Beavers not responsible for flooding, study finds

A new study by Stirling University has found that a local population of beavers may be preventing flooding, rather than causing it - as previously thought. 




After intense flooding in the Perthshire village of Alyth in July last year, locals thought evidence pointed to the beavers upstream, after finding tree debris that displayed their distinctive teeth marks.


However, in October an investigation by Perth and Kinross Council, the Scottish Environmental Protection Agency (Sepa) and Scottish Natural Heritage (SNH) found that all the beaver’s dams were still standing after the flooding.

This new study investigated the beaver’s impact in further detail, and discovered that the dams act like natural sponges, gradually storing and releasing water, helping to protect against flooding. 

Dr Nigel Willby, of Stirling University’s School of Natural Sciences, told the Guardian: “Our work points to the fact that by having the beaver dams present on a stream, the floods are locally mitigated, as these dams store and slowly release water, unlike undammed, straight streams where water flows without obstacle.”

Additionally, researchers found that the gathered water had a positive effect on biodiversity. The series of pools created by the beavers was up to seven times richer in organic matter and had 20 times more aquatic plant life.


The report also stated that while dam building by beavers may improve degraded environments, these benefits “should be evaluated against evidence of any negative effects on land use or fisheries.”