摘要：The analysis of water losses should precede the decisions on repairing or modernizing a water network. Water balance and water losses indicators established by the International Water Association (IWA) standards can constitute the basis for the analysis. The methods recommended by IWA are gaining increasing popularity in many countries, including Poland. The aim of the paper is the analysis and comparison of water losses in two middle-sized water distribution systems during the period of 10 years. The compared networks are similar in respect to many parameters, including water intensity indicator value (circa 48 m 3 /d/km). Analyses were conducted on the basis of water losses indices recommended by IWA, such as Real Losses Level per connection per day ( RLL ), Non-Revenue Water Level ( NRWL ) and Infrastructure Leakage Index ( ILI ). The results indicated that water losses in both systems are lower than in the literature data for other similar networks.
