Invest in beaver dams, ponds and wild driveways to curb flooding, report urges

Natural flood prevention measures from beaver dams to “wild driveways” can deliver 10 times the value of every pound invested, a study has found.

The study highlights the “positive cost-benefit ratios” of investing in natural schemes that soak up water and slow its flow, including ponds, dams and hedge and tree planting as well as rain gardens and removing paving from driveways.

These schemes can tackle the UK’s most expensive natural hazard – costing around £2.2 billion annually and set to rise with climate change – as well as boosting nature, well-being, carbon storage and water quality, the report commissioned by the Wildlife Trusts and RSA Insurance said.

But with just 1% of public flood spending going to natural measures, the report urges the Government and businesses to prioritise and invest more in such schemes to help curb flooding and restore nature.

The research looked at 10 natural flood management schemes by individual wildlife trusts, and found they had an average benefit of £4 for every pound spent, over 10 years, which rose to £10 benefit for every £1 spent over 30 years.

They include a project on the Upper Sherbourne, where Warwickshire Wildlife Trust installed a series of leaky dams – barriers of natural wood placed in streams and ditches to slow the flow of water – and ponds to curb flooding in a suburb of Coventry.

Gloucestershire Wildlife Trust has been helping communities in Cheltenham and Gloucester, with measures including rain gardens with plants to absorb water, wild driveways that replace paving with gravel and planting, and greener verges and bus stops to reduce urban run-off.

That scheme is estimated to reduce flooding for 50 homes directly, delivering an economic value of £2.99 million over 10 years and £9.1m over 30 years, the report said.

The study also looked at the River Otter, in Devon, where wild beavers have created wetlands and dams that have reduced flood flows by 30% upstream from a flood-prone village.

The research comes after the Government gave the go-ahead for wild releases of beavers in England, with new projects expected to come forward this year, while many beaver families are already living in enclosures as part of flood reduction and wildlife-boosting schemes.

In the Limb catchment, which runs off the Peak District into Sheffield, a range of techniques have been deployed, including wetland expansion, more than 50 leaky dams, hedge planting and taking streams out of culverts.

Other schemes include measures such as managing peat bogs and creating new woodlands.

Kathryn Brown, director of climate change and evidence at the Wildlife Trusts, said: “One in six houses across the UK is currently at risk of flooding and climate change is leading to more frequent and heavier rainfall – and we know that this will become more severe in the future.

“The good news is our research proves that restoring natural habitats can help us tackle the effects of climate change – and in doing so, help reverse nature declines.”

She said that just 1% of public funding for managing flood risk in England went to natural flood management measures and called for natural approaches to be the “first port of call wherever appropriate”.

Ken Norgrove, chief executive of UK and international at RSA Insurance, an Intact Company, said: “Climate change will continue to be a defining issue of our century, so it’s important for society to prepare, adapt and become more resilient.

“By investing in innovative natural flood management solutions, we can help safeguard people, businesses, and the environment for a sustainable future.”

The report calls for a standardised approach to designing, monitoring and valuing projects to increase investor confidence, a Government-led framework for increasing investment in natural flood management, and a more active role for the private sector.