Water loss management in Europe: perceptions, drivers, responses/strategies, and results

“Despite global efforts to reduce non-revenue water (NRW), average levels remain at 30% worldwide and 25% in European countries. This paper investigates whether these persistent water losses stem primarily from uncontrollable environmental factors or from management practices. Through two rounds of questionnaires with water utilities across multiple countries and exploratory data analysis of data on 120 utilities, the research examines geographical conditions, utility characteristics, and water loss reduction strategies. Findings reveal that geographical conditions significantly impact Infrastructure Leakage Index (ILI) levels across Europe, suggesting that these factors should be considered when setting reduction targets. Also, a clear progression exists from low-resource measures implemented by high-ILI utilities to sophisticated technologies adopted by low-ILI utilities. While underinvestment likely contributes to high water losses, limited network investment data prevented a comprehensive analysis. The study recommends that the EU drinking water directive should account for utility size, establish measurement standards, encourage partnerships between large and small utilities, and include smaller utilities in reporting requirements. Additionally, incorporating economic metrics and investment data for pipe rehabilitation and digital technologies would enhance understanding of effective water loss reduction strategies. Comprehensive, standardized data collection could catalyze innovations to reduce ‘unavoidable’ losses and significantly decrease overall water losses across Europe.”

(Citation: Peter van Thienen, David Bernhard Steffelbauer, Ina Vertommen – Water loss management in Europe: perceptions, drivers, responses/strategies, and results – Water Practice and Technology 1 September 2025; 20 (9): 1921–1938. doi: https://doi.org/10.2166/wpt.2025.113 – (Open Access))