Could Calgary's water crisis happen in Ottawa?

It takes a skilled team of tradespeople, operators and engineers to ensure Ottawa's water filtration system runs efficiently and reliably — and also to avoid the water woes that have plagued Calgary residents.

After the catastrophic rupture of a feeder water main last month caused Calgary to declare a local state of emergency, questions poured into CBC's This Is Ottawa podcast as residents wondered about the state of their own city's water infrastructure.

But according to Gen Nielsen, the city's director of water facilities and treatment services, Ottawa's water system "is in really good shape."

The Ottawa River is the starting point for most of the city's potable water, which undergoes purification at one of two plants. 

Lemieux Island, situated on the river between Ottawa and Gatineau, Que., houses the city's largest water purification plant, with the second located in the west Ottawa community of Britannia.

"The plants take less than one per cent of the volume of the Ottawa River, so there is an enormous amount of water," Nielsen said.

Once at either Lemieux Island or Britannia, the water undergoes a treatment process that includes screening, coagulation, sedimentation, filtration and disinfection.

Each step is monitored and controlled by operators and automated systems.

"We don't have a lot of industry upstream of us," Nielsen said. "So the raw water we're starting with is in really good quality compared to perhaps what other municipalities might have to deal with."

The water then gets pumped through over 3,000 kilometres of pipes across the city — which would, coincidentally, stretch all the way to Calgary.

According to Nielsen, having two operational water plants to supply the city is extremely beneficial. 

"If we need to take down one for maintenance, for example, we can still feed the rest of the city off of the other plant," she said.

Lessons learned from 2011 rupture

The recent pipe break in Calgary resulted in about 1.6 million people having to ration water for about a month.

But Ottawa experienced a similar water main break in 2011, Nielsen said.

A main on Woodroffe Avenue broke, restricting outdoor water use and mainly affecting residents in the city's south end.

"There was a rupture, and as it turns out, it's a similar type of pipe to the one that failed in Calgary," she said. 

In the wake of that rupture, the city's water mains are now proactively checked for leaks and structural damages.

According to Nielsen, repairs are made to one small section of pipe at a time. Another preventive measure taken by the city involves the installation of acoustic fibre optic cables — "little wires that wrap at high tension" around water mains, Nielsen said, providing structural integrity.

"What can happen with some of these pre-stressed pipes is that those wires over time can corrode and then snap," she explained.

"When they snap, they actually make a sound, and that fibre optic cable can pick up the sound."

A computer program is responsible for detecting these sounds, and anytime a single wire breaks, a report is sent to the city, notifying authorities of the issue the next day.

Nielsen said that a single wire break is not an issue. However, if there are numerous wire breaks on one piece of pipe, the structural integrity "isn't there anymore."

Last fall, traffic on Woodroffe Avenue was reduced to two lanes after the city detected a problematic pipe. 

"We got out there before it ruptured, and it had minimal impact to the public. So I know the traffic impacts are frustrating, but it was really only a week or two as opposed to weeks upon weeks," Nielsen said.

"And you're not fixing a giant hole that you could have if you had a rupture."