In the wake of Calgary’s water main break, citizens of the Alberta’s biggest city were turning off their taps again.
On the afternoon of June 5, the City of Calgary began receiving calls that water was flowing out onto the street along the west portion of 16 Avenue. Within several hours, both Montgomery and Bowness neighbourhoods were asked to conserve water use as the City dealt with a water main break.
As further news and days unfolded, more restrictions were put in place. Bowness underwent a boil water advisory, while all of Calgary’s citizens were asked to voluntarily stop all unnecessary outside water use and conserve 25% inside.
By day 10 (June 14), it became clear that the solution was not going to be quick and easy for the water main. The City had to tell Calgarians that the Bearspaw south feeder was found to have five other problem “hot spots” in the pipe, meaning more repairs would prolong the water restrictions for three to five weeks. By day 11, the City of Calgary was put under a state of local emergency.
Infrastructure Issues
Mike Murray, Executive Director for the Bow River Basin Council, said that Calgary’s water situation and flows of the Bow (after some above average precipitation) had returned to near low normal range. Unfortunately, this event moved the City back into a more precarious position. Murray says, “This is a delivery issue not a source water availability issue where the infrastructure cannot deliver regular volumes to citizens. ‘ Although the City is doing a tremendous job meeting most of the demand, it is urging its citizens to do what they can to use less water.”
Fortunately, the City of Calgary situation has 2 rivers for its water supply and two water treatment plants (WTP). The smaller Glenmore WTP draws its water from the Glenmore Reservoir and usually provides 40% of the City’s treated water. The Bearspaw usually handles 60% of the City’s treated water and draws from the Bearspaw Reservoir, which is part of the Bow River system.
Feeder Pipe’s Lifespan Cut Short
The City explained that steel reinforcing wires around the pipes snapped – until it was further revealed that the concrete sleeve around the wire was the real problem. The south feeder’s concrete pipes — used by the City of Calgary between 1955 to 1990 — are said to be more porous and vulnerable to chemical exposure than what was originally thought. The pipe’s projected 100-year lifespan was cut in half, having been installed in 1975.
University of Tennessee professor, Graham Bell, explained to the CBC that when WWII demanded more steel, concrete pipes wrapped in steel went to a composite material. This led to what he called “the law of unintended consequence”, as exposed wires developed issues and snapped. Bell says other cities across North America have dealt with similar situations, also without warning following an overload or surge.
Water Security and Drought
As for drought, Murray says that drought has definitely been top of mind for the major water users in the Bow for a long time. “They have already been working together – and there are modelling exercises and initiatives around water management for the past 15 years plus – that talk about managing the water as a collective, rather than as a series of decisions as you go downstream.”
Murray says the event may put “the importance of water in the public eye.” He says it’s easy to forget about when water just comes out of the tap and hopes residents will think about why resources may have to go “to something they never see or think about.” Murray believes that the challenges of water security will be an ongoing issue for the city as it continues to grow but adds, “No municipality is immune from this risk.”
Murray says the situation is being handled well. “Although, the emergency break has been very disruptive and will take time to fix, The City of Calgary is fortunate to be able to draw from two different sources for water and the community has been working together to overcome the challenges. I think this demonstrates the resilience of Alberta communities.”