Geotextiles

Geotextiles are land surface erosion control products that come in numerous forms and are made from synthetic and/or natural products. Most commonly, geotextile products are used where vegetation will provide the long-term erosion protection, but initial assistance is required to prevent erosion, protect revegetation, suppress weeds and retain soil moisture.

Geotextiles are generally used in combined vegetation management and physical intervention actions. Physical intervention is often required to initiate a required action and assist the establishment of vegetation. This strategy should be focused on a long-term goal of vegetation establishment to achieve the goal.

Filter cloth, a form of geotextile, is used to provide a filter layer between a structure (e.g. rock chute) and the in-situ bed and bank material to prevent the movement of soil through the structure. Geotextile is very effective when used for this application.

Potential benefits for rehabilitation:

• Geotextiles can reduce the amount of maintenance required at a site and may mean weed killer applications are not needed or are reduced.
• Rapid reduction in sediment delivery can occur at an application site especially those that have been reshaped as part of bank battering.

Potential negative implications for rehabilitation:

• Difficulties often arise in installing these products flush against or around irregular bank shapes, vegetation and tree roots.
• Geotextile products are often not capable of addressing the underlying erosion process.
• The synthetic components of geotextiles are often non-biodegradable materials (e.g. plastics).
• The geotextiles can be swept free from the revegetation areas if the plants are not well established and/or during significant storm events. This can create significant downstream issues as well as on-site impacts.

Intervention considerations:

• Seek appropriate specialist advice and check legal obligations (e.g. permits).
• Assess whether the installed geotextile product will address the process of erosion.
• Research if a fully biodegradable product can be sourced.
• Consider the design life required from the erosion control product and whether vegetation can establish adequately in this timeframe.
• Timing of geotextile installation should consider seasonal conditions and is best installed at the end of flood season to provide the best chance for vegetation to establish.
• Safety of volunteers and employees including seasonal exposures (e.g. heat) and high risk areas (e.g. crocodile presence in waterways or areas with soil contaminant risks).

Additional information

Publications:

Rickson, R.J., 2006. Controlling sediment at source: an evaluation of erosion control geotextiles. Earth Surface Processes and Landforms: The Journal of the British Geomorphological Research Group, 31(5), pp.550-560.

Last updated: 22 June 2022