Managing waterways on farms
Fencing (5-3)
Fencing farm waterways has many benefits. It helps stabilise banks by preventing treading and
erosion and reduces the risk of stock bogging or drowning.
Fencing to keep animals out of waterways leads to better water quality by reducing the amount
of faecal matter and sediment deposited directly into it. This will contribute to a better habitat for
fish and other freshwater life, improve the appearance of the waterway and reduce drain
maintenance costs.
Fence set-backs and options
Consider the overall layout of your farm when planning for waterway fences. Along with
protecting waterways, new fencing could improve subdivision for grazing management and
stock control.
For fence placement:
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Go for a minimum set-back of one-metre where the paddock slope toward the waterway is
less than 10 degrees. (The set-back should be greater if you are going to be planting.)
Go for a three-metre set-back of ungrazed vegetation where the slope is greater than 10
degrees.
As a rule of thumb where the land gets steeper the width of the set-back should increase.
Set it further back where banks are unstable.
Where there are seeps or shallow depressions adjacent to the stream these should be
fenced off (these areas can provide a disproportionate input of contaminants entering the
stream).
Weigh up straight lines (less materials and labour to install) versus following the waterway
course (possibly less grazing land lost).
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Farmfact 5-3
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Choose fencing that suits your budget and your current set-up. Just be sure it’s stock-proof!
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Seven to nine wires with battens is best for permanent fences.
A two- or three-wire electric fence with permanent posts is satisfactory to prevent cattle
entering the waterway.
For a single wire fence on a one-metre set-back, increase the margin a little to allow for
the grazing that will occur under the fence.
Allowing for access
Be sure to allow for access when needed:
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For margins retired permanently, removable wooden rails in a convenient spot will make it
easy to free stock that might get in.
For areas that require drain clearing, an electric fence that can be removed or dropped will
allow easy access. Where fencing is more permanent, adequate spacing should be left
between the waterway and fence for digger access.
Coping with floods
Simple one-wire or two-wire electric fences are good choices in flood prone areas. They are
less likely to collect debris or be swept away in floods. They are also easier to stand back up
after a flood event.
Here are some more ways to reduce damage and repair costs in areas prone to flooding:
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Place fencing a greater distance from the waterway (especially on the outside of bends).
Place posts further apart.
Put fence wires on the paddock and/or downstream side of posts so they pop their staples
and drop rather than breaking.
Use un-barbed staples so wires can pop more easily.
Construct separate ‘blow-out’ sections across flood channels.
You should also think about the height of the bottom wire relative to expected flood levels.
Recording flood heights will be helpful with placement of fences in the future.
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Use of temporary fencing
Temporary electric fences are helpful to protect sensitive areas at critical times. For example,
you can run a hot tape around wet areas and seeps in winter to keep stock out and avoid
pugging.
If you graze fenced waterway margins occasionally for weed control, it’s crucial to use
temporary fencing to keep stock out of the water. To minimise impacts on the waterway,
the best approach is short, sharp, intense grazing, done infrequently, and preferably using
young stock.
Seek Early Advice
Many regional councils provide free advice on fencing and other aspects of waterway
management. Most provide free locally-focused and helpful publications. Be sure to contact
them in the early planning stages. Along with professional guidance, council staff can alert you
to any possible regulations as well as funding opportunities.
Secure Water Supply for Stock
Fencing off waterways sometimes removes a valuable source of stock water. Putting in a
reticulated water system could be expensive, but can be done in stages over a period of time. A
reticulated system contributes to both animal health and milk production and is well worth the
investment.
Managing Without Fences
Here are a few simple things you can do to protect waterways in paddocks still to be fenced:
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Provide shade and shelter away from the water.
Monitor grazing and move stock if they start to damage banks.
Avoid grazing near waterways during wet periods (use temporary fencing).
Put in culverts or bridges where stock naturally cross waterways. (See Farmfact 5-9)
Provide reticulated water.
DairyNZ appreciates the assistance of Horizons Regional Council in the preparation of this Farmfact.
January 2012
©DairyNZ 2012