The trouble with water loss
Water loss is the difference between the total amount of water produced by a utility and the total amount of authorized water used and recorded by a utility. For the Water Bureau, these authorized uses include using water at homes and businesses, fighting fires, running the Benson Bubblers, and many other activities. Water loss includes things like leaks on storage tanks, water lost when a pipe breaks, and unpermitted hydrant use.
The largest sources of our water loss are leaks and main breaks in our 2,200-mile pipe system and 190,000 customer connections. Most of these leaks are small, underground, and hard to find, making locating and fixing them one of the Water Bureau’s biggest challenges.
Even small leaks can cause big problems, including potholes and damage to other infrastructure. Water loss also has conservation and sustainability impacts, and reducing those losses is an important part of our commitment to using resources wisely.
The bureau has a leak survey team that uses acoustic equipment to listen for and find leaks to be repaired. However, there might be a better way: using satellites to scan for underground leaks. This technology presents an exciting opportunity to locate leaks in a faster, more cost-effective way. When we find leaks earlier, they cost less to fix, have fewer impacts to water quality, and waste less water, helping us in our mission to serve our customers excellent water every minute of every day.
What is satellite leak detection?
In the summer of 2021, the Water Bureau contracted the services of Asterra for a satellite leak detection pilot program designed to find underground leaks throughout the city. This satellite technology was originally developed to find water on Mars and was adapted by the consulting team at Asterra to help cities like Portland find leaks. Asterra uses ground-penetrating radar to search for underground pools of water. The technology searches for characteristics that are unique to treated drinking water, including conductivity and chlorine signatures. The satellite scan results are then compared to a map of our water pipes to assess where a leak may be occurring. Water Bureau staff can investigate the list of potential leaks and initiate repairs as needed.
Did the satellite leak detection pilot program work?
Yes! The numbers show faster and more thorough leak detection:
- 160 leaks found in four months! This is three times more than we normally find in a year using traditional leak detection methods.
- 95 percent of leaks detected werenot visible from the street.
- 338 million gallons per year is the estimated savings from finding leaks using this technology.
In fiscal year 2021–22, the Portland Water Bureau had a water loss rate of just under ten percent of water supplied, a significant improvement compared to previous years. This satellite pilot program is likely one of the reasons for this improvement.
Will we use this technology again?
Yes! Searching for leaks is a continual effort, and the Water Bureau plans to do a second phase of this work in summer 2023. This satellite technology helped the bureau save water, staff time, and ratepayer money. If this second scan is as successful as the first, we will consider adding this emerging technology to our regular set of tools to reduce leakage and water loss.
You can help reduce water loss
Reporting leaks and main breaks is one way you can help reduce water loss. If you see water running from streets or sidewalks or pools of water where it should be dry, call the Water Bureau’s 24-hour emergency line at 503-823-4874.