A Parameter Classification System for Nonrevenue Water Management in Water Distribution Networks

Table 1

Components of water balance [14, 15, 29].

System input volume	Authorized consumption	Billed authorized consumption	Billed metered consumption (including water exported)	Revenue water
			Billed nonmetered consumption
		Unbilled authorized consumption	Unbilled metered consumption	Nonrevenue water
			Unbilled nonmetered consumption
	Water losses	Apparent losses	Unauthorized consumption
			Metering inaccuracies
		Real losses	Leaks in transmission and/or distribution mains
			Leaks and overflows at a utility’s storage tanks
			Leaks in service connections to customer meters