Leak detection

How utilities can systemically reduce non-revenue water

Non-revenue water is any water that a utility produces for which it does not collect any income. In the United States, about 24 percent of all water produced by utilities is non-revenue. We spoke with experts at Xylem’s Sensus and Visenti brands to learn how companies can reduce non-revenue water, save money and extend the life of their assets.

Non-revenue water can be divided into several categories. When utilities are looking at the water they produce and how it gets used, they need to look at authorized versus unauthorized consumption, billed consumption versus unbilled consumption and apparent losses versus real losses.

“A lot of people misconceive that all non-revenue water is due to leaks,” says Travis Smith, Director of Smart Water Strategies at Sensus. “A significant portion of it is actually in the apparent loss category. Apparent losses are things that result from either meter inaccuracies, billing errors or unauthorized use. Real losses are the leaks.”

These losses matter to utilities because a significant part of a municipality’s revenue generally comes from water-related services.


“Typically, money associated with water and wastewater services is the number two source of revenue in any municipality, behind taxes,” says Smith. “So revenue from water pays for many of the services that a city offers, or supplements them in some respect. If utilities follow a number of steps to reduce non-revenue water, they could increase revenue by 5 to 15 percent, and costs could be reduced 5 to 15 percent, which would have a significant impact.”

A step-by-step plan to reduce non-revenue water

Sensus is a global leader in smart meters, network technologies and advanced data analytics solutions for water, gas and electric utilities. Sensus helps utilities find ways to quickly and effectively reduce non-revenue water, and it has developed a number of steps that move from simpler to more complex solutions.

“We recommend a sequential approach to reducing non-revenue water, because if the steps are done in the right order each step should actually pay for the next step,” says Dan Pinney, Senior Director of Global Water Marketing at Sensus. “In the first two steps, we suggest that utilities focus on improving their billing and metering accuracy, starting with commercial and industrial customers. They can get very quick and impactful results starting with these customers, depending on how old their meters are.”

Quantity wise, commerce and industrial customers represent about 5 to 15 percent of a utility’s customers, but they represent 35 to 60 percent of their overall revenue. Because their volume of meters is so small but the revenue is so large, utilities can get a very good return on their investment by either testing or maintaining their meters every six months or every year.

Hardware and software solutions for each step

“Our non-revenue water strategy starts with simpler steps, such as improving commercial and industrial accuracy, reducing billing system errors and improving residential accuracy,” Smith says. “Then utilities can start looking at unauthorized use, the water mass balancing, acoustic solutions and advanced leak detection. These actions can significantly change a utility’s economic picture.”

Sensus has solutions to reduce non-revenue water for each step. These include water meters with unprecedented accuracy, sensors to detect and localize leaks and the FlexNet® communication network to securely transmit and receive customer-usage data. Sensus can also help utilities with another type of non-revenue water, which is water that has been billed but not been collected.

“Utilities have a significant amount of write-offs for bad debt or collections and spend a lot of time trying to administrate that,” says Pinney. “Sensus helps solve this with the ally® water meter that enables utilities to remotely reduce flows so they can minimize exposure to lost revenue.”

Visenti’s solutions for smart water analytics

Aside from billing and metering accuracy, both Sensus and Visenti have a number of solutions to help utilities detect and prevent leaks. If left untreated, leaks will only get worse over time and utilities will have to produce more water without getting additional revenue for the water.

Visenti, acquired by Xylem in 2016, offers software and hardware solutions for smart water analytics, leak detection and leak prevention. The company got its start in Singapore, which today has the largest smart water network in the world. Singapore’s PUB water agency has hundreds of Visenti’s sensors deployed throughout its network.

“Singapore has been very forward thinking as a utility,” says Michael Allen, a co-founder of Visenti and Executive Director of Embedded Systems. “They know in the future that water management will get more difficult, with increasing populations, aging pipe infrastructures and limited budgets. They want to use smart technology and capabilities to improve their network and how they manage it. They use all of Visenti’s solutions.”

Addressing more complex causes of non-revenue water

Visenti’s solutions include three main products: View, LeakView, and SurgeView. View is Visenti’s main analytics platform that enables utilities to collect and analyze all of their data in one place.

“Utilities have a lot of sensor data for business functions, asset management, leak detection and forward planning,” Allen says. “It’s typical that these business functions in utilities are quite siloed. Our product View allows utilities to pull all of these data streams together, along with existing analytics and hydraulic models, to get better insights into what is happening in the network.”

Allen says that these insights about the network become increasingly important as a utility chips away at the causes of non-revenue water.

“If your utility has a huge amount of non-revenue water, say 50 percent, there are a few basic things you can quickly fix,” says Allen. “Are your sensors and meter readings accurate? Are you missing big leaks somewhere? A lot can be gained in these areas just by applying best practices. But as you get closer to less than 10 percent non-revenue water, it gets harder to make those gains. This is where smart water analytics can help, enabling you to find smaller improvements.”

In part through using Visenti’s solutions, Singapore has been able to reduce their non-revenue water so that it is just five percent of all water produced.

Tracking non-revenue water and extending asset lifetime

LeakView and SurgeView from Visenti include hardware that can be added to the View system. LeakView is used to both track non-revenue water and detect and localize real-time pipe failure. It involves the installation of flow meters, pressure transient units and hydrophone units.

“Leak View warns utilities as early as possible if a pipe has burst, so that they can get to it quickly and avoid catastrophic scenes that make the news, like a huge fountain shooting up from the ground,” says Allen. “We also work to reduce false positives, so that utilities do not waste resources on investigating leaks that aren’t actually happening. In Singapore, our work with reducing false positives has meant that they have gone from two alerts every hour to two alerts a day.”

Visenti, which also has extensive deployments in Australia and the Middle East, works with utilities to extend the lifetime of their assets. Its product SurgeView combines high-rate pressure sensing with analytics so that utilities can reduce stress on pipes. SurgeView also monitors critical water mains in order to predict where and when they might fail in the near future. Utilities can then make more informed decisions about how to use, maintain and update their network.

The combined advantages of Sensus and Visenti

According to Allen, Sensus and Visenti can provide an end-to-end water management system for utilities that will help them lower non-revenue water and ensure smarter water management.

“Sensus has an incredible line up of advanced metering systems and a network to carry data. If you’ve got the best sensors deployed, the best way to transmit that data to a central place and the best analytics to look at that data, this brings a lot of benefits to utilities.”


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