Moving from drainage to a sponge habitat
River Aller, Selworthy Farm on the Holnicote Estate, Somerset
In West Somerset, the National Trust’s Holnicote Estate comprises a patchwork of small farms, and occupies much of the upper catchment of the River Aller. Like many rivers, the Aller has been heavily modified; the river and its feeder streams are no stranger to historic drainage interventions that encouraged water to rapidly flow off the land to support agriculture. As a result, the landscape no longer holds water as it should, resulting in poor soil health and erosion, increased flood risk downstream, poor climate change resilience, and a steep decline in biodiversity.
Reconnecting floodplains to make space for water
As part of massive source-to-sea river restoration works, National Trust restored 1km of the upper Aller river catchment, reconnecting rivers and streams with their floodplains with low-tech, nature-based solutions. At Selworthy Farm, a stage zero technique was applied—acting as a reset button for the area. The river was filled in with soil and the surrounding land was skimmed to instantly reconnect the watercourse with its floodplain, creating an eight-hectare wetland habitat vital for wildlife, improving water quality and recharging groundwater.
Scroll through the gallery to see images taken before, during, and after the floodplain restoration work:
Wetlands restore biodiversity
An 8ha wetland habitat has been created. Free from its straightened channel, the water now moves downstream slowly through the network of wetland and ponds, and biodiversity has flooded back. Flood peak and flood risk has been significantly reduced. In fact, in the first winter following the work, the flood-prone villages of Allerford and Bossington downstream experienced no flooding despite heavy rains.
“We can already see the early signs of what is happening on the ground - you can see and hear it! The longer-term benefits will be huge! The scheme will slowly develop a section of the River Aller from a managed single-thread channel with limited ecosystem function, to a dynamic and complex system that benefits wildlife and the local community.”