Scientific evidence proves the value of British beavers

Exeter University study shows how a Devon rewilding project has dramatically lowered downstream pollution and reduced flood risk

Exeter University study shows how a Devon rewilding project has dramatically lowered downstream pollution and reduced flood risk
Beaver kit hard at work. Pic: Nick Upton/naturepl.com

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Scientific proof that beavers have dramatically positive effects on the natural environment in Britain has just been published. The findings make a convincing case for the use of rewilding in tackling man-made problems such as flooding and pollution.

Research was undertaken at the Devon Beaver Project, a controlled reintroduction programme in South West England.

In early spring 2011, a pair of Eurasian beavers was introduced to a three-hectare enclosure – roughly the same as 4.5 football pitches – on a stream in the headwaters of the River Tamar. Their activity on the site, according to the report from the University of Exeter, has “created a complex wetland environment, dominated by ponds, dams and an extensive canal network.”

This, in turn, has led to benefits including:

  • Increased water storage within the site and a reduction in water flow out of it. This is due to the way the beavers have engineered the environment. The report says “this is highly likely for the observed attenuating impact upon flood flows across a range of storm event sizes”.
  • Reduced sediment, nitrogen and phosphate. Combined with reduced flows, this has resulted in significantly lower pollutants downstream.

The full report is called Eurasian beaver activity increases water storage, attenuates flow and mitigates diffuse pollution from intensively-managed grasslands and can be seen on the sciencedirect website.

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