Non revenue water (NRW) is water that has been produced and is “lost” before it reaches the customer. Losses can be real losses (through leaks, sometimes also referred to as physical losses) or apparent losses (for example through theft or metering inaccuracies).

High levels of NRW are detrimental to the financial viability of water utilities as well to the quality of water itself. NRW is typically measured as the volume of water “lost” as a share of net water produced. However, it is sometimes also ex-pressed as the volume of water “lost” per km of water distribution network per day.

NRW management often offers superior cost-effectiveness compared to supply augmentation. At the same time, revenues from saved water improve a service providers’ bottom line whilst lower water abstraction increases city resilience.