Loss Management Strategies of Drinking Water in Water Distribution Network of Isfahan City

The loss of drinking water from water distribution network is one of the problems of Water and Sewage Companies worldwide, which reduces a remarkable part of the company's profit. Therefore, the aims of this research are: determination of strategies and their evaluating criteria for the loss management in water distribution network, prioritization of those strategies and criteria as well as selection of the most effective strategy. This study is a practical research and data gathering was performed via researcher-made questionnaires on snowball sampling based on the idea of 10 experts employed in Water and Sewage Company of Isfahan province. Four strategies of water loss management of water distribution network assessed in questionnaires were selected based on the recommendations of International Water Association, American Water Works Association and the regulations of the non-revenue water committee by the deputy directorate and under supervision of the Water and Wastewater Company of Iran, 2020. Data gathering and analyzing were carried out using paired comparison matrix and analytic hierarchy process by the Expert-choice software. The calculated inconsistency ratio of questionnaires was determined to be 0.02, and therefore the most effective strategy of water loss management of Isfahan water distribution network was determined to be the pressure drop strategy with weight of 0.400. Three other strategies of active leak detection weight 0.259, network repair weight 0.175, and speed and quality of emergencies weight 0.167, were prioritized in the next ranks, respectively. Likewise, the criteria of financial supply weight 0.463 in the first rank, the criteria of technical supply weight 0.289 in the second rank, the criteria of training update weight 0.146 in the third rank, and the criteria of legal supply weight 0.102 in the fourth rank, were prioritized. By increasing the ratio of circular intubation in water distribution network and construction of water storage tanks in the northwestern heights of Isfahan, it is practical to develop the pressure drop strategy in flat districts of Isfahan city leading to the minimum water loss of Isfahan distribution network.