Investigation of water losses in drinking water distribution systems by integrated use of hydraulic modelling and pressure management

Water losses in water distribution network is the difference between the amount of water supplied to the network and the amount billed to the water. Water losses are examined in two parts; the physical (real) losses and the apparent (commercial) losses. Water losses are inevitable in water distribution networks. Especially, in developing countries, such as Turkey, water losses are approximately 50 %. As mostly stated in the related literature, countries follow programs to reduce water losses up to 10-15% levels. It is often not economical to reduce water losses below this level. Different applications are carried out to reduce water losses all over the world. One of these applications is pressure control management. Pressure control management is the process of preventing unnecessary high operation pressures in water distribution networks to reduce high water losses in the network. However, it is usually difficult to decide about the level of pressure reduction and the pressure control method. After the application of pressure reduction method, it is important to predict how much water losses reduction is to be achieved. This thesis study was carried out in eighteen different District Metered Areas (DMA) located in the study area of Konyaaltı region in Antalya City. Hydraulic model was established separately for each DMA. Model input data were obtained from the ASAT-GIS database and SCADA stations that were installed at the entrance of each DMA in the pilot area. The established hydraulic model was calibrated and verified. Spatial and temporal changes of pressure levels were studied for each DMA by the verified hydraulic model. Using the hydraulic model, suitable pressure levels were tested for each DMA and their effects were investigated. If the pressure levels were decided to be reduced, hydraulic model was used to choose type of pressure release valve (PRV) and the pressure level to be adjusted to PRV. According to the results of the hydraulic model studies, applied for 18 different DMAs of Konyaaltı region water distribution network, 10 DMAs were identified to have high pressure and pressure management was recommended for these DMAs. Water loss model was established for 8 DMAs with high minimum night flow rate and where pressure management was recommended. By integration of hydraulic and water loss model, total water saving is computed approximately as 45 m3/h if conventional fixed outlet PRVs are installed for the selected 8 DMAsEPANET water quality and hydraulic model has been used in this application which has been used widely all over the world and it has many verified applications. The main advantage of EPANET model is the easy integration with GIS and SCADA data. In addition, EPANET can be used to estimate reduction of water losses by integrated use of the hydraulic model.