Calgary Mayor Jyoti Gondek says further extensive repairs will be needed to the city’s water distribution system, which will require a temporary return to Stage 4 outdoor water restrictions later this month.
She made the announcement at a press conference on Wednesday after seeing the results of the PipeDiver inspection in the Bearspaw supply line. A PipeDiver is an electromagnetic and ultrasonic pipe inspection device used to monitor large diameter water pipes.
Sixteen new hotspots have been discovered along the main line. Scheduled maintenance will be performed over the next few weeks. City officials say more hotspots will likely be discovered during the repairs.
“To be clear: There is no risk of a pipe burst at any of these locations. Rather, there are enough weak points or stress points in these sections that the maintenance work must be completed before the end of September,” said Gondek.
Level 4 outdoor water restrictions will come back into force on August 26 when repair work begins. In the meantime, Level 1 restrictions will remain in place.
The work is expected to be completed by September 23, but officials say this date could still change.
Under Level 4 water use restrictions, outdoor water use is not permitted. This includes sprinklers, hose watering, hand watering, watering new grass, washing cars, windows, sidewalks, driveways and walkways. Filling pools, hot tubs, fountains or other decorative features is also prohibited under Level 4. A full list of permitted and prohibited water use restrictions under Calgary’s water use restrictions can be found here. Visit the city’s website.
Officials say the northwest communities of Bowness and Montgomery will be affected by the repairs as the city plans to close the Bearspaw main drainage line and excavate certain areas for repairs.
Hotspots along 33rd Avenue NW, Parkdale Boulevard and 16th Avenue NW require immediate repair and will be prioritized starting August 28.
Instead of replacing sections of the pipe as it has done in the past, the city plans to reinforce problematic sections of its water system by encasing the damaged pipes with concrete.
Residents and businesses across Calgary are again being urged to conserve water during this time, however, businesses are not being asked to close unless absolutely necessary.
Michael Thompson, Calgary’s general manager of infrastructure services, said businesses will be asked to reduce their water usage by 25 per cent starting Aug. 26. He added that work to fix the problems will continue around the clock.
As a result of the repair work, no public swimming pools or stadiums would have to be closed, the authorities said.
“We need to do everything we can to reduce the risk of another unplanned outage on the main line,” Thompson said.
“We also need to complete the repairs within a certain timeframe to ensure we can maintain Calgary’s water supply throughout the winter.”
While the Bearspaw main supply line is shut down, Calgary relies on the Glenmore Water Treatment Plant to distribute water throughout the city.
The Bearspaw Generating Station gets its water from the Bow River, while the Glenmore Generating Station gets its water from the Elbow River. Thompson said the Glenmore Reservoir acts as a sort of “bank” for Calgary’s water supply during the winter months.
River levels are usually high in the spring and summer, but with only the Glenmore Generating Station supplying all of Calgary with water during repairs, the city needs to ensure there is enough water in the riverbank during the winter, Thompson said.
“We need to act now so we can complete the urgent repairs in time for the river to refill Glenmore Reservoir for the winter. We also need to minimise the risk that the main line will break unexpectedly in winter and we will then be unable to refill the reservoir because the river is running low,” Thompson said.
The rupture of the first supply line is expected to cost Calgary between $20 million and $25 million, according to the city. That does not include the lost revenue caused by the rupture and the cost of upcoming repairs, officials said.
The city will provide another update on its water system on Friday.
Calgary shut down a third pump at the Bearspaw water treatment plant last Friday out of an abundance of caution. Flow to the main supply line remains at 70 percent of its maximum capacity.
Since the line was repaired and reopened, 12 wire breaks have been reported. The city monitors the coils of wire that are wrapped around the main line and help strengthen it. While these breaks are not a sign that the line will break, authorities say they are an indication of how much stress the line is under.
Calgary has been suffering from water supply problems for some time, triggered by a catastrophic failure in the southern main supply line from Bearspaw on June 5.
Under Level 1 restrictions, the use of sprinklers and underground sprinkler systems is permitted for two hours per week.
Residents are permitted to irrigate using these methods, but they must adhere to the city’s irrigation schedule: even-numbered addresses may irrigate on Wednesday or Saturday, and odd-numbered addresses may irrigate on Thursday or Sunday.
Irrigation with sprinklers and underground systems is permitted between these times, according to the City website:
- 4 to 7 a.m.
- 9 to 11 a.m.
- 7 p.m. to 10 p.m.
Watering with a hose with a spray nozzle is permitted at any time, the city says.
Under existing Level 1 restrictions on outdoor water use, the following water-related activities remain prohibited:
- Washing driveways and sidewalks.
- Washing vehicles in the driveway or on the street.
- Cleaning windows or external building surfaces unless this is carried out by an approved company.
- Filling fountains and decorative water features. However, bird baths are permitted.
