The National Botanic Gardens has become the first site in Wales to trial a novel ‘compost sock’ method of controlling riverbank erosion
Pont Felin Gât, a 20-acre native wooded valley, has been managed for more than 11 years by the National Botanic Gardens. The River Gwynon, which flows through the valley, has gradually eroded footpaths and parts of the hillside are collapsing.
For a sustainable solution, the National Botanic Gardens turned to WRAP (Waste and Resources Action Programme) Cymru, which promotes the use of quality compost in landscaping and regeneration projects.
Using an entirely new technology developed by Filtrexx in the US, the team created a protective barrier made up of compost socks. Plastic skins were filled with compost from municipal kitchen and garden waste and placed within a number of sock membranes. The socks were pegged in position, with willow, hazel and wood-rush stakes being used to further stabilise the bare earth on the hillside.
Tim Bevan, estate curator at the National Botanic Gardens, said: “This technology provides us with a long-term solution to the difficulties that we have faced. In a few years’ time the netting and membrane socks will be out of sight and should appear part of the woodland itself.”
Meanwhile Lance Jones, organics project manager at WRAP Cymru, said he hoped the success of the project would encourage other organisations to try the method.