A Case Study of an Intermittent Water Supply Network in Lahan, Nepal

<p dir="ltr">There is currently scant evidence on the withdrawal behaviours of households under IWS conditions and how they interact with the distribution of water around the network. This study aimed to fill that gap, investigating the influence of supply conditions and household characteristics on water withdrawal behaviour in an IWS network. In partnership with The Beacon Project, the IWS network of Lahan, Nepal was monitored in greater detail than any previous study on IWS. A series of 56 household volumetric flow meters were installed coupled with a household survey and pressure sensors distributed across the network. Together they form a first-of-its-kind dataset revealing the dynamics of an IWS network. The data revealed ‘pooling’ phenomena where by water drains down the network and sits at the lowest elevations, leading to a portion of Lahan receiving continuous water supply. Households employed a range of adaptations that were influenced by both their wealth and local supply conditions. Highly variable withdrawal behaviours were observed; the specific withdrawal signature of a household was strongly associated with their volume of storage. Current simplifications utilised by modellers do not accurately reflect this highly heterogeneous and coupled behaviour. The quantity of water that households withdraw was not found to correlate with their local supply hours suggesting a more complex relationship between household water demand and IWS conditions. Analysis of the Lahan case study led to the development of a new framework that describes the relationships and processes that govern water access under IWS supply.</p><p dir="ltr">This paper was presented at the 21st Computing and Control in the Water Industry Conference (CCWI 2025) at the University of Sheffield (1st - 3rd September 2025).</p>