Water Use Efficiency

Controlling Water Loss

Quick links to information on this page:

Pilot Program to Reduce Water Loss

Ten water systems worked with national water loss control experts using AWWA methodology and best practices. They gathered and validated water loss accounting data. Read the WUE Water Aduit Report (PDF) to learn more.

Training and Resources

2017 North American Water Loss Conference:

Description: The California-Nevada Section AWWA and Alliance for Water Efficiency and the NAWL 2017 Conference Planning Committee hosts the 2017 North American Water Loss Conference. Discussions will take place over two days on developing water loss policies, auditing your system, reducing apparent losses, controlling leakage, managing pressures, and documenting your progress, both for you and for your regulators.

Improving Your Operations and Reducing Costs by Evaluating Water Use Data: Listen to the recorded Webinar (registration required.)


When you submit your annual water use efficiency reports, you must provide metered information (total production and authorized consumption).

  • Total Production is all metered water that enters the distribution system through an intertie, from a water source or treatment plant.
  • Authorized Consumption is water you gave someone permission or authorization to use. Even if the water wasn't billed or metered, it is still authorized consumption and must be tracked, otherwise it counts as water loss.
  • Unaccounted-for Water is an outdated term used to describe water loss. Industry standards have recently changed to a more responsible method of water loss management, suggesting that no water is unaccounted-for, but that all water should be accounted for (PDF).

    In order to more effectively track where and how the water loss occurred, it's critical to understand the two broad types of water loss: Apparent Losses and Real Losses (PDF).
  • Apparent losses are the non-physical losses that occur in utility operations due to customer meter inaccuracies, systematic data handling errors in customer billing systems, and unauthorized consumption. In other words, this is water that is consumed but is not properly measured, accounted, or paid for.
  • Real losses are the physical losses of water from the distribution system, including main breaks, leaks, and storage overflows.

Did you know?

  • Each year, 6 to 8 percent of the water systems in Washington report they sold more water than they pumped, resulting in negative leakage!
  • Worldwide, fire fighting uses 0.4 to 0.9 percent of the total production.
  • In 2011, Washington water systems lost about 26 billion gallons of municipal water supply to physical leaks, poor accounting, and other unauthorized consumption.

If You Can't Measure It, You Can't Manage It

In order to effectively manage real and apparent water loss, your water utility should be able to answer several questions:

  • How much did the water loss cost the utility?
  • Where did we lose the water?
  • How much water was lost, expressed as a volume and percentage?
  • Why did we lose the water?
  • Are all of our services metered (for example, city parks and city hall)?
  • Have our source meters been calibrated recently (within the last five years)?
  • Are we using hydrant meters to track fire department or contractor uses?
  • Did we track the amount of water used for maintenance flushing or tank cleaning? How?
  • Have we sought technical assistance from leak detection experts? If not, ask an Evergreen Rural Water of Washington circuit rider to perform a leak detection survey.

Water Audit Method

Still not sure where your water's going? Many other states are using a new industry standard to evaluate water loss by completing a water audit derived from the American Water Works Association (AWWA) and the International Water Association (IWA). Download the water audit software.

Use the chart below to better understand water audit terms (PDF).

Funding Your Leak Repair Projects

Fixing leaks means saving water and saving energy. You can also get paid to save energy while fixing leaks at the same time.

For More Information:

Contact Mike Means, 360-236-3178