The Capilano River, fed by rainfall and snowmelt.

Source and supply

Our water comes from rainfall and snowmelt in the mountainous areas called watersheds, located north of the cities. There are three watersheds: Capilano, Seymour and Coquitlam – which together cover an area 150 times the size of Stanley Park. The watersheds are closed to public access, protecting our water supply from human disturbance and providing some of the best drinking water in the world.

The rain and melting snow flows downhill through creeks and streams into three large lakes - the Capilano, Seymour and Coquitlam Reservoirs.

Each watershed reservoir provides about one-third of the region's drinking water. The Capilano Reservoir is contained by the Cleveland Dam, and is the most westerly reservoir. The Seymour Reservoir is contained by the Seymour Falls Dam and is just north of the Lower Seymour Conservation Reserve, a popular recreation area. Metro Vancouver also draws water from the Coquitlam Reservoir, which is contained by the Coquitlam Dam. The dam is owned and operated by BC Hydro.

Water is stored year-round in the reservoirs. While rainfall replenishes the reservoirs during the winter and spring, dry periods and higher demand for water in the summer combine to lower the reservoirs' water levels – and our drinking water supply.

The Capilano Reservoir, the source of drinking water for about one-third of the region.

The Seymour-Capilano Filtration Plant on the North Shore.

Treatment, testing and distribution

Our drinking water is treated right as it leaves the reservoirs, in two state-of-the-art water treatment plants.

The Seymour-Capilano Filtration Plant, the largest of its kind in Canada, can treat up to 1.8 billion litres of water per day. Underground tunnels transport water over 7 kilometers from the Capilano Reservoir, so that water from both Seymour and Capilano can be treated at one facility.

The Coquitlam Water Treatment Plant treats around 380 million litres of drinking water each day, about one-third of the total water supply delivered in the region.

Each treatment plant is specifically designed to treat the unique conditions of the water coming from its corresponding reservoir.


Work is not finished once the water is treated. Metro Vancouver conducts daily tests on our drinking water—analyzing around 30,000 water samples each year. Water is tested at the reservoirs, through the water mains, and again in each municipality to ensure it's clean and safe all the way to your tap.

Metro Vancouver delivers about one billion litres of drinking water each day (rising to over 1.5 billion in summer) to local governments using a network of dams, water mains, pump stations, storage reservoirs and disinfection stations, all connected by over 500 kilometres of water mains. The water flows seamlessly into local government distribution systems, from where it is delivered to the taps of businesses and residents.

Operating this vast water system requires constant upgrades, improvements, maintenance and expansion, which add up to billions of dollars. By using less drinking water for daily activities, we can reduce demand and minimize the high costs required for new infrastructure.

Interior of the Barnston/Maple Ridge Pump Station, which pumps water to Maple Ridge, Langley and Surrey.