Estimating water audit inputs in cities without detailed water loss data

Intermittent water supply (IWS) systems are widespread across developing countries but remain difficult to manage due to limited data availability, particularly on water losses. Accurate water audits are essential to assess the feasibility of transitioning from IWS to continuous water supply (CWS), yet conventional methods require detailed data that small utilities rarely possess. This study presents a methodology for estimating key audit inputs which are System Input Volume (SIV), Revenue Water (RW), and Non-Revenue Water (NRW) by using only billing data and national datasets and understanding the possibility of potential transition with existing water resources. A case study is conducted in Tillo, Turkey, where statistical distribution analysis of water balance data from 58 cities is applied to generate probability distributions for NRW and SIV. Results indicate that Tillo’s SIV falls between 140 and 200 L/capita/day with 54% probability, and the probability of successful transition to CWS without additional water resources is approximately 61%. These findings demonstrate that robust estimates can be derived even in data-scarce environments, providing utilities with a low-cost decision-making tool for assessing transition feasibility.