Nature inspires a flood alleviation solution
An unconventional flood alleviation scheme, designed to work with nature and emulate naturally occurring woody debris, could help relieve north Buckinghamshire communities of flooding threats from a swollen river.
Twenty five 'leaky barriers' are being built in the headwaters of the River Leck to store and slow the water during heavy rain in order to reduce flood risks downstream. And they perform not unlike the kind of dams beavers build!
Buckinghamshire County Council's Flood Management Team commissioned the construction of the £85,000 leaky barriers in the summer: a scheme which uses locally-produced timber to act as barriers.
When they are all built, the barriers should alleviate peak river flows by up to 10%. This, says Bill Chapple OBE, Cabinet Member for Planning and Environment, will help protect downstream communities, such as Leckhampstead, from the risk of flooding.
"Who'd have thought we'd ever turn to the beaver to teach us about river flow management!" said Bill. "This process will help these headwaters behave naturally, almost like they did before we humans ever got anywhere near them!"
The leaky barriers scheme - a 'first' for Buckinghamshire and one of the first for lowland southern England - will be monitored in partnership with landowners during the next couple of years to measure their effectiveness, with a view to replicating it in other parts of the county.
Bill said: "The beauty of these barriers is that in the event that they don't initially work as our flood management team modelled, they're flexible enough to adjust, or even move."
The scheme is truly a local enterprise, said Bill. The County Council is working with three landowners, one of whom provided the timber for the project for free, and former local farm manager David Gowton who now runs Escapes, the agricultural and landscaping contractor, has been handling the construction.
Design and oversight has been led by Peter Case, of Freshwater Habitats Trust, who have been building and testing similar dams for their Water Friendly Farming project in Leicestershire, and Andrew Waugh of the BCC Flood Management Team.
And it comes with its own creative technological solar-powered monitoring system in the form of converted car reversing sensors that detect rising river levels and measure the capability of the barriers to hold back water.
Leckhampstead Parish Council are fully behind the scheme. Parish Councillor, Richard Gurney, said: "After working with Andrew Waugh from the County Council and Peter Case from Freshwater Habitats Trust for over three years, it’s great that we will finally have 25 of these impressive dams in place ahead of the planned schedule and we are confident that this will reduce the flooding risk to those village properties that have been affected in the past.
"The Parish Council extends its thanks to their parish neighbours and the landowners for enabling this project. Being the first such project in Buckinghamshire will also mean Leckhampstead will be providing an example of the potential for other such projects in the future.”
One of the key landowners, Oliver Robarts of the Tile House Estate, commented: "With the excellent support of the Freshwater Habitats Trust, the Tile House Estate is very fortunate to be able to help contribute to flood risk reduction on downstream communities. The innovative combination of natural flood defences, 'leaky dams' and the high-tech monitoring stations will no doubt prove to have a beneficial impact on downstream flooding and the wider environmental concerns."
The scheme is being funded by a £50,000 award from the Department for the Environment, Farming and Rural Affairs secured by the County Council’s Flood Management Team, and £35,000 from the County Council's flood management budget.
Leaky barriers have been assessed under university-led research conditions in Northumberland and the Gloucestershire uplands, and this project is one of the first practical examples to be completed in lowland southern England.