Q-2, r. 35 - Protection Policy for Lakeshores, Riverbanks, Littoral Zones and Floodplains

Schedule Disposition versions

2012-09-01

ANNEX 1

FLOOD-PROOFING MEASURES APPLICABLE TO STRUCTURES, UNDERTAKINGS AND WORKS IN FLOODPLAINS

Authorized structures, undertakings and works must comply with the following flood-proofing standards, adapted to the specific context of the infrastructure concerned:

1. no opening (window, cellar window, door, garage, etc.) may be lower than the 100-year flood elevation;

2. no ground floor is allowed at a level that is lower than the level of the 100-year flood elevation;

3. drains must have a non-return valve;

4. for any structure or part of a structure built below the 100-year flood level, a study must show the structure’s resistance to flooding and must include calculations relating to:

—  waterproofing;

—  structural stability;

—  reinforcement necessary;

—  seepage water pumping capacity; and

—  resistance of the concrete to compression and tension;

5. the filling of land should be restricted to protecting the area immediately around the structure or undertaking concerned and should not extend to the entire landsite; the average slope downward from the top of the fill next to the protected structure or undertaking should not be less than 33⅓% (vertical to horizontal ratio of 1:3).

When implementing flood-proofing measures, if the 100-year flood elevation was not established at the time the limits of a mapped floodplain were delineated, the elevation of the highest reference floodwater level should be used to replace the 100-year flood elevation in determining the limits of the floodplain, to which 30 cm should be added for safety reasons.

O.C. 468-2005, Ann. 1.