Research supports underground dams

Research conducted by the National Centre for Groundwater Research and Training (NCGRT) has found there is good potential to store water underground during time of flood for use in time of drought. The study follows a recent announcement from the Australian Bureau of Meteorology saying there is a 70% chance of a new El Niño event.

The team, which was led by Professor Tony Jakeman of the Australian National University (ANU), conducted their research in the Namoi River region of NSW. Professor Jakeman said it may be cheaper to store water in buried aquifers rather than in surface dams, which suffer from heavy evaporative losses as well as high construction costs, and that the concept has found strong support among the farming community.

“The Murray-Darling Basin covers a seventh of the continent, is the nation’s main food bowl and has nationally and internationally significant natural and cultural assets,” said Professor Jakeman. “Its water resources are under particular pressure due to overextraction of surface flows in some areas, barriers to connectivity, declines in water quality and the depletion of aquifers.

“However, our research indicates there is an opportunity to rectify some of these challenges with the use of managed aquifer recharge, or water banking as it is sometimes called.”

Water banking can be adopted at farm scale, in volumes suitable for supplementing irrigation supplies in a dry season. Professor Jakeman added that the technique could also potentially be used to store water for towns, cities and industrial uses; it is cost effective; and the idea of storing water underground enjoys broad community support.

“The work was done in the Namoi region and shows there is excellent potential for managed aquifer recharge there,” he said. “But the principles apply right across Australia - wherever there are rivers that flood, suitable aquifers and communities or industries which need water.

“So long as you have surplus water which you could pull out of streams or rivers when there is plenty - for instance, during a flood - and you have suitable aquifers to hold it, as well as suitable conditions on the surface to get it into the aquifer, then water banking should be seriously considered as an option.”

The director of the NCGRT, Professor Craig Simmons, said the Namoi work is an important demonstration of the potential for establishing a national water bank - an idea which was proposed by Professor Simmons last month. His concept involves a monitored network of underground and surface resources that use underground aquifers to store water.

“Professor Jakeman and his team have provided invaluable practical proof of the concept of Australia storing substantial amounts of surplus water underground in an area which is strongly reliant on water for agricultural production,” Professor Simmons said.

“It adds up to a major case for Australia taking the idea of water banking in underground aquifers far more seriously. This is the sort of infrastructure development that will meet the needs of a growing nation with growing industries far into the future.”

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