Calgary's surge in frozen pipes worst in 40 years, says city official

The city is experiencing an epidemic of frozen water mains, thanks to a frosty February. It may get worse before it gets better, says a city manager.

Frosty February leaves homes vulnerable to frozen water lines

The City of Calgary is advising homeowners who've had problems in the past with frozen pipes to run a continuous stream of water the width of a pencil or straw through their taps to prevent freezing. (CBC )

Calgary's problem with pipes freezing may get worse before it gets better.

That was the message Monday from city hall, where David Duckworth, general manager of utilities and environmental protection, spoke to council about the severity of the situation.

In just the first week of March, the city received more than 80 calls related to frozen water services.

By comparison, there were only 10 such calls in all of 2018.

The situation prompted Mayor Naheed Nenshi to ask Duckworth what's going on.

"Could you just explain a little bit about why we've had so many breaks?" Nenshi asked. "And why — despite the nice weather — we might not be out of the danger zone yet?"

Duckworth explained that even though temperatures are on the rise, that doesn't necessarily mean the problem with frost underground is going away any time soon.

"The frost depth is actually in the order of 10 feet (3 metres), which is where many of the water mains — particularly in our communities — are built to," Duckworth said.

"While it's getting warmer out, the frost up there is still very deep," Duckworth said.

The city says it received more than 80 calls related to frozen water services in the first week of March. (CBC)

"We suspect there's probably many more water main breaks that we'll see when the water can start to come to the surface as well, which is why we think it's probably going to get worse before it actually gets better."

According to a release issued by the city last Thursday, the normal average frost depth is seven feet, or about 2 metres, according to Chris Huston, the city's drinking water and distribution manager.

Duckworth conceded that longtime staff members say this winter is the worst for burst pipes since the 1970s.

"Many staff who have been here for an upwards of 40 years have never seen this before," Duckworth said.

"I used to think the freeze-thaw cycles are bad for our pipes. Now I know the freeze cycles are bad for our pipes," Nenshi said.

The frozen pipe scenario coincided with warm chinook winds that blew into Calgary, prompting a wind warning Monday from Environment Canada.

An extreme case of frost in an attic. (Darrell Paul/Qualistat)

Opening the taps

On the Calgary Eyeopener, host David Gray asked building consultant Darrell Paul about a recent notification from the City of Calgary advising people to run a continuous stream of pencil-thick water through their taps in order to prevent them from freezing.

"The frost is pushed into the ground really deep and because of the extended cold that's created the problem — and not only that, but we [also] had the the lack of snow, which insulates the ground," said Paul, who owns Qualistat Building Performance Consultants in Olds, Alta.

"Now that you've got frost in the ground, the sun comes out," he said. "[It] starts to warm everything, [the] temperature goes up and it drives the frost deeper.

"Initially, you're going to start to see a few more burst pipes, and running the water mixture — the water flowing through those pipes — is going to reduce the chance of frost and freezing pipes."

Use the cold water line, which comes in directly from outside; the hot water line simply drains the hot water tank. 

According to the notification issued by the city, homeowners who run their taps continuously will have their water bills adjusted so that they won't be on the hook for the extra water. The customer has to sign up for the "frozen pipes program" or have reported an incident to 311.

Paul noted that if pipes burst inside a homeowner's property line, they are on the hook for the cost of fixing them.

"That's the reason that you want to run that water line," Paul said.

Paul added that homeowners also have to take precautions against rapid snowmelt, which could cause a number of other problems.

"Make sure you don't have a lot of snow accumulation and build up," he said. "Keep an eye on it if you've got a big build up of ... icicles hanging off the roof."

"Make sure your eavestroughs are down," he added, "and they're running and water can get away."

With files from the Calgary Eyeopener.


Stephen Hunt

Digital Writer

Stephen Hunt is a digital writer at the CBC in Calgary. Email:

Files from Scott Dippel