Non-revenue water loss analysis shows how much of the water put into a network is actually billed, and splits the rest into physical (real) losses such as pipe bursts and commercial (apparent) losses such as meter errors, misreads and illegal connections. It starts with a water balance for the whole network, then divides the network into district metered areas and tracks night-time flow to show where losses are concentrated. Doing it properly takes accurate measurement, frequently read meters and software that brings those data together in one place.
How the problem looks inside a water utility
In most utilities, the loss rate is calculated once a year as the difference between water produced and water billed. The number is high, but on its own it says very little: which district, pipes or meters, day or night? Crews go out when a burst is reported; leaks that never reach the surface can run for months or even years.
Commercial losses are even less visible. An old meter stops registering at low flow, a reader enters an estimate at a locked door, and an illegal connection is only found when someone reports it. None of these losses is fixed by repairing pipes; they need measurement and reading discipline.
In short, the problem is not that the loss rate is high. It is that nobody knows where the loss is or what kind it is. And unknown losses can only be reduced by guesswork, which means expensive, scattered field work.
What doing nothing costs
Türkiye's loss rate is falling, but it still trails both the legal target and developed countries:
According to Türkiye's Ministry of Agriculture and Forestry, the average water loss rate in drinking water networks fell from 39% in 2015 to 31.6% in 2024, and metropolitan and provincial municipalities must bring it down to at most 25% by 2028. (Ministry of Agriculture and Forestry — Urban Water Efficiency)
On the same page, the ministry notes that loss rates in developed countries range from 8% to 24% and describes its ultimate goal as around 10%, not 25%. Among the measures it recommends are wider use of remote monitoring and control systems, district metering and pressure management zones, and minimum night flow analysis. In other words, the method is not in dispute; the challenge is implementation.
The obligation covers every municipality. Türkiye's 2014 Regulation on the Control of Water Losses in Drinking Water Systems also requires smaller municipalities to reach at most 30% by 2028 and 25% by 2033.
Every lost cubic metre has already been treated and pumped, and its energy paid for. Globally, the World Bank's assessment of non-revenue water estimates that 126 billion cubic metres of water are produced but never billed each year, costing nearly $40 billion annually in waste and foregone revenue.
The water balance: splitting losses by type
The first step is to split the water entering the network by where it goes. The widely used water balance approach of the International Water Association (IWA) does it like this:
| Component | What it means | Typical source | How to reduce it |
|---|---|---|---|
| Billed authorised consumption | Water that is metered and billed | Customer consumption | — |
| Unbilled authorised consumption | Permitted use that is not billed | Firefighting, parks, mains flushing | Measure and record it |
| Apparent (commercial) losses | Water consumed but not measured correctly | Meter inaccuracy, misreads, illegal connections | Meter replacement, automatic reading, theft checks |
| Real (physical) losses | Water escaping from the network | Leaks at pipes and joints, tank overflows | Pressure management, active leak detection, fast repair |
Non-revenue water is the sum of the last three rows. Without this split, every investment decision is made blind: buying meters for a network dominated by physical loss, or replacing pipes where commercial loss dominates, is money spent in the wrong place.
Locating losses: a seven-step framework
- Verify production and inlet metering. If flow meters at sources, reservoirs and pumping stations are inaccurate, the whole water balance is wrong. Calibrate the inlet side first.
- Build the water balance. Fill in the table above for your own network using the last twelve months of production, billed and unbilled consumption. Seeing which type of loss dominates tells you where to spend.
- Divide the network into district metered areas (DMAs). Create zones bounded by closed valves, with inflow and outflow measured by flow meters. Comparing the water entering each zone with its customers' consumption brings losses down to neighbourhood scale. Defining these zones in a geographic information system (GIS) puts customer and network data on the same map.
- Monitor minimum night flow. Legitimate consumption is at its lowest in the small hours; if inflow to a zone at that time is higher than expected, the zone is leaking. A sudden jump in night flow is the first sign of a new burst, and anomaly detection can catch it automatically.
- Manage pressure. Excess pressure increases leakage and triggers new bursts. Pressure-reducing valves at zone inlets, with different day and night settings, cut physical losses before any repair.
- Tackle commercial loss at the meter. Prioritise old meters that have lost low-flow accuracy, read meters remotely, and link zero consumption, reverse flow and tamper events to automatic alerts.
- Measure active leak detection and repair time. Send acoustic listening teams to zones with high night flow, and record the time from report to repair for every burst. Losses fall when leaks are repaired, not just when they are found.
What these steps share is the need for continuous, reliable field data. Steps 4 and 6 are impossible with monthly meter reads and a loss rate calculated once a year.
The data foundation: from meter to decision
Sustainable loss analysis depends on four data sources coming together:
- Customer meters: at least daily readings through automatic meter reading, with hourly profiles in zones under analysis.
- Zone inlet flow meters and pressure points: continuous measurements that build the night-flow and pressure curves. The trade-offs between LoRaWAN, NB-IoT and cellular for these points are covered in our LoRa vs NB-IoT vs cellular comparison.
- Network and customer map: a GIS layer showing which customer belongs to which zone (we cover the set-up in GIS for municipalities).
- Fault and repair records: when each burst was reported and when it was fixed.
When these data stay in separate systems, the analysis has to be rebuilt by hand every time. Combined, they let you follow loss rate by zone, night-flow trends and repair times daily in a single management dashboard. Use the method in how to set KPIs to choose which indicators belong on it.
How we deliver water loss projects at Digital Bridge
We handle metering devices, communications and software together. Because hardware and software come from the same team, data flows from the meter to the dashboard without hand-offs between suppliers.
- We map the current situation with you. We review your water balance data, meter stock and measurement points, and identify the most meaningful pilot zone. Technical feasibility on the hardware side is free.
- We make meters remotely readable. With our AMR meter reading system we read customer meters over GPRS/4G, LoRaWAN, NB-IoT or M-Bus depending on site coverage; the software raises alerts for zero consumption, suspected theft and unusual spikes, and passes billing data to your billing system via API.
- We bring zone measurements into monitoring. We carry inlet flow and pressure data to the centre through our remote monitoring infrastructure and, where needed, make pumping stations and reservoirs visible alongside it with SCADA. With a custom SCADA, the source code belongs to you.
- We shape the project around your organisation. For municipalities we work through our public sector and municipal solutions; for water utilities and distribution companies, through our energy and utilities solutions, designing around your existing processes and software.
The order is the same on every project: needs analysis, a written proposal setting out scope, phases and cost, a pilot zone, then roll-out based on measured results.
Next step
The first step needs no new investment. Gather twelve months of production and billed consumption data, an approximate count of customers and meters, and any zone inlet measurement points you already have. Then get in touch through our contact page; we will interpret your water balance together and plan how to run a pilot in the zone where losses are highest.