The City of Calgary said that with the repaired water feeder main running at its current capacity, if restrictions were further relaxed they would have difficulty meeting water demand.

They’ve also detected a third wire snap in the feeder mains, but director of capital priorities and investments Francois Bouchart said in a Thursday afternoon update that the pipe is not in danger of another imminent break.

Calgary water used jumped to 567 million litres on Wednesday, up from 555 million litres on Tuesday, Bouchart said. This was an expected jump, given the hot weather in Calgary right now, he said.

Bouchart said they want to reduce restrictions down to Stage 2, allowing people to use hoses and sprinklers in some cases, but they’re not there yet. He said they will continue to proceed with caution.

“Yesterday, we saw an example of why this is important,” he said.  

“If we had been in stage two restrictions, we believe our water demand would have been 70 to 100 million liters higher due primarily to running of sprinklers and hoses. With the current water flow rate through the feeder main it would have been hard for us to meet this higher demand.”

The biggest barrier to dropping down to Stage 2 is ensuring they have enough water to meet the increased demand, including through heat waves and other demand spikes, Bouchart said. Right now, the Bearspaw feeder main is still operating at only 55 per cent.

“The water system also needs to continue supplying water as regular maintenance and repairs occur,” he said.

Yesterday, the City of Calgary, as they resumed their daily briefings since the State of Local Emergency expired, added an exemption for outdoor pools, non-residential outdoor pools and kiddie pools.

Oh snap

Bouchart expanded on the third snap that was detected along the 11-kilometre feeder main in Thursday’s briefing.

He acknowledged that these are areas of concern, with the pipes structurally weaker now at these points. Bouchart said the wire is wrapped 350 times around each 16-foot pipe segment. The three snaps were detected at three different spots along the feeder main.

Bouchart said the three snaps were not an immediate cause for concern. Nor are they unusual for this type of pipe.

“However, they do show that the pipe is under some stress under the current flow conditions,” he said.  

“To comfortably move to the next stage, we will need to increase the flow in the pipe, but we’re moving very cautiously because we don’t want to risk another significant break that could set back our progress.”

Bouchart said there are groups of internal and external engineers who are continuously monitoring and providing expertise on whether the feeder pipe could see increased pressure, thus allowing restrictions to be relaxed.

Acoustic monitoring continues, and they are installing additional fibre optic cables that will be used for ongoing monitoring. Bouchart said they will have to create a medium- to long-term solution for the rehabilitation or replacement of some areas.

Calgary Mayor Jyoti Gondek said earlier Thursday that she was aware of the additional wire snaps. She said this is a different situation than with the water main break.

“There were enough wire stamps in those spots that it warranted repair work. This is not the same thing,” she said.  

“We continue to flow water, we continue to increase capacity and volume and pressure, and we will keep monitoring as we do that.”

Results from the PipeDiver, a pipeline data collection and monitoring machine that was used when capacity was turned back on, will be available in roughly three weeks, Bouchart said.

Meanwhile, another update on the independent, third-party review panel will be coming up at the July 16 Public Hearing Meeting of Council.