Calculation of losses in water distribution systemsEskişehir city example

Water is the most important element of human life. The water demand has been increasing day by day and resources to meet this demand are becoming limited, making it essential to reduce water loss. All water distribution systems have loss of water. The only difference in these systems is the amount of loss. Volume of water loss depends on the condition of the pipes, system pressures, type of soil, number of trained personnel, and equipment used to detect losses. In this study, Gündoğdu, Sazova, Şirintepe, and Ertuğrulgazi districts located within Eskişehir city center are chosen as pilot regions. Water loss rates in the municipal water network for these areas are determined using minimum night flow method. In this method, the data from Subscriber Information Management System (SIMS) and Geographic Information System (GIS) are first used to determine the pressure zones in the network and then the physical water loss is calculated from lowest daily night flow measured within SCADA. As a result of the study, monthly physical water loss rates in the pilot region Gündoğdu are calculated as 11.5% in 2011, 23.59% in 2019, for Sazova region, 3.9% in 2011 and 28.5% in 2019. For the areas of Şirintepe and Ertuğrulgazi in 2019, physical water loss rates are determined as 20.0% and 46.35% respectively. Afterwards, for Ertuğrulgazi network, where the physical water loss rates are high, the pressure is managed sensitive to flow for one week and later to critical point in the following week. When these two different strategies are compared to constant pressure management, a water savings of 3.84% and 9.36% is achieved for flow and critical point respectively. Extending the regions carried out in this study can guide ESKİ in determining: priority areas for physical water loss, correct maintenance investments and efficient pressure management strategies.