Multiobjective design of water distribution networks through the generation of pseudofronts in the hydraulically feasible region

The design of a WDN is conceptually a multi-objective problem characterized by stringent constraints. Even in its most simple formulation, which requires only the maintenance of minimum pressures, is difficult to handle, and the simplifications introduced often impair the practicality of the solutions found. The paper aims at integrating an engineering approach to the optimization problem by generating pseudo-fronts in the hydraulically feasible region of the search space. The optimization algorithms provides a strictly feasible trade-off between cost and considered constraints, which may be directly used by a hypothetical decision maker. This engineering approach requires a fast tool in the search of feasible solutions: the recently developed algorithm GHEST (Genetic Heritage by Stochastic Evolution Transmission) used herein, has proven to be effective and efficient in solving the optimal design problem of WDNs. Tests are carried out on two real size water distribution networks (Balerma and Modena), using the GHEST algorithm, here modified in order to account for several objectives.