Water Leakage

Water leakage refers to water that is abstracted, treated, or introduced into a system but does not reach its intended destination due to physical losses (drips, pipe bursts, underground leaks) or apparent losses (metering errors, fraud, illegal connections).

Types of losses according to the IWA

Real losses (physical):

• Pipe and joint failures.
• Reservoir overflows.
• Exfiltration from tanks and valves.

Apparent losses (commercial):

• Under-registration from ageing meters (>10 years).
• Deliberate tampering or bypassing.
• Incorrect billing and estimates.

Key indicators

• Non-Revenue Water (NRW) Index = (Water supplied – Water billed) / Water supplied.
• Real losses in L/service connection/day.
• Burst frequency index = number of bursts / 100 km/year.
• Average repair time (ART) < 6 hours (optimal).

Step-by-step audit methodology

1. Water balance: collect input and output volumes by supply zone (DMA).
2. Smart sectorisation: install flow meters and RTUs with telemetry to create DMAs with <1,000 connections.
3. Leak detection campaign: acoustic correlators, noise loggers, infrared thermography.
4. Apparent loss assessment: mass meter calibration, anti-fraud inspections, anomaly detection algorithms (machine learning).
5. Master action plan: cost–benefit prioritisation, KPIs, and financing.

Enabling technologies

• IoT (NB-IoT / LoRaWAN): pressure and flow sensors every ~200 m.
• Hydraulic digital twins: EPANET-based models with predictive AI (LSTM) to locate incipient leaks.
• Drones and SAR satellites: detection of underground moisture in rural areas.
• Smart meters: 15-minute readings with alerts in the end-user app.

Business models and financing

• Performance contracts: contractors recover investment through guaranteed water savings.
• Blue bonds: municipal issuance with NRW reduction KPIs; step-up coupon linked to performance.
• NextGen EU funds: “urban water cycle digitalisation” line (€3.4bn in Spain).

Expected results and co-benefits

• Typical 25–35% reduction in physical losses in <5 years.
• Improved service quality (stable pressure and fewer outages).
• Fewer road works and customer complaints.
• Water freed up for climate resilience and urban growth.

Water leakage represents a waste of water, energy, and money. With data-driven audits, IoT technology, and performance-based business models, utilities and industries can recover their investment in 3–7 years and strengthen resilience against scarcity and rising energy prices.