A BASIC DECISION SUPPORT SYSTEM FOR IMPROVING SERVICE LEVEL IN INTERMITTENT WATER DISTRIBUTION SYSTEMS

An efficient management policy of water distribution networks should be based on the monitoring of both network conditions and operation hydraulic parameters, as well as on records of maintenance and rehabilitation works done over the years. Network areas with rehabilitation priority are the oldest system characterized by higher frequency of breaks and water losses. One of the main problems connected with these areas is certainly the optimization of their management. A possible approach to this management problem, is a multi-objectives optimization procedure based on the genetic algorithm NSGA-II, pragmatically aimed at determining the best intervention options on the base of concise performance indices and representing a basic Decision Support System (DSS). In situations characterized by limited water resources and an high level of leakage, intermittent distribution is commonly used to reduce water losses and to try to equally divide resources among users. Such practice has a negative impact on service levels and alternative solutions should be preferred. In the present paper a numerical model was coupled with the DSS for analysing the service levels during the filling process and the subsequent steady state operational conditions of intermittent distribution operated in water shortage conditions. The model was applied to a real network in Palermo (Italy). The equilibrium between the reduction of the inequities and the maintenance costs was investigated.