Leave it to the beavers: How active mammals are helping to stop London's flooded canals

When a mother beaver called Willow frolicked in the open, there was silence in the happy crowd taking part in a “beaver safari” in the British capital.

The mammals may have become an attraction in the area, but the colony also seems to have helped solve a long-term problem in the area. By simply doing what beavers do best – building dams – they protected the roads near the Greenford pipeline station from regular flooding.

“Everything downstream is more protected from flooding than before, all this is because they want to block that water so that they have enough water to swim and feel safe,” it said. Şeniz Mustafa, with the Ealing Beaver Project.

“There's a good secondary benefit for us.”

The return of the beavers to London

Beavers are being transported to London from Scotland in 2023 as part of a pilot effort “repeat” pockets of a large urban city.

Beavers haven't lived in London for about 400 years. As elsewhere in the UK, they were hunted for their fur, meat and musk and disappeared from the area.

A limited number began to be returned to the region in 2009, starting in Scotland. London got its first beavers in 2022, after male and female pairs were released from a specially fenced area in Enfield, in the northern part of the city.

They were given the names of Justin Beaver and Sigourney Beaver.

A year later, after several community groups came together to push for another beaver project in London, five were released in a wetland called Paradise Fields, less than 10 kilometers from Heathrow airport.

A big part of the original project was that, as environmental engineers, beavers could reduce flooding, allowing the local council to cancel or postpone planned, expensive engineering work.

After two-and-a-half years, the project workers say that the Greenford station has not flooded since then.

A great mother

There are believed to be eight beavers on the 10-hectare site, including Willow, who Mustafa says has a big role in being the heaviest beaver ever taken to the UK At the time, she weighed 30kg.

“I'm sure she's put on a lot more weight now, but I don't want to embarrass her, but she's a great mom.”

The matriarch of the colony had tools, in 2024 and 2025, including two workers named Chompy and Chewy. She recently gave birth again, but it is unclear how many kits she had.

The Ealing beaver enclosure project is part of an effort to improve the natural environment that is often lacking in London.

There are proposals to release more beavers in Croydon, south London.

In 2021, London Mayor Sadiq Khan launched a regeneration fund that provided £2.48 million ($4.5 million) for a number of projects to create and restore housing in the capital.

In a statement sent to CBC News, his office said it was “great” to see the beavers in the Ealing area thriving in their new habitat.

“It's amazing how in just a few years they've helped stop flooding at the local station, turned Paradise Fields into a thriving wetland and helped improve biodiversity in the area.”

Enhancing biodiversity

Beavers create dead wood that provides homes for insects, which, in turn, become food for other species.

Mustafa says there appear to be new fish, as well as birds and insects such as dragonflies.

He's the “urban beaver officer,” and part of his job involves engaging with the community and promoting the idea that beavers and people can coexist peacefully.

The park is accessible to the public, and unlike many of London's gated green spaces, it is open 24 hours a day.

Mustafa says he has heard users of the park say that the presence of beavers has made the area feel safer. Not only do they cut down the trees which made the canopy less dense and more open, but they also attract crowds of people to the area.

Beaver safari

Several times a week at dusk, Mustafa leads beaver safaris that are often sold out, costing about £28 pounds, or more than $50. People are given binoculars, escorted to the site and taught about all things beaver, including the fact that those in London are Eurasian animals.

They are similar, but not identical, to the North American species found in the forests and swamps of Canada.

Safari participant Amanda Ram, 25, excitedly held her binoculars as Willow wandered through the crowd and counted down 15 minutes.

“That was the most amazing thing I've ever seen,” he said in an interview with CBC News afterward.

Ram signed up for the tour after reading about the project in a David Attenborough documentary called Wild Londonwhich focused on the intersection of wildlife and the urban environment.

Outside the brightly painted gates that mark the entrance to the project is a large shopping mall made up of department stores. The tube station is a short walk away.

“I think it's really good that there's a McDonald's here and there's a TK Maxx and then there's, like this project you wouldn't expect it to be in this park,” said Ram.

Beavers are a protected species in the UK, of course the case to kidnap, kill or disturb them.

Last year the UK government changed the law to allow beavers to be released into the wild in England, if the government grants a license after considering the infrastructure around farming.

The Wildlife Trusts, made up of dozens of wildlife conservation groups across the UK, hope to deliver 100 beavers of wild this year.

“I hope we will encourage other activities,” said Mustafa.

“We're going to prove … that people and beavers can coexist in an urban environment.”