 June 2026). Informational page: your municipality, insurer and lender decide for your address.

Our proof, not our promises

The Loaa & Manseur team, led by Lotfi Manseur and Loaa Al Daow, is the number 1 team at RE/MAX Platine in 2024 and 2025, 6th RE/MAX team in Quebec, 15th in Canada and in the global top 50 of large residential teams according to the official RE/MAX ranking, computed on actual transactions. Its Google profile counts more than 220 reviews with a 4.9 rating. Its offices are at 55 avenue de l'Équinoxe in Brossard, one bridge from the island, and every broker's licence can be checked in the OACIQ public register. Three things to verify yourself before calling us, and to demand of any other broker.

Also available in French: version française de ce guide.

Published September 7, 2026 by the Loaa & Manseur team, the number 1 team at RE/MAX Platine in 2024 and 2025, 6th RE/MAX team in Quebec, 15th in Canada and in the global top 50 according to the official RE/MAX ranking. Tell us about your project.