Repairing Leaks in Rural and Farm Dams
A dam on a farm is more than just a hole in the ground that collects
water, it is a renewable source of water to feed livestock and provide
irrigation for crops. A common misconception we get with customers is
that if a dam leaks, it probably wasn’t built properly and a cheap dam
liner can be utilised to fix the problem. Dams will become part of the
landscape eco-system and so must be properly designed and maintained (in
most cases approval is also needed by local councils or water boards).
Soil conditions determine how the dam is to be initially constructed
and ideally a dam is build on a clay based soil, any other soil to some
degree will leak. The worst soils are sandy, loam based soils and shale
rock soils. Dams are then made with either a clay or bentonite layer and
the use of things like dam liners is uncommon as the cost his higher.
Liners only employed where other sealing techniques have failed.
Dam leakage can not only be due to the soil condition, but by ground
movement, erosion, incursion by tree roots and damage from livestock,
just to name a few. In cases where leakage occurs, several different
types of solutions can be undertaken:
- Rebuild a new dam at a different site.
- Adding a sealant to the dam, however success is low when there is
still water in the dam and it is greatly increased with the dam empty.
Adding a sealant to a full dam means that the application is largely
uncontrolled, and thus success is not guaranteed. The treated layer will
also not be compacted making it prone to being disturbed and damaged.
Sealants include synthetic polymers, clays such as sodium and calcium
bentonite clay and other materials like gypsum.
- Other options include the use of sodium trippolyphosphate (for certain soil conditions), bitumen and concrete .
- Completely cleaning out the dam, and re-compact the soil.
- Use of a dam liner, often very expensive, but has a very high
success rate and can last from 10 to 30 yrs depending on soil conditions
and material choice.
When looking at a dam liner, there are a few different types of material that can be used, including:
Polypropylene and Polyethylene are the most common types of liners. PVC was once a common usage for large dams, but not so any more. It
is too costly and doesn’t offer a long life expectancy. It is still
suitable for smaller installs though. A quality HDPE liner can provide for a long life expectancy, and EPDM and butyl based rubber liners tend to give the longest lifespans, with 30+ yrs not being uncommon.
For further information on leaking dams and possible remedies, we
recommend reading the resource on leaking dams is provided by the
Western Australian Government at
also see the NSW Government’s resource handbook on dams, which discusses methods of fitting the dam-liners into the eco-systems:
For More Information Visit:- Dam Liner
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