Officials have not said when further relaxation of outdoor water restrictions would be contemplated
Lingering uncertainties over the strength of the northwest water feeder main could delay the lifting of outdoor water restrictions until September, a member of city council suggested Friday.
But a city official said Friday are weighing the possibility of increasing the flow of water in the repaired stretch of northwest pump that could ease restrictions.
Ward 2 Coun. Jennifer Wyness said she also suspects city administrators aren’t being completely transparent with Calgarians over the possible duration of the measures, which ban the use of most outdoor sprinklers and hoses.
“I suspect we won’t be able to remove water restrictions until September because the amount of water we want to move could blow the pipe,” said Wyness, who sits on the city’s infrastructure and planning committee.
“There’s a hesitation to tell people we can’t do it until the fall.”
By then, the peak water use period would have passed and the taps could be opened further, she said.
Wyness made the comments after workers stabilizing and monitoring repaired sections along a five-kilometre stretch of feeder water main pipes detected three failed reinforcement wires in separate spots this week, even though water flow and pressure on the line were only at 55 and 80 per cent respectively.
Additional data on water main integrity weeks away
But a senior city administrator on Friday said over the weekend they’ll be weighing the merits of staying the Stage 3 course or increasing the flow from the Bearspaw Reservoir that could ease restrictions.
“(There are) options for turning on more pumps at the Bearspaw Treatment Plant and (seeing the) impact of additional pressure in the pipe that would be caused by turning on more pumps,” said Francois Bouchart, director of capital priorities and investment.
“On Monday, we’ll be making a decision and will share more information for what it means for water restrictions.”
Wyness and others have raised concerns about the integrity of the rest of the 11-kilometre northwest line running from the Bearspaw Reservoir, which supplies 60 per cent of the city’s potable water.
“It’s an 11-kilometre pipe, so we have to come up with a replacement plan — we’re trying to do a lot of things at once,” she said.
One possible way of funding that work, she said, was using the city’s share of dividends from city-owned Enmax, which amounted to $82 million in 2022.
Currently, a device known as a pipe diver is assessing the pipe’s integrity, but city officials say they won’t have data back from it for about three weeks.
When asked Wednesday if Calgarians will have to wait that long for outdoor water restrictions to be eased, the city’s director of capital priorities and investment Francois Bouchart said: “It depends on the work we’re doing right now and whether we have significant confidence the risk (of a pipe failure) is significantly mitigated.”
He said while the number of snapped wires found in the past week is small in comparison to those that failed on June 5, they do pose a concern for the pipe’s strength if full water volume was to resume.
Wyness said those concerns are fully valid, given that even with the lower pressure, there have been less serious water pipe breakages in places such as the Crowfoot commercial area and Bowness after June 5.
Not as pessimistic about the duration of the outdoor water restriction is Ward 10 Coun. Andre Chabot, who said there’s now an improved monitoring system being used along the affected line that should provide faster certainty.
But he noted only about five kilometres of the entire 11-kilometre line has been repaired, and he raised questions about the rest.
“The fact that we can at least monitor gives us an advantage and I don’t expect we’ll see a failure in this (five-kilometre) section, but we haven’t fully analyzed that (other six kilometres),” said Chabot, who’s also a member of the infrastructure and planning committee.
“And we’ve got to figure out what the root cause of it is — these pipes were supposed to last 100 years, so we’ve got to do a better job of assessing the integrity of the whole system.”
‘Watering with sprinklers tends to use a lot more water’
On the city’s daily update of the situation, Bouchart again reiterated the need to cautiously stabilize the water feeder main system, meaning Stage 3 restrictions governing outdoor water use will remain for at least the weekend.
“Watering with sprinklers tends to use a lot more water than other water uses,” he said.
On Thursday, amid temperatures that reached around 30C, Calgarians consumed 565 million litres of water, down slightly from the previous day’s 567 million litres, said Bouchart.
“We have been able to meet the current demand,” he said.
While administration originally intended for a timeline of five months to accommodate council’s November budget deliberations, city chief administrative officer David Duckworth told the committee the review will likely take a year or longer, with results presented to council toward the end of 2025.
The panel’s findings would not only determine what caused the feeder main to rupture, but also take a deeper dive into assessing the viability of Calgary’s water distribution network.
— With files from Scott Strasser