A “leaky dam” is not something I’d heard of before coming to Broughton Hall Estate in North Yorkshire, but, as I discovered, it’s very aptly named.
Leaky dams have been constructed in streams across the estate as part of a natural flood management project.
The “leaky” part is very deliberate.
An inspiration from nature
These dams, constructed from twigs, leaves and natural debris, manage the flow of water downstream while still allowing fish to pass.
Slowing the flow of water through the estate helps to prevent flooding in communities in nearby lower-lying land.
Something similar to these leaky dams would naturally be done by beavers, but you won’t find them at Broughton these days, they were hunted to extinction in Yorkshire in the sixteenth century.
Replicating their efforts is part of a larger project on the estate being overseen by Professor Alastair Driver – an expert on conservation and rewilding.
He said: “If you roughen up the landscape with a big rewilding project and you implement these natural flood management interventions you are going to make a significant difference.”
A history of floods
The techniques they are employing here to manage water flow are significant for people living in areas surrounding the River Aire, particularly Leeds.
In 2015 Leeds, and other parts of the North of England, experienced catastrophic flooding. The Leeds Flood Alleviation Scheme is a £160m project designed to protect 1,048 homes and 474 businesses from future flooding.
Broughton is a sprawling and beautiful estate within the Yorkshire Dales.
The work there forms part of that scheme, partly by making sure water has more space to flow on the estate before it hits urban areas like Leeds. This involves “daylighting” water that has, for many years, been flowing through pipes underneath the estate’s fields.
Broughton Hall has been owned by the same family for almost 1,000 years, and sheep farming has been a long-running part of the estate’s history.
There are still sheep here today but the land is now being used for other purposes to serve the environment and surrounding communities more effectively.
Professor Driver says that the water pipes beneath the fields were probably created to free up space above ground for grazing.
Looking across this “daylighted” stream, the water looks free to find its own course.
Professor Driver says when he last came to see the progress of the stream a heron flew out of it. That moment felt symbolic, it reminded him of the importance of the “back to nature” approach they are taking at Broughton.
They are also planting hundreds of thousands of trees here. Not only will trees help to reduce the risk of flooding by slowing the flow of rainwater – they also store carbon.
More to be done to counter climate change
Combatting climate change is a vital part of the work they’re doing on the estate and shows how flood management techniques can have other important benefits like reducing emissions.
“We need to be thinking about the wider environment, climate change, biodiversity, people’s health and well being. All of these other benefits need to be part of that,” says Professor Driver.
But of course, there need to be incentives for farmers across the country who rely on sheep to make a living.
The government wants farmers to apply for subsidies under a scheme designed to allocate “public money for public goods”, meaning they’ll be paid to use their land to deliver environmental benefits.
This is supposed to stop farmers from taking a financial hit from becoming more green. Professor Driver says this scheme is needed, but many farmers want to see assurances about long term funding so that landowners can have confidence in investing in more eco-friendly methods and technologies.