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Source Water Protection

Source water is an important resource for The City of Calgary and surrounding areas. Protecting source water is the first line of defence to minimize the risk of contamination to our drinking water.

Much of the source watersheds that supply Calgary's drinking water remain relatively pristine. It is important to The City of Calgary as well as the broader region that we protect our source water to supply clean, safe, reliable drinking water to our customers.

Calgary's approach to safe drinking water

Drinking water systems contain three main parts: the source watershed, the drinking water treatment plant and the distribution system. The source watershed is the focus for The City of Calgary's Source Water Protection Plan, which has established a vision, goals and priority actions to protect source water quality.

Source water flow chart 

Source water: Water in its natural or raw state, prior to being withdrawn for treatment and distribution as a drinking water supply.

Calgary's source watersheds

All municipal utilities draw their water from a source environment. For the City of Calgary, this includes surface water in the Bow and Elbow river systems. This water is ultimately generated by the source watershed, which includes all lands from which water collects and flows downstream to the municipal treatment plans.

The City of Calgary has two watersheds associated with each of its two drinking water plants:

  • A 7,800km2 source watershed upstream from the Bearspaw water treatment plant on the Bow River
  • A 1,200km2 source watershed upstream from the Glenmore water treatment plant on the Elbow River.
These two watersheds include lands governed by the federal, provincial, municipal and First Nations governments. As The City lacks direct jurisdiction and control over land and water use outside of its boundaries, effective source water protection requires close cooperation with upstream stakeholders and partners

Some of The City's source water is also located within city limits. It is important that we protect watersheds within city limits as well as those outside of Calgary. The highest risks have been identified as stormwater runoff from land development and transportation systems, and widespread wildfires on forest lands or grasslands.

Jurisdictions in Calgary's source watersheds

​Jurisdiction ​% of Bearspaw Plant's Source Watershed ​% of Glenmore Plant's Source Watershed % of Total Source Watershed Area​
​National Park ​46% ​0% ​39%
​Provincial Park ​21% ​31% ​22%
​Other Provincial Crown Land ​13% ​31% ​15%
​Rocky View County ​10% ​20% ​12%
​First Nations Reserves ​6% ​14% ​8%
​Town of Canmore ​0.8% ​0% ​0.7%
​City of Calgary ​0.2% ​3.7% ​0.7%
​Town of Cochrane ​0.4% ​0% ​0.3%
​Other ​2.5% ​0.2% ​2.2%
​Total Area (km2) ​7,768 km2 ​1,227 km2 ​8,995 km2

Vulnerable areas in Calgary's source watersheds

City of Calgary

Working together

Proactive source water protection with management actions, partnerships, and stewardship can provide a wide range of economic, social, and environmental benefits. Expenditures to protect source water such as riparian and wetland restoration, can be more cost effective than building and operating more advanced treatment facilities.

By protecting our source water, we are taking steps to ensure we have reliable, clean water for current and future generations