New concepts and tools for pipe network design

Water Distribution Network design has been traditionally approached as a cost minimization problem, constrained by some additional restrictions intended to ensure an acceptable level of customer service. Although the ideas have existed for same time, it was only recently that various researchers developed new network optimization approaches trying to address the minimization of design costs, while maximizing the benefits through some other performance indicators assessment in a risk-based scenario. Unfortunately, network simulation is still performed within a demand-driven context, even when reliability is considered among the benefits, and leakages are given as a constant percentage of nodal demands instead of being computed as a function of pipe pressure. This article introduces a more realistic approach to network design and simulation, performed using pressure-driven leakages employing a recently developed simulation model. Thus, the design procedure is conceived as multi-objective optimization, performed considering the minimization of pipe cost and together with total network leakage flow. The approach was tested on a small-size Italian real network which supplies an industrial area, and on a simpler network that yielded some interesting observations about the proposed paradigm