Define 'non-revenue water.'

Non-revenue water refers specifically to water that is produced and distributed by a water utility but is not billed to customers. This category encompasses various issues, such as water leaks, theft, metering inaccuracies, and water used for maintenance or firefighting, which ultimately leads to economic losses for utility companies.

Understanding non-revenue water is essential for water utilities, as it reflects the efficiency of the water distribution system and highlights areas needing improvement. By reducing non-revenue water, utilities can enhance their revenues and provide better service to their customers. The other options provided do not accurately capture the essence of non-revenue water, focusing instead on different aspects of water management and usage.