London brought back beavers after 400 years to fight floods: How the animals built dams, created natural reservoirs and turned a railway station’s flood-prone surroundings into a surprising wetland defence

Beavers are often called “ecosystem engineers” for a simple reason: they physically change the places where they live.

They cut branches, fell trees and build dams across waterways. Those dams slow flowing water and create pools and wetlands. And that is exactly what happened at Paradise Fields.

Within months of their arrival, the Ealing beavers had built dams, creating areas where water could collect rather than rushing immediately downstream. London City Hall says the animals were also helping create habitat for fish, birds, amphibians and other wildlife.

The project says the dams allow water to move through the site more slowly during heavy rainfall, reducing the amount of water reaching flood-prone areas at once.

And the animals did not need a construction crew, concrete or heavy machinery.

They simply did what beavers have been doing for thousands of years.