International Report: Performance assessment in the water industry

National contributions from 16 countries and additional information were used for an international state-of-the-art report on performance assessment (PA) in the water industry. The purposes of this international report are i) to discuss areas of PA within the water supply and wastewater sector, ii) to analyse aspects of practical relevance and iii) to look on future trends and developments. Several aspects of PA are discussed, such as the quality and the availability of data, the importance of definitions and explanatory factors, the use of information from PA, and practical aspects such as willingness to participate and costs. Standardised PA frameworks of the International Water Association (IWA), the World Bank, and the Water Utility Partnership are presented, and an outlook on research and development of PA tools is given.