Meet the latest recruit to the UK flood defence team: the beaver

Beavers could be put to work building dams to stop a village from flooding in the Forest of Dean, in what would be the first such scheme on government land.

The Forestry Commission has been an enthusiastic advocate for the release of a family of beavers into a large fenced area surrounding Greathough brook above the village of Lydbrook, on land owned by the commission.

Experts predict that the beavers will rapidly create dams, canals and ponds, slowing the stream’s flow and potentially holding back 6,000 cubic metres of water to prevent huge floods inundating Lydbrook, a village that suffered badly from flooding in 2012.

Villagers are mostly supportive, hoping the scheme will not only protect the village but boost local wildlife and tourism. “It’s a brilliant idea,” said Stuart Aken. “There were about 100 people in the village hall when they made the announcement and there wasn’t a single dissenting voice. People are in favour because of the potential to help against flooding and most are interested in the increase in wildlife that it will bring to the area.”

One villager spoke of concerns that the beavers would escape the enclosure and pose similar problems to those caused by the burgeoning wild boar population. But Sid Phelps, a Green councillor who lives close to Lydbrook, said beavers would not stray far from the watercourse. They will also be tagged, so if they escaped they could be recaptured.

“This seems to be an innovative idea to deal with both climate change and the risk of increased flooding,” said Phelps. “There’s a little nervousness in the Forest of Dean because of the boar but the Forestry Commission did an excellent job of assuaging any fears.”

But despite the beaver scheme not costing the taxpayer a penny – it would be funded by landfill taxes – it was abruptly postponed last month.

A source close to the project said it had been blocked by a minister in the Department for Environment, Food and Rural Affairs – and the Forestry Commission was “hopping mad”.

A spokesperson for Defra denied that the scheme had been blocked by a government minister and said that the Forestry Commission would announce the next steps in the coming weeks.

Derek Gow, a beaver expert who has worked on reintroductions in Scotland and England, said: “This is a tremendous opportunity. The science suggests these animals will hold back 6,000 cubic metres of water.

“This has the potential to prevent a once-in-30-years flood event. These animals will also open the forest canopy to light and create a biodiversity jewel in this forest.”

Landowners, ecologists – and according to some insiders, the environment secretary, Michael Gove – are increasingly interested in the potential of using beavers as a cost-effective form of natural flood defence. The government is overseeing a trial to assess whether the beaver, which was driven to extinction more than 400 years ago, should be allowed back as a native species into England. The Scottish government last year recognised the beavers on its waterways as a native species, giving them legal protection. At an experimental site run by Devon Wildlife Trust on farmland, a pair of beavers have been shown to hold back 1,000 cubic metres of water, with their dams and canals drastically slowing the flow of floodwater.

In Cornwall, a farmer linked up with the Cornwall Wildlife Trust earlier this year to release beavers on to fenced land above the village of Ladock, which has been hit by severe flooding in recent years.

Within two weeks of two beavers being released there, newly created waterways were holding back 1,000 cubic metres of water.

Gow said he was hopeful that Gove would approve the Lydbrook scheme. He said: “Many ecologists were very apprehensive when Michael Gove was appointed [as environment secretary] but his approach has been overwhelmingly positive and really quite visionary.

“He’s obviously very knowledgeable about and sympathetic towards the natural environment. We’re all waiting with bated breath to see what the man is going to do.”

Lydbrook would set a precedent for dozens of similar schemes in western British river systems, Gow says, particularly in upstream areas where beaver dams act as a giant sponge, lessening peak flows of water and slowly releasing more during times of drought.

But Gow said that beavers were unlikely to be allowed back into Britain’s easterly arable landscapes, where their activity can flood valuable agricultural land.

HOW BEAVER DAMS PROTECT THE LAND

Beavers prefer to live in deep water so if they are released into a small upland stream, they quickly build a series of dams and canals they can use. These dams store water and the land close to the stream in effect becomes a giant sponge.

At a 2.8-hectare test site in Devon, two beavers have created 13 ponds that hold 650 cubic metres of water. Floodwater has been drastically slowed. The dams also remove pollutants and create a rich habitat for rare invertebrates and plants. If the dams are washed away by floods, these busy engineers rapidly rebuild them. Ecologists say the trial in Devon can be replicated at other sites.

This “natural” flood defence works only in small streams in upland areas. In deeper rivers, beavers do not need to rapidly create dams. In lowland areas, beaver activity can also cause flooding.

But those in favour of their reintroduction to England and Wales say beavers can be returned to western river systems and will not spread to low-lying eastern areas, such as the Fens, where their activity could cause valuable agricultural land to flood.