Evaluating the Hidden Costs in Low-Pressure Water Distribution Networks

Abstract

Water pressure management in the Metropolitan Waterworks Authority (MWA) water distribution networks has long been a persistent issue. Consumers often encounter low water pressure at certain times, necessitating the installation of water pumps and storage tanks at their own expense. This situation not only increases electricity costs and hidden expenses but also shifts the financial burden onto consumers. Moreover, it can adversely affect the overall quality of the water supply. By integrating geographic information system (GIS) data from multiple agencies, the study analysis of the hidden costs associated with users' installation of pumping systems revealed that the total electricity cost amounts to approximately 2.32 million baht per year, while the combined cost of installing the pumping system, water storage tanks, and maintenance reaches as high as 43.95 million baht. In contrast, if MWA installs a booster pump at the entrance of the service area to maintain an adequate average water pressure, the annual cost is 1.80 million Baht, which is significantly lower than individual household pump installations. A cost-effectiveness analysis further showed that if MWA invests in the booster pump, a benefit-cost ratio of 13.29, while the net present value (NPV) would stand at 66.04 million Baht, without imposing additional electricity costs on consumers. These findings highlight the economic viability of reducing energy costs, addressing low-pressure problems, and improving water quality. Nonetheless, booster pumps address only the symptoms of the underlying issue. Upgrading the water distribution networks and increasing baseline water pressure represent more sustainable long-term strategies to accommodate growing demand.