Erosion Control

Silt Laden Run-off Control, Erosamat Type 1 and 2 - Cobrey Farm, Ross-on-Wye, UK

Client Cobrey Farm

Cobrey Farm

Consultant Cranfield University

Erosamat Type 1 – Biodegradable Jute

Erosamat Type 2 – Biodegradable Coir Mesh



  • Approved for use on Site of Special Scientific Interest
  • Reduction of land take for the waterways reduced the cost of losing productive farmland
  • Protects silt from erosion
  • Protection for grass seed and seedlings during initial growth
  • Fully biodegradable
  • Easy to install

Project Description

Cobrey Farm is a family run business in the picturesque Wye Valley. The farm grows a range of crops over its 1,500 acres of land, and is known for being one of the UK’s largest and most innovative growers of asparagus, fine beans, and blueberries in this hilly area.

The Wye Valley is home to a number of rare and highly sensitive species of crustaceans. The eco-system is very sensitive, so the area has been designated a SSSI (Site of Special Scientific Interest) to protect it.

Environment Agency monitoring revealed that during heavy rainfall significant volumes of runoff were picking up soil particles and discharging into protected waterways.

The Challenge

Many years of farming in the area had caused a reduced level of organic content in the soil, which meant low capacity for water retention. This caused high surface runoff volumes during heavy rainfall, washing expensive fertiliser treatments away, and causing further erosion of soil particles as they are lifted and carried from the fields.

Drainage ditches had been installed to combat this, but they proved unable to cope with the volume of water and required frequent maintenance. Previous attempts to establish grass had also proven difficult due to residual levels of herbicide in the ground.

The Solution

Cranfield University designed planting layouts incorporating grassed waterways to control runoff and reduce the damaging effects of erosion. Establishing grass is the key to the long term success of this approach, but the residual levels of herbicide meant the grass took a long time to take hold.

After consultation with ABG, Erosamat Type 1 Jute based and Erosamat Type 2 Coir based erosion control mats were specified for different areas to provide immediate erosion control for the new waterways, as well as protection for the grass seed during the extended growth period. This protection allowed the waterway to be 50% smaller than without Erosamat biodegradable erosion control mesh, so the land loss to the waterway was reduced. Further soil erosion was prevented, and the degradation of Erosamat added organic content to the soil.

This solution was deemed so successful that Cranfield University and the Environment Agency invited ABG to present at a “Better Soil and Waste Management” event to educate other farms in SSSI areas on how to manage their sites as successfully.

Erosamat Type 2 Biodegradable Coir Mesh structure

The ABG Service

ABG expertise helped to select the correct Erosamat for each area, and confirmed appropriate installation methods.

Contact ABG today to discuss your project or specific erosion control requirements and discover how ABG Erosamat or other erosion control geosynthetics can help on your project.

Additional information