Non revenue water (NRW) is ...

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 expressed as the volume of water “lost” per km of water distribution network per day.

UFW =NET PRODUCTION - LEGITIMATE CONSUMPTION

NRW =NET PRODUCTION - REVENUE WATER

    = UFW  + WATER WHICH ACCOUNTED FOR, BUT NO REVENUE  IS COLLECTED (UNBILLED  AUTHERIZED CONSUMPTION)