Croatian environmental regulations regarding hydrotechnical projects

Since 1984, the obligation has been casted by the Croatian regulations to prepare an Environmental Study for particular projects, including the hydrotechnical. The article presents the basic concepts of the Study development, acceptance and results application. The Kosinj Reservoir has been used as an example, with total capacity of 561×10 6 m3 and the surface area of 16×10 6 m2. The major negative and positive effects of this structure on environment have been described, as well as the measures to be undertaken prior to construction and during exploitation of the reservoir in order to mitigate eliminate the negative and achieve the planned positive effects.