Gradual transition from intermittent to continuous water supply

ABSTRACT This study presents a comprehensive methodology for the gradual transition from intermittent water supply (IWS) to continuous water supply (CWS), aligning with the recommendations of the WDSA CCWI (2022) conference's battle of intermittent water supply (BIWS). The approach comprises three key stages. First, the existing network is thoroughly assessed to identify causes of performance degradation and highlight vulnerable areas. Second, the network is partitioned into sectors using the modularity index (via Gephi) and the closed pipes and valves layout, enabling more targeted interventions. Third, the main infrastructure upgrades are implemented, with pipe diameters optimised using non-dominated sorting genetic algorithm II to maximise reservoir withdrawal and minimise costs. The rehabilitation aims to improve water inflow, reduce leakage, and minimise head loss, all within financial and resource constraints. Although energy consumption increases due to reactivating a dormant pump station (the performance indicator for total pump energy consumption, I8 = 5,276 MWh over 5 years), the benefits in service delivery are substantial. Key performance indicators show a significant reduction in leakage (I3 from 0.502 to 0.256), increased water supply (I4 from 0.853 to 0.965), and improved supply equity (I9 from 0.823 to 0.954), demonstrating the method's effectiveness in enhancing both efficiency and customer service.