Bioengineering Practice - Case Studies

The use of pre-planted coir rolls as an erosion control measure has been widely used by the A.G.A Group on a number of projects. The A.G.A Group often get invited by Local Authorities to compile tenure reports for proposed pond and lake remediation work which involves this methodology. By positioning the pre-planted coir rolls around sections of a lake they not only stop erosional processes taking place but as they are pre-planted with marginal aquatic species they provide habitat and nutritional benefits for the lake.

One such example of the use of this methodology is a project undertaken at the Cricketers Pond, Sarratt, Hertfordshire where a sloped terrace was created using coir and reclaimed material from the lake to protect the bank from erosion and create a ‘new’ bank-side. The A.G.A Group designed and carried out the construction phase for which the company was awarded the landscape design award 2007.

The height of the pre-planted rolls can be adjusted by using rock rolls or faggots or alternatively they can simply be attached to the existing bank. The methodology has proved extremely successful in achieving the aims of the clients and providing a ‘green’ solution whereas in the past hard erosion measures have been used. By using bio-engineering techniques you not only improve the aesthetics of a site but provide habitat that encourages biodiversity both above and below the waterline.

Another example of the bio-engineering work the A.G.A Group carry out is a bank reclamation project for the Environment Agency and Cirencester Town Council. The A.G.A Group we approached to carry out the work and used a methodology which involved the use of silt from the river to backfill behind constructed coir and faggot revetments. The approach proved extremely effective in protecting the river bank and reducing erosion.