4 minute read
Wendling Beck
Worthing, England, United Kingdom
Mimicking nature’s engineers for flood control and habitat restoration. The village of Worthing is subject to flooding from two incoming rivers, Wendling Beck and the River Blackwater. Attempts to drain and crop the floodplain after World War II left both rivers deepened and straightened, degrading the habitat and increasing arable runoff. As a result, the area lost a great deal of good habitat, and the spoil banks left behind after the dredging meant the rivers rushed downstream towards Worthing instead of spilling onto their floodplains during heavy rainfalls. Between 2017 and 2019, the Norfolk Rivers Trust, a nonprofit conservation organization, worked the landowner and the Environment Agency to improve habitat and store more water on the floodplain. The team removed banks, reconnected meanders, and installed woody debris that mimicked beaver dams, the country’s first use of beaver-dam analogs. These techniques lowered dredging embankments and raised the riverbed through natural sediment deposition rather than by importing gravels. Hydrological monitoring and field surveys are ongoing to assess the impacts on fish, invertebrates, and plant life; but now Wendling Beck’s complex habitat is thriving—clearer waters, reduced flooding, and increased biodiversity.
Article cover: With more water stored upstream, aquatic vegetation such as starwort (Callitriche spp.) thrives. (Photo by Norfolk Rivers Trust)
Producing Efficiencies
Rather than importing gravel, the team raised the riverbed through natural sediment deposition, and for the structure and function of the engineered log jams, the team took as their inspiration the engineered dams of beavers. Using a single excavator from one end of the reach to the other, they felled trees and laid them in the watercourse and used only materials found on site. This technique minimized fuel and carbon costs and delivered cheap, effective flood control mechanisms that require no ongoing maintenance.
Using Natural Processes
The project aimed to reverse the effects of six decades of intensive management by accelerating natural processes: felling large trees into the river and creating beaver dams in their absence. The team also excavated several ponds and backwaters in the floodplain to mimic features previously filled in to improve grazing. All these processes improve habitat complexity and push water onto the floodplain, where it will naturally be stored. The power of Norfolk’s lowland, spring-fed rivers is so slight that the damage would otherwise take centuries to reverse.
Broadening Benefits
This project will reduce the frequency and severity of flooding at 20 different properties and two public highways, preventing future clean-up and recovery costs that would otherwise have been paid for through taxes and private insurance. By storing more water in the floodplain, the project promotes vegetative growth, creating the foundation of a resilient, self-sustaining ecosystem and building habitat for numerous species. The project also improves the overall health of the River Wensum site of special scientific interest, arguably one of the most ecologically and socially important rivers in England.
Promoting Collaboration
Norfolk Rivers Trust coordinated the project on behalf of one of the riparian landowners, who provided the majority of funding. The trust worked with the Environment Agency and local drainage board on the project design and received further public funding from the Environment Agency. The trust also liaised with local councils and neighboring riparian owners, increasing the initial scope of the project significantly and leading to a much broader area of restored riverine and floodplain habitat.
