Legal status obtained for conservation of Croatia’s Mrežnica and Tounjčica Rivers

In early March, Croatia’s Karlovac County Assembly officially confirmed the protection of the Mrežnica and Tounjčica rivers and the establishment of two new protected areas. The two rivers are among the last free flowing rivers in Europe, and there is a growing number of stakeholders who have worked together to achieve its protection.

The decision was reached following an initiative led by the Public Institution for Nature Protection, Natura Viva, and supported by the Karlovac County and The Nature Conservancy (TNC). According to Martina Furdek Hajdin, the Mayor of Karlovac County, the river is an important recreational area with tourism potential, but there has also been a lot of construction along the river in recent years, and there was a need to protect the river by setting rules for infrastructure development.

According to Irma Popovic Dujmovic of TNC, the Mreznica is a typical karstic river, which means that the riverbed is composed of limestone and is generally poor in plant nutrients. A special characteristic of the river is that the chemical characteristics of the river support the growth of tufa stone. Tufa is a special stone, that grows in specific physio-chemical conditions of water by deposition of calcium carbonate on algae and moss. As it grows, tufa stone creates barriers and waterfalls (the most famous ones are on Plitvice lakes). It grows some 2-3 mm a year and is very fragile and closely depends on physio-chemical characteristics of the water. In addition, it can break easily on impact, and therefore most human activities such as paddling or walking, can result in damage. The preservation of tufa is the main conservation purpose of river Mreznica. Tufa has many biodiversity values – it creates different habitats - rapids, waterfalls, deeper parts and shallows, which are all home for abundance of animals and plants. Additionally, it gives unique and scenic value of the landscape, which is a special feature for Mreznica. There are more than 100 of tufa barriers on 64 km of Mreznica river.

As a result, the upper part of Mreznica and Tounjcica rivers have been protected as a ‘Monument of Nature’ which the International Union for the Conservation of Nature , IUCN, classifies as a ‘category III’ monument.  

This decision builds on recent precedents to protect the Krupa, Mura, and Drava rivers and comes as the result of robust community engagement through the United for Rivers initiative—a cross-regional coalition of NGOs working to protect 13 rivers across five Western Balkan countries. These areas mark the first official protections resulting from this campaign and longstanding efforts led by local communities to preserve these iconic rivers.

The decision to establish a monument to nature in the upper course of the Mrežnica River and a significant landscape in its middle course is of great importance for both nature and local communities. It ensures the implementation of conservation measures on one of Croatia’s most spectacular rivers, providing sanctuary for diverse plant and animal species, and protecting the dozens of tufa waterfalls the river is known for.

“We are pleased with the large number of people who were involved in the public consultation during the declaration process for the protection of the Mrežnica River. We hope that local communities will continue to show interest in protecting this area to ensure its sustainable management and the preservation of important species and habitats. We still have a lot of work that can only be accomplished through constant communication and the inclusion of all stakeholders in the process, finding joint solutions based on nature”, said Antonija Bišćan, director of the Public Institution Natura Viva.

This decision is not merely a legal designation; it is a promise to safeguard the natural beauty, biodiversity, and social and cultural significance of Mrežnica and Tounjčica. The Public Institution Natura Viva, Karlovac County, and TNC are committed to continued collaboration, ensuring proper implementation of conservation measures, and commitment to sustainable management of new protected areas.

“Residents of Karlovac County appreciate their rivers, and the Mrežnica is special in that regard. We affectionately refer to it as ‘a beauty,’ ‘a pearl,’ a truly unique and magical river. Therefore, I believe that this is a significant step in our efforts to preserve the Mrežnica River for generations to come. We aim to ensure sustainable management of this valuable natural resource in collaboration with relevant ministries, the non-governmental sector, and the local community. This decision puts us on the right path to achieve it,” said Martina Furdek Hajdin, Karlovac County Prefect.

The protected areas will play an important role in preserving the natural and social values of the river, offering sustainable recreational opportunities for locals and visitors alike while preserving important habitats and species.

“The Nature Conservancy views the protection of Mrežnica and Tounjčica as flagships and exemplary models aligning with our strategy for durable river protection. Engaging closely with local communities through our United for Rivers initiative, we recognize them as the backbone of river conservation and the sustainable use of river resources. We are delighted to witness the successful protection of Mrežnica and Tounjčica, and proud to contribute to this process. We are fully committed to providing ongoing support for the continuing conservation of these rivers and we hope this milestone will inspire other countries in the region to strengthen their river conservation efforts,” said Irma Popović Dujmović, TNC Freshwater Program Director for Croatia.