Calgary turns off third pump at Bearspaw plant, no new wire snaps detected Thursday

Calgary has turned off the third pump at the Bearspaw water treatment plant on Friday, meaning flow to the key feeder main will stay at 70 per cent of its maximum capacity.

Michael Thompson, the city's general manager of infrastructure services, said in a Friday afternoon update the decision to shut down one of the pumps came out of caution.

"Based on this flow rate we can meet demand under Stage 1 outdoor water restrictions, but we would not be able to meet demand if we lifted restrictions entirely," Thompson said.

He added the city will be pausing the daily livestream updates on the status of the feeder main over the weekend. The next update will come at some point next week.

"We will share more information on the PipeDiver findings, progress on the feeder main rehabilitation plan, and costs of the response efforts," Thompson said.

A PipeDiver is an electromagnetic and ultrasonic pipe inspection tool used to monitor large diameter water pipes.

The city will provide daily updates on water usage and the general status of water distribution on its social media channels.

Calgary used 706 million litres of water on Thursday, up slightly from Wednesday's 701 million litres — which Thompson noted was higher than expected. He said hot, dry weather and sprinkler usage over the past couple of days likely contributed to higher water demand.

No new wire snaps were detected along the Bearspaw feeder main Thursday, however two were detected in different locations on Wednesday. This brings the total number of wire snaps since the pipe was repaired to 12.

The city monitors the wire coils that wrap around the feeder main, which help strengthen it, for snaps. While these snaps are not a sign that the pipe will break, officials say it is a way of assessing how much stress the pipe is under.

Thompson added the city will be continuing to analyze the data that it received from the PipeDiver inspection over the weekend. Calgary is working on a long-term rehabilitation plan for the feeder main, and the inspection data will be incorporated into it.

Officials have previously said monitoring how the feeder main holds up with increased water pressure from the pump will inform their decision about whether to lift water restrictions further.

Calgary has been experiencing ongoing water supply issues that were triggered by a catastrophic failure in the Bearspaw south feeder main on June 5. 

Under Stage 1 restrictions, the use of sprinklers and in-ground sprinkling systems are permitted for two hours per week.

Residents are allowed to water using those methods but must follow the city's watering schedule — even number addresses are permitted to water on Wednesday or Saturday, and odd number addresses are allowed to water Thursday or Sunday.

Watering with sprinklers and in-ground systems is allowed between these hours, according to the city's website:

• 4 a.m. to 7 a.m. 

• 9 a.m. to 11 a.m. 

• 7 p.m. to 10 p.m.

Watering using a hose with a trigger nozzle is allowed at any time, according to the city.

Under Stage 1 outdoor water use restrictions, the following water-related activities remain prohibited:

• Washing driveways and sidewalks.

• Washing vehicles in the driveway or street.

• Washing windows or exterior building surfaces, unless it's done by a business licensed to do so.

• Filling fountains and decorative water features. Bird baths, however, are allowed.