Determination of Economic Level of Leakage in Water Distribution Networks

One of the main responsibilities of water and wastewater companies in the field of operating of water distribution networks (WDNs) is the management and control of leakage from these networks. In this regard, active leakage control (ALC) is one of the main strategies in reducing leakage and achieving economic level of leakage (ELL). In this paper, a practical methodology was developed to determine the ELL which is included the steps determining the points of pressure and flow rate measurements, collecting of required field data and cost data, the estimation of leakage level in the network and the determination of the ELL of the network based on the ALC strategy. Economic performance indicators such as the economic leakage index (ELI) and the economic network efficiency (ENE) are also obtained using the determined ELL. The developed methodology was applied for a district of the WDN of Mashhad. The results showed that the ELL in the study area is 27.5 m3/connection/year. While the current level of leakage was estimated to be around 49.2 m3/connection/year, based on the minimum night flow (MNF) analysis. Moreover, the ELI and ENE were calculated 1.79 and 56% respectively. The developed methodology in this paper can assist practitioners and managers of water and wastewater companies for target-setting of the level of leakage and determining of the ELL based on it.