Riparian fencing to control stock/feral animal access

Fencing to exclude or control the access of domestic stock and feral animals to the river channel and adjoining riparian areas or other wetland systems can be an effective management technique. A range of fencing materials and methods (e.g. multi-strand, mesh, drop down, electric, virtual) can be used subject to the target animals for exclusion, the scale of the site, the adjoining land uses and the requirements of native animals to access the site.

Unregulated access of domestic stock (e.g. cattle, sheep and horses) and feral animals (e.g. pigs, goats, deer) to the riparian area and channel can degrade vegetation, limit regeneration and revegetation, cause soil compaction, cause riverbank erosion, introduce weeds and add additional nutrients (leading to poorer water quality) and pathogens. For example, calves shed 57 million oocysts per day on average in their manure which may include cryptosporidium. This number can be compared to a beef cow, which sheds on average 2,400 or a dairy cow at around 80,000 oocysts per day (Juvenile stock in waterways).

Fencing may involve total exclusion of target animals or controlled seasonal access of grazing stock to the riparian zone. Controlled access facilitates beneficial outcomes such as grazing of palatable weeds and the control of dry season fire fuel loads. Managed animals predominantly include domestic grazing stock (e.g. cattle, sheep and horses). Feral animals can include cattle, horses, donkeys, pigs, goats, deer, feral predators such as foxes and invasive species such as cane toads.

Potential benefits from this intervention:

• Addresses many rehabilitation objectives simultaneously where animal access is one of the primary drivers of degradation.
• Enhances the viability and sustainability of other rehabilitation actions, such as riparian revegetation or regeneration.
• Provide a cost-effective broad acre tool for reach scale and larger rehabilitation outcomes.
• Existing rehabilitation sites can encourage further uptake amongst local landholders.
• Improved water quality, including reduced pathogen levels where juvenile stock access is excluded.

Potential negative implications from this intervention:

• Fencing can exacerbate erosion if vegetation is cleared on sodic or other highly erosive soils.
• Total exclusion of grazing animals can promote a range of secondary impacts such as the invasion of palatable weeds and accumulation of understorey fuel loads that risk hot fire impacts.
• In remote or flood prone landscapes, sustaining exclusion fencing requires ongoing vigilance and can have a high maintenance cost. During flood events debris can get caught in fences causing other issues. This is particularly a concern if fences are located in the flood zone.
• Fences can impact native fauna, such as where barbed wire is used, or where chain linked fences do not allow access for species which need access to the waterways.
• Perceived or potential loss in profit where riparian zones are valued for production (food and water source for stock).

Intervention considerations:

• Seek appropriate specialist advice and check legal obligations (e.g. permits).
• Cattle fence lines can concentrate water and accelerate gully erosion when improperly placed, constructed, or maintained.
• Minimise negative impacts by:
  • locating fences away from highly erodible soils to minimise future erosion and prolong the life of the fence
  • minimising river, creek and gully crossings
  • avoiding or reducing soil disturbance
  • minimising removal of native vegetation
  • using live trees as fence posts (“tree to tree”) on steep banks and crossings.
  • use plain wire instead of barbed wire (on the top strand at least) to minimise risk of injury to wildlife.
• Environmental sensitivity of bank and channel areas and benefits of total exclusion of grazing animals versus controlled or seasonal access.
• Ensure fencing extends around the wetland or both sides of a river, otherwise the benefits may not be achieved if stock can access the site from another area.
• How prone the landscape is to flooding and associated maintenance or replacement of fencing over time.
• When choosing the fencing, consider access to water source and movement of native terrestrial animals.
• Provision of alternative off-stream water sources and availability of shade away from rivers for stock should be considered.
• On site safety including seasonal exposures (e.g. heat) and high risk areas (e.g. crocodile presence in waterways).

Additional information

Publications:

DEEDI. 2011. Grazing for Healthy Coastal wetlands: Guidelines for managing coastal wetlands in grazing systems. State of Queensland, Department of Employment, Economic Development and Innovation, Brisbane.

Doupé, R.G., Mitchell, J., Knott, M.J., Davis, A.M., and Lymbery, A.J. 2010. Efficacy of exclusion fencing to protect ephemeral floodplain lagoon habitats from feral pigs (Sus scrofa). Wetlands Ecology and Management 18, 69-78.

Price, P. and Lovett, S. 1999. Riparian Land Management Technical Guidelines. LWRRDC Canberra.

Rutherfurd, I.D., Jerie, K. and Marsh, N. 2000. A Rehabilitation Manual for Australian Streams, Volumes 1 and 2. CRC for Catchment Hydrology and LWRRDC. Canberra.

Tait, J. 2011. Guidelines for the Use of Grazing in the Management of Exotic Pasture Weeds in Wetland and Riparian Habitats. WetlandCare Australia, Ballina, NSW.

Waltham, N., and Schaffer, J. 2017. Continuing aquatic assessment of wetlands with and without feral pig and cattle fence exclusion, Archer River catchment. TropWATER James Cook University, Townsville Australia, p. 44.

WetlandCare Australia. 2008. Wetland Rehabilitation Guidelines for the Great Barrier Reef catchment. Compiled for Department of the Environment, Water, Heritage and the Arts.

Links:

Queensland Government Feral pig population control techniques

Australian Government Department of Agriculture, Water and the Environment Reef Trust Gully and Stream Bank Toolbox 3rd Edition, March 2022 (awe.gov.au)

NSW Government and Australian River Restoration Centre Stock And Waterways Guideline – a practical guide to help New South Wales farmers manage stock and waterways for productivity and environmental benefits.

Victorian Government Controlled grazing guidelines within the fenced riparian areas

Victorian Government Flood-prone Fencing Guidelines

Victorian Government Juvenile stock in waterways information

Last updated: 28 June 2022