The existence of safe and abundant raw water sources is a priceless treasure for any country. Water resources are of particular importance for Montenegro, especially for the development of tourism and agriculture which represent the backbone of its economic development. With respect to water potential, Montenegro is at the top of Europe. However, it is not a sufficient factor, but the very way it is used and protected, as well as the improvement of its valorization. Economic development which is not based on the conservation and good governance of natural resources may have negative consequences for the overall development. The aim of the paper is the study of natural properties of karst ground waters and their changes through interrelation of some ions, as indicators, on the example of five intakes in use. The paper presents the results of the research on the said waters and the values of indicators which point to their exceptional benefits for the water supply. However, the effects of the anthropogenic factor are evident, which are reflected in the range of the mole ratio of Ca /Mg ions ranging from 5.4 to 9.6, and the values (eqv.SO4/Cl) ranging from 0.3 to 2.0. Protection of the environment, especially preservation of the quality of water resources of Montenegro, imposes the urgency of implementation of the objectives of the Water Framework Directive.