Optimal Design of District Metering Areas

The search for optimal segmentations aimed at defining district metering areas (DMAs) is a challenging and crucial issue in the analysis, planning and management of water distribution networks (WDNs). The need to select optimal segmentations relates to a number of important technical reasons. Today, the most relevant one is the leakage management by means of pressure-control zones. This contribution proposes a novel two-steps strategy for DMAs planning. The strategy is based on the segmentation design as first step, to achieve a scenario of optimal locations of conceptual cuts; during the second step, these are the candidate for the location of (closed) gate valves or flow measurement devices that gave rise to district monitoring areas (DMAs). The segmentation step is performed solving a multi-objective optimization problem (i.e. WDN-oriented modularity maximization versus the number of conceptual cuts minimization). The second step accomplishes the real DMAs design by solving a three-objective optimization, i.e. the minimization of the background leakages versus the unsupplied customers demand versus the flow observations. This means that the procedure will search for a set of scenarios having a number of closed gate valves installed at the conceptual cuts that do not decrease the WDN hydraulic capacity below that necessary for a sufficient service to customers, while contemporarily reducing the background leakages. A pressure-driven modelling approach is used to predict background leakage reduction and the unsupplied customers demand. The procedure is explained on a benchmark network from literature, the Apulian network.