Major ecological engineering project restores Somerset floodplain

A groundbreaking river restoration project in Somerset has reconnected a section of the River Aller to its original floodplain, resulting in a transformed landscape that offers multiple environmental benefits. Using the "Stage 0" restoration approach, a technique developed in Oregon, USA, the project allows the river to flow naturally across the floodplain. This rewilding effort is the first large-scale attempt in the UK to return a river to its pre-managed state, creating a complex, ecologically diverse wetland. 

Restoring natural river flow to combat flooding and drought 

The "Stage 0" approach involves filling in a 1.2-kilometer section of the river that was previously straightened and deepened, encouraging the river to spread over the floodplain and form new channels, pools, and wetlands. This transformation covers an area of seven hectares, equivalent to more than ten football fields, and serves as a buffer against both floods and droughts. When heavy rains occur, the restored floodplain holds water longer, releasing it gradually, which reduces the risk of downstream flooding. During dry periods, this stored water seeps into the environment, alleviating drought conditions. 

This approach creates a "sponge" effect, where the floodplain absorbs excess rainwater and filters it naturally, slowing the flow of water through thick vegetation and capturing sediment. In the past, rivers were often channelized to prevent flooding, but this project demonstrates the benefits of allowing rivers to behave as they naturally would—spreading out, creating diverse habitats, and supporting a wide array of wildlife. 

Benefits for biodiversity and carbon storage 

One of the main objectives of the project is to increase biodiversity by creating varied aquatic and terrestrial habitats. Wetlands are vital for many species, providing shelter and food sources. Since the project’s completion, the River Aller floodplain has developed a mosaic of habitats, from fast-flowing riffles and gravel beds to slow-moving pools and dense vegetation. This diverse environment now supports numerous species of fish, birds, and invertebrates, with notable increases in dragonflies, brown trout, and other aquatic life. 

Additionally, wetlands are effective at storing carbon in their vegetation and soils, helping to mitigate climate change. As native trees and plants grow and mature in the restored floodplain, they contribute to carbon sequestration. In the long term, this project will help to offset emissions, supporting the fight against global warming. 

Enhanced habitat for endangered species 

The restoration has shown early signs of success in supporting wildlife recovery. Water voles, a species facing severe decline in the UK, are already re-colonizing the area. The new wetland provides an ideal environment for these and other animals, with abundant food and shelter. The project team expects that populations of various species will continue to grow as the habitat matures and stabilizes. 

The increase in available wetland area is substantial. Since the project’s completion, aquatic habitat in the floodplain has grown by 1,780%, providing ample space for wildlife to thrive. The new landscape includes wildflower meadows and areas of woody debris, which provide additional habitats for insects, birds, and mammals. Native wildflowers, such as meadowsweet and devil’s-bit scabious, attract pollinators, enhancing biodiversity even further. 

A model for future river restoration 

The Somerset project is being closely monitored to track the environmental effects and inform future restoration efforts across the UK. Through drone and sensor technology, researchers are observing changes in water flow, sediment levels, and wildlife populations. Early results have shown a 38% reduction in downstream flood peaks and a 41% decrease in water turbidity, or cloudiness, which improves water quality for downstream ecosystems. 

This project is part of a broader movement to implement nature-based solutions for climate resilience. By returning rivers to their natural states, these restoration efforts aim to make landscapes more adaptable to extreme weather. As climate change continues to increase the frequency of both heavy rainfall and droughts, projects like this demonstrate the potential of natural floodplain management to protect communities and ecosystems. 

Reversing the trend of wetland loss 

In the last century, over 90% of the UK’s wetlands have been lost, largely due to land drainage and agricultural expansion. Wetlands are among the most productive ecosystems on Earth, and their destruction has had lasting effects on biodiversity, water quality, and carbon storage. This restoration project is a step towards reversing that trend, providing a habitat for native species and creating a landscape that can better handle environmental pressures. 

By allowing rivers to flow naturally through their floodplains, the project showcases an approach that restores ecosystems and strengthens resilience to climate impacts. As the first large-scale "Stage 0" river restoration in the UK, the project has set a new standard for how rivers can be managed to benefit both people and nature. The success of the River Aller floodplain restoration may pave the way for similar projects nationwide, contributing to a future where natural landscapes are an integral part of climate adaptation strategies.