Construction update
Last Friday, we marked all the locations where pipe repairs are being made pink. We also spoke to residents to explain what the other colors of the road markings mean. These additional markings help us identify and protect existing utility lines during construction.
Starting today, workers will begin sawing out sections of the pavement on 33 Avenue NW. This is the first step in the excavation process to expose the main service line. Actual demolition of the road sections will begin on August 26.
Next, we’re working on safety measures, including where to put up fences and how to ensure residents can get to their homes safely, knowing many of them have no where to go. At the same time, we’re planning where to close roads and reroute them to make room for all of our equipment and other logistics.
We are also planning waste and recycling services, emergency response and contingency plans for unexpected water supply disruptions. An impromptu meeting will be organised this week for residents directly affected by the construction work. Details will be announced shortly.
Impact on residents
Of the 21 pipe sections requiring repair, 13 are located along 33 Avenue NW. This means that residents here will not only feel the citywide water restrictions, but also the direct impact of construction on the Bearspaw South Feeder Main. While this work is essential, we understand that many Calgarians are concerned about how construction along 33 Avenue NW may impact their properties.
Our teams are working hard to finalize construction plans and assess impacts to properties and roadways along 33 Avenue NW. Typically, projects like this take three to six months to plan, but we are compressing this process to two weeks to address concerns as quickly as possible.
We have spoken to the most affected property owners to discuss what impact the construction work may have on their green spaces and driveways and what remedial work we will undertake once the work is complete. We will continue to update you as new information becomes available.
Impact on business
We have been working on plans to minimize impacts to businesses in the Montgomery Business Improvement Area along 16th Avenue NW and 33 Avenue NW. This time, we can leverage lessons learned from previous construction phases to improve detours and driveways. Based on our initial assessment, we do not anticipate having to close driveways and customers will continue to have access to businesses in these areas. More detailed plans will be announced later this week.
Parkdale clarification
Last week we mentioned that there would be no further water restrictions for Calgary residents during pipe repairs on Parkdale Boulevard NW between 26th and 27th Streets NW. After review, it is too early in the process to guarantee that there will be no further water restrictions. While this next phase of work does not require a main line closure, our teams are working on plans to minimize disruption and we will provide more information once those plans are finalized.
How Calgary’s water distribution system works
Our water distribution system is a complex network designed to provide Calgary residents with clean, safe drinking water. We have two main water sources: the Elbow River and the Bow River. Water from these rivers is not immediately safe to drink, so it is piped to one of our two water treatment plants for treatment.
The Bearspaw Water Treatment Plant on the Bow River is the largest and can treat between 500 and 550 million litres per day (MLD). The Glenmore Water Treatment Plant on the Elbow River at Glenmore Reservoir can treat between 350 and 400 MLD.
After the water is treated, it flows through large pipes called supply pipes that are powered by pumping stations. These pipes transport the treated water to underground storage reservoirs. Unlike the Glenmore Reservoir, which contains untreated water, these underground reservoirs store clean, treated water ready for distribution to Calgary residents.
The underground storage tanks have the capacity to supply approximately one day of water for Calgary, with additional reserves for emergencies such as firefighting. This system ensures that Calgary residents always have access to clean drinking water.
When the Bearspaw South Feeder Main is out of service for repairs, the Bearspaw Water Treatment Plant can only contribute about 100-130 MLD to the system, a significant reduction in its normal output. The Glenmore Water Treatment Plant is not designed to meet all of the town’s needs alone.
For example, on a typical summer day, Calgary’s water demand is 650 MLD, and in hot weather it can reach 800 MLD. With the Bearspaw South Feeder Main out of service for repairs, we are unable to meet this demand.
Our safe water production limit during the repair period is 450 MLD, which is the full capacity of the Glenmore Water Treatment Plant and the reduced production of the Bearspaw Water Treatment Plant. We must keep our water use within this limit to ensure there is enough water for essential services such as hospitals and fire services.
If we do not reduce our water use and demand exceeds the capacity of the system, the underground storage facilities will eventually run out, causing water pressure to drop. Adequate water pressure is critical to water safety. Without it, contaminants can enter the system, potentially leading to a boil water advisory for the areas served by the depleted underground storage facilities.
A citywide boil water advisory is possible if several underground reservoirs are depleted. Refilling would not immediately solve the problem because the system would need to be flushed to remove all contaminants. This process requires a large amount of treated water. At this time of year, the flow of the Elbow River naturally decreases and we rely on the water stored in Glenmore Reservoir to get us through the winter. Should a boil water advisory be issued, it could be several months before enough water is available in the spring to safely flush and clean the system.
This scenario highlights the importance of Calgary residents working together to keep water use within safe production limits during the repair period.
We know how difficult the water restrictions have been for everyone – residents, businesses, industry and our regional partners, especially as we have been under certain restrictions since June 5. We thank you for your understanding and support as we complete these critical repairs to the Bearspaw South Feeder Main.
