City of Calgary workers find third snapped wire in major water main

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City workers monitoring a repaired stretch of northwest water feeder main have found a third snapped reinforcement wire, leading to concerns over the system’s strength.

The discovery was made Thursday along the northwest stretch of pipe where five sections have been repair or upgraded. Two other failed wires that wrap around the pipe — all in separate locations — were found earlier this week.

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“The three snaps are not an immediate cause for concern but they do show the pipes are under some stress under the current pressure,” said Francois Bouchart, the city’s director of capital priorities and investment.

“There are other areas where we have detected snapped wires and the pipe is structurally weaker . . . we know we’ll need to create a medium and long-term rehabilitation plan for these sections.”

As the city moves slowly to stabilize the system that ruptured June 5 in Montgomery, that pressure is only 80 per cent of the norm, with 55 per cent of the typical water flow.

For that reason, the city’s still not willing to ease the currently imposed Stage 3 water restrictions to Stage 2, which would allow unfettered use of sprinklers, hoses and irrigators.

And Bouchart said a sophisticated monitoring device known as the pipe diver that began gauging the strength of the water feeder main line last week won’t return data for another three weeks.

Some gardeners, landscapers and irrigators say waiting that long would mean numerous lost jobs and severely damaged trees and lawns.

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Bouchart wouldn’t say if they and the rest of the city will have to persevere for three more weeks.

“It depends on the work we’re doing right now and whether or not we have significant confidence the risk is sufficiently mitigated for us to get to that next stage — I don’t want to underemphasize the risks that we’re taking by moving through the various stages of operation,” he said.

“If we determine the pipe can handle increased pressure, it’ll allow us to look at moving to Stage 2.”

With this week’s hot weather, Calgarians’ water consumption continues to rise, with 567 million litres used on Wednesday, up from 555 million on Tuesday and 540 million for Monday.

“We’ve been able to meet the demand . . . this is a normal pattern during a heat wave,” said Bouchart.

If the city had moved to Stage 2, Calgarians on Wednesday would have consumed an additional 70 million to 100 million more litres mostly through the use of sprinklers and hoses, he added “and it would have been hard for us to meet this higher demand.”

On Wednesday, the city eased some outdoor water restrictions by green-lighting the use of private and backyard pools to allow Calgarians to cool down in sweltering heat that’s exceeded 30 C for a few days.

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The weather forecast for Calgary calls for temperatures in the mid-to-high 20 C range over the next several days, with the chance of showers on several of them.

But the 30 C heat is expected to return in about a week.

Bouchart said he’s confident the vast majority of Calgarians will adhere to the outdoor restrictions that limit gardening to the use of watering cans.

“We’ve seen a tremendous response from Calgarians even if the restrictions don’t legally allow us to enforce them on people,” he said of indoor restrictions that have now been relaxed.

One industry that oversees large irrigated landscapes are golf courses, but those in Calgary draw non-potable water from nearby streams, rivers or from stormwater to keep their greens and fairways lush. They say using treated city water would be far too expensive.

BKaufmann@postmedia.com

X: @BillKaufmannjrn

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