Water Journal : Water Journal April 2012
feature article water APRIL 2012 73 the Murray--Darling Basin Authority to present transparent, rigorous science that is well communicated. The independent Wentworth Group of Concerned Scientists is urging the plan be withdrawn, saying it fails to provide information to make an informed decision on the future of the river system. The group says the modelling does not take into account the impact that increasing groundwater extractions will have on surface water flows. Many of the groundwater systems in the basin are linked to the river system. Also the plan does not identify the volume of water needed for a healthy working river system and there is no information on how effective it would be in coping with long dry periods. "The change in volumes between the guide and the proposed plan must be transparent, clearly explained and well justified so that we have the confidence in its ability to deliver ultimately what it needs to, and that is a healthy, working river system. This is a very challenging problem but one with huge national significance and one we have got to get right," says Professor Simmons. "The key to effective groundwater management is knowledge: knowing with precision how large is the resource, how long it takes to recharge, how it connects to surface waters, and how quickly it is being depleted by competing social, economic and environmental demands on it. These are obvious and ongoing challenges, but at the heart of effective policy. "Public trust and confidence are significant issues with groundwater. We see this exemplified with current national issues such as CSG and the plan for the Murray--Darling Basin. It means we have to work even harder on making sure that our science is robust and that we are being transparent, communicating effectively and working closely with the community," he said. Managed Aquifer Recharge On the positive side, Australian scientists working in Adelaide, the Bowen Basin in Queensland, and around Perth, have demonstrated great scope to store surplus surface water -- such as city runoff -- in aquifers underground, where the water undergoes a natural cleansing process. This points to the potential for 'underground dams' where water is stored, safe from evaporation, for the needs of the future or for dry times to come. Dr Peter Dillon, a senior researcher with CSIRO in water recycling and diversified supplies, said Australia was a world leader in areas such as the re-use of stormwater in aquifers and managed aquifer recharge. Reinjection is already taking place in mining, with companies such as Fortescue Metals pioneering advanced recharge systems. The company recently won national recognition for its Cloudbreak Managed Aquifer Recharge Scheme, which has the capacity to replace 25GL of water each year. Dr Dillon is confident that reinjection schemes in mining, including coal seam gas, will increase to the stage where it is standard practice. But he believes government regulators should be doing more. "A big issue for me is that most regulators look at groundwater management being demand management and they are not taking seriously their role in recharge of aquifers, which is well and truly warranted," he says. "Most government departments see themselves in a regulatory role rather than a functional role and most water banking is for immediate recovery not long term. "But at the same time I don't want to advocate strategic reserves in places where there's no surface water or groundwater cap. There has to be a cap in place, otherwise we're wasting our time and we could be causing environmental havoc downstream." In its Waterlines Report Series No. 13, the National Water Commission describes managed aquifer recharge as being at the cutting edge of integrated water management, with the potential to help sustain groundwater supplies and dependent ecosystems in heavily used aquifers. But so far its uptake has been low compared to other alternatives such as desalination, recycling and using groundwater. The National Water Commission says that in 2008, managed aquifer recharge delivered about 45GL to irrigators and just 7GL to urban water supplies across Queensland, South Australia, Western Australia and the Northern Territory. Urban use could be increased to 200GL by using aquifers mapped in Perth, Adelaide and Melbourne. Recharged water can be obtained from multiple sources including rainwater, stormwater, reclaimed water, mains or other aquifers. And in addition to significant environmental benefits, the cost savings from urban-managed aquifer recharge are also considerable -- an estimated $400 million per year cheaper than using the equivalent 200GL from seawater desalination. The National Water Commission says there are also substantial opportunities for managed aquifer recharge in other cities and rural catchments that have yet to be assessed. Keeping the Milkshake Glass Full Robert Glennon, Professor of Law at the University of Arizona and author of Unquenchable: America's Water Crisis and What To Do About It, sees many parallels between Australia and the US in the over-exploitation of groundwater. He's currently visiting Australia as a distinguished guest lecturer at the National Centre for Groundwater Research and Training and predicts that international water woes will get worse before they start to improve. He likens groundwater aquifers to a giant milkshake glass, with each well representing a straw in the glass. "What both the US and Australia have done is to permit a limitless number of straws in the same glass, and that's a recipe for disaster, an unsustainable use of a finite resource," he said. "It took Mother Nature millennia to accumulate the water in our aquifers but we're pumping that water out in mere decades. The essence of the problem is allowing limitless private access to a finite public resource." Looking Forward Despite these challenges, Professor Simmons is enthusiastic about the future of groundwater research, and the interest and engagement that is beginning to build around the topic. "At the beginning of the 21st century, Australia is well placed to manage the challenges and opportunities groundwater presents us," he says. "We now have the scientific capacity and infrastructure, and the policy imperative, to begin successfully answering the big questions and making informed decisions about groundwater use and management. We have made excellent progress in this country and we must not forget that. But there are miles to go before we sleep."
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