SEPA approves use of Green Terramesh banking for burn flowing through new residential development

07/04/2005

Green Terramesh® from Maccaferri, specialists in retaining structures, slope reinforcement and erosion protection, has been used to divert and control a burn flowing though a new residential and leisure development in Paisley, Scotland. Approved by SEPA (the Scottish Environmental Protection Agency), the solution developed with Glasgow-based consulting engineers Stuart MacTaggart, offers an easily maintained and 'greener’ alternative that was preferred to the original proposal for a design based on gabions and Reno mattresses.

The development site consists of new homes, which will include both flats and terraced houses developed by Carvill Homes (Scotland) Ltd with associated leisure and health care buildings being developed by Vico Properties Scotland Ltd. Working with local council and SEPA, the developers agreed a specification for the groundworks including provision for 1 in 200 year flood protection, ensuring that water could run safely through the burn even at times of exceptionally heavy rainfall. To satisfy this requirement, the ground has been built up to a height of 4 metres and the burn re-routed to run through the centre of the site.

Located in a deep cutting, the stream now flows in a shallow concrete channel with steeply sloping grassy banks on each side. Supplied by Maccaferri and installed by specialist contractor JC Allan Plant & Civil Engineering Ltd, 600 Green Terramesh® baskets has been used to reinforce the sides and ensure that the banks will be able to contain the water during periods of very heavy rainfall.

Protected by 6ft fencing, the steeply sloping banking has been constructed to a height of four Green Terramesh® units. When installed each unit is formed into three sections, a horizontal soil reinforcement tail, a 600mm high facing section and a horizontal return top section, all formed from a single sheet of hexagonal, double-twist woven steel mesh.

Providing the environmentally sensitive solution required by SEPA, the Green Terramesh® banking was starting to 'green up’ within a month of installation. A layer of biodegradable coir geotextile located behind the front face ensured that sufficient topsoil was retained for rapid grass seeding.

The Green Terramesh® solution also offered cost benefits to Vico Properties. JC Allen was able to use site won material as backfill, avoiding the need for costly removal of excavated spoil and the importing of stone or blocks. Installing Green Terramesh® is quick and easy, bracing triangles ensuring accurate installation. Units are either laced or can be fixed together with special rings dispensed using a 'Spenax’ pneumatic tool, available from Maccaferri Ltd.

The UK arm of Maccaferri Industrial Group, headquartered in Italy, Maccaferri Ltd specialises in gabions, geotextiles, geogrids and geomats. In addition to a full range of products for retaining structures, slope reinforcement and erosion protection, the company offered an in-house, construct, design and consultancy service.

Related Pages