Dam it! How beavers could save Britain from flooding

Since their trial reintroduction in Devon, the animal's engineering skills have reduced floodwater and created a paradise for local wildlife. Should we bring them back for good?

At a secret location in the rolling pasture of west Devon lies a marshy patch of farmland protected by 35,000-worth of solar-powered electric fencing. This isn't to keep people out but to restrain the tree-chomping, river-damming residents of these three hectares. Outside the fence is a typical small valley, with a trickle of a stream, willow thickets and pasture grazed by cattle. Inside the enclosure, the tiny stream has been blocked by 13 dams, creating pools and half-metre-wide canals. These have been built by Britain's newest wild mammal, the beaver, which uses its waterways like we do - to transport goods. And as the beavers have coppiced trees, the willow thicket has been replaced with sunny glades of wild flowers - marsh thistles, watermint, meadowsweet - which dance with dragonflies and butterflies.

"The beavers have transformed this little trickle of a stream into a remarkable, primeval wetland," says Mark Elliott, lead beaver project officer of Devon Wildlife Trust, which released two beavers here in 2011. "This is what the landscape would have looked like before we started farming, and it's only six years old. That's the amazing thing."