New channel for the Glaven at Bayfield
A new channel for the Glaven at Bayfield
A new meandering river channel has been created at the Bayfield Estate in Norfolk. The channel, which is part of the River Glaven, will provide a rich habitat for wildlife – particularly those which are associated with rare chalk streams.
At 1200 m in length, the new channel is one of the longest man-made stretches of river in the UK. The channel’s design is based on the untouched remnants of natural chalk streams still found in Norfolk.
Why?
The Glaven’s natural course had become disrupted by an estate lake and an enclosed, brick culvert. The new course, which bypasses the lake, has over thirty gravel riffles – suitable for fish spawning – as well as many deep pools.
Work has also taken place in a meadow upstream of Glandford Ford, with the aim of enhancing the Glaven river and creating a new wetland area. The channel was narrowed in places to provide a varied flow, and marginal embankments were removed to reconnect the river with its floodplain.
Further upstream, between Little Thornage and Thornage, meanders have been constructed using natural materials to alter the straightened sections.
Getting the balance right between enhancement and interference in this project was critical: Firstly, the restoration measures needed to maintain existing ground water levels over most of the valley floor for grazing to continue. Secondly, it was important to ensure that there was no increase in the frequency of inundation in the reaches not being restored and that there was no adverse impact on flood risk downstream. Thirdly, water voles and native crayfish were present at this habitat.
Acknowledgements:
This project was part of the overall ‘Nine Chalk Rivers’ project. A huge thanks to the Wild Trout Trust, River Glaven Conservation Group, Professor Richard Hey and the Environment Agency for making this work.
Since the river was last dredged at Thornage, reeds – especially burr reed – had encroached into the main flow, making the channel considerably narrower in the straightened sections.