1998
River Serven, Gloucestershire
Environment Agency
Environment Agency
Environment Agency
River Severn Erosion Protection in Gloucestershire Sustainable Flood Bank Stabilisatio
Existing scour line
Newly installed Reno mattress / Geomac
SSSI established in the Geomac
Challenge
A 200-metre stretch of the River Severn in Gloucestershire was experiencing severe erosion along the high tide line, posing a significant risk to the stability of the flood bank. Despite prior protection using traditional stone cladding, the defence had proven insufficient against persistent tidal forces, allowing erosion to continue unchecked. This not only threatened the integrity of the flood defence system but also increased the risk of flooding to surrounding areas.
The project presented additional environmental challenges, as the mudflats directly in front of the flood bank are designated as a Site of Special Scientific Interest (SSSI). This status required that any riverbank stabilisation or erosion control solution be environmentally sensitive, limiting the use of heavily engineered methods and prioritising approaches that would support habitat preservation and ecological enhancement.
Solution
To effectively address the acute riverbank erosion while meeting strict environmental regulations, Maccaferri Ltd implemented a sustainable and integrated erosion control solution. Recognising that soft engineering techniques alone, such as coir logs, root wads, or riparian planting, would not provide adequate protection, a hybrid approach was developed combining structural resilience with bioengineering principles.
The solution utilised stone-filled Reno Mattress units, manufactured from durable double-twisted hexagonal wire mesh, to form a flexible yet robust revetment along the flood bank. These mattresses were securely laced together to create a continuous protective layer and filled with suitably graded stone to resist hydraulic forces and prevent further erosion.
To enhance ecological value and improve visual integration within the natural landscape, soil was brushed into the voids between the stones. This encouraged rapid vegetation establishment, allowing plant roots to bind the structure and further stabilise the bank over time. Known as the Geomac system, this approach delivers long-term erosion protection while supporting habitat restoration and biodiversity.
This project demonstrates an effective solution for river erosion control, flood bank protection, and environmentally sensitive engineering within protected areas such as SSSIs, combining proven geotechnical systems with sustainable design principles.
Used Products
