Water utilities face a significant, yet often invisible challenge: Non-Revenue Water (NRW).
NRW is water that is collected, stored, treated and introduced into a distribution system but is never paid for. Put simply, it is the gap between how much water a utility supplies and how much it successfully bills. While widely discussed within technical teams, NRW is increasingly recognised as a strategic issue that spans across operations, finance, asset management and customer outcomes.
Taggle shares insights as to why NRW deserves greater attention, how digital water meters can highlight these invisible losses, and why NRW plays a critical role in the business case for digital metering.
What makes up Non-Revenue Water?
NRW is not a single type of loss, but a combination of different mechanisms that occur across the water network.
Physical losses are where water escapes through leaks, bursts and overflows before reaching a customer connection. These losses are worsened by ageing infrastructure, deteriorating materials and excessive or fluctuating pressure. They can remain undetected for long periods, quietly increasing operating costs and asset stress.
Apparent losses occur when water successfully delivered to customers is not billed correctly. Meter inaccuracies, billing issues and unauthorised illegal connections all fall into this category. Although the water reaches end users, the associated revenue is never realised.
The third component is unbilled authorised consumption including firefighting, system flushing and certain municipal uses. While necessary, these activities still incur the full cost of abstraction, treatment and distribution and must be considered when assessing overall system performance.
Why NRW matters more than ever
High levels of NRW have consequences well beyond water loss alone. Operationally, it increases the cost per kilolitre sold, as utilities pay for energy, chemicals, labour and maintenance associated with water that generates no return.
NRW undermines water security. This is particularly true in periods of scarcity when every megalitre lost puts additional strain on catchments and infrastructure. This results in unnecessarily harsh water restrictions which erode customer satisfaction and reduce quality of life.
Calculating NRW: simple in theory, complex in practice
NRW is the difference between system input volume and billed authorised consumption. While the formula is straightforward, the reliability depends on data quality.
Accurate NRW calculation requires data from bulk meters, customer meters, billing systems and time alignment between datasets. Without this, NRW becomes a disputed number rather than a trusted metric. Utilities may know they have a problem, but struggle to quantify its scale, source or financial impact.
The hidden cost in the Profit & Loss statement
NRW rarely appears as an identifiable cost in the Profit & Loss statement. Water that is lost or unbilled is not invoiced or shown as lost revenue; it simply never exists in reported figures. As a result, the true size of the opportunity is masked.
Costs associated with producing and distributing that water are fully recorded. Energy for pumping, chemicals for treatment, labour for operations and maintenance, and depreciation of assets all appear in the P&L, but the percentage of those costs that are not billed for is rarely identified. The result is higher operating costs per unit sold, reduced margins and lower returns on investment, without a clear causal line back to water loss.
NRW also influences capital expenditure in subtle ways. Persistent losses can drive the oversizing of treatment plants, earlier network augmentation and additional storage and pumping capacity. These investments appear as normal capital programs, even when NRW is a key underlying driver.
The role of digital water meters in quantifying and reducing NRW
Network meters provide critical insight into how much water enters the system, digital meters on every property and outlet collects timely consumption data, and with mass balancing, losses become quantifiable.
Digital meters improve the visibility of failures in the meters and enable much earlier intervention reducing apparent losses. At a network scale, aggregated meter data helps utilities pinpoint zones with higher losses, allowing leak detection and pressure management efforts to be targeted with far greater precision.
Targeted water loss management
Traditional leak detection programs often attempt to cover the entire network evenly. While well intentioned, this approach frequently results in high activity but relatively low returns, as crews spend time investigating low-impact areas and identifying minor leaks.
By concentrating resources in areas with high NRW and utilising data to narrow down searches, utilities consistently recover more water per intervention, reduce reactive maintenance and achieve faster payback on investment. This targeted approach transforms leak management into a strategic operational efficiency program.
Case Study
The township of Nundle, Tamworth Regional Council, experienced persistently high levels of NRW. While staff knew there was a problem, they lacked clear visibility into how much water was being lost and where those losses were occurring. Suspicions ranged from ageing under-registering meters to network leaks and illegal connections, yet repeated investigations failed to uncover anything obvious.
The problem surfaced dramatically with the installation of digital meters. Losses were now accurately quantified, revealing that approximately 50 per cent of the town’s water supply was not accounted for. The local water treatment plant was producing around 200,000 litres per day, while recorded customer consumption totalled only 100,000 litres per day. Where were the remaining 100,000 litres going?
With meter inaccuracy ruled out, council was able to redirect its focus to the network itself. Field investigations uncovered the source of the loss: an open valve at the end of a pipeline, allowing treated water to flow continuously into a nearby creek for an unknown period.
The discovery highlighted how hidden losses can persist for years without accurate data, and how digital metering can transform assumptions into evidence, enabling targeted action and rapid recovery of lost water.
Making NRW visible and actionable
When NRW remains hidden, investment decisions become harder, savings are underestimated, and finance and operations remain disconnected. Digital water metering data allows utilities to make NRW visible in both volumetric and financial terms, linking losses to real dollars and measurable outcomes. Digital metering does not simply support more accurate billing. It plays a foundational role in making NRW visible, measurable and manageable, turning what was once an estimated problem into one that can be addressed with confidence.
NRW is not simply water that disappears. It is water that utilities pay to produce, treat and distribute, but it never gets paid for. Making it visible with digital water meters is the first step toward reducing it, and toward building more efficient, resilient and financially sustainable water systems.