Insights from a nation-wide environmental relicensing of hydropower facilities in Sweden: a review of court verdicts from a biological perspective

Hydropower, utilized for centuries, is promoted globally as renewable energy. The many ecological costs associated with hydropower facilities can be mitigated, but the perceived socio-economic benefits often outweigh environmental concern. The EU Water Framework Directive (WFD), implemented in 2000, established a framework for community action in the field of water policy. It constitutes an instrument to compel hydropower facilities to align with environmental requirements. Based on the WFD and national law, a National Plan for Modern Environmental Conditions for Hydropower (NAP) was formulated in Sweden to renegotiate the environmental permits of around 2000 hydropower plants and dams. The NAP process commenced in 2022 and is estimated to last approximately 20 year. In this review, we assessed the 33 court cases completed until the end of 2024, out of which 22 resulted in permit withdrawal and dam removal, while 11 received decisions requiring remedial measures. The primary focus of remedial measures was re-establishing longitudinal connectivity; other environmental aspects received less attention, and monitoring requirements were almost non-existent. We recommend measures using adaptive design, prioritizing functionality, and monitoring over detailed technical specifications. In addition, greater attention should be given also to aquatic habitats in affected reaches: addressing e.g., flow, water levels, and temperature. In conclusion, this nation-wide process provides a unique opportunity to implement measures that could benefit entire riverine ecosystems.