Intermittent Water Supply System Rehabilitation through a Multiphase Methodology Based on Network Analysis and Hydraulic Modeling

Intermittent water distribution systems supply over a billion people worldwide, a number expected to increase due to water scarcity, population growth, and urbanization. This study proposes a multiphase methodology for the definition of strategies (i.e., investments and controls) for the rehabilitation of complex intermittent systems over multiple-year periods. The multiphase methodology was developed in the context of the Battle of Intermittent Water Supply (BIWS) and is based on the use of EPANET 2.2 software for hydraulic modeling in combination with MATLAB version 2019a programming software. First, the hydraulic analysis of the deteriorated network is conducted to localize its main vulnerabilities. Second, multiple intervention strategies for network initial layout and subsequent rehabilitation (i.e., control modifications and investments) are identified considering different subsets of decision variables in turn. The effectiveness of each defined rehabilitation strategy is then quantified by means of a group of indicators reflecting the multiobjective nature of the problem. Finally, the best solution among all the defined rehabilitation strategies is identified and iteratively revised in order to further enhance its effectiveness on the deteriorated system. The application of the proposed rehabilitation method to the realistic and complex water distribution network considered as a case study in the BIWS—consisting of nearly 3,000 nodes—allowed obtaining an effective intervention solution for the reduction in the critical issues related to the system, ensuring 97% of users would be continuously supplied at the end of the rehabilitation period.