Assessing Equity and Demand Satisfaction of an Intermittent Water Supply Using a Non-Iterative Implementation of EPANET 2.2: A Case Study of Itanagar Water Distribution Network

Intermittent Water Supply (IWS) is a water supply system in a developing country where water is supplied intermittently for a limited duration. Factors responsible for IWS are water resource scarcity, inadequate facilities, unaccountable water losses, etc. The IWS systems, however, frequently result in variable pressure levels, water quality issues, and potential customer dissatisfaction. Furthermore, a crucial feature of the Water Distribution Network (WDN) is that it provides adequate water to consumers to meet the required demand with satisfactory performance. Thus, in this study, consumer satisfaction is assessed through demand satisfaction and the level of equity for the WDN of Itanagar (Arunachal Pradesh). This study is unique of its kind for Itanagar WDN, as no study of this kind has been undertaken on this network. This study also compares different equity formulae available in the literature. Moreover, EPANET version 2.2 was used to simulate the Itanagar WDN. The results highlight that the water supply depends on the availability of water at the Itanagar WDN source. Furthermore, it is also found that the pressure varies significantly at nodes. Consumer dissatisfaction is high due to insufficient access to drinking water in Itanagar town under IWS. A huge discrepancy in the supply-demand ratio was observed in the Itanagar WDN, where more than half of the demand nodes are facing a shortage of supply against their demand. As such, some consumers are getting more than their required share of water, and others are not getting the required demand or supply to sustain their livelihood. Consequently, the equity value is found to be approximately 0.5 under full supply conditions, as against its ideal value of 1. This signifies that there is insufficient access to drinking water in Itanagar for a supply duration of 4 hours.