Working with Action for the River Kennet (ARK) and the Environment Agency we carried out restoration works on 500m of the River Kennet in Marlborough. FiveRivers worked closely with ARK and the landowner to complete the restoration with a fluid and flexible onsite design approach.
The restoration of natural processes and increasing biodiversity for 500m of the River Kennet. Measures delivered included:
- Gravel causeways installation
- Bank reprofiling and channel narrowing
- Wetland scrape creation
- Selective tree limb hinging and securing
- Installation of Woody log deflectors
- Course brushwood mattress installation
- Construction of large-scale hibernacula feature
FiveRivers were instructed to carry out the installation of features in line with the plans and field fit accordingly. Designs and techniques were adjusted according to site variations, protected species and ground conditions.
A colony of watervoles were identified living in part of the reach, their presence inhibited the re-grading of the bank. The river is exceptionally wide and deep at this location so an alternative approach to narrowing the river was required. An onsite solution was developed in partnership with the client and landowner, narrowing the river with trees and ensuring the protected species and burrows were not impacted. The large woody material will trap sediment.
Lowering of the true right-hand bank offered an opportunity to reconnect the River Kennet with its floodplain, increasing flood storage and reducing flood risk down stream.
We returned in June 2022 to see the progress of the works. The client and landowner are delighted with how the project has bedded in, the gravel causeways and bank re-grades are colonised with marginal species of local providence and the actions delivered have transformed the geomorphology of the reach. The borrow pits required for the site won gravel and soil are well established ponds, significantly enhancing the biodiversity of the floodplain.
In the locations where the water voles are present, the large woody material is accreting with sediment. Some marginal species are establishing in the shallower margins but the of the depth channel means it will take a couple of years. Volunteers will return in the near future to translocate site won colonisation and further accelerate the colonisation process.