Defining the level of the Non-Revenue Water in Kozani, Greece: is it a typical case?

Abstract

Water Losses in pipe networks usually represent the biggest "water use" due to the high leakage occurring. Water utilities are forced to apply effective Non-Revenue Water (NRW) reduction strategies, as climate change conditions put an enormous stress on the water resources reserves. WATERLOSS project attempts to assist towards NRW reduction through developing a decision support system (DSS) that will provide water utility managers with a prioritized list of NRW management/reduction measures. Kozani city water distribution network was one of the pilot cases where the integrated methodology developed within WATERLOSS was applied to. The results revealed that although the specific network experiences high NRW values, the local water utility has not implemented any integrated NRW reduction strategy so far. The reason for that could be the use of the fixed charge in the water bills, rising up to 70% of the NRW when expressed in equivalent water volume. Similar studies in Greece and the results of WATERLOSS project verified that water utilities' common practice involve the fixed charge in water bills as a means to keep costs and revenues balanced. The fixed charge should represent the opportunity cost consumers have to pay for water services in a socially fair billing practice.