Generally speaking, we believe that an evaluation and improvement of a water supply network must be carried out by following the following steps. First evaluation of the network. Water balance. Collection of network data. Selection and application of performance indicators. Construction of the mathematical model of the network. First quantitative assessments. Application of optimization models. Work with scenarios. Identification of network criticalities. Decisions on where and how to take action to improve the good. For points 1 to 3, the methodology has already been developed in scientific literature and in professional practice, starting from the “ancient” book of Coelho and the procedures that IWA develops and updates frequently. These procedures are already applied in professional practice by the engineering companies that work in the sector and are updated to the state of the art. The course will explain the already established methodologies, to show the results carried out by the research group at Politecnico di Milano (and applied in real cases) related to optimization, search of the leakages and sectorization, in order to develop a procedure which goes beyond the simple models so far available. The procedures will be applied to case studies.