Nature-based solutions for natural flood management
How beavers help prevent flooding
As a child did you read The Beaver Twins? A book by Jane Tompkins written in 1944 that I read avidly in the 1960s, a story about giant mammals and their wetland lives, spent carving rivers. Creative creatures that had been extinct in the UK since the 1300s (although some evidence suggests beavers may have retained small, isolated populations until much later). In England, bounty specifically listed beavers as late as 1789 with payments still being made for their pelts.
So, no beavers, and what does that mean for the environment?
This week the Environment Agency issued over 200 flood warnings, with 150 alerts that flooding is possible and 88 indicating flooding is expected.
While flooding is devastating for anyone unfortunate enough to be affected there are simple measures that help prevent it:
1: stop building in the floodplain: tricky when much of lowland Britain is floodplain (including a large part of London). Rivers and their floodplains are dynamic systems, naturally flexing and morphing into water meadows, where land becomes spongelike absorbing the flood and gaining in fertility as a result. The river needs space to act as it adapts the landscape, in fluid, continuous motion and we encroach on it too readily.
2: upstream catchment storage: higher land at the head of the catchment is the best place to capture and slow the speed of water run-off so that the land has time to absorb it. And there are effective natural ways to attenuate the fast downhill rush of rainwater that include mass tree planting. Flood water volumes are accelerated and exaggerated by the extent of building and hard surfacing across lower areas of the catchment where there is little space for water storage or capacity for attenuation. Historically rivers in towns and cities have been canalized and restricted, ostensibly to speed the passage of water through the built area. This means that we not only lose water quickly to the sea which could be retained for farming and nature’s benefit, but also the height of the flood walls must continually be increased to provide capacity and prevent overtopping as the volume of the flood grows[1].
3: ecological engineering: The UK has finally woken up to the potential of natural systems to help prevent flooding in settlements, and with this awareness comes the reintroduction of beavers. The Swedes began reintroducing beavers in the 1920s with other European countries following suit – even the USSR started reintroducing them in the 1930s. In fact 24 countries reintroduced the Eurasian beaver before Great Britain.
Arguably GOV.UK mistrusts nature and has historically misunderstood the benefits of working with natural process rather than trying to control it. Opinions are changing though, and the position statement published July 2025 (link below) sets out the Environment Agency’s summary of the benefits of nature-based solutions on flood management. Their current analysis shows that for every £1 spent on nature-based solutions for natural flood management £10 is delivered in benefits. This set against the huge cost of hard engineered solutions provides an even more cogent argument for deeper consideration and greater investment in natural solutions.
Beaver dams provide a host of benefits not only for beavers, but also for people, and their actions support ecosystem diversity (something the UK is catastrophically short of)[2]. By impounding water and slowly releasing it through leaky structures beaver dams make river systems more resilient to drought by increasing base flows in dry periods and decreasing the risk of flooding downstream during high flows.
The creation of complex wetland behind a dam provides habitat for a diverse range of plant and invertebrate species. This in turn provides breeding, foraging and shelter opportunities for a range of birds, bats, mammals and amphibians.
(map image courtesy of UK WT)
In October 2022, England's beavers were at last added to the European Protected Species List and the UK Wildlife Trusts state that wild beavers are now in Argyll, Cornwall, Dorset, Devon, Essex, Herefordshire, Kent, London, Montgomeryshire, Nottinghamshire, Shropshire, and Tayside. And Somerset. Beavers are recorded on the River Frome and while canoeing recently, my colleague Lizzie was delighted to see an adult swimming just ahead of her, in the centre of Frome. This beaver was one of a family who escaped from a planned reintroduction upstream of the town, they took up residence in the Rodden Brook Nature Reserve. A project that Novell Tullett created 20 years ago as part of a flood relief scheme to compensate for lost capacity in the River Frome in the building of an Asda supermarket.
If you build it they will come so they say.
Oh, and do you remember that beaver lamb coat your mother had in the 1950s? (Or maybe that was just my glamorous mother?) it was most likely sheepskin that had been combed, straightened and dyed – not beaver at all. By the early 1900s beaver would have been impossible to get hold of in the UK. A relief to me that my mother wasn’t wearing the pelts of slaughtered rodents given my ongoing obsession with them.
Look out for a living one in a river near you or visit one of the schemes where they are actively being introduced. For inspiration see https://beavertrust.org/beaver-basics/science-database/
References
Tompkins, Jane (1944) The Beaver Twins Illustrated by Comstock, Enos B. Frederick Warne & Co., Ltd., London
Gow, Derek (2022). Bringing Back the Beaver: The Story of One Man's Quest to Rewild Britain's Waterways. Chelsea Green Publishing UK.
https://www.gov.uk/government/publications/nature-based-solutions-environment-agency-position-statement
https://www.wildlifetrusts.org/saving-species/beavers
https://beavertrust.org/beaver-basics/beaver-history/
https://beavertrust.org/beaver-basics/science-database/
Etymology
Beverley (East Yorkshire): Originally Beoferlic, meaning a clearing in the woods frequented by beavers near the River Hull.
Beverston (Gloucestershire): The name echoes the presence of beavers in the area.
[1] While at LUC in the 1990s Jane Fowles worked on 13 flood relief schemes in the River Colne catchment
[2] UK most nature depleted country in Europe https://stateofnature.org.uk/
Across the UK species studied have declined on average by 19% since 1970.
Nearly one in six species are threatened with extinction from Great Britain.
151 of 10,008 species assessed have already become extinct since 1500.
12% of assessed species were at risk of extinction
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