Much of Australia has just come out the other side of restrictive water use regulations in an attempt to halt the dramatic decrease in water-storage levels. Levels have recovered, but a new study shows that Australia should start banking its water underground now in preparation for future dry times.
“There is enormous national potential to store surplus water in aquifers, ensuring sufficient water is available for cities, homes, industry, farming and the environment when drought strikes”, says researcher Andrew Ross of the National Centre for Groundwater Research and Training (NCGRT). “We need to start thinking of surface water and groundwater as a single resource – and managing them together, in an integrated way over time.”
“We also need to tune water management to our climatic cycles and to harness the power of floods to help us to deal with drought. That means banking surplus water underground during wet periods and bringing it up for use during dry times.”
“While it needs national leadership, the concept of water banking can be implemented at grassroots level by landcare and catchment management groups, even by individuals, as well as by larger organisations and agencies. This role can breathe new life into the landcare movement,” he adds.
Mr Ross’ doctoral thesis proposes that Australia should develop and implement water banking at a national scale, and soon. His observations of water management included the Murray Darling Basin (MDB) and the western USA, and he argues that “water banking can provide a big part of the solution to Australia’s perpetual boom/bust relationship with water and the climate”.
“Historically Australians have relied on dams to provide water for agriculture and cities,” Ross says. “This strategy is not sufficient to cope with increasing climate variability or droughts as demand for food and water grows. Water banking can help ensure that there is enough water both for food production and the environment in the MDB – rather than having to close down irrigation when drought hits.”
“Water banking augments the natural processes of water storage in the landscape, avoiding evaporative losses. In the MDB up to 3000 gigalitres (GL or billion litres) of water a year evaporates from surface water storages.”
“We are already storing about 45GL of water underground in the Burdekin region of Queensland every year – for use in agriculture and horticulture. In Orange County California they store around 300 GL a year – enough for the annual household use of 2.3 million people. This gives an idea of the potential,” he explains.
“The known capacity of aquifers to store additional water below Perth, Adelaide and Melbourne could meet the needs of 2.5 million people per year– and may be far larger. Water banking thus offers a way to ‘waterproof’ Australia’s major urban centres for decades to come, ensuring water is available to support predicted population growth,” Ross adds.
“Some people argue that there is no spare surface water to store underground, but this ignores hundreds of gigalitres per year in dam spills and floodwater, recycled stormwater and wastewater, irrigation drainage and water entitlement sales.
“Others object that storing water underground costs more than storing it on the surface – but this fails to account for the high engineering and environmental costs of dams and reservoirs. Also on the surface you can lose a third or more per year due to evaporation, and no-one seems to count this cost.”
Source: National Centre for Groundwater Research and Training
Image Source: Jeremy Buckingham