A pan-European survey on river continuity restoration.

A pan-European survey to strengthen and improve policies and strategic planning regarding river continuity restoration.

River barriers, including dams, weirs, culverts, fords, sluices, and ramps or bed sills, are man-made obstacles that are installed in rivers for specific, mostly provision-related, ecosystem services such as flow regulation, hydropower generation, water level control or erosion reduction (AMBER, 2020). Other functions include transport (navigation), recreation, water storage for agriculture (irrigation) and drinking water, flood protection, and cultural heritage. However, they obstruct a river, disrupting the longitudinal flow of the water, sediment and aquatic biota. The disruption of river continuity has been shown to result in a major decrease in species diversity (Joy & Death, 2001; Morita & Yamamoto, 2002), as well as population declines and even extirpation of freshwater fishes and mammals (Allan & Flecker, 1993; Miller et al., 1989; Page et al., 1997). Only 37% of rivers around the world that are longer than 1,000 kilometers are still free flowing and only 23% flow into the ocean without interruptions (Grill et al., 2019), so the current status of global river continuity is not good, and it is worsening.

A river continuity survey approach made it possible to investigate the current situation in every participating country regarding the recognition of the importance of river continuity in national policies and the potential for restoration. By getting to know the country specific situations, the questions have provided insight into policies and the required support concerning guidance and tools. In order to advance river continuity restoration, what should be the main strategy per country and/or group of countries? This has been analysed through 60 questions, put to national governments which covered the following topics:

1. Recognition of river continuity in current national policies
2. The potential of river continuity restoration in each country
3. Observations/opinions on the importance of and opposition to river continuity restoration

The answers to this survey and the results of their analyses have allowed initial conclusions and recommendations to be drawn as to the current situation regarding river continuity restoration policies and strategic planning in wider Europe. This information can be used in follow-up activities to formulate advices, improve current policies or propose and develop new policies and national restoration strategies, and generate greater support. Altogether, this could subsequently be developed into a Europe-wide openly accessible database on the plans, progress and status of river continuity, assisting national governments and river authorities in restoring river continuity. This will be beneficial for all the participating countries for achieving the relevant water legislation targets and UN Sustainable Development Goal 6.5.