Australian farmers want excess water from large floods to be ‘banked’ in aquifers for use in dry times.
A survey by the National Centre for Groundwater Research and Training (NCGRT), which included Charles Sturt University (CSU) researchers, shows that farmers in the Namoi catchment area in the Murray Darling Basin (MDB) mainly support water banking, or storing extra water underground, from large floods.
Their positive response is a big step towards providing rural and agricultural communities with additional water without drawing more from the over-extracted rivers of the Basin, says Professor Allan Curtis from CSU’s Institute for Land Water and Society (ILWS).
“Australia’s farmers manage around 65 per cent of the continent and have access to large volumes of surface and groundwater,” Professor Curtis said. “With scientists predicting less rainfall and runoff in the southern MDB over the next 60 years, we urgently need to help them address the growing threat posed by scare water.”
Professor Curtis believes water banking, or managed aquifer recharge (MAR), should be the next step in water management in the Basin.
“Storing water underground is more efficient than saving it in surface dams, on which Australia currently relies. This is because large volumes of water are lost from surface storage by evaporation. Each year, farm dams in the Basin lose more than 1000 gigalitres (GL) due to evaporative loss, enough to supply Melbourne, Sydney and Adelaide for that year.”
As more places around Australia turn to water banking for later industrial or recreational use, researchers at NCGRT are exploring the possibility of re-charging depleted aquifers in farming landscapes using excess water from large floods. The survey of 210 farmers in the Namoi region reveals that two-thirds support the concept.
“The Namoi is one of Australia’s prime agricultural regions and extracts the largest volume of groundwater for irrigation in the MDB,” Professor Curtis said.
“It’s an ideal location for implementing water banking using excess flood water, as large floods occur regularly in the lower Namoi, and researchers predict that this will continue to happen in the future.
“We found that the supporters of water banking are more business-like and more interested in fostering equal opportunities for all community members,” he said. “They generally have larger areas for irrigation, buy water more frequently, own larger entitlements and spend more time on their land.
“One respondent wrote, ‘it is about time someone promoted artificial recharge. Farmers in our area have been trying to convince government departments to develop the process for years’.”
On the other hand, those who expressed concern or opposed the idea said they needed more information about the concept, or were worried about possible negative environmental impacts, the survey reveals.
“It seems that they are less interested in production and profit if these outcomes negatively impact the health of the environment,” Professor Curtis said. “They are also more likely to have had the property in the family for longer.
“There is clearly strong support for water banking, but we also need to address other views, because their concerns are valid and deeply felt. We also need to explore issues such as how water banking fits with existing water sharing plans and local and Basin-wide allocations, who will pay for the infrastructure where there are private benefits, and how to secure rights to water which has been stored in aquifers.”
Providing that it is carefully managed, Professor Curtis believes water banking using water from large floods offers a largely ignored opportunity to achieve significant environmental, economic and social benefits.
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