Abstract
Intermittent water supply (IWS) systems serve millions of people around the world. In many IWS systems, water supply through the piped network is rationed among sub-zones in the network following different scheduling schemes. When defining supply zones and developing their supply scheduling, utilities often aim to maximize users' demand satisfaction while minimizing operating costs, with little attention given to the issue of water loss due to leakages. In this paper, we study the relationship of network zoning (and supply scheduling) with water losses through leakages in the network. A hydraulic model is developed to simulate the performance of IWS networks with the consideration of network leakages. The model is used to explore different variations of network zoning and/or supply scheduling for zones, subject to the operational feasibility of zones' isolation valves. The model is demonstrated in a real network of a city in the Middle East. The results of the study show how changing network zones and/or their supply scheduling affects leakage rates, demand satisfaction, and supply efficiency. It was found that changing the supply schedule could save up to 22% of the leaked water while maintaining the same level of household demand satisfaction. The developed model can assist water utilities in reducing the nonrevenue water due to leakages resulting in improved financial efficiency.