Maximising efficient water capacity through reservoir configuration with a case study for Malang City of Indonesia

All forms of water supply systems had unique characteristics of idle capacity. However, achieving a sustainable water supply over the long term could not eliminate idle capacity. This paper discussed methods for providing efficient capacity without compromising long-term water requirements. The objective of efficient capacity was to reduce idle water capacity and water-carrying infrastructure. This study method reviews previous research results with an in-depth case of a piped water supply system in an urban area. The assessment method referred to the pattern of water demand by consumers. Fluctuations in water demand determined the dimensions of all water supply system components. The results of this study showed that water distribution determines the minimum idle capacity, which directs the need for priority areas for efficient capacity and opens reservoir placement options. Under these priority areas, a decentralised reservoir position resulted in an efficient system dimension. The closer the reservoir was to the consumer, the smaller the idle capacity, which was the contribution of the onsite reservoir. The critical implementation was based on the flexibility of the phasing of water supply and infrastructure. The flexibility addressed the use of flow rates for a certain period, diversification of water sources, and system configuration that determines the dimensions of the infrastructure and maximising utilisation.