The city has three different types of sewer systems to deal with the stormwater from rainfall and wastewater produced by daily activities.
Storm sewer systems capture and convey natural runoff through a network of ditches or pipes and then discharge it into the natural bodies of water through gravity and pump station outfalls.
Sanitary and combined sewers are an underground network of service connections, pipes, manholes and pump stations that collect and convey wastewater to the regional trunk sewers and wastewater treatment plants operated by Metro Vancouver.
Combined sewer systems collect both the sanitary sewage and storm water into a single pipe. The city is replacing this type of sewer because during large storms the rainwater can result in the system reaching its capacity and overflowing into the Fraser River.