Broadwell Leat – Bank repair and flood control

Heavy erosion produced by the burrowing activity of an invasive species of Crayfish caused a breach.

Project Brief

Broadwell Brook is a secondary tributary of the River Thames that runs from the western edge of the Cotswolds, in Oxfordshire, through Langford and Little Clanfiled into the Radcot Cut. Late in 2017, a branch of the brook, known as the Broadwell Leat, breached due to heavy erosion produced by the burrowing activity of an invasive species of Crayfish. Native to North America, the Signal Crayfish has become a Europe-wide problem, causing devastating erosion in European rivers as well as spreading a disease deadly to local species of crayfish.

Having flooded a vast area of the neighbouring fields, an emergency solution was put in place by Cain Bio-Engineering in January of 2018 using sand bags and geo-textiles to contain the river. Later in the year, the temporary repair structure was removed and replaced by a solid and long lasting solution, protected from further erosion by a two-tier coirnet revetment.

The Solution

The breach in the stream bed was plugged using a filling of clay, gravel, and membranes designed to collect sediment and completely stop the flow of water. Additionally, a coirnet revetment was installed to reinstate the bank and stop continuing erosion.

Our bio-engineered solution will allow the regrowth of vegetation, providing added support to the structure and recovering the stream habitat.




The finished project was delivered clear of vegetation, strongly resistant to further erosion from the river and with a walk path along the bank of the river, extending the use of the garden.