Border mountain area of eastern Serbia has a distinct potential and importance in the function of surface water sources, which are characterized by range of geographical and environmental characteristics and similarities determined by mountainous character of the territory. For the purposes of this paper, border area of Serbia towards Bulgaria is provisionally determined by iso-border of 25 km. On the defined area of eastern Serbia there are 11 individual territories allocated in the function of being surface water source. Key objects for the realization of the goals of rational and functional exploitation of surface water sources are accumulations. They are the link between the system of surface water sources and water supply system.