Free Korana River Project: Mapping river barriers to preserve biodiversity
The NGOs Zelena akcija and Eko Pan, in cooperation with the company BIOTA d.o.o., implemented the Free Korana River Project from February 2024 to January 2025. The project objective was to identify artificial barriers in the Korana River and define those with the strongest negative impact on biodiversity, with a focus on the possibilities for their removal or adjustment.
Research results and key findings
The final conference held on 24 January 2025 at the Nikola Tesla Experience Centre in Karlovac brought together the project leaders and representatives of the Institute for Environmental and Nature Protection, Hrvatske vode, public institution NATURA VIVA, the WWF, and the representatives of the local community, presenting research results and plans for the initiative to continue. The field work covered around a hundred sites with as many as 74 artificial barriers identified along the Korana River - on average one per each two kilometres of the river course. These are mostly old, neglected dams of former mills, but also more recent structures built for recreation purposes.
Although not high on average, these barriers significantly hinder the migration of fish and other aquatic organisms, particularly since the majority of fish species in the Korana are not fast swimmers or jumpers. The key parameters of each barrier were analysed under the project, including:
✅ Impact on fish migration
✅ Ecological importance of the site
✅ Views of the local community
This data was used for the definition of priorities for the future removal or adjustment of river barriers, taking administrative barriers into account as well.
Legal analysis and challenges
Parallel with the research, a legal analysis of the procedures required for the removal of river barriers in Croatia was made. It was established that there are at present no clearly defined administrative steps in place, which points to the need to develop a legal framework that will facilitate the restoration of river ecosystems.
The Free Korana River Project is part of a wider initiative focused on improving the ecological status of rivers. The Improve River Life Project, implemented on the Vrljika and Jadro Rivers, was also presented at the conference, with particular emphasis on the development of a national database of river barriers and a new management policy for freshwater ecosystems. Both projects share the same goal – contribution to global, European and national efforts in the preservation of rivers. Europe is now recognized as a continent with the largest number of river barriers – on average one per each kilometre. The objective of European legislation is to make as much as 25,000 km of rivers free-flowing again by 2030. The data collected through activities on the Korana River may serve as a model for similar initiatives in the region, and cooperation between these projects may contribute to the development of better strategies and legal solutions for the preservation of rivers.
The Free Korana River Project is financed by the European Open Rivers Programme, with support of the Arcadia Fund.