Calgary's water supply still at risk, repairs expected to continue through weekend

As work to repair a break in a major water feeder main continued Tuesday, Calgary Mayor Jyoti Gondek said residents should expect limitations on their water use to last through the weekend.

On Tuesday morning, the mayor thanked Calgarians for continuing to limit their water usage amid the ongoing threat to the city's supply. However, she added that Monday's use reached 472 million litres, up from the weekend's daily usage by 15 to 30 million litres.

"I think people were getting caught up on their laundry, on their dishes and their showers. But I'm confident that we can continue to reduce our water usage today and into the weekend," said Gondek.

The mayor added that the largest users of city water are "doing what they can" to reduce water usage.

"I've heard that local breweries and bottling companies have put water saving measures into place, and I can tell you that Enmax's Energy Centre is running at half production, reducing their water usage dramatically."

Gondek says businesses represent roughly 35 per cent of Calgary's water consumption, and the rest is used by residents.

"We need to keep practising reduction measures," she said.

While the boil water advisory for the northwest community of Bowness was lifted late Monday — after the city said it made changes to deliver safe drinking water from the Bearspaw Water Treatment Plant by bypassing the damaged feeder main — Stage 4 water restrictions remain in place.

Under the restrictions, watering lawns, filling pools and fountains or washing outdoor surfaces, including cars, are all prohibited. Calgarians are also being asked to limit their non-essential water use, and a citywide fire ban is still in effect.

Officials say that, while crews are working 24/7, it will still take days to fix the 50-year-old piece of infrastructure that supplies water to roughly 60 per cent of the city.

In an interview with the Calgary Eyeopener on Tuesday, University of Calgary assistant professor Kerry Black said a rupture this large is rare.

"We expect some level of failure of certain pieces of infrastructure, but you don't expect something as catastrophic as that," said Black, a Canada Research Chair in integrated knowledge, engineering and sustainable communities with the university''s civil engineering department.

"You expect a warning sign that there's a problem and then you fix it before it turns into a major rupture."

Calgary has over 15,000 kilometres of underground pipe, says Black, adding that she believes the City of Calgary does take a proactive approach to maintaining its infrastructure when compared to other municipalities.