Managing water loss

It is important to reduce the volume of water lost to leaks and breaks. The City proactively addresses water loss through a balance of actions that target leaking pipes, through identification, repair and prevention of leaks, as well as ensuring all water used is metered and accounted for like water used for firefighting or municipal use. By carefully managing Calgary’s water supply and demand, investing in efficiencies and managing the operations of Calgary’s water treatment and distribution systems, we are ensuring there is a secure and reliable water supply for all Calgarians now and into the future.

Managing water loss ensures that we are:

• Keeping water services affordable by maximizing service from existing infrastructure and reducing the volume of water to treat and distribute. 
• Ensuring water is available for Calgary’s growing population by reducing the per-customer amount of water withdrawn from our rivers.
• Making Calgary more resilient to drought by using water wisely.

The Accelerated Water Loss Program will improve the monitoring, identification and detection of system leaks, as well as target infrastructure repair, replacement and protection programs to reduce and prevent water loss. The program includes: 

• Advanced technology to support leak detection: Multiple pilots were conducted in 2023 to test and evaluate the effectiveness of new leak locating technologies including satellite imagery and semi-permanent acoustic sensors. Successful pilots have indicated that advanced acoustic sensors can effectively geolocate and target leaks within the system. The City is utilizing the proven technologies internally for both proactive and reactive response to leakage events. Additionally, The City will begin installing a network of flow meters in our system in 2025 to inform targeted areas for leak investigation.
• Expanding the leak detection program: The City will undertake a proactive leak detection survey targeting 1,000 km of pipe per year or 20% of the total system. 
• Additional repairs to fix leaking pipes: Using a balance of internal and contracted resources we will evaluate find and fix non-surfacing leaks, in addition to any watermain break repairs that are needed.
• Accelerate Asset Management Practices: The City will increase pipe replacement rates, expand existing programs on feedermain leak detection and condition assessment, and continue to monitor, evaluate and scale up additional programs and investments where possible.
• Preparing annual updates on water loss, including: 
  • Undertaking a third-party review on water use trends and water loss practices.
  • Updating the Water Loss Strategy in 2025, including identifying an appropriate longer-term water loss target (2026-2030) and action plan.

Water loss is the difference between the volume of water that is treated by the water treatment plant and the volume of water billed for at customer meters under the same time frame, minus that which is used for municipal purposes such as firefighting and system flushing.

As per industry best practices, the key performance indicators for water loss that are tracked include loss/service connection/day and Infrastructure Leakage Index (ILI). ILI is a ratio of the current rate of water loss against a theoretical lower limit based on system parameters such as system length, number of connections, and average system pressure. This metric takes into account the fact that all distribution systems leak, and larger, more complex systems leak more than smaller, simpler systems. An ILI of 4 is at the top of the moderate/B grade for the International Leakage Performance Category.