Wetlands and coastal protection

Wetlands can act as natural buffers to reduce wave energy.

Natural coastal protection and risk reduction by intertidal wetlands

1 Department of Geography, Trinity College, Dublin, Ireland

2 Cambridge Coastal Research Unit, University of Cambridge, United Kingdom

Natural flood management (NFM) protects, restores or emulates the natural functions of rivers, floodplains, catchments and the coast to reduce flooding and coastal erosion. It can take the form of wetland restoration. Wetlands can be very beneficial for reducing flood risks while also providing wider environmental benefits.

Research from the Cambridge Coastal Research Unit (CCRU) demonstrated the critical role that coastal wetlands play as natural buffers against storm impacts. This work not only transformed understanding and attitudes toward coastal ecosystems, but has influenced policy and practice.

The findings from CCRU helped to shift the narrative on coastal management. The UK Climate Change Risk Assessment (CCRA2) highlighted flooding and coastal change as the highest climate risk for the UK, and identified an urgent need for effective, sustainable solutions. With rising sea levels projected to impact approximately 1,000km (20%) of England’s coastal defences by 2100, reliance solely on hard engineering is becoming increasingly untenable (Environment Agency, 2024).

The CCRU’s extensive research provided compelling evidence that coastal wetlands, such as salt marshes, significantly dissipated wave energy during storms, and by doing so helped to protect coastal communities and infrastructure. By acting as natural barriers, these ecosystems reduce the wave heights that reach man-made structures, either decreasing the need for hard engineering solutions or the cost of their construction and maintenance where they are needed.