SCOTLAND’S beavers could help prevent flooding despite critics’ claims, a study has found.

Wild beaver populations were accused of contributing to flooding in the Perthshire village of Alyth, but research by Stirling University has found beaver dams actually help mitigate flooding by storing and slowly releasing water. The study also found the mammals can boost biodiversity and minimise pollutants.

Examining headwater streams which drain water from 13 hectares of Scottish countryside, scientists compared areas where beavers had been active with areas in which they were absent.

Plant life was up 20 fold in areas where beavers were active, with concentrations of phosphorus slashed in half and nitrate levels down more than 40 per cent.

The study formed part of a programme of research at the site by Stirling scientists that has been ongoing since 2003.

Dr Nigel Willby said: “

Their dam-building skills help restore degraded streams and increase the complexity of the surrounding habitat, consequently increasing the number of species found by 28 per cent. The dams also help improve pollutant levels and store flood water.”

He added: “We discovered that dams helped restore local biodiversity, but also had value for nutrient retention and storage of water during flood peaks, suggesting benefits downstream.

“The beavers’ engineering is therefore transforming low-quality habitats in regions where the animal has long been absent.

“These benefits, however, must be weighed against the potential for occasional negative impacts on fisheries, forestry and farm crops.

“With decisions on the beaver’s future in Scotland set to be made in the coming months, this research opens up an important dialogue on the pros and cons of reinstating these animals to the Scottish countryside.”