Ville de Laval

    Spring Flooding, Ice and Floods

    Laval is an island surrounded by water. The Division sécurité civile of the Service de police de Laval steps up its monitoring of water levels at certain times of the year in order to prevent flooding.

    ​On this page

    Status of the Situation

    From March 15 to May 15 of each year, the Division sécurité civile (emergency preparedness division) of the Service de police de Laval carries out its seasonal spring flood watch. By closely monitoring weather forecasts and hydrological conditions, it can provide an overview of forecast flooding conditions.

    Subscribe to Important Notices

    Ville de Laval strongly recommends that in order to be quickly informed, Laval residents subscribe to the City's communications in the event of important notices or emergency situations.

    Response Strategies

    Floods Caused by Excessively High Water Levels​​ (Spring Flooding)​

    The City has identified operations planning zones (OPZs) for the des Prairies and des Mille Îles rivers as well as sensitive sites. This map is divided into 4 zones (A-B-C-D).

    When a flow forecast indicates that an operations planning zone (OPZ) will flood in the days to come, residents are notified by an automated phone message, sand bags are proactively distributed to the addresses of the targeted area and the installation of temporary protective measures will begin.

    Maps of Planning Zones for Spring Flooding-Related Operations

    To find out in which zone your home is located, consult the interactive map or call 311.

    Find out the planning zones 

    These OPZs are used for organizing emergency measures during floods and should not be used as a reference for enforcing urban planning bylaws on the floodplain.​

    ​​Instructions for Receiving Sand Bags

    • Before any delivery, you will receive an automated call from Ville de Laval to inform you of the situation. Make sure we have your up-to-date contact information! Subscribe to our important notices and alerts​ in case of emergency situations.
    • You will then have to indicate, by means of an X marked on the ground, a flag, a piece of cloth, etc., where you want the pallet of sand bags to be placed. It cannot be placed on the street or sidewalk. If there is no visible marker, the sand bags will automatically be placed at the bottom of your driveway.
    • If you don’t want to receive any sandbags, please phone 311.​
    • You are responsible for setting up your own dike. However, if you are unable to do so, please call 311.
    • When the alert is lifted, you will need to dismantle your dike and place the sand bags on your property near the street so that the Service des travaux publics can pick them up. If you are unable to dismantle your dike, please contact 311. 

    Temporary Protection Measures 

    The temporary protection measures implemented by the City in 2020 on the streets will be re-introduced and optimized as the situation develops.

    Permanent protection and mitigation measures

    Certain permanent protection and mitigation measures are being considered at the present time.

    What to Do in Case o​f a Flood?

    Floods: Documentation and General Information

    Floods can be caused by one of the following elements, all of which have a direct impact on water levels and flow rates: 

    • Increase in the flow of a watercourse by heavy rainfall, snowmelt or dam failure
    • Reduction of water flow space through the formation of frazil ice or ice jams 
    • Local increase in water level at locations exposed to high winds

    Floods bring many consequences :

    • Damage to objects and buildings
    • Food and drinking water contamination
    • Damaged or closed roads and bridges
    • Power outages
    • Evacuation from home or workplace
    • Accidents and drowning

    Flood-Prone Areas

    Land and buildings in the 0-20-year floodplain (high-velocity zone) have a greater than 5% chance of being flooded every year, while those in the 20-100-year floodplain (or low-velocity zone) have between 1% and 5% chance of being flooded annually. Beyond this area, the annual risk of flooding is less than 1%. 

    The rules applicable to development, construction and renovation in these areas as well as the flood levels and maps defining their boundaries are defined by the following 3 legal instruments:

    Watercourse Monitoring

    14 telemetry stations are strategically located around Île Jésus and monitor the water levels of the Des Prairies and Mille-Îles rivers, making it possible to monitor the changes in levels and issue alerts in the event of a problem situation. A camera has also been installed to monitor specific situations in real time. However, this data is not available in real time, as it must be validated and interpreted in advance. Ville de Laval also has access to government probes that improve its system.

    During spring flooding season, flow rate forecasts are produced by the Ministère de l'Environnement et de la Lutte aux changements climatiques and by Hydro Météo to guide the City's actions. When the situation becomes more worrisome, the City can also deploy an on-site watch in more sensitive areas.

    Public Tools for Monitoring Watercourses

    ​​Flow rate and level forecasts for the Montréal archipelago (in French)​ (Ministère de l'Environnement et de la Lutte contre les changements climatiques)

    ​​Water level and flow forecasts for the Ottawa River  (Ottawa River Regulation Planning Board)

    ​​Water levels and flows recorded for the Ottawa River (Ottawa River Regulation Planning Board)

    ​​Flood watch in the Laval region (Ministère de la Sécurité publique)

    ​​Public hydrometric stations (Ministère de la Sécurité publique) 

    ​​Active floods in the past 72 hours​ (Natural Resources Canada)

    ​​Satellite imagery ice charts​ (Ministère de la Sécurité publique)

    ​​Current weather conditions and forecasts for Laval​ (Environment Canada)​

    For more Tips

    Évitez de vous retrouver... les pieds dans l'eau, 1 Mb (in French​)

    Insurance Bureau of Canada - All about insurance and water damage, 1 Mb

    Insurance Bureau of Canada - To better understand: flood insurance, 462 Kb

    ​​Barreau du Québec - Inondations au Québec : Aspects juridiques (in French)

    ​​Corporation des maîtres électriciens du Québec - En cas de sinistre​ ​(in French)​​

    ​​Ministère de la sécurité publique - Flooding​

    ​​CISSS Laval - Inondations (in French)

    ​​Public Safety Canada - Get prepared

    ​​Canadian Red Cross - Floods​

    ​​Sécurité publique Québec - Preparing for ​Disasters

    ​​Programme général d’indemnisation et d’aide financière lors de sinistres réels ou imminents (in French)

    ​​Hydro-Québec - Spring runoff

    Spring Flooding 2019 Monitoring and Recovery