Prof Fiona Mathews believes beavers can be used as part of an effective natural flood defence

Prof Joseph Alcamo believes natural flood management can make a big contribution to flood protection

Beavers have become major ecosystem engineers in parts of Europe. Pic by Nick Upton/NaturePL.com

Farmers should be paid to give over parts of their land to enable beavers to create natural flood defences, a University of Sussex scientist has said.

Professor Fiona Mathews, a professor of environmental biology, hopes that post-Brexit reform of agricultural subsidies could be used to greater incentivise farmers to allow their land to be set aside for use for a range of natural flood defences which could include reintroducing beavers who help to slow the flow of water through river catchments with their extraordinary engineering skills.

Speaking at a Sussex Sustainability Research Programme event celebrating World Water Day, Professor Mathews said expanding the numbers of beavers reintroduced into the UK would have huge benefits in reducing flood risk, improving water quality and diversifying habitats.

She cited the example of the huge benefit just two beavers in North Devon have had within a year with their network of little damns creating habitats for frogs and encouraging much greater birdlife to the area while other parts of the UK have benefitted from beavers creating complex wetland ecosystems to the benefit of wildlife and water quality and reducing water flow speeds.

She added: “Elsewhere in Europe, where beavers have been allowed to recover, they become major ecosystems engineers. There are examples in Germany where beavers have been allowed to restore a network of wetlands in the middle of a quite intensively farmed landscape.

"We should be exploring whether farmers could be paid to allow beavers to live on their land to give us all benefits in terms of flood control instead of putting all their fields into agricultural production. There is a lot of exciting discussion about what could be done to make agricultural subsidies more effective in delivering ecosystem services after Brexit.

"We are not saying they are a universal panacea. But beavers are a very, very important tool in the kit. They are not the only solution, and are not appropriate everywhere, but they should definitely be in the mix.”

Professor Mathews added there was resistance to inexpensive natural flood defences in an engineering sector which favoured large, concrete-based projects with greater opportunities for turning a profit.

She said: “Major construction projects obviously involve a hierarchy of people. Whilst there is often an ecologist involved, they are often led by civil engineers and people focussed on hard engineering solutions. So there’s a cultural issue that needs to be grasped to move this forward. ‘Soft solutions’ like planting trees, managing farmland in ways that encourages water to be absorbed into the soil rather than running straight off into rivers, and reintroducing beavers have an important role to play.”

Professor Mathews’ call for more nature-based flood defences also found support among the rest of the panel at the event organised by the SSRP, a key global centre at the University of Sussex that aims to deliver science to support the UN Sustainable Development Goals. The SSRP currently funds 20 interdisciplinary and global research projects.

Dr Lydia Burgess-Gamble, principal scientist from the flood risk research team at the Environment Agency (EA), said a review after the devastating 2007 floods, estimated to have cost the country £3 billion, concluded that it was not effective to keep building bigger and bigger concrete flood defences and that a bigger portfolio of flood defence types, including natural solutions, were needed.

EA studies show every one of 14 types of natural flood management measures in England have the potential to reduce flood risk whilst also providing wider ecosystem service benefits. She added natural flood defences were in some cases the only option in some communities where larger engineered solutions were either not cost beneficial or not feasible due to the topography of the catchment.

Tom Ormesher, an environment and land use adviser for the National Farmers’ Union, said farmers are willing and able to contribute to wider ecosystem services in the form of wildlife enhancements and flood storage; and have been doing so in one form or another for many years.

He added: “However there needs to be a fair policy and system of payments to allow farms to provide the services that wider society wants and needs; and we shouldn’t forget that British farmers also provide safe, nutritious high quality food for a population that is set to increase rapidly over the coming decades. On a global scale, the number of people supplied by just one farmer doubles every 20 years and as such we need to make sure farmers can stay in business in the challenging years to come.”

Commenting on the event, SSRP Director and former UN Environment Chief Scientist Professor Joseph Alcamo said: “Natural flood management is very much an idea in its pioneer phase and it has to compete in a field dominated by civil engineering thinking.

"Now the big questions are: Can it compete? Can it be scaled up and be as effective everywhere as engineering works in protecting people from extreme river flows? Will it protect us from the more severe weather we are expecting under climate change?

"I personally believe the answer to these questions is that it can make a big contribution to flood protection in river basins everywhere, but we need more research from the SSRP and other organizations to prove the concept.”