Removing large woody debris from a watercourse—Frequently asked questions
- What is large woody debris?
- Should large woody debris be removed from a watercourse?
- Who can remove large woody debris?
- Who do I need to inform?
- How should I remove large woody debris?
- Do I need permission to remove large woody debris from a non-tidal watercourse?
- Do I need other approvals?
- Who is responsible for paying costs associated with removing large woody debris?
The questions and answers listed below provide information for landowners planning to remove large woody debris from a watercourse.
What is large woody debris?
Large woody debris is dead tree branches, large limbs or whole trees which have fallen or been washed into a watercourse. Large woody debris usually remains in place where it falls into the waterway and can be found exposed, submerged or semi-submerged.
During periods of flood, debris may wash downstream and come to rest against an embankment, other debris or large rocks. Debris may get lodged behind a bridge, culvert openings and pumping equipment, and can cause localised flooding, land inundation and property damage.
Should large woody debris be removed from a watercourse?
Large woody debris serves important functions in river systems and generally should not be removed unless the quantity is excessive, restricts the flow of water or can potentially cause more damage. Debris such as branches and logs can enhance the ecology of a watercourse by providing habitat for aquatic plants and animals. It creates a vital habitat and shelter for many fish species.
Large woody debris also helps maintain natural river processes which contribute to the physical and ecological components of the river system. Debris settles in the bed of watercourses to form control points that are important for reducing the potential of bed erosion. Stable beds are important for maintaining stable stream banks. The accumulation of debris can help to store sediment and create pools and new flow channels in a watercourse.
If woody debris needs to be moved, align with the flow of water so that it will not cause further damage through erosion or water diversion. If removal is necessary, dispose of the debris outside the outer banks of a watercourse.
Who can remove large woody debris?
Anyone can remove large woody debris from a non-tidal watercourse including landowners, local government and river improvement trusts. The Department of Natural Resources and Mines does not provide a service for physical assistance in the removal of large woody debris.
Who do I need to inform?
You do not need to notify anyone before removing large woody debris from watercourses flowing through or adjacent to your property. However, as a courtesy, it is a good idea to talk to your neighbours.
How should I remove large woody debris?
Removing small debris from a watercourse should not require heavy machinery where materials can be removed by hand, however this may not always be practical. You may need to cut larger logs and trees blocking the watercourse into manageable pieces before dragging the pieces out of the watercourse. Standing trees should be left as they are. When trimming partially fallen trees with an intact root system, leave the root ball for bed and bank stability.
You should burn (conditions permitting), bury, secure or remove all woody debris from the floodplain so that the next flood does not re-deposit this material. This activity is best undertaken during low flow periods.
Wherever possible, avoid placing large machinery in the watercourse. Seed or revegetate any disturbed areas along the channel immediately to avoid unnecessary bank erosion. If bank erosion has already occurred where debris has been removed, it is important to restabilise the bank by using techniques such as planting vegetation.
How do I gain access to a watercourse?
To minimise impacts on the watercourse and surrounding vegetation, you should consider the following:
- Use existing tracks and crossings where possible and minimise disturbance to these tracks.
- Use a single track for vehicle access to and from the project site to avoid unnecessary damage to the watercourse and surrounding vegetation.
- Maintain a buffer zone of at least 25m between the outer banks of the watercourse and the vehicle track.
- Use smaller entry points from the vehicle track to the watercourse to access woody debris. Where possible, orientate these entry points so that they are perpendicular to the stream channel.
You may require a permit to clear vegetation to construct a track for vehicles. Before starting any clearing, contact a vegetation management officer at your local departmental office.
Do I need permission to remove large woody debris from a non-tidal watercourse?
No, except in wild river areas (see below). In non-tidal watercourses, removing large woody debris is not regulated under the Water Act 2000. You do not need to obtain a permit or use a guideline when removing this material from a watercourse, except in wild river areas.
You may need to clear vegetation in a watercourse in order to access large woody debris. Clearing vegetation is a regulated activity and must be undertaken in accordance with the ‘Guideline—Activities in a watercourse, lake or spring carried out by a landowner (PDF)*’.
If you are undertaking regulated activities including clearing vegetation that exceed the limits specified in this guideline, you must obtain a permit before carrying out the activity. Contact your local departmental office for information on this guideline or applying for a permit.
Do I need other approvals?
Depending on the location of your property, you may need to obtain a permit before starting work. If your property is located:
- in a wet tropics world heritage area, you may need a permit from the Wet Tropics Management Authority
- near wetlands of high ecological significance, contact the Department of Environment and Heritage Protection before starting any activity
- in a wild river area, you will need to obtain a riverine protection permit or use the ’Guideline—Activities in a watercourse, lake or spring carried out by a landowner (PDF)*’ before removing debris from a watercourse. Contact the Department of Environment and Heritage Protection for more information about wild rivers. To apply for a riverine protection permit, contact the Department of Natural Resources and Mines.
You need to consider legislative requirements that apply to works associated with removing debris from a watercourse. For example, clearing vegetation to gain access to a watercourse may require a permit before you can start clearing.
You may need a permit under the Nature Conservation Act 1992 to clear endangered, vulnerable or near threatened plants. Contact the Department of Environment and Heritage Protection before starting any clearing.
Who is responsible for paying costs associated with removing large woody debris?
There is no obligation for landowners to remove large woody debris from a watercourse. However, if you choose to carry out this work, you are responsible for any costs incurred.
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Last updated 14 September 2012