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Water Courses & Aquatics Engineering

A whole range of products are used extensively for revetment protection, vegetation establishment and enhancement and watercourse reconstruction works. Frequently several products are used in conjunction where a scheme has several factors influencing the problem.

Bio-rolls and Bio-Pallets

-Bio-rolls and Bio-pallets are manufactured from 100% coir fibres
-Supplied pre-established with native species marginal plants with a mix or onespecific species or grown to order
-Supplied unplanted with 6 planting holes per linear metre. Local indigenous aquatic plug plants can be supplied separately for on site planting as necessary
-Bio-rolls can be supplied in a variety of diameters with 300mm being the standard size. Rolls can be stacked to provide greater protection against fluctuating water levels
-Bio-rolls can be supplied in a variety of diameters from 200mm to 500mm with 300mm being the standard and lengths from 3.0m – 6.0m. Rolls can be stacked
-Bio-pallets are manufactured in a pad size of 1.25m x 0.80m x 0.1m thick. Other sizes available on request
-Bio-rolls and Bio-pallets are quick and cost effective to install using wooden stakes or steel pins to fix into position.

Willow Revetments

Willow provides an excellent alternative to traditional hard landscaping or engineered solutions where rock and concrete are being considered. Willow is a biomass crop and cuttings can be used for other repairs etc. Willow can enrich a river’s habitat and is suitable for a wide range of projects including SSSI and conservation sites.

Coastal River and Floor Protection

Typically the need for protection results from erosion of the watercourse bed or erosion of the banks of the watercourse. It is a similar situation for coastal protection works where it may be beach erosion or erosion of the protection bunds. The specification of the type of gabion depends upon the corrosion protection required. Where the gabions are subjected to saline conditions or where the water quality may be detrimental to zinc coatings, PVC coated gabions should be specified. In neutral environments where the soil/water acidity is in the stable zone for zinc (PH7 to 10) then galvanised or galfan coated gabions can be specified.

Gabion protection generally takes on two forms, either as a sloping bank protection using a mattress laid on the slope with a geotextile membrane underneath or as a retaining structure to form a steeper face with a geotextile membrane behind and beneath the structure. In both cases consideration must be given to the possibility of erosion at the toe, therefore a mattress toe protection or an embedded gabion must be provided to prevent underscour. The main functions of a geotextile used beneath rock armour or rip-rap for erosion control are filtration and separation. A Geofabrics’ filter/separator provides high extension together with excellent puncture resistance which means little damage occurs when placing large rock. Sustained flow capacity and sand tightness are achieved at all strains. In very exposed areas where it is possible that accretion of sands may not occur, a secondary mineral filter layer is placed prior to the primary rock armour.

Download a PDF of our Geotechnics Guide here