Montréal is a large urban area that is heavily mineralized. Rainwater rarely infiltrates the ground. In increasingly frequent cases of heavy rains, this causes sudden overflows of the sewer system and accumulations of water on the street that can cause flooding. 

To adapt to this new climate reality, Montréal has created a plan with 3 components and 10 key measures: 

Part 1: supporting owners in the process of adapting their buildings 

Provide technical and financial assistance to owners of residential buildings affected by flooding.

Measures 

1. Enhance the subsidy program to reduce adaptation costs for flood-affected homeowners.

2. Amend city by-laws to facilitate adaptation of existing buildings. 

3. Provide advisory support to homeowners with regards to reducing the vulnerability of their building. 

4. Check the effectiveness of flood protection measures for homes with a counter-slope garage entrance. 

There are solutions for your home. Learn how to protect your building.

Part 2: focusing on prevention by adapting by-laws 

Amend urban planning by-laws to ensure that new buildings are no longer vulnerable to the risk of flooding. 

Measures 

5. Include provisions to regulate certain uses in sectors vulnerable to flood risks in the 2050 Land Use and Mobility Plan. 

6. Amend the city’s By-law concerning the construction and conversion of buildings to take materials and measures to make buildings flood resistant into account.

Part 3: continuing actions to improve public infrastructures 

Increase water retention capacity in sewer systems, retain surface water and provide contingency plans to mitigate extreme effects.

Measures 

7. Ensure that each new public development project is systematically designed to capture and absorb excessive runoff volumes. 

8. During reconstruction or repair, modify street design to direct surface drainage to a natural environment or green infrastructure (advanced sidewalks, tree pits, etc.); draining where possible. 

9. Identify key vulnerable points, such as a water main underneath a major street near a hospital, and develop a bypass road plan during heavy rain 

10. Prioritize investments and responses to improve the drainage system in problematic areas 

See some examples of adaptation infrastructures, such as sponge parks.