35-40 percent of the drinking water produced in the municipality of Tjörn was lost to leakage, while the water treatment plant and water towers were already operating at full capacity. Through smart meters and measurement methods developed by RISE, combined with investments in the main distribution network, the municipality has gained much better control of its water infrastructure. And the leaks? Today, losses are down to around 20 percent.
Large parts of Sweden’s water infrastructure were built during the 1950s, 60s, and 70s and are now in need of extensive maintenance. On Tjörn, an island municipality with many scattered holiday homes, the challenge is particularly significant due to the extensive pipeline network in relation to the number of residents. Until 2020–2021, between 35 and 40 percent of the drinking water produced was lost through leakage.
– The national average for non-revenue water is around 17 percent, meaning water that is lost before it reaches customers, often through leaks. Our leakage levels were extremely high, and we wanted to bring them down significantly, says Tobias Hansson, Project Manager for IT and Automation at Tjörns Vatten och Avlopp.
Previously, we experienced around 30 major leaks per year. Today, that number is down to five or six minor or medium-sized leaks.
Investments Reduced Major Leaks
Between 2018 and 2021, major investments were made in the main distribution network. This reduced water losses to around 25–30 percent and eliminated many of the major leaks.
– Previously, we experienced around 30 major leaks per year. Today, that number is down to five or six minor or medium-sized leaks. The investments made a significant difference, but over time it became more difficult to locate the remaining leaks and determine where maintenance efforts should be prioritized, says Tobias Hansson.
Smart Metering
To take the next step, the municipality launched a project in 2021 together with RISE and other partners. The aim was to use smart water meters and new measurement methods to more easily detect leaks and improve maintenance planning. Since then, the distribution network has been divided into several zones equipped with connected district meters, and around 3,500 of the municipality’s 5,200 properties have been fitted with smart water meters. Olle Penttinen, a researcher at RISE, has played a leading role in the project and subsequent initiatives.
– By collecting measurement data from the water treatment plant, water towers, district meters, and property meters, we can calculate water balances for different parts of the network. This allows us to see how much water is supplied to an area and how much is actually consumed. The difference may, for example, be due to leaks or losses in the production process, says Olle Penttinen.
Open Platform
RISE has worked both on ensuring measurement quality and on developing the platform where data is collected, managed, and presented through a user interface. An important principle has been to ensure that the solution remains open and does not lock the municipality into a specific vendor.
– The municipality retains full ownership of all data and can add new functionality as needed. The platform can also be used for applications beyond water and wastewater management, says Olle Penttinen.
Now we can quickly narrow the problem down to a specific area where the leak is located.
Easier Leak Detection
When the distribution network is divided into smaller zones, it becomes easier to pinpoint problems. By comparing how much water is supplied to an area with how much is actually consumed, deviations and leaks can quickly be identified. The information is presented in a dashboard with maps used for both operational monitoring and maintenance planning.
– Previously, our technicians had to search across the entire island. Now we can quickly narrow the problem down to a specific area where the leak is located. We spend far less time searching and are also able to detect more smaller leaks than before, says Tobias Hansson.
The municipality can also take a more strategic approach to maintenance.
– Emergency repairs are very costly. If we can instead allocate resources to planned maintenance, we may be able to replace several hundred metres of pipeline rather than simply repairing a single leak. This improves the quality of the network and is far more cost-effective.
Reduced Water Production
Today, water losses are around 20 percent. As leakage levels have decreased, the need for water production has also declined, resulting in lower chemical consumption, a reduced climate footprint, and allowing the municipality to avoid major infrastructure investments.
– Previously, we operated the water treatment plant at full capacity and had no room to increase production. Today, we have greater margins in the system and have been able to avoid investments of up to SEK 80 million, says Tobias Hansson.
Efforts to reduce water losses are continuing, even though the current levels are considered relatively good.
– Twenty percent may sound high, but it is actually low compared with many other municipalities, especially considering the length of pipeline we have per customer. Not all of it is leakage either, some water losses are a natural part of the production process, says Tobias Hansson.
Can Also Help Property Owners
The smart meters also create new opportunities to detect leaks at individual properties.
– We can identify changes in consumption patterns and detect suspected leaks in buildings. In one case, we noticed unusually high water consumption that turned out to be caused by a leak. We contacted the property owner, who was able to shut off the water before any major damage occurred, says Tobias Hansson.
He emphasizes that even small leaks can become costly over time.
– Today, this process is handled manually, but in the future it could be automated, says Tobias Hansson.
Olle Penttinen at RISE also sees further opportunities going forward. Current regulations require water meters to be replaced every nine years, regardless of whether they are functioning correctly or not.
– With the help of the algorithms we have developed, it may be possible to identify meters that are providing inaccurate readings and replace them only when necessary rather than at fixed intervals. This could save both time and money, and is something we would very much like to explore further in future projects, says Olle Penttinen.
