Calgary distribution network losing billions of litres of water a year

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Leaky pipe connections caused Calgary to lose nearly one-quarter of its treated water in 2022, or more than 30 billion litres.

A May 9 letter to the city from BILD Calgary Region CEO Brian Hahn stated that Calgary experienced a water loss rate of 22 per cent in 2022. The letter added that Calgary’s water loss that year, specifically from leaks, amounted to approximately 31.6 billion litres.

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About 88 per cent of Calgary’s water loss is through system leaks, according to Hahn.

Considering the average Calgarian uses 170 litres of residential water per day, Hahn noted the amount of water the system lost due to leaks was akin to having an extra 1.5 residents per home.

“Until these system water leaks are repaired, substantial improvements in water consumption per person are limited to improvements in end-user consumption,” he wrote.

‘We need to scrutinize this’

Hahn referred to these figures when presenting to the infrastructure and planning committee on June 12 and July 3. During those presentations, he compared Calgary’s water loss rate to Edmonton’s from 2021, which was much lower at just 5.4 per cent, according to Epcor Water Services’ reporting.

Hahn told committee members that BILD would like a networkwide assessment of Calgary’s water efficiency and water loss to be included in the scope of the third-party review that will investigate the June 5 rupture of the Bearspaw south feeder main.

The feeder main’s rupture last month has put the city’s water system “into sharper focus,” according to Hahn, who added the incident begs the question of whether the efficiency of the system is being optimized when considering what customers pay in water utility rates.

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“I think (this review) affords an opportunity for the City of Calgary to go, ‘OK, let’s step back and have a look at our water network,’” Hahn told Postmedia. “Even before the break, when we had that 5.4 per cent (water loss) in Edmonton and 22 per cent in Calgary, we were kind of like, ‘Wait a minute here, we need to scrutinize this.’

“The obvious question that comes out of that is, if that was an abrupt break and it wasn’t leaking and there was no evidence of that, what does that mean for the balance of the system?”

Calgary’s water efficiency plan: 30-in-30

Calgary’s water distribution network includes more than 5,400 kilometres of pressurized water pipelines and approximately 345,000 service connections.

In 2005, the city adopted a water efficiency plan, which sought to hold steady the amount of water the city draws from the Bow and Elbow rivers at 2003 levels.

Dubbed 30-in-30, the plan committed to reducing Calgary’s water consumption by 30 per cent over 30 years — a goal the city claims it reached a decade ahead of schedule.

Thanks to conservation programs and behavioural changes, Calgarians have cut back their collective water use from 518 litres per capita per day in 2003 to the 30-in-30 target of 350 litres in 2023, according to the city’s website. That total includes both residential and commercial/industrial use, however. For residential use, the average is 170 litres per capita per day.

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The city’s website indicates it will be updating its water efficiency plan this year, in lockstep with the city’s drought resiliency plan. The update will include new water efficiency targets that align with Calgary’s growth, water availability and a changing climate.

But even though consumption has dropped to 2003 levels, water loss rates have been a challenge. A 2020 city report on Calgary’s water treatment and supply mentions that performance indicators “have suggested increasing trends in water loss in Calgary’s distribution network.” The same report states that preliminary investigations indicated the city’s water loss “is significant and requires attention.”

“A strategy is currently underway to validate the amount of leakage, develop recommendations to address this issue, and determine a resource plan to support the recommendations,” the report stated.

‘Reducing water loss is critical’: city admin

Calgary manages its water loss through a proactive leak detection system and a cathodic protection program to delay metallic pipes from deterioration, according to city officials.

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The system uses satellite imaging and acoustic sensors to target and identify leaks and an annual replacement, testing and inspection program.

Peggy Chan, communications lead for the city’s infrastructure services, told Postmedia that some water loss is unavoidable, as leaks occur in all distribution systems.

After the adoption of a new water loss strategy in 2019, Chan said the city successfully cut water loss by 15 per cent over three years, from 337 litres per connection per day in 2019 to 286 litres per connection per day in 2022.

She said reducing water loss is critical to meeting the targets set out by the city’s water loss strategy, adopted in 2019, as well as improving overall water system efficiency.

The city aims to further reduce and prevent water loss by increasing leak survey rates and repairing and replacing older pipes, according to Chan.

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Comparing to Edmonton not apples to apples: city

While Edmonton’s 2021 reported water loss rate was much lower than Calgary’s, Chan said it is challenging to compare water loss across utilities, as other jurisdictions may use different methodologies for tracking and reporting their statistics.

In looking at the Canadian Infrastructure Benchmarking Initiative data for 2019-2022, she argued that Calgary’s water loss was lower than some municipalities and greater than others.

A 2019 water use and conservation report from the Calgary Metropolitan Region Board, conducted by Associated Engineering, bears this out; Cochrane was losing 13 to 17 per cent of its treated water at the time of the study, whereas Okotoks was losing 23 to 35 per cent, and Wheatland County, with older infrastructure, was losing as much as 52 per cent of its water.

A key factor that drives Calgary’s water loss is challenging geotechnical conditions, Chan added. Edmonton has primarily clay-based soils, which means leakage from water pipes surfaces quickly, allowing crews to repair the damaged mains faster. Calgary, meanwhile, has primarily gravel-based soils, which cause water main leaks to drain downward, meaning the pipes take longer to detect.

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But some members of city council may not justify the argument that Calgary’s water loss should so drastically exceed Edmonton’s.

Ward 2 representative Jennifer Wyness has been one of the most outspoken councillors since the recent feeder main rupture. During staff briefings on the emergency to council, she peppered administration with questions about how often Calgary’s water infrastructure is reviewed and inspected and why the city wasn’t able to anticipate the feeder main’s failure.

Wyness said Calgary’s high water loss rate highlights that the city has not prioritized water loss in the system — something she argues should be corrected.

“If we’re going to say we have to conserve water, we have to look at the age of infrastructure and start reinvesting in some of it,” she said.

While acknowledging that such investment would require significant costs, Wyness said council needs to better prioritize spending.

“What are the roles or responsibilities of a municipal government and what are the value-based decisions that have to take a backseat given that water and wastewater are a standard that needs to be upheld and maintained?” she said.

“It’s becoming more apparent that all municipalities, after our catastrophic fail, have to be more aware about how we provide and use water for all citizens. It’s something we do take for granted and showcases that without proper maintenance and preventative maintenance, it puts a lot of people at risk.”

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