River floodplains hold a central role in supporting the status of water, nature and biodiversity conservation, climate change mitigation, and ecosystem services. They build an important link between rivers and their catchments, mainly through their water retention capacity and the lateral connectivity controlled by flood events and groundwater exchange, together with the presence of structural features such as side channels and wetlands. Today, floodplains are environmentally degraded due to many human activities such as settlement and agriculture existing for centuries.
The preliminary assessment results reveal clear signals of degraded floodplain condition. Almost 75 % of Europe’s floodplain area shows a severe reduction of floodplain extent, whereas 14 % is substantially degraded, leaving only 12 % of the area with moderate or no loss.
Similarly, 41 % and 38 % of the floodplain area show severely or substantially degraded structure. Severely degraded structure occurs where land use is almost entirely characterized by urban areas and agriculture, both of which contribute strongly to degrading floodplain structures as a consequence of modified river channel, drainage and dikes.
The floodplain processes module shows the combined integrity of physical processes expressed as base flow, degree of flow regulation and sediment transport, all of which are important for maintaining floodplain habitats and support the lateral connection between river and floodplain. The assessment shows severe or substantial alterations in 60 % of Europe’s floodplains.
Future restoration objectives for floodplains should target re-establishing lateral connectivity with rivers, as this is a fundamental property for improving its condition. It also needs a broad approach to establish space for rivers by considering improvements to floodplain extent and structures as well as the integrity of natural processes. Such improvements are needed in the upcoming process of implementing the 2030 Biodiversity Strategy under the European Green Deal. It includes a target to achieve 25 000 km of free-flowing rivers through the removal of barriers and restoration of floodplains and wetlands.