Cost benefit analysis of different pressure regulating valves in drinking water systems

Leakages occurring in drinking water distribution networks for various reasons cause severe economic costs for water canal administrations. When the studies in the literature are examined, it is seen that various methods, such as pressure management, active leakage control, and pipe material management, are applied to eliminate the leaks in the network. Water canal administrations obtain different financial benefits from applying these methods in an actual field. In addition to the benefits obtained, implementing these methods in the network brings costs, such as providing the equipment required for the selected method, isolating the region, and providing remote monitoring and operation systems. For this reason, benefit and cost analyses should be conducted before conducting the necessary water loss management studies. In this study, pressure management was applied in 4 different isolated sub-regions within the scope of water loss management. The isolated sub-regions under pressure management were selected from the networks operated by the Kayseri Water and Canal Administration (KASKİ) with different pressure regulation methods. The financial benefits of pressure regulation were theoretically calculated using algorithms. The algorithm's accuracy was tested by comparing the accuracy of the theoretical calculations with the actual field application results. After analyzing the accuracy of the theoretical calculation, the costs were also calculated, and the return period of the investment was calculated by making a benefit and cost analysis. As a result of the analyses, it was found that the flow regulated method, among the different pressure regulation methods, offers the most significant benefits in reducing leakage, followed by the time regulated and constant output methods. When the cost analysis of the implementation of the methods in the field was made, it was seen that the most economical methods were fixed outlet, timed and flow regulated methods, respectively. Calculating the return period of the investment by making benefit and cost analysis, it is concluded that although the flow-regulated pressure control method is the most expensive method, it is the method that pays off its cost in the shortest time, and although the constant output pressure control method is the most economical method, it is the method that amortizes its cost in the longest time. It is anticipated that the algorithm developed within the framework of this thesis will serve as a robust decision-making tool. It will aid in determining whether to implement pressure management in the isolated region and which pressure regulation method should be adopted in the network if pressure management is to be implemented.