Located in the heart of Montreal, the Turcot interchange was built more than 50 years ago. Some 300,000+ vehicles rely on it per day and the structures were nearing the end of their useful life. WSP was awarded the detailed design, including the stormwater management for the project. Consequently, construction of numerous water management structures was planned, including surface retention ponds, line retention, flow controllers and two pump stations.
The Turcot interchange drainage network relies on the City of Montreal's rainwater collection and domestic water collection system, and more specifically on the Saint-Pierre high and low level sewer network (combined sewer network). This raised several challenges related to the hydraulic capacity of the City of Montreal's collection system, the control of overflows (particularly from the combined sewer) to the St. Lawrence River, and the impact of flooding in neighboring areas. In particular, WSP had to ensure that the planned Turcot interchange stormwater management system met the environmental and municipal stormsewer network requirements, in terms of peak water flows and piezometric level to the collectors and annual report.
During stormwater management design it was identified that it would be beneficial to incorporate the two planned Turcot project pumping stations (SP-01 and SP-02) into the city’s intelligent sewer management system. On the island of Montreal, the intelligent sewer management system operates all interception works based on precipitation forecasts, to optimize the use of available retention and minimize overflows to the river. Thus, by integrating the two pumping stations with the city’s automated dynamic management system, it was possible to optimize the available retention volume for overflow control and reduce overflows to the river.