Phased Methodology for the Optimal Rehabilitation of a Network with an Intermittent Water Supply Based on Hydraulic Criteria

Abstract

The intermittent supply of drinking water represents a major technical and social challenge, affecting more than 1 billion people worldwide. This paper proposes a methodology with three stages to rehabilitate a deteriorated system with intermittent service in a time horizon of five years as part of the Battle of Intermittent Water Supply problem. First, the initial assessment stage identifies vulnerable areas and critical supply hours. The network is analyzed to establish whether it is possible to deliver the desired demand in a scenario without any leaks. The latter is to set a baseline scenario for the upcoming stages. The sectorization stage defines the optimal district metered areas to reduce water losses and increase supplied water through the improved control of flows and pressure. This stage is divided into clustering, by means of the Girvan–Newman algorithm, and partitioning by defining the location of valves. Finally, the third stage determines the optimum investments for asset rehabilitation. The optimization process is performed individually and sequentially for valve settings, pump replacements, storage tanks upgrade, pipe rehabilitation, leakage repair, frequency inverter installation and pumping operation modification, and simple controls. The final solution validates how hydraulic criteria, in combination with optimization techniques and engineering judgment, can significantly improve the operation of an intermittent water distribution system.