A New Stormwater Detention System For Boulevard Hymus

The Challenge

The new stormwater chambers would run along Montreal west’s Boulevard Hymus, between Avenue Manfred and Avenue Delmar, adding two stormwater detention systems to reduce the stress on the existing stormwater infrastructure. Responsible for managing the stormwater network for the area, the City of Pointe-Claire assessed various LID technologies to find one that could best manage the specific watershed needs. Located beneath the City’s bicycle path, the chambers were installed between the road and the backyards of neighbouring homes. The tight space along the roadway had many interfering structures such as Hydro poles, trees, and a drainage ditch on either side. Armtec provided specific drawings to address the complex footprint and accommodate both the existing and proposed structures.

The Solution

A pre-construction meeting with Roxboro Excavation, was held in advance of the installation to ensure the contractor’s crew had all of the necessary details. This helped to avoid any down time during that actual install, saving time for both the contractor and the City and limited traffic interruptions for the surrounding community. Due to the high water table and ground water pressure that would be acting on the geo-membrane, a decision was made to pour a structural slab of concrete under the chamber to help with the pressure distribution and would ultimately hold the membrane in place. With the completion of this detention system, the upgrade will reduce flooding and stress on the stormwater network for this Pointe-Claire neighbourhood.

Technical Details