Every utility loses water between the treatment plant and the customer meter. We help you measure it precisely, locate it faster, and prioritize the interventions that pay back — using the IWA/AWWA water-audit methodology and the operational data you already collect.
Drinking-water · wastewater · bulk-supply utilities — district-level to system-wide
NRW is the gap between the water a utility puts into distribution and the water it bills for. It bundles three very different problems: physical leakage, metering and billing shortfalls, and legitimate unbilled use. Left unmeasured, it drains revenue, wastes energy and chemicals, accelerates main breaks, and forces premature investment in new supply.
Apparent losses — meter under-registration, billing errors, unauthorized use — are water consumed but never paid for. Recovering it is often the fastest payback in the whole program.
Every leaked gallon carries embedded energy and treatment cost. Cutting real losses reduces pumping, chemical dosing, and the carbon footprint of supply.
Reducing losses recovers existing capacity. Utilities routinely meet demand growth for years without new sources by tightening the network.
Everything starts here. The water balance accounts for every volume entering the system and sorts it into what's billed (revenue water) and everything else (non-revenue water) — then splits the losses into apparent and real. It's the common language regulators, lenders, and operators share, and the starting point of the AWWA M36 audit.
NRW = System Input Volume − Billed Authorized Consumption. The art is decomposing that one number — because each component is solved a completely different way. Expand each below:
Both IWA and AWWA discourage percentage NRW as the only metric: it moves with consumption and pressure and flatters or penalizes utilities for the wrong reasons. Analytics-led programs track volumetric and infrastructure-normalized indicators instead.
The Infrastructure Leakage Index is the ratio of Current Annual Real Losses to the Unavoidable Annual Real Losses for your specific network — a function of mains length, connections, and pressure. It's dimensionless, so a small rural system and a dense city can compare real-loss management on equal footing. An ILI near 1.0 is the technical floor; higher values signal room — and an economic case — to act.
Target ILI is set by the economic level of leakage, not a universal number — it depends on the value of water and the cost of intervention in your system.
Set each AWWA water-audit component to your system. The model computes your non-revenue water, splits the economics (apparent losses at the retail tariff, real losses at production cost), and flags each component against illustrative benchmarks. A validated audit refines every input.
AWWA components · order-of-magnitude · illustrative
The water balance tells you how much you're losing. Analytics tells you where, when, and what to do first. We work with the data you already own — production meters, district inflows, smart meters, pressure loggers, work orders, and the hydraulic model.
Segment the network into District Metered Areas and analyze night-time inflow — when legitimate demand is lowest — to quantify and localize leakage zone by zone.
Mine AMI/AMR interval data to flag meter under-registration, profile demand, and detect anomalies that signal apparent loss and unauthorized use.
Combine break history, pipe attributes, pressure, and environment to score mains by failure risk — shifting repairs from reactive to planned.
Use FAVAD / N1 leakage-pressure relationships to model how PRV zoning and modulation cut leak flow rates and new break frequency.
Integrate acoustic loggers, correlators, and satellite leak-detection passes into a single ranked survey plan — not a blind network-wide walk.
Raise your AWWA data-validity score by tracing each input to source, reconciling SCADA against billing, and documenting the grading.
The IWA Water Loss Specialist Group frames real-loss control around four complementary methods. Analytics decides the right mix for your network and the economic point at which to stop.
Lower excess pressure to cut leak flow rates and reduce new bursts — often the highest-return first move.
Proactively find hidden leaks via DMA monitoring and night-flow analysis instead of waiting for them to surface.
Shorten the awareness, location, and repair time of every leak — run-time drives total loss.
Targeted rehabilitation and mains replacement, prioritized by failure-risk analytics.
A program built on weak data wastes capital. We follow the AWWA M36 methodology and the Free Water Audit Software, grade every input for reliability, and pursue validation — the standard a growing number of states (California among them) now require.
Assemble system input, authorized consumption, and losses from existing records for a defensible first water balance.
Score each input 1–10 for reliability to produce the overall Data Validity Score, and target what most limits confidence.
Independent review against AWWA practice — the basis for regulatory reporting and for trusting the numbers enough to invest.
Break real losses into background, reported, and unreported leakage; value apparent losses at tariff; build the case per intervention.
Execute the prioritized mix, then re-audit to confirm savings and reset targets.
The AWWA audit grades overall confidence 0–100. Below ~70, the priority is better data before major capital. This example sits at 76.
The best-performing utilities show that high NRW is a management problem, not a permanent condition. Each turned data, metering, and disciplined leakage control into dramatically lower losses.
Cut NRW from 72% in 1993 to about 9% by 2023 via metering, regularizing illegal connections, leak repair, and reform — a landmark turnaround.
Used District Metered Areas as the backbone of decentralized field operations to reach among the lowest NRW in Asia, from far higher historic levels.
Sustains one of the lowest unaccounted-for-water levels in the world through proactive detection, pressure and asset management.
Decades of systematic leakage management hold losses to roughly 3% across a vast network — a global benchmark.
Figures as publicly reported by the named utilities and international agencies; cited for context, not as a guarantee of results.
NRW is not a developing-world problem. Across roughly 48,000 U.S. community water systems, aging networks lose a striking share of treated water every day. These figures are drawn from public sources and vary by methodology — but the order of magnitude is consistent.
Just five states — California, Texas, Florida, New York, and Illinois — account for over a third of national water losses. On policy, California's SB 555 has required validated annual water-loss audits from urban retail suppliers since 2017, and the State Water Board is advancing volumetric real-loss performance standards; Georgia, Texas, and Indiana have moved on similar reporting. The data increasingly exists — turning it into prioritized action is the work.
Compiled from public reporting (Bluefield Research, U.S. EPA, ASCE, AWWA, California DWR / State Water Board). Estimates vary by source and methodology; shown for context.
Send us your system size and what data you collect today. We'll outline a first water audit and the fastest paths to recovered water and revenue.
support@nrwaudit.com