4 minute read
Flimby
Flimby, England, United Kingdom
Making small interventions to create a big impact. On the west coast of Cumbria, four watercourses run through the village of Flimby, which experienced a major flood in 2015 affecting 100 homes. Three of the four watercourses run under the village, culverted, becoming inundated often. Farming practices have compacted the soil, and increased rainfall combined with decreased tree cover have led to greater overland and coastal flooding. In February 2018, the West Cumbria Rivers Trust partnered with the Environment Agency and the Forestry Commission to address these problems by introducing a number of small, nature-based interventions upstream of the village. The mixed woodland of the area provided a perfect source of local materials to build leaky dams and install woody debris at nearly five dozen strategic locations along the catchment. During periods of high flow, the water still passes through these barriers but at reduced rates, allowing the floodplain more time to store the water. With work scheduled to finish in 2021, these numerous small interventions add up to a larger, incredibly cost-effective solution. They have reduced flood risk and rebuilt habitat by restoring the natural function of the river, its floodplain, and the wider catchment.
Article cover: The leaky barrier functioning as designed during high flow, slowing the flow while letting water pass through. (Photo by West Cumbria Rivers Trust [WCRT])
Producing Efficiencies
Traditional flood defenses, such as large-scale, hardengineered floodbanks and coastal engineering, are physically and economically unsustainable. In contrast, natural flood management techniques use natural and locally sourced materials, reducing economic and environmental costs, which makes the project’s delivery and maintenance far more sustainable. The reduction in downstream silt also translates to lowered dredging costs and less frequent clearing of the culverts, creating operational efficiencies. The saved money, time, and resources can aid other flood management projects, benefiting multiple communities.
Using Natural Processes
The Flimby project used trees from the local woodland to make leaky natural barriers that slow the flow while still letting water pass through. Combined with tree planting and the creation of new cross-slope bunded hedgerows to hold back water, these strategically placed features work to maximize benefits to the community while creating habitat for wildlife. Other measures such as subsoiling to improve soil structure aim to help kick-start natural processes to further improve soil structure and boost infiltration rates in an agricultural landscape.
Broadening Benefits
The Flimby natural flood management project aims to reduce flood risk, protecting the local economy from costly disaster relief and recovery disruptions. But the environmental benefits are also numerous: increased carbon storage through tree planting and improved soil structure, improved landscape character and biodiversity value, habitat connectivity through new hedgerows, and increased farm productivity through better soil productivity and shelter for stock. These measures also enhance the water quality by reducing runoff of nutrients and siltation. Further, natural flood management solutions are less expensive and require less maintenance than upgrading infrastructure.
Promoting Collaboration
A number of stakeholders worked together to make this project a reality, including the West Cumbria Rivers Trust, Forestry Commission, Environment Agency, Farmer Network, Woodlands Trust, Cumbria Woodlands, and Cumbria County Council as well as landowners, farmers, foresters, and the local community. Local volunteers assisted with plantings, and the Flimby Flood Action Group ensured members of the local community were represented and informed during the project’s implementation and will continue to represent them during the monitoring period. Further, the Farmer Network and West Cumbria Rivers Trust are working together to engage the farming community.
