Without the public’s cooperation on upcoming water restrictions during Bearspaw feeder main repairs, the City of Calgary has about three to four days of water supply, they said.

With the latest repairs set to begin next week, City of Calgary officials set the stage Tuesday for a maximum 450 million litre cap in daily water use starting Aug. 26 before there would be a drawdown of regional storage reservoirs. Typical August usage is about 600 million litres daily, the City said.

Francois Bouchart, the City of Calgary’s director of capital priorities and investment, said Tuesday that 13 of the 21 planned repairs are along 33 Avenue NW.

“Our neighbours in this area will be impacted not only by the citywide water restrictions but also by the construction of the feeder main for the benefit of all Calgarians,” he said.

Bouchart said that typically the planning process for a construction program this large would take three-to-six months, and they’re pushing it into a two-week period. Last week, they marked where the pipe repairs had to happen, along with the other utilities in the area.

Beginning today, crews would begin sawing into pavement, with pavement removal starting next week, Bouchart said. They also continue to nail down plans for things like detours, construction fencing, emergency response plans and services like garbage and recycling pick-ups.

Bouchart said there would be a pop-up open house later this week for residents that will be directly impacted by the construction.

More details on construction sequencing, including exact locations and detours will also be shared later this week.

Meanwhile, the City of Calgary said that since Aug. 13, they have detected no further wire snaps in the Bearspaw feeder main. There was only one recorded at that time.

Stage 4 outdoor water restrictions, voluntary indoor conservation needed

Chris Huston, manager of drinking water distribution with the City of Calgary said they’ve set the safe target for water consumption at 450 million litres per day. That’s about what they can get for supply from the north feeder from the Bearspaw water treatment plant and the Glenmore water treatment plant.

“If we use more than we can produce, we actually start to run out of water in those reservoirs,” Huston said.

“So, for example, if we continue to use the average daily demand this time of year of 600 megaliters a day, but we can only produce 450 (megalitres), we run out of water in three or four days.”

What that does is it sets off a potential chain reaction that leads to multiple boil water advisories, that may not be able to be fully lifted until next spring, he said. Huston said those storage reservoirs provide pressure for the system to push the water into homes. If, due to an inability to refill those reservoirs on any given day, it depressurizes the system.

“In order to lift a boil water advisory, it’s pretty complicated, and if you have multiple reservoirs go dry, then the boil water advisory spreads and can eventually encompass the entire city,” Huston said.

While they’d eventually be able to refill the reservoirs, Calgarians wouldn’t be able to drink that water until the entire system was flushed, requiring massive amounts of water.

“The next available time for us to do flushing of that magnitude wouldn’t be until next spring,” he said.

“Obviously, this is not a scenario anyone wants to see happen.”

That’s why Stage 4 outdoor water restrictions are necessary, and the voluntary measures are encouraged, Huston said.

Calgary Fire Chief Steve Dongworth also spoke during Tuesday’s media conference, and said that this time around they won’t have to implement a fire ban inside the city. There also won’t be a hotworks ban.

“We’re assured by our friends at water services that we will have the pressure, the flow and the volume of water that we need for firefighting from the fire hydrants, we’ve decided to ramp back a little bit from the last experience,” Dongworth said.

They also won’t be washing fire trucks and they won’t be doing some training that requires larger volumes of water.

“I guess the last part of my message would be just as we did last time, we would ask Calgarians to do everything they can to prevent fires during this time. That’s another way we can reduce water use,” Dongworth said.

More information will be made available later this week.