Environment Agency: Natural Flood Management in Reducing Flood Risk

The Environment Agency today published data, case studies and evidence about the role of natural flood management in reducing flood risk.

Working with natural processes to reduce flood risk is not a new concept but this is the first time that all the evidence has been brought together, with the intention of enabling more uptake.

‘The evidence behind natural flood management’ contains more than 60 case studies from across England and explores how successful the approach is, how it could be used elsewhere and what research may still be needed, the agency said.

Natural flood management is when natural processes are used to reduce the risk of flooding and coastal erosion. Examples include: restoring bends in rivers, changing the way land is managed so soil can absorb more water and creating saltmarshes on the coast to absorb wave energy.

At Hesketh, on the Lancashire coast, a ‘managed realignment’ scheme has created more than 300 hectares of saltmarsh which protects 143 residential properties, 3 commercial buildings and 300 hectares of farm land.

Coastal schemes such as this not only dissipate wave and tidal energy but can also reduce impact on defenses, reduce tidal surges and lead to slightly lower water levels at defenses, the agency said.

The study includes a project in Debenham, Suffolk, where modelling has shown that installing a range of natural flood management features along the River Deben could provide more than 30,000 m3 of water storage – thereby reducing annual average damages to properties and farmland by 31%.

On Lustrum Beck, in Stockton-on-Tees, modelling showed that providing 100,000m³ of storage in the upstream catchment, using wetlands, features to reduce run-off and river restoration, could reduce flows by more than 10%.