Water Journal : Water Journal April 2012
feature article 68 APRIL 2012 water feature articles The future of Australia's groundwater reserves -- one of our most precious yet little-understood resources -- is the subject of fierce debate as we grapple with contentious issues such as climate change, coal seam gas and population growth. Over the past several decades, groundwater use in Australia has grown. An estimate widely accepted by scientists and policymakers is that it now supplies about 20% to 30% of the nation's total water needs. This figure nearly doubled during the recent drought when about 50% of water in Australia's parched south-east came from under the ground -- a time when groundwater reserves could least afford it. And there are fears that figures on current usage may be too conservative and that total usage is far greater than most imagine. Of major concern are illegal bores, which appear to be multiplying. When surface water is in short supply people sink additional bores. As a result, whenever authorities conduct surveys more illegal bores are found, even in areas that are intensely managed. Estimating the cumulative impact of these thousands of bores drawing water from complex and varied aquifers is incredibly difficult. Groundwater is the lifeblood of numerous rural towns as well as cities such as Perth, Newcastle and Alice Springs. Agriculture cannot survive without it and it is vital for many industries, including mining and manufacturing. Delicate ecosystems will also suffer if groundwater extraction goes unchecked. Over the next 40--50 years the need for fresh water will escalate as Australia's population doubles. More droughts are expected to occur and with climate change we can expect less rain and more evaporation in the nation's south-east. At the same time we are dealing with major policy issues such as the proposed Murray--Darling Basin Plan, which recommends a near tripling of groundwater usage from 1580GL to 4340GL a year. Policymakers and scientists are also working through the potential long-term impacts of coal seam gas (CSG) mining, with the National Water Commission estimating that large volumes of water will be taken from groundwater systems over the next 20 years as a result of CSG operations. Tragedy of the Commons Accurately quantifying total groundwater extraction from these multiple industrial and community uses is just one side of the ledger. Estimating recharge is even more challenging with just as many, if not more, unknowns. Professor Craig Simmons is one of the many groundwater researchers in Australia who is trying to find answers and drive policy change. As director of the National Centre for Groundwater Research and Training, Professor Simmons is heading a comprehensive research program focused on finding answers to technical as well as social and policy issues. "Because groundwater is underground we pay it insufficient attention -- often treating it as a free and infinite resource to be tapped at will," he says. "If that continues, we risk another tragedy of the commons. Such attitudes must change if we are to have sufficient water for the some 42 million Australians that current estimates suggest could inhabit this continent in 50 years. "Groundwater needs to feature much more prominently in our national and local water debates, planning and reform. The critical nexus between water, population, climate and energy must be a major driver for national water reform as we move into the 21st century." Filling the Policy Vacuum It's a view shared by Dr Rick Evans, President of the International Association of Hydrogeologists Australia, who says that for years there was a complete vacuum regarding government policy in Australia on groundwater. Key policy measures such as the National Water Initiative have resulted in major advances and a myriad of reforms such as full-cost accounting and charging for surface water. But while huge strides have been made in cost recovery for surface water, very little progress is being made in terms of groundwater. "Surface water reforms have tended to be applied to groundwater, which in many cases has been good," says Dr Evans. "But overall this approach is far too simplistic, because groundwater is quite different and many of the concepts and management regimes simply do not apply." One of the critical issues with groundwater is that the processes of recharge are very long term -- often thousands of years. Underground storages are not an infinite supply, yet falling groundwater levels are now a feature around the world. In the Great Artesian Basin water tables started declining within a few years of the first bores being sunk. Other aquifers in Australia have now dried out completely. It has been demonstrated that some of the Great Artesian Basin waters are only recharged on a timescale of hundreds of thousands of years. Elsewhere, groundwater is often equally old -- this gives us vital clues about recharge rates, slow flow rates and the size of aquifers. "People talk about the need for groundwater reform during the drought, but the second it rains the conversation stops," says Dr Evans. "It's the old story of 'out of sight, out of mind'. But unless we get serious about the management of groundwater, then we will destroy the main water supply of the world, and the implications of that are absolutely horrific." National Groundwater Action Plan Efforts to improve our understanding of groundwater were accelerated in 2007, when the National Water Commission initiated an $82 million National Groundwater Action Plan as part of the National Water Initiative. Australia's Groundwater: The Nation's Buried Treasure This article was commissioned by AWA and developed by the National Centre for Groundwater Research (NCGRT). The NCGRT would like to thank Ian Williams for his help in preparing this article.
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