Our latest recruit: the beaver, nature’s engineer
Posting date:3/2/2020 3:19 PM
02 March 2020
Atkins, a member of the SNC-Lavalin gorup's, Environment practice has recruited an unusual supply chain partner to help deliver a natural flood management project on the Spains Hall Estate in Finchingfield, Essex – the Eurasian beaver.
Members of our Catchment Science team in Oxford are working in partnership with the Environment Agency and local conservation NGOs using these wetland engineers to try and reduce flooding in a nearby village. The beavers were introduced to the estate in March 2019. Since then, they’ve built about 10 dams with more being constructed every time it rains. A complex of wetlands has developed behind the dams, slowing the flow of water, trapping sediment and nutrients, sequestering carbon and providing habitat for a range of wildlife.
Doing what beavers do best
The beavers are the first to return to Essex for over 400 years and now live on the estate in a 9.8 acre woodland surrounded by a special fence to keep them safe. Beavers were extinct in the UK for generations, as they were hunted for their meat, fur and scent glands in the 16th century. They’re now being gradually reintroduced and it’s only now that we’re beginning to understand the benefits that people and biodiversity can gain from their natural habits. On the Spains Hall Estate, the beavers have been given free reign to alter their environment by building dams, flooding areas, cleaning water, trapping silt and generally doing what beavers do!
David GascaTucker, Project Lead comments: “This has been a great project to work on and it’s making a real difference to our flood risk management and water quality management approaches. In time, we hope that the beavers will make the woodland a better place for wildlife, with their dams holding water during times of flood and releasing it slowly once rains have passed. The dams will also trap and cycle nutriment and sediment, helping to clean water as it passes through them.”
The Spains Hall Estate has also installed a number of ‘leaky dams’ in streams to redirect water coming off fields, allowing water back on to old water meadows. Leaky dams are stacks of wood that are designed to hold back water after heavy rain but not impede flows under normal circumstances (or prevent fields from draining). In addition, these small wooden structures force flood water out of the ditches and onto the meadows, slowing it down. This should help reduce flooding in Finchingfield and local roads.
Both approaches – natural beaver dams and leaky dams – will be compared to assess which one is more effective at delivering different ecosystem services, including flood risk management. This should help create new localised wetlands as well as improve water storage in flood events. Following their work on this project, the team is now in discussion with other large estates and are hoping to move on to their next project soon.
Our team, with the landowner and some volunteers collecting data to support the project
The Spains Halls Estate project is part of a partnership with the Environment Agency, Essex and Suffolk Rivers Trust, and Essex Wildlife Trust.
For more information please visit the Atkins Catchment Science YouTube channel to see some short films of the team’s activity on this and other sites where they are delivering similar projects. Finally, you can find out more about the project here and an open event is being held at Fichingfield Village Hall on 14 March.