Clifton-on-Bowmont Riverbank Erosion Protection
Bowmont Valley, Scotland
Through the Farm Resilience Planning approach being developed through Cheviot Futures (see the farm resilience planning section under projects on this website for further details), a key issue identified for Clifton-on-Bowmont was that of flood risk and associated riverbank erosion.
Working with the farmer, we have developed and implemented a programme of works to showcase four different approaches to green bank protection works, in line with SEPA authorisation requirements, to protect against further erosion, and assist the repair and stabilisation of the riverbank.
The site now has four distinct sections of work completed - a 30m long bank protection 'Engineered Log Jam', an 80m length of protection using the innovative Filtrexx product (plastic socks filled with pre-seeded compost), a 35m stand-alone Engineered Log Jam structure to prevent further erosion of a floodbank feature, and an 80m length of protection using an enhanced specification willow spiling approach (woven willow panels that will mature to create a living barrier).
The intention is to use the site as a demonstration, allowing easy comparisons to be made between the techniques employed, including a consideration of relative ease and indicative costs of construction, comparable across a per m guide price.
This site represents the first capital works project fully completed on the scottish side of the project area.
A case study document relating to this project is available.
UPDATE: Following the large flood event of September 2012 and subsequent high water flows, the works at Clifton have shown variation in their response.
The ELJ site upstream of Clifton Bridge was undamaged; both the willow spiling and Filtrexx sites suffered some relatively minor damage to the downstream extent which will require repair works to be undertaken. The vertical revetment timber design fared less well, with some of the structure removed by high waters earlier in 2012, and replacement works removed in September.
The response of the different sites offers valuable lessons in terms of placement and specification of riverbank erosion protection works.
Please find below documents relating to the project.