City officials reported Thursday that monitoring equipment along the Bearspaw Southern Access Pipeline has detected another broken wire in the pipeline since restrictions were eased, bringing the total to three broken wires.

However, Francois Bouchart, director of capital priorities and investments at the City of Calgary’s infrastructure services department, says this does not mean the water main will suffer another catastrophic failure like it did just over a month ago.

“Earlier this week we discovered two more wire breaks in the pipe, and today we discovered another one,” Bouchart said.

“These breaks do not indicate that another break is imminent. The wire wraps around each 16-foot (4.8-meter) section of pipe approximately 350 times, and the breaks were spread across three locations along the main supply line.”

Bouchart says that when crews discovered five “hot spots” along the main line, there were about 50 individual wire breaks in each pipe segment that was replaced.

The section of the Bearspaw south feeder main that ruptured is shown here. The feeder main is a prestressed concrete cylinder pipe, a composite pipe material composed primarily of concrete. (City of Calgary)

He says the city is aware that a long-term plan needs to be developed to renovate the structurally weaker sections of the pipeline.

“The three additional fractures are not immediately a cause for concern. However, they do show that the pipe is under some stress under the current flow conditions.”

A diagram shows the construction of the water supply line. (City of Calgary)

The City of Calgary has been gradually lifting water usage restrictions, but the government continues to urge residents to return to normal water usage as crews work to fully stabilize the system.

Calgary remains under Stage 3 water restrictions as crews monitor how the city’s water system responds to the relaxation of water conservation measures.

On Wednesday, the city announced that all outdoor pools have been exempted from ongoing outdoor water restrictions, allowing Calgarians to cool off in the heat.

Bouchart said Wednesday that Calgary’s distribution system can meet water demand as long as Stage 3 outdoor water restrictions remain in place.

On Thursday, he said that in order to move to the next step in easing water restrictions, flow through the pipe would need to be increased, but crews were proceeding “very cautiously.”

“We don’t want to risk another major rift that could reverse our progress,” Bouchart said.

Water consumption increases during heat wave

Water consumption on Tuesday was 555 million liters, up from 540 million liters used on Monday.

By Wednesday, that number had risen to 567 million liters.

City officials say the Bearspaw south feeder main — which burst on June 5 — is running at 55 percent of its capacity in terms of water flow. As of Thursday afternoon, Bouchart said the pipe is experiencing about 80 percent pressure.

To increase flow, employees must be confident that the pipeline can handle the increased demand for water.