Q: Tell us more about the project. How did you first assess the land's potential and design the programme?
ARB: We started with a boots-on-the-ground investigation to track where water was accumulating on the estate and its flow paths, supporting this where relevant with open-access water models. This helped us identify the areas where intervention would make the most possible impact.
Then in 2019, we created a four-hectare woodland enclosure around one strand of the Finchingfield Brook, and introduced a pair of beavers from a conservation specialist in Devon.
This beaver dam was complemented by a man-made natural flood management on a second strand of the brook, using a 'leaky dam' approach.
'Leaky dams' essentially involve securing tree branches or trunks across a watercourse to help slow the water flow after heavy rain, and help create wetland that will release water in drier periods. With timber sourced from the estate, these structures are fairly simple and cost-effective to put together. While the impact on immediate storage is modest, they are primarily designed to reconnect the floodplain and increase water storage during storms.
We also introduced field edge runoff attenuation, using features like swales, ponds, and bunds, to filter the runoff from fields, and thereby improve water quality and support aquatic life. Typically, that runoff would have carried pollutants from agricultural processes into nearby ditches, while now it has time to infiltrate into the soil.
To monitor the impact of all three, we worked closely with King's College London and the Environment Agency to station equipment and other sensors around the leaky dams and beaver enclosure. The woodland enclosures double as natural research spaces to study and report on the connections between wildlife, water management, and agriculture.