River Ouse nr Piddinghoe – Erosion control

The bank failure is thought to have been exacerbated due to freshwater lakes on the landward side of the embankment.


The bank failure occurred along the TLHB of a tidal section of the river Ouse near Piddinghoe, New Haven, East Sussex. The failure is thought to have been exacerbated due to freshwater lakes on the landward side of the embankment, which encouraged permeation of water through the bank. A solution was required that would extend the life of the embankment by 3-10 years to allow time for a preferred strategy option to be delivered by the Environment Agency.

Cain BioEngineering installed a brushwood mattress along the section of localised bank slip (~35m), secured in place by Sweet Chestnut hardwood stakes, retained by an inert geotextile and Coir blanket.

Once installed, the brushwood mattress along with the Coir blanket would accrete sediment over time, due to the tidal nature of the channel. This sediment accretion would increase bank stability and further increase the protection of the failing bank over time.

An upstream view of the scour hole to TLHB at low tide
An upstream view of the scour hole to TLHB at high tide
During the installation of the brushwood mattress and retaining post structure
An upstream view of completed brushwood mattress
A detailed view of sediment accretion by the brushwood mattress after 5 years