Why erosion happens and how riparian zones help
Floods can cause serious erosion, especially when riverbanks have little or no vegetation. Erosion affects water quality, damages land and infrastructure, and leads to high recovery costs.
Riparian zones are the areas next to creeks, rivers, streams and wetlands. Healthy riparian zones help to:
- trap sediment and nutrients to protect water quality
- hold soil in place and reduce erosion
- provide shade and habitat for animals and plants.
Vegetation binds the soil, especially during floods. The wider and more diverse the vegetation, the better the protection.
What to consider when managing erosion
Managing erosion takes planning and the right approach for your land. Healthy riparian zones, careful land use and livestock management all help reduce erosion.
Vegetation and riparian zone width
Erosion increases when vegetation is sparse. Pasture grass alone does not provide enough protection.
Wider riparian zones offer better flood resistance. Recommended widths:
- More than 50 metres on both banks for major rivers (stream orders 3 and 4)
- At least 10–20 metres on both banks for minor creeks and gullies (stream orders 1 and 2).
Use a mix of reeds, grasses, shrubs and trees. Combine root types (fibrous, tap, creeping and tuberous) to hold the soil in place.
How land use and livestock affect erosion
Livestock can damage riparian areas by:
- compacting soil
- creating ruts
- trampling vegetation
- spreading weeds.
You can reduce erosion by:
- rotating grazing near waterways
- installing off-stream watering points
- restoring native vegetation
- controlling invasive weeds.
Techniques to manage erosion
There are practical steps you can take to reduce erosion and protect waterways. These techniques help stabilise riverbanks, support native vegetation and reduce damage during future floods.
Use fencing to manage livestock
Electric fencing is affordable and easy to move before or after floods. It helps protect sensitive areas from trampling.
Replant native vegetation
Widen and restore riparian vegetation using local species such as:
- watergums
- lomandra
- river bottlebrush.
Plant a mix of shrubs and trees with varied root systems for better erosion control.
Control weeds
Weeds can outcompete native plants and leave banks exposed. Manage vine weeds carefully as they can pull down trees and leave gaps during floods.
Keep fallen logs in place
Snags are native trees that fall into waterways. They slow water, reduce erosion and support fish habitat. Snags are protected under the Fisheries Management Act 1994.
You can reposition snags to support bank stability if you get permission from NSW DPIRD Fisheries and Forestry.
Managing erosion through structural works
Major floods can cause serious erosion. Avoid doing repairs yourself without expert advice.
Some types of erosion control are 'controlled activities'. These include:
- erosion control structures
- realigning river channels
- building bed control structures
- creating crossings, like bridges or causeways.
You may need approval or permits before starting this work.
Things to consider before doing erosion work yourself
Many riverbeds and banks are Crown Land and need formal approval before any work can begin.
Environmental impacts
Unauthorised erosion work can affect:
- farms and local businesses
- Aboriginal and community heritage
- the health of waterways.
Legal and financial risks
If you do unauthorised work, you may face:
- legal action
- fines or penalties
- liability for damage
- responsibility for fixing the site.
Safety risks
Riverbank work is dangerous without proper training. Risks include:
- unstable ground
- heavy machinery accidents
- underground pipes and cables
- contaminated soil or water.
Always check fill material before use as it may be contaminated.
Get expert help
Qualified river management professionals have the tools and experience to do the job safely and legally.
If the work does not suit the site, the next flood could damage or destroy it. This can waste your time, effort and money. Without expert guidance, you might also make erosion or flooding worse in other areas.
Best practice erosion control
Use environmentally safe materials that support river health and aquatic habitats.
Avoid using tyres or concrete waste. These materials can:
- release harmful chemicals
- break apart under pressure.
Design your erosion control to suit the river’s natural flow. The River Styles Framework can help you:
- define your site’s target condition
- match design to the river’s behaviour
- plan for the river’s future changes.
Get help with erosion recovery
If you have erosion damage after floods, contact Local Land Services for guidance. You may be eligible for help through the river rehabilitation project.
Contact Local Land Services NSW
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