Calgary work crews are making progress on repairs to the Bearspaw water feeder main repairs, as water may be slowly reintroduced to the system in a few days.
This and other information was shared in updates provided by CEMA head, Sue Henry, General Manager Michael Thompson and Mayor Jeromy Farkas.
Henry said the water system remains under strain, with 507 million litres consumed yesterday, which she added was unsustainable.
"The longer we're in the red, the worse it gets," she said, adding the Glenmore Reservoir is dropping and not re-filling as water is delivered to storage reserves across the city.
“Once the pipe is back in service we will be working on a medium term strategy that will stay in place until the replacement feeder main work is complete. This is being done as we cannot guarantee we will not experience another failure as the pipe comes back into service.”
“If each of us saves 30 liters a day, we can return to sustainable levels together.
Thompson said repairs are progressing well.
“The damaged section of pipe has been removed and the new pipe segment has been now been welded into place. There are still several important steps before the pipe can go back into service. The backfilling of soil around and above the pipe started last night. Once completed, crews will start repairing the road above the pipe.”
Other critical steps ahead include making sure the water quality meets all regulatory standards and is safe t drink.
“In the days ahead we restore service to the feeder mean and stabilize our system,” said Thompson. “Next is filling the feeder main, testing the water, stabilizing the system and easing out of water conservation. Each one of these steps carries risk, and it is likely that we could have setbacks along the way.”
“A seven kilometer section of the pipe is empty and we need to refill it, by opening valves, and inserting the flow water from the Bearspaw plant into the pipe.”
Thompson estimates it will take approximately 48 hours to fill the pipe and during the filling stage, the pipe will experience an increase in pressure, which increases the risk of stress and potential further breaks.
“The risk on this pipe is increased because of its fragile condition. We are managing this risk by filling the pipe carefully and monitoring the pipe with sensors as we fill it. Once the filing is complete, the second step is to ensure that the water in the feeder main is clean and safe.”
After confirming it is safe, the next step is to start flowing water from the feeder main through the rest of the system.
“This step involves turning on pumps at the Bearspaw plant, which will increase the pressure in the feeder main and start water flowing through our network,” said Thompson. “Stabilizing the system will take about 48 hours.”
This stage has the highest level of risk.
"Whether from flushing, filling, or adding additional pumping capacity, pipe connections and pipe walls experience additional stress, said Thompson. “We will be carefully monitoring the performance of our system during this stage and making necessary adjustments.”
There are no guarantees the pipe will not break again.
“If we do experience another pipe break, we will not only repair that break, we will also complete a number of urgent repairs using the concrete encasement method," said Thompson.
Farkas opened by mentioning the independent report presented to council on Wednesday, adding the report's authors collectively brought “two-and-half centuries of experience in critical infrastructure, utilities, risk management and engineering to this work.”
“The panel was asked three questions. What happened, why did it happen and how do we make sure it never happens again?” said Farkas. “That's why council acted immediately last night, voting to fast-track implementation plans to address these findings. At the same time, the administration is already moving ahead on the work that doesn't require council direction.”
“We're not slowing down, we're not passing the buck and we're not waiting for another failure to force action. As your mayor, I am taking personal responsibility. This work is underway and it will be seen through at the same time.”
Farkas emphasized the city isn't in the clear yet, but there is good news.
“Yesterday Calgary's water use dipped slightly, but it is still in the red zone,” he said. “Reducing water use right now protects the overall health of the system and supports firefighting capacity, so we need to see shorter showers, full loads of laundry and dishes and limited flushes.”
“Doing the right thing right now is simple and powerful.”
