Multiobjective Optimization of Control Valve Installation and DMA Creation for Reducing Leakage in Water Distribution Networks

This paper presents a novel methodology for optimizing simultaneously the installation of control valves and the creation of district metered areas (DMAs) in water distribution networks (WDNs). This methodology was developed through the multiobjective approach, by considering, as decisional variables, the sites for control valve installation and isolation valve closure. The proposed algorithm is based on the hybrid combination of three algorithms, a multiobjective genetic algorithm, which is entrusted with valve site search, and two embedded algorithms, the first based on iterated linear programming (LP) and the second based on graph theory, aimed at searching for the optimal settings of control valves and at partitioning the WDN into DMAs, respectively. The hybrid algorithm attempts to find optimal solutions in the trade-off between the following objective functions to be optimized simultaneously: total installation cost, daily leakage volume, and demand uniformity across DMAs. The applications to a small Lebanese WDN proved that the methodology can find, especially for high values of the total installation cost, effective control valve installations, and isolation valve closures in terms of leakage abatement while obtaining a uniform distribution of demands across DMAs.