River Case Study: Erosion Control – Charmouth STW

Project Brief

Restore an aggressively eroding outside meander at the toe of a recently constructed Sewage Treatment Work.

Solution

Our technique involved the construction of an armoured sloping revetment using hardwood posts, geotextiles and locally sourced gravels from the emergent point bar.

The re-claimed cavity was carefully contoured to ensure smooth transition of flood flows  over the new  sloping bank face.

A complimentary downstream riffle was also installed to manage scour over the first series of winter floods.

The completed bank face was planted with live willow stakes and left to vegetate naturally with waterborne root stock and seed bank.

The result has been a sustainable, aesthetically pleasing solution, which is in keeping with the geomorphologic and environmental needs of the site.

Charmouth Before

Erosion hole during early winter spate – Nov 2005

 

Charmouth - After

Naturalised structure 10 months later

“This potentially catastrophic problem was resolved using a specialist in-house technique. The solution was cost effective, environmentally friendly and pleasing to the eye, enabling the stakeholders to buy into the emergency project with the minimum of delay”