Water balance and submetering

Define the boundary

Draw the facility, campus or network boundary first. Identify mains supply, wells, tanker deliveries and alternative sources; then separate process, domestic, irrigation and reuse lines. A difference between unmatched meter totals cannot reliably be labelled leakage. Account for reservoir storage changes and data uncertainty.

From measurement to decisions

• Main inlet: volume, instantaneous flow and time
• Submeters: building, plot or process use over the same interval
• Pressure points: upstream, downstream and critical service points
• Reuse: water produced and actually reused
• Data quality: gaps, replacements and clock alignment

Water loss is not identical to non-revenue water

Keep authorised consumption, physical/apparent losses and non-revenue water conceptually separate. Non-revenue water may include authorised unbilled consumption. For regulatory reporting, follow the required definitions and templates; for engineering assessment, record the assumptions and uncertainty.