Calgary lost nearly a quarter of its water last year

Calgary lost 23 per cent of its treated water in 2025 — roughly 40 billion litres — due to aging infrastructure and a leaky distribution network, according to a report coming to city council's infrastructure and planning committee Tuesday.

The loss rate falls within the average range of 20 to 24 per cent experienced since 2019. Water loss is estimated by comparing how much the city's two treatment plants produce with how much is billed through customer meters.

"The older infrastructure gets, the more chances there are for it to leak and the more that number goes up," said Dr. Kerry Black, a civil engineering professor at the University of Calgary and Canada Research Chair in integrated knowledge, engineering and sustainable communities. "When you start to see water loss rates between 20 to 30 per cent, these are not necessarily surprising. But it doesn't mean it's not concerning and that something shouldn't be done to address it."

Calgary distributes water through more than 5,500 kilometres of underground pipes serving over 1.6 million customers across Calgary, Airdrie, Chestermere, Strathmore and the Tsuut'ina Nation. The city produces 550 million litres of water per day on average, though summer demand is significantly higher.

Recent failures of the Bearspaw south feeder main have reinforced the need to reduce water loss. The city's administration is calling for a $342 million investment over four years to address the infrastructure challenges. Black said now is the time to act. "When you have people's attention and people caring about water in Calgary — that's the time to be pushing forward ambitious agendas for water," she said.