Rehabilitation of water distribution systems for water loss reduction and cost-benefit analysis

It is important to identify, reduce, prevent and control the water losses for sustainable urban water management and efficient use of resources in potable water distribution systems. In order to determine the method to be applied in the management of water loss and the way to be followed, an economic analysis is required. In this study, the reduction of water losses in water distribution systems, the removal of duplicate old pipes, the definition of district metered area (DMA) in existing network conditions, the definition of the DMA with the rehabilitation of pipes and fittings and the comparative economic analysis for each approach were aimed. For this purpose, the water distribution system of the central city of Malatya was chosen as the application area. In order to better manage the system in the application area, two different DMAs have been designed and implemented, maintaining the existing network conditions and completely rehabilitation the network pipelines. In these two DMAs design, first the water loss analysis was performed and the improvement in the performance of the system was observed. Then the initial investment and operating costs were calculated and the investment amortization period was determined in the selected pilot regions in the DMAs designed in two different ways. It was observed that in areas where the network pipe is not replaced, the initial investment cost is low, but the application of leakage detection and prevention methods improves network performance. On the other side, it was seen that the water loss rates of the DMAs, which are formed by changing the network pipes in the areas where there is a lot of old pipe density, are 10-15%. As a result of the study, it can be said that the ÖABs provide significant contributions to the urban water management and the network renewal in the areas with the old pipe ratio considerably reduces the operating cost and water loss rate and is very useful in terms of water management in the long term. KEYWORDS: District metered area, water losses, urban water management, and cost-benefit analysis