In the presented academic work I study the allocation of obligations between the Republic of Slovenia and the local communities for drinking water supply in the regions of Slovenska Istra, Kras and Brkini with Reka valley. Rižanski vodovod Koper, Kraški vodovod Sežana and Komunala Ilirska Bistrica are public companies that provide the water supply in the area of study. Their main water sources are Rižana, Brestovica and Bistrica. The regions are dealing with the problem of lack in water quantities, especially in the summer months. Because Rižanski vodovod Koper has to buy the missing quantities of water from the neighboring
water sistems, it faces the most critial problems with water supply. A problem of the sudied water sistems is also the provision of spare water sources, that represent one of the basis for quality water supplies. Many different studies were made, with the intent of sloving the water
problems, but none of them were realised. This time, I decided to look at the problem from a different point of view, a way that allocates obligations between the local community and the Republic of Slovenia. Based on the results of SWOT and GIS analysis, I can claim that the
best option for future water supply would be option C. In this case is the water supply manegement entirely under the responsibility of the Republic of Slovenia.