Getting Practical About Non-Revenue Water

By Christian Bonawandt

Problems faced by water utilities seem to grow in both quantity and complexity each year. Among the most persistent challenges is non-revenue water (NRW). In a recent Water Online Live event, Non-Revenue Water: Industry Perspectives On A Persistent Challenge, industry experts gathered to discuss this multifaceted challenge. Kevin Westerling, chief editor of Water Online, hosted the session, which featured Will Jernigan, COO at Cavanaugh and a leading voice on the AWWA Water Loss Control Committee, and Jennifer Stephens, Technical Practice Director for Digital Water at Carollo Engineers.

The discussion moved beyond the 10,000-foot view and dove deep into the technical nuances of data validation, the economic logic of intervention, and the critical “human side” of water loss management.

Redefining The Complexities

The presenters began by reframing NRW as a complex, multi-part problem rather than a single “unaccounted for” figure. Jernigan emphasized that the industry standard AWWA approach is important because it separates a massive issue into smaller, more manageable components. NRW, he explained, is defined as water supplied into a system that fails to return revenue to the utility. This includes physical losses, such as leakage, and apparent losses, including meter inaccuracies, data errors, and theft.

Jernigan also argued that without breaking these down, utilities cannot know which solutions to apply or where the most significant portion of their problem resides. “The process is all about taking a high-level problem and breaking it down into actionable pieces,” he said. “Otherwise, you don't know which solutions to apply or where the biggest part of the problem is.”

The Issue Of Data Trust

A central theme of the session was the lack of trust many utilities have in their own NRW data. Stephens noted that this uncertainty often stems from disconnected systems and an inability to reconcile multiple data sets, including production flows and billing information. She suggested that improving visibility should be the first step toward building the confidence required for operational staff to act.

Jernigan highlighted the depth of the data integrity issue by pointing to a Water Research Foundation study, which found that 20% to 40% of submitted water audits showed implausible results, such as negative water loss. Mistakes like this, he insisted, are “baked” into the systems themselves. “Error in the water audit data is not, for the most part, coming from human error,” he said. “It is coming from error that is sort of inherent to the systems that we get the data from.”

Common systematic errors include mis-programmed supply meters where minimum and maximum flow ranges are incorrect, or issues with how SCADA systems totalize information. For example, some systems act like a car odometer, Jernigan explained, while others sample rates every few minutes and average them. The latter method can introduce inaccuracies over time. He also pointed to multipliers or conversion factors in billing systems as frequent sources of data corruption.

The Economic Logic Of Intervention

Once the data is validated, utilities face the challenge of deciding where to invest their limited capital and man-hours. Stephens noted that while it may seem logical to address the largest volume of water loss first, that “might not always be the most optimal way to produce results that are practical and defensible.” Instead, there is an “economic and intervention level” specific to each utility. For instance, a utility that produces its own water at a low marginal cost may find leakage less financially damaging than a neighbor who purchases water at a retail rate.

Jernigan noted that many utilities prioritize apparent losses over physical leakage for early wins. Although leakage is almost always larger by volume, apparent losses have a greater economic impact because they represent lost retail revenue. By fixing billing errors or faulty meters, utilities can generate a quick return on investment (ROI) to build political support for more expensive leakage programs.

Practical Use Of Digital Tools

While tools such as analytics and system modeling are powerful, Stephens said they are merely enablers of a broader strategy, not the strategy itself. Analytics can identify patterns, such as abnormal night flows or high-risk pressure zones, which might be invisible in isolated audits. System modeling further allows utilities to test what-if scenarios, moving them from reactive guessing to defensible, risk-based prioritization.

“Digital tools genuinely help move that needle in visibility and prioritization and enhance that speed to action,” she said. “If we can get AI or a digital tool to get us 80% of where we need to be, then we can focus on our efforts and our time on that last 20% to really get in and make those decisions.”

Stephens warned that deploying technology for its own sake is a mistake, particularly if the underlying data is weak. The goal, instead, should be to create a repeatable process that can be sustained by existing staff. She advocated for democratizing data by moving it out of individual spreadsheets and into centralized dashboards that the entire organization can use.

The Human Side Of Water Loss

Both experts agreed that the most significant obstacle to long-term NRW reduction is the organizational culture. Jernigan described NRW as a “unicorn” issue because it is the only operational aspect that requires a shared goal across nearly every department, including engineering, finance, customer service, and distribution.

However, Stephens insisted that without clear ownership, NRW becomes “everybody's problem, but nobody’s priority.” Successful utilities are those that embed NRW awareness into daily workflows rather than treating it as a one-time “check-the-box" project. Sustaining progress requires ongoing coordination that survives shifting budgets and personnel turnover.

Universal Principles For Small And Rural Utilities

Smaller utilities often struggle with minimal budgets to address NRW. Still, Jernigan observed that the principles of the mass balance (water supplied must equal consumption plus loss) are universal and do not change based on system size. Even though small systems have fewer resources, they often have the advantage of visibility; a significant leak in a small system is often immediately apparent in tank levels or SCADA. In addition, managing data quality for a single supply meter is far simpler than managing it for a large system like San Antonio, TX, which may have 175 points of measurement.

Jernigan’s primary advice for all utilities, regardless of size, is to start immediately. As he put it, “Your data will never be perfect, but it can and should be improved over time. I have seen hard-earned lessons of sort of deferring looking closely at NRW for a few pending capital projects and all the while that NRW cost is impacting every year it’s ongoing.”

Advancing DMAs And Pressure Optimization

From there, the panelists examined advanced strategies, including district metered areas (DMAs) and pressure management. DMAs are common globally but remain less prevalent in North America because many systems were not designed with the necessary isolation points.

However, both presenters spoke enthusiastically about pressure optimization. Jernigan argued that while leak detection addresses the symptom of NRW, pressure management addresses the root cause. By reducing excess pressure, particularly at night, utilities can not only slow the flow of existing leaks but also prevent the development of new breaks.

Stephens highlighted that system optimization allows utilities to compare modeled expectations with real-world sensor data to refine operations. Jernigan pointed out that many North American utilities believe they are already managing pressure via pumps and zones, but in reality, they are rarely optimizing it for loss reduction.

A Path Forward

The webinar concluded with a look at the evolving regulatory landscape. Jernigan observed that more states are mandating water loss reporting using AWWA best practices, which he views as a positive force for wide-scale adoption. Stephens reiterated that even if a digital investment hasn't shown immediate results, it often means the utility is still in the necessary stage of building trust and targeting the right data.

The final takeaway was that NRW reduction is a continuous journey that combines technical data validation with a committed organizational culture. By breaking the complex problem into parts, leveraging digital tools for visibility, and fostering cross-departmental ownership, utilities can turn data into lasting operational action.

To hear the full panel discussion and audience Q&A, watch the full webinar on demand here.

About The Speakers

Jennifer Steffens is Digital Water Technical Practice Director, Carollo Engineers. She has 20 years of experience delivering digital solutions across the full spectrum of water utility operations, from operational control and asset management to capital planning and regulatory compliance. As digital water technical practice director at Carollo Engineers, Steffens leads the firm's national effort to embed digital intelligence into planning, design, and operations. Her work focuses on advancing tools and technologies — including digital twins, asset management platforms, and AI/ML applications — that help utilities optimize performance, reduce risk, and make data-informed decisions.

Will Jernigan, PE, is Chief Operations Officer at Cavanaugh. He has worked with over 2,000 water systems across North America where he is recognized as a leader in the water loss industry. Will is the chair and chief architect behind the AWWA Water Audit Software and the AWWA North American Water Loss Conference.He was also appointed as the U.S. expert to an international task force developing the ISO Water Loss Standards. Will was Co-Principal Investigator for the Water Research Foundation Projects in 2016 and 2020 which formally codified the Level 1 water audit validation methodology.

Christian Bonawandt is an industrial content writer for Water Online. He has been writing about B2B technology and industrial processes for more than 25 years.