Hamble Restoration: Phase 2

The Hamble Brook is a winterbourne stream that has been extensively modified over many centuries, through activities such as agricultural cultivation, ornamental landscaping and flood alleviation. Most of human activities have negatively impacted the stream’s natural function and ecology.

In 2022 the Chilterns Chalk Streams Project completed the first part of the Hamble Brook restoration project, involving 1100m of the stream. The length of the restoration equates to 16% of the entire length of the Brook, one of the largest winterbourne restoration projects ever attempted. The restoration involved ‘re-wiggling’ the channel, creating a meandering stream with a more natural shape and flow regime and re-profiling banks to better connect the brook to the surrounding landscape. The impact of the work and the changes to the stream’s biodiversity have been monitored with Riverfly and MoRPh surveys by citizen scientists, along with researchers from Queen Mary University of London and Nottingham Trent University.

In 2024 the CCSP has been able to extend the Hamble Brook project thanks to funding from the Environment Agency and Farming in Protected Landscapes.

This second phase of the restoration has created 2500m² of wetland, widened a spring channel and created a willow island. Sixty native saplings were planted to improve shading, providing natural temperature control.

The highest flows in a decade that followed the completion of the work has provided an early insight into how positively the river corridor can respond under the right circumstances. The surveys confirmed sightings of the winterbourne stonefly and the scarce purple dun mayfly. This is the first record of Paraleptophlebia werneri –Scarce Purple Dun, in both Buckinghamshire and the Chilterns National Landscape. This a winterbourne specialist and needs the dry periods to complete its life cycle. It also requires well vegetated stream habitats, which the restored Brook possesses in abundance.

(From the left: Paraleptophlebia  werneri nymphs, P. werneri, P. werneri male. Hamble Brook 2023. Credit Allen Beechey)

The project has generated a positive interest from the local community and other national organisations and media, resulting in visits from Natural England, the National Trust and Environment Agency groups. The staff involved in the project were invited to community talks and events and the Environment Agency press release resulted in a positive coverage on BBC South Today and across local news media. Display material about the project was presented at two conferences and the extent of the restoration has been captured in the video-case study above.

Further funding from the Environment Agency will support continued Citizen Science involvement as well as the development of the next stages of channel improvement, hopefully leading to a doubling of the restored river length over the next couple of years.