Erosion & Sediment Control
Silt Fence
Silt Fence is used to prevent silt movement caused by wind or water flows over exposed soil from entering waterways and infrastructure such as stormwater pipes. Silt Fence can be supplied with a full complement of silt fence accessories including Steel Y Posts, 2.5mm tensioning wire and safety caps. Silt Fences are typically installed on earthworks sites at the downstream boundary or immediately downstream of soil stockpiles.
The installation of silt fences follows local sediment control guidelines where supporting post spacing is typically no more than 2m apart and the silt fence extends to a height of 600mm above ground. Geotas supplied accessories provide support to the silt fence to meet the local council requirements. In all cases regular maintenance of silt fences is required which includes inspections after storms and removal of excessive silt deposits.
Silt fence comes in rolls 860mm high x 100 M long
Bluemont Rock bags
Bluemont rock bags are a cost effective solution for the protection of high value assets like bridge and dock piers. The double layered, anti-tear netting can contain two or four tonnes of material, and will act like one big rock when set in place. Able to be placed in a row, layered one on the other, or even stacked back on an eroding slope, these rock bags are simple to install and require little to no subgrade preparation.
These bags work to absorb the energy from fast flowing water, while at the same time providing a steadfast foundation for crumbling riverbanks because not only does their structure create a 2 tonne foundation, but the small gaps and voids in the bag allows for sediment capture and even vegetation growth.
The installation of these bags is a quick job. The bags are placed in a steel box allowing for easy measurement of rock, tied off, and then lifted into place with a machine. Dependant on travel for the machine, a bag can be filled, tied, and placed all within 5 minutes. Geotas can supply a steel box for installations and are always happy to lend advice to anyone with questions.
Bluemont bags are available in 2 or 4 tonnes, but can be custom ordered to suit your job.
Concrete Canvas
Concrete Canvas GCCM (Geosynthetic composite cementitious mat) is a flexible concrete impregnated fabric that forms a thin but durable layer that is resistant to fire as well as waterproof. The rolls allow for concrete construction without the need for a plant or onsite mixing equipment, once the rolls are deployed and set in place, they simply need water set them off (It can be any water type, including sea water). Concrete Canvas is widely used as a cheaper alternative to non-structural shotcrete.
The canvas is available in three different grades, CC5, CC8, and CC13, which are 5, 8, and 13mm thick, respectively.
EARTHLOK
Australian made EARTHLOK is a flexible concrete matting system made up of a grid of 50 Mpa concrete pyramids that are 165mm squared on the base and rise up 60mm to a 50mm square top. Each block is bordered by a 40mm gap that allows for flexibility in addition to the option for vegetation growth; If the vegetation option is utilised, the lifespan of the system can extend up to 100% on top of the expected lifetime of 50 years. EARTHLOK provides permanent hard armour protection against erosion form wind, rain, tides and wave action, and other forms of water damage. The pyramid shape of each block uses the pressure applied by the flow of water to further anchor the system onto the surface and stabilising and protecting the surface underneath as designed.
Silt Curtains
Silt curtains are for instillation in waterways to prevent pollution and suspended sediment, caused by construction activities, from contaminating the greater area. Depending on the need, silt curtains can either be permeable or impervious to the passage of water and are deployed using floats fastened along the top and are weighed down with ballast along the bottom. The sides of each module can be zipped to another to provide a curtain that extends as long as is required, ensuring that any job, big or small, can be catered to. Silt curtains are not meant as a filtering system, but as a boundary behind which sediment suspended in the water has time to settle.
Geobags
Geobags, also known as dewatering bags, are used in the construction and mining industries to filter sediment from contaminated water. They are a simple, but efficiently effective method and as a result, can be used in a range of situations; dewatering applications (such as after rain events), dewatering dredged material, or dewatering of sludge from treated wastewater. The simplicity of this system means the need for troubleshooting is almost non-existent, the upkeep over time is minimal, and maintenance is a non-issue. Geobags come in a variety of sizes to suit any project, and have a flow rate of 80L/m2/sec out of 90-micron size pores.
Silt Socks
Silt socks provide a simple and easily manageable solution to control water movement and reduce soil erosion by blocking and redirecting the flow around, or away from, vulnerable areas. Starting at 1-meter lengths, and easily used in tandem, silt socks can be deployed over a long distance, or just a short span, depending on the need. Common uses for these socks are: diverting stormwater, redirecting sediment laden water into sediment traps, preventing silt polluted water from entering waterways, and reducing the energy and flow rate of water.
Geotextile silt socks are fabricated to a robust standard using heavy duty material.
Rubber filled silt socks are fabricated to the same standard, but use a UV resistant HDPE shade cloth instead, and these more robust socks can endure more and can even be driven over without being compromised.
Grassroots
Grassroots is an erosion control matting designed for long term use protecting underlying soil on steep slopes, channels, surfaces that are susceptible to rain splash erosion, and even shallow surfaces that will be subject to a mid to high volume of water transit. This system is made of heavy synthetic UV stabilised fibres which are needle punched together to form an ‘open weave synthetic scrim,’ meaning it creates a three-dimensional structure with pockets and crevices for vegetation to take hold and grow, even in extreme conditions. This aesthetically pleasing surface treatment blends into the environment even when unvegetated and will eventually become a hidden structure. The product is un-rolled and pinned down over a pre-seeded area, and the grass will then grow up through the product.
Geoweb
Initially designed by Presto Geosystems in partnership with the US army to allow heavy vehicle transit over soft terrain, Geoweb consists of a robust three-dimensional grid made up of a network of interconnected cells that confine, compact, and stabilise the selected soil or aggregate. Mostly used for the reinforcement of roads, erosion control, slope stability, retaining structures, and high velocity channels, Geoweb caters to a range of different subgrade issues, solving them in an efficient and cost-effective way. Due to the small holes set in the webs, perpendicular to the roll direction, water can pass through the structure without detracting from the stability, and this is also beneficial to the top layer, as water runoff will be far less significant and corrosive. Once the system is installed it blends in with the environment, benefitting the surrounding area, without detracting from it.
Bunkermat
Bunkermat is a ‘three-dimensional matting’ (meaning it has a porous surface) and is used when constructing bunkers on golf courses. The open structure of the fibres allows for sand to be trapped on the surface and this, in turn, provides a bunker that stays in a good playable condition.
BunkerMat is also a filtration barrier which limits the migration of fines from the subsoil rising to the base of the bunker and contaminating the bunker sand, making them unplayable. The synthetic mesh backing on BunkerMat creates strength and durability in the product, thus preventing tearing of the BunkerMat when sand is being raked.
Enkamat
Enkamat is a dense three-dimensional permanent turf reinforcement mat used when naturally grown vegetation cannot prevent soil erosion on its own. Enkamat functions as a protective reinforcing layer to the root system increasing the hold of the plants to the ground below. Once a layer of vegetation is established, Enkamat provides root systems with permanent reinforcement, resulting in an integrated, effective erosion control system on soil slopes, spillways, landfills, shorelines, or in waterways.
Macmat-R
MacMat R is a mesh reinforced three-dimensional geomat that can be applied as an erosion control mat for sloped embankments, channel linings and soil-veneer applications. It was developed to meet the need for permanent erosion control material which was both strong and environmentally acceptable.
MacMat R turf reinforcement matting is a unique composite material of MacMat and Maccaferri’s double twist hexagonal woven mesh reinforcement. The MacMat component is made from an open three-dimensional mesh with a high open area to hold soil and provide a medium for root reinforcement, and the double twist mesh provides resistance to rupture of the geomat on steep slopes when soil filled as well as improving the efficiency of soil anchors.
The double twist mesh component means this product is perfect for use where control of rocks from falling onto infrastructure is important.
Jute mat
Jute Thick Matting is made from 100% natural jute fibres and is a robust material used for weed and erosion control. Jute matting acts as a layer of mulch providing weed suppression and moisture retention to enhance plant establishment whilst protecting the top layer of soil from erosion. When used in conjunction with our installation sheet, this product will last in the field between 8 – 18 months dependent on environmental conditions, which allows enough time to establish ground cover and soil holding plants and trees on the area to be protected. Jute matting can be provided with pre-cut slits to allow for plants to grow through the material, or plain no slits.
The Jute mat is available in rolls 1.83M x 25 M long.
Jute mesh
Jute Mesh is a natural, flexible, loose woven jute ‘cargo-net’ mesh used for erosion control and seed establishment. Jute Mesh is an inexpensive and flexible product that is easily separated to be used around existing vegetation. This natural fibre assists in capturing wind blown soil and native seeds, and is perfect for when you are establishing grasses, while also protecting against soil loss from wind and rainfall erosion.
Jute mesh is ideal for natural rehabilitation of areas like sand dunes, where a combination of natural and seeded rehab is being conducted. It is a cost effective, 100% natural fibre, that helps to retain moisture, as well as adds organic matter when it breaks down.
coir Logs and mesh
Coir Logs provide erosion and wave control structures in riparian zones, and sediment capture in drainage lines and swails. They can be for river banks, streams and road-sides to slow water runoff and capture sediments. They are also used to protect steep gullies and embankments from scouring due to surface water runoff. These products are ideal for slowing water run-off and sediment in a variety of settings.
Coir Matting is an open weave matting that is applied over the top of soil to promote growth of new plants, maintain soil stabilisation and prevent erosion or land degradation. This is available in either 700 or 900 GSM thickness depending on your projects specifications and needs.
Coir Logs & Mesh are manufactured in India from coconut husk and fibre. They are biodegradable, have no plastic or artificial components and are an eco friendly solution for your erosion and sediment control needs.
Waterway erosion control
The control, prevention, or repair of locations that are affected by the damaging affects of fast flowing water, is a rather complex area, and something that requires serious consideration at the least, and generally the advice of engineering experts. Geotas has had many years of experience in assisting clients with both engineering suggestions, and product in numerous waterway scenarios. A majority of these solutions are based around the use of Maccaferri Gabion baskets, Reno mattresses, and Terramesh, which have a history of over 140 years,- so well tried and tested!
Each situation will have it’s unique set of circumstances that need to be considered in order to provide the best solution. Please contact us, and preferably have some photos of your problem area, and we will seek advise from our engineers, about the best solution that we can offer. Design suggestions can then be offered, which may then need approval from your own engineer, prior to works.
The following pictures will provide some examples of types of treatments that can be considered:
