One of the major challenges facing water utilities is the high level of water loss in distribution networks. If a large proportion of water that is supplied is lost, meeting consumer demands is much more difficult. Since this water yields no revenue, heavy losses also make it harder to keep water tariffs at a reasonable and affordable level. This situation is common in many Asian cities. Non-Revenue Water (NRW) defined as the difference between the amount of water put into the distribution system and the amount of water billed to consumers averages 35% in the region's cities and can reach much higher levels.