What 'running out of water' could actually mean for Calgary

As Calgary enters its second week of water restrictions and critical supply issues following the rupture of the city's largest water main, citizens have been inundated with messaging about water conservation. 

Officials continue to warn residents that, if the effort to conserve water isn't their number 1 priority, Calgary could run out of water.

"Calgarians, I need you to do more. And I know that's frustrating for you to hear, but there is still a real threat that we could run out of water," said Calgary Mayor Jyoti Gondek on Thursday.

And on Friday, the mayor reinforced the message.

"If our water usage continues to trend up and our water supply can't keep up, the taps will run dry at some point."

These are warnings that some residents will find ominous, or possibly even dystopian, and it puts the issue of water conservation directly in the spotlight.

But what could running out of water actually look like in Alberta's largest city?

One expert says that the warnings aren't necessarily about running out of water, but instead, it's about the pressure needed to move water through Calgary's large underground network of pipes. It could have serious implications for emergencies, such as fighting fires and water access in hospitals, if taps run dry. 

Tricia Stadnyk, a professor and Canada Research Chair in hydrologic modelling with the University of Calgary's Schulich School of Engineering, says it's really the city's treated water supply that's at risk right now. 

"I know it's a big mystery to people that aren't familiar with water distribution or water supply, but it does highlight some of the vulnerabilities, things that we take for granted every day as Canadians," said Stadnyk.

Time and time again, the city has been reminding Calgarians that crews are working 24/7 to get the near 49-year-old pipe back online. 

The section of the feeder main that is being replaced is roughly seven metres long (23.5 feet), and the massive, labour-intensive repair process isn't a simple fix. In fact, it's so complicated that the city announced on Friday that repairs could take another three to five weeks.

"Our experts say this is the most dramatic and traumatic break of a feeder main they have ever seen. This pipe is only at the halfway point in its life cycle. From all accounts, this should not have happened, but it did," said Calgary Emergency Management Agency (CEMA) chief, Sue Henry, on Friday afternoon.

But in order to make sense of how this major break has impacted Calgary's treated water supply, it's important to understand the ways in which water moves through the city.