Flood zones
The Quebec government publishes a database of flood zones. The high-velocity zone (zone de grand courant) has a 1-in-20 or greater chance of flooding each year (0–20 year recurrence); the low-velocity zone (zone de faible courant), between 1 in 20 and 1 in 100 (20–100 year).
In a flood zone, building, extending or rebuilding is regulated, sometimes forbidden in the high-velocity zone. Flood insurance may cost more or be hard to get. Since 2026 Quebec has been publishing new maps by risk level, city by city.
Our pages compare the lot outline (in Montréal) or the address point (elsewhere) with the published zones. Outside a zone does not mean no water risk: sewer back-up is a separate risk. Get an insurance quote before you remove your conditions.
General information, not legal or professional advice.