A simple fix for leaking dams

Whether for irrigation, stock watering or emergency uses such as fire-fighting, a reliable water supply is at the heart of any successful agricultural enterprise. Despite the earthmover’s best efforts, new dams often seal imperfectly, while older dams may deteriorate over time.

Dam repair has traditionally involved draining away the remainder of the precious water and bringing in heavy equipment to carry out repairs. 

There is, however, a much simpler and cheaper alternative. A specialised range of super absorbent polymers (SAPs), manufactured by Polymer Innovations, provides a fool-proof do-it-yourself solution. A polymer solution typically costs several hundreds of dollars – not thousands.

The Water$ave range was developed by the company’s managing director Andrew Evans. After developing slurry management solutions for some of Australia’s largest underground miners, Mr Evans recognised the potential for SAPs to seal problem dams.

After extensive field and laboratory testing Water$ave PLUG was released in 2000. Further refinements saw Water$ave SEEP introduced to seal leaks in finer, more porous soils. PLUG and SEEP have the same application method – the polymer, in the form of a white powder, is applied to the water surface so there is no need to drain the dam or use heavy earthmoving equipment.

“The products are easy to apply and don’t require specialised equipment or skills,” Mr Evans said.

“They are safe, non-toxic, and are able to target specific areas rather than treating the entire water surface. It’s really quite simple to work out how much polymer you need. An easy method is to pace out the area and then measure how many steps you take in 20 metres.”

From this point it is a simple exercise to determine the area of the dam with some accuracy. An online mapping tool such as Google Earth can also provide an accurate location and measurement.

“For a typical repair the polymers are applied at a rate of 100gm per square meter,” Mr Evans said.

“So divide the total area by 10 to determine how many kilograms of product are needed.  As an example, an area of 300m2 would require 30 kilograms of polymer. More aggressive leaks may require more product.”

Once the treatment area is identified, the polymer is applied by hand to the water surface. A fertiliser spreader may also be used, taking care to spread the product no more than 1.5m to ensure the various sized particles are not separated.

The polymer particles descend and begin to hydrate and expand almost immediately. Results can often be seen in two to three days, while in some cases the full effect takes up to three weeks and with particularly aggressive leaks a second application may be required.