The production of water in a drinking water supply system (WSS) comprises all drinking water enter in the net, while the consumption of water generally comprises all billed amounts of water in a WSS. The production and consumption of water in a drinking WSS depend on different factors. Consumption rates depend on the consumer structure and habits, industrial demand, time of year, water pricing, climatic variables, secondary water losses and many other factors. One of the interesting factors is air temperature. It is especially important in the frame of climate change and global warming. Temperature impact on water consumption in a WSS is not uniform temporally (particularly throughout the year) and spatially (different climate regions and countries, different habits and different conditions in each WSS). Obtained correlations for the two biggest cities in Serbia (Belgrade and Niš) are presented in the paper and compared with some examples worldwide.

In the context of this paper, the term “price of water” refers to the charges for drinking water supply and sewage services. The current price of water in Serbia is generally set at an affordable level and does not reflect the real costs. It varies from approximately 0.4 €/m³ in smaller settlements of less developed regions of the country, to approximately 1.0 €/m³ in some cities of more developed regions. Lower prices in some cases are the result of fact that these settlements do not provide sewage services (SS). The average price of water in the country is currently about 0.7 €/m³. This paper presents the current and economic price of water in Serbia, and its structure, from a sample of 34 public utility companies (PUC), which perform water supply (WSS) and sewerage services (SS).

Non-revenue water (NRW) can be expressed using different parameters (indices) in certain water supply systems (WSSs). The most used are percentages (as a share of NRW in system input water) and the infrastructure leakage index (ILI) based on the IWA methodology. The technical indicator of real losses (TIRLs) is also an index used for the estimation of certain WSS efficiency. Both real and apparent losses are significant in many WSSs in the Balkan region. Thirty-seven WSSs in Serbia and Montenegro, which differ in many aspects, were analyzed. After presenting the methodology and discussing the results, a conclusion is drawn, as well as general guidelines regarding the approach for the reduction of NRW for this region.