The issue of (un)uniformity in reducing losses in water supply systems

The paper presents an analysis of water losses from 42 waterworks in the Republic of Serbia using the ILI indicator and expressing losses as a percentage of input system volume. The analysis was performed using available data, with missing data being adopted by assessing operating conditions. The analysis clearly indicated the advantages of using the ILI indicator, which takes into account the local specificities of the configuration and operation of the waterworks system. Paper points out the risk of using data on water losses expressed as a percentage of system input volume, and in particular of arbitrarily prescribing a target percentage of water losses, without analyzing the state and characteristics of a specific waterworks system, as this approach can lead to setting unrealistic and unachievable goals. A preliminary methodological framework for defining targeted water losses in Serbia is presented as well as the need for further research and improvement of the reliability of data on distribution water systems in order to increase the reliability of water loss estimates and realistically set water loss reduction goals.