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Calgary's water supply

Learn more about where Calgary's drinking water comes from, which rivers supply water to different parts of Calgary, and where water is treated and tested to ensure water quality.

Where does our water come from?

The Bow River supplies the Bearspaw Water Treatment Plant and the Elbow River flows into the Glenmore Reservoir, which is the source for the Glenmore Water Treatment Plant.

The Bearspaw Plant primarily supplies water to the north of the city, while the Glenmore plant supplies the south. However, water is interconnected through large diameter transmission mains to ensure a reliable supply to all times.

We withdraw water according to demand and within the rules set out by Alberta Environment. We are careful not to exceed our licenses for daily and annual withdrawals and are also careful to maintain enough flow in the river systems to support other users of the water system.

Almost all of the water that is removed from the Bow and Elbow Rivers for use in Calgary is returned to the Bow River system after treatment in Calgary's wastewater treatment plants.

Learn more about the water treatment process by taking our Water Treatment Tour.

The Elbow River Watershed

The Elbow River is the source for nearly one half of the city's water supply. The Elbow Valley watershed covers an area of 1,210 square kilometres and drains into the Glenmore Reservoir. The Elbow River is 120 kilometres long and passes through four sub-climates before it enters the Glenmore Reservoir. The Elbow River is the source of water for the Glenmore Water Treatment Plant.

We draw water from the Glenmore Reservoir in order to provide treated water to citizens, but we also play an important role in flood control for this region. The reservoir is maintained at a level, depending on the flow rate of the Elbow River, that minimizes the risk of flooding around the reservoir and downstream of the dam.

The Bow River Watershed

The Bow River watershed covers an area of 7,770 square kilometres. The river originates on the Bow Glacier north of Lake Louise and is one the three main tributaries of the South Saskatchewan River.The Bow River supplies the Bearspaw Water Treatment Plant.

The Bow River Basin Council is a charitable organization supporting the improvement and protection of the waters of the Bow River watershed.

The Bow River Basin Council's state of the watershed tool provides information related to the watershed's water quality and quantity, its landscape and biological community, and land use activities.​​​