The Blackwood dam, located at the outlet of Lac-Brome’s Etang du Moulin, plays a key role in managing the waters of Coldbrook Creek. Damaged by Hurricane Irene in 2011, it had lost its ability to maintain the pond’s level, necessitating a complete rebuild. The aim of this project was not only to restore the pond’s historic elevation to 204.0 m, but also to ensure the structure’s compliance with the Dam Safety Act, while increasing flood discharge capacity for improved safety.

Artelia was commissioned to design the plans and specifications and supervise the reconstruction work. The project replaced the old gates with a reinforced concrete spillway with a fixed “C”-shaped weir, increasing spillway efficiency while respecting site constraints. The adjacent dykes were upgraded with a geomembrane seal and raised, improving their stability and flood management capability. Downstream, a dissipation basin was designed to reduce flow velocities and protect surrounding infrastructure. An achievement combining precision engineering and respect for the local environment.