Project Description


Following the partial collapse of the River Coly’s banks, a road was rendered impassable and had to be closed. Our task was to install a rock armour stone retaining wall from two tonne boulders.


Like most projects, this revetment presented some key issues. First, the emergency works had to be carried out in December and January, with a constant risk of flash flooding. Secondly, we needed to use a long-reach excavator and grab attachment to remove the material that had collapsed into the river – 500mm below the existing riverbed level. As excavators can cause possible contamination issues with leaks or a burst pipe, we used biodegradable oil in its hydraulics to minimise the impact of any possible contamination.



Within six weeks, we were able to build up the riverbank’s edge to road level, enabling the road to be reinstated and reopened.


Quick facts

Client: Devon County Council

Value of works: £40,000

Project type: Bridges & Structures

Scale: 3m x 50m