A new assessment by the Environment Agency highlights the critical role beavers and other natural measures can play in tackling flooding and coastal erosion in the UK. The updated Working with Natural Processes Evidence Directory outlines how nature-based solutions, such as beaver dams, oyster reefs, and saltmarshes, can complement traditional flood defences to enhance resilience against climate change.
Beavers: Nature’s Flood Engineers
Beavers, once hunted to extinction in Britain 400 years ago, are making a comeback and proving to be invaluable in flood management. By building dams and creating channels, beavers reduce peak water flows, slow down water movement, increase groundwater storage, and trap sediment. These activities not only mitigate flooding but also reconnect floodplains, support biodiversity, and store carbon.
The Environment Agency’s directory highlights the need for more UK-specific evidence to optimize beaver reintroduction, including understanding the ideal number and location of dams for maximum flood reduction benefits downstream. While beavers were granted legal protection in 2022, conservationists are urging the government to approve wild releases to further harness their ecosystem engineering capabilities.
Natural Flood Management: A Multi-Benefit Approach
The directory evaluates 17 natural measures, including river restoration, catchment woodlands, and coastal habitats like saltmarshes and sand dunes. These solutions not only reduce flood risks but also deliver co-benefits such as carbon storage, improved water quality, and enhanced wildlife habitats.
- Catchment Woodlands: Planting trees across water catchments can significantly reduce floodwater height, particularly during smaller flood events. A study in Cumbria found that woodland slowed water flow by 14% to 50% compared to pastureland.
- Saltmarshes and Mudflats: Restoring these coastal habitats protects against storms while storing carbon and filtering sediments. For example, the Steart Marshes project in Somerset created 250 hectares of saltmarsh, storing 36.6 tonnes of carbon per hectare—comparable to woodland.
- Oyster Reefs and Seagrass: These underwater ecosystems help reduce wave energy and coastal erosion, though more research is needed to determine optimal reef depths and development methods.
Government Investment and Future Plans
The Environment Agency is mainstreaming natural flood management as part of a £25 million program, supported by the UK government’s £2.65 billion flood defence package. This initiative aims to test and scale up nature-based solutions, ensuring they are integrated with traditional engineered defences.
Julie Foley, Environment Agency Director of Flood Risk Strategy, emphasized the importance of working with nature to build resilience: “With climate change increasing the threats of flooding and coastal erosion, we must work together with nature to boost resilience across the country.”
Kathryn Brown, Director of Climate Change and Evidence at The Wildlife Trusts, welcomed the directory, stating: “Getting the best evidence to support our collective efforts to build resilience is critically important. I’m delighted to see the latest science on natural flood management coming together in one place.”
Looking Ahead
The Environment Agency’s evidence directory will guide investment decisions and on-the-ground implementation of natural flood management measures. By combining traditional and nature-based solutions, the UK aims to create a more resilient landscape that not only addresses flooding but also delivers environmental and economic co-benefits.
