Challenges and opportunities in restoring European free-flowing rivers

Free-flowing rivers (FFRs) across Europe hold high ecological value and clear economic benefits. They support biodiversity by providing habitats for a wide range of aquatic and terrestrial species and strengthen local economies through sustainable practices while reducing the need for costly artificial flood control and water treatment. Rivers also carry deep cultural meaning for European communities, shaping identity, belonging, and wellbeing. Given this ecological, economic, and cultural weight, we argue that safeguarding remaining near-natural or pristine rivers should be the first priority, alongside restoring degraded systems, where meaningful gains are feasible. Herein, we review definitions, restoration objectives, and historical changes in FFRs, and highlight the importance of setting realistic reference conditions that recognise both ecological constraints and future climate change. We stress the value of combining multiple temporal and spatial perspectives in project design and discuss practical restoration and rehabilitation approaches, including the role of stakeholder involvement and public awareness, to achieve successful outcomes. We then consider how biodiversity and climate policies can support protection, restoration, and long-term management of river ecosystems across Europe. Finally, we examine the opportunities and challenges tied to implementing the Nature Restoration Regulation and the EU Biodiversity Strategy for 2030, as well as other policy initiatives, that can help remove obstacles and create better conditions for accelerating progress in restoring free-flowing rivers. Near-pristine rivers should be protected immediately, even with incomplete data. Freshwater systems need more political attention and stronger stakeholder involvement. Solutions for FFR restoration should be tailor-made for each unique situation. FFRs connect diverse ecosystems, needing both meta- and local ecosystem approaches. Few reference rivers exist; clarifying reference sites and ecological conditions is needed.