Case Study
Bio engineered erosion protection on the River Rother, East Sussex
Location
Udiam Banks, Robertsbridge, East Sussex
Date
March 2017
Client
AMCO Engineering, Environment Agency
Stakeholders
East Sussex County Council, private landowner
Tasks
- Planting osier willows Salix viminalis along 800m of scoured bank
- Installation of soft engineered scour protection to four locations totalling ~40 linear m using chestnut stakes, willow faggots, willow brushwood, held in place by polypropylene rope.
- Installation of four retaining wall structures and one bridge, built out of green oak.
- Removal of asbestos sheeting revetment of 8 linear m
- Associated vegetation clearance to enable access to the working areas, largely from the southern bankside
Key remarks
- The south bank of the River Rother has been undergoing scour during flood events. Several discrete channels have been formed through the existing flood defence of an earthwork embankment.
- Prior to the works the overflow channels and scour of the existing flood embankment presented a significant risk to public safety. A public right of way passes along the crest of the flood defence, and East Sussex County Council have installed footbridges and handrails to protect users of the public right of way
- The worksite is within the High Weald Area of Outstanding Natural Beauty. The large mature trees on the flood embankment will be retained to maintain habitats for bats and other species. The works were and carried out in accordance with the NEAS Landscape and Environmental Design Guidance, to maintain the landscape qualities of the High Weald AONB
- Ecological surveys were carried out to assess the presence of protected species, badgers, water voles, otters, dormice, reptiles and nesting birds. The works incorporated the ecological mitigations recommended by the ecological surveys
Effects
- Improvement to flood defence
- Protection of public right of way
- Restoration of scoured embankment
