Hydrogeology of the Hinterland of Sibenik and Trogir, Croatia

Abstract

Intense karstification of carbonate rocks in the study area is the reason why the surface streams disappear and why sea water penetrates deeply into the coastal area. Locally occurring impermeable rocks have the function either of true or of hanging hydrogeological barriers. It has been discovered that the hanging barriers produce complex hydrogeological conditions, especially near major karst springs. The consequences of insufficient knowledge of these conditions are the reason why only a part of the existing drinking water resources are used nowadays (despite heavy demand) in such areas, and why the protected areas are disproportionally large if compared with the use of drinking water. Groundwater tracing, performed recently, considerably revised earlier opinions on the catchment areas of the most important springs of the area: the Jaruga, Torak and Pantan springs. These springs drain an area in excess of 1000 km2. The discharge of these springs can be increased by constructing several surface reservoirs and by a controlled recharge of the karst underground with that water. Field conditions are not suitable for underground water storage.