IWA best practice water balance and performance indicator (originally published in Lambert & Hirner 2000)
System input volume | Authorized consumption | Billed authorized consumption | Billed metered consumption | Revenue water |
Billed unmetered consumption | ||||
Unbilled authorized consumption | Unbilled metered consumption | Non-revenue water | ||
Unbilled unmetered consumption | ||||
Water losses | Apparent losses | Unauthorized consumption | ||
Customer metering inaccuracies | ||||
Real losses | Leakage on transmission and/or distribution mains | |||
Leakage and overflows at storage tanks | ||||
Leakage on service connections up to point of customer metering |
System input volume | Authorized consumption | Billed authorized consumption | Billed metered consumption | Revenue water |
Billed unmetered consumption | ||||
Unbilled authorized consumption | Unbilled metered consumption | Non-revenue water | ||
Unbilled unmetered consumption | ||||
Water losses | Apparent losses | Unauthorized consumption | ||
Customer metering inaccuracies | ||||
Real losses | Leakage on transmission and/or distribution mains | |||
Leakage and overflows at storage tanks | ||||
Leakage on service connections up to point of customer metering |