Effectiveness of water loss performance indicators for asset management

Introduction Water loss management in hydraulic infrastructures is a major concern for utilities worldwide since leakages undermine their economic, environmental and energy sustainability. Long-term investment plans for reducing leakage levels are often cost-intensive and always target a specific water loss performance indicator (WLPI). The choice of a proper and effective WLPI is thus a relevant issue because of its direct impact on the quality of public expenditure.Objective This work compares and discusses the most used WLPIs: the density (otherwise named “linear”) and percentage WLPIs; the infrastructure leakage index (ILI) and the recently proposed WLPI, asset management support indicator (AMSI).Methodology Analysis and discussion of the WLPIs are based on their mathematical formulation and application to a real case study.Results This paper confirms that the percentage WLPI indicator is unfit for directing investments and demonstrates its illogical and contradictory outcomes for common hydraulic schemes, with the risk of impairing leakage management plans, unlike the density WLPI which can be properly applied for this purpose. However, the most effective indicator, also with respect to ILI, appears to be the recently proposed AMSI, which is physically based and results to be consistent with data management in the digital transformation framework.