Fencing smarts from the Emerald Isle
While a leading New Zealand brand seems to have a stranglehold on the local electric fencing market, a company from the Green Isle seems to be making significant inroads, particularly in the Northern Hemisphere.
Fencing will help to maintain and improve water quality and create a habitat for birds and freshwater species.
Fencing waterways is a priority under the Sustainable Dairying Water Accord, as follows:
All stock must, by May 2017, be excluded from permanently flowing rivers, streams, drains and springs wider than 1m and deeper than 300mm
All lakes must have all stock permanently excluded by May 2017
Any significant wetlands, as identified in a regional plan or policy statement, must also have all stock permanently excluded by May 2017.
Planning your fencing
Waterway fences must be far enough back to allow for movement/flooding of the waterway.
Start by mapping your waterways and create a fencing plan.
Consider the overall layout of your farm; along with protecting waterways, new fencing can improve grazing management and stock control. Plan out fence lines and crossing points.
Determining where your fence should go
The area between the fence and waterway will slow runoff to filter out bacteria, phosphorus and sediment before it can enter the waterway.
Choose your fence setback depending on how you are going to manage the area. There are four main ways to manage your riparian areas as outlined below. All have the benefit of excluding stock and reducing phosphorous and sediment entering waterways.
Additional benefits and limitations for each option are listed below to help you decide on the fence setback that will best suit your needs.
1. Grass filter strip between fence and waterway
Additional benefits:
Low cost
Small loss of grazing land
Limitations:
Weed control required
No shading of stream
Minimal habitat for bird and aquatic life
Minimal bank stabilisation without deeper rooted vegetation
2. Low planting between fence and waterway
Additional benefits:
Stream bank stability
Small loss of grazing land
Can make use of sprays targeted to broadleaf species
Helps control weed growth
Shade and cover for fish and insect life
Limitations:
Weed control required
Minimal habitat for birdlife
3. Full planting between fence and waterway
Additional benefits:
Reduced drain maintenance
Attractive asset for your farm
Provides shade and keeps water cool
Increased habitat for birds
Limitations:
Higher cost
Larger loss of grazing land
Needs weed control for at least two to three years
May require animal pest control
4. Extend fenced area to include seeps, wetlands, swamps and springs
Additional benefits:
Reduces stock losses
Provide habitat for bird life
Limitations:
May result in loss of grazing land
Needs stringent weed control
Higher cost if planting required
Working in flood-prone areas
- Use fewer upright posts and less wire; this way less debris will catch on the fence. Do not use netting as it will trap debris.
- Put wires on the downstream back side of posts so the staples can pop and the wire drop rather than pulling out the posts and strainers.
- Use non-barbed staples so wires can pop off more easily.
- Erect fences parallel with the way the stream floods so the fence does not collect debris.
- Set fences further back where active erosion is occurring.
- Construct separate ‘blow-out’ sections across flood channels.
Maintaining access to drains
-Build an electric fence that can be dropped or removed to allow access. e.g. use pinlock insulators so the wires can easily be lowered for machinery to cross.
-Position the fence so that a long-reach digger can reach over the top.
-For wide waterways, place a fence far enough back to allow a digger to work between the fence and the bank. This still allows for a wide grassy margin and you can plant low growing plants on the waterway margin if you wish.
-Do not cut off gateways that give diggers access to neighbouring paddocks.
