A considerable amount of water is wasted by leakage from distribution systems, resulting in major economic losses. According to assessments, on average, 28 to 50% of the water produced in Iran is not accounted. The loss of water can be identified as an apparent or a real loss. With that said, the present case study of the Mahdis region focused on developing an integrated conceptual model for analyzing and managing the Unaccounted-For Water (UFW) in the Ahvaz urban water distribution network. Drawing on the capabilities of the WaterGems hydraulic analysis model, a network of 23 nodes, 27 pipes, and a reservoir was formed with the network characteristics taken into account comprehensively. Then, assuming no leakage, the network was analyzed, and the node pressures were obtained. The results revealed eleven suspected points of leakage in the interval. According to reports from the Ahvaz Water Organization, the nodes within this interval exhibit more leakage at night-when consumption is low and hydrostatic pressure is high- due to their greater altitude difference from the reservoir relative to the other nodes. The results are suggestive of the merits of the proposed method for predicting where leaks take place in water distribution systems. Furthermore, this study investigated the impact of pressure management on the minimum night flow, the results of the investigation are suggestive that the minimum night flow decreases by reducing the upstream network pressure. Reducing the upstream network pressure curtailed the night flow by 20-50% in the network. The inflow to the network was reduced by up to 25% by adjusting the network pressure. Considering the fact that the inflow to the network is a measure of daily consumption and leakage from the network, one can conclude that not only network pressure management reduces the leakage, but also it can limit the surplus consumption. This is particularly significant as regards water demand management. Ultimately, it is safe to say that this study demonstrates the great potential for reducing the leakage and consumption in water distribution networks.
