ABSTRACT
The paper deals with complex hydrogeological conditions of a large karst polje, the Vrgoračko Polje, situated in Croatia, in the classical karst of the Dinarides. This polje is the lowest “hydrogeological cascade” to which groundwater flows from hypsometrically higher karst poljes: the Livanjsko, Duvanjsko, Imotsko and Rastok Poljes. The area under study is extremely rich in good-quality spring water of which only a very small part has been used for public water supply.
By pouring tracers into ponors, whose underground flow paths pass relatively close to each other, the existence of separate catchment areas of three major karst springs - Klokun, Modro Oko and (on the Adriatic Sea coast) Žrnovica - has been determined.
