On August 19, a mechanical failure occurred at the Larry-Cool pumping station. The station includes an equalization basin to absorb excess rainwater during heavy rainfall which is then emptied into water wells and pumped to the aerated lagoons. This helps to prevent the Mille-Îles River from overflowing.The valve at the entrance of the station closes when the tank is full. Because of the very heavy rain of recent weeks, the valve failed to close completely when the basin was full. Which meant that even when the basin was full, the pumping continued and this caused the overflow in Parc Central and on 15th Avenue. Mechanical failure also occurred at one of the station’s pumps.

Public works employees and experts from the firm of Qualinet came to clean the station before mechanical repairs were made.

For several days there was temporary and partial overflowing in the Mille-Îles River. The Ministry of Sustainable Development, Environment and the Fight against Climate Change was notified of the accidental spillage.