Scientist warns that the world is mining groundwater supplies unsustainably
Education
CRAIG Simmons has a blunt message.
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For the world to avoid running short of clean, fresh water there is an urgent need for better governance of groundwater and the rapid global sharing of technologies, policies and practices.
National Centre for Groundwater Research and TrainingNCGRT
Many countries have significantly overestimated their available reserves and are mining them unsustainably.
As a result, major economies such as China, India, the US and parts of the Middle East face critical scarcities which may imperil their future growth.
Groundwater provides around 30% of all freshwater used in Asia, for example, and a sustained or permanent shortage could threaten food security, economic growth and even the existence of huge cities.
“Countries where this is happening are keenly aware of the risks but this is not a simple issue to resolve; you can’t just turn off the tap,” Professor Simmons said.
The problem is that often we simply “don't know how much we have, or how quickly it can be depleted, or how quickly it is recharged”. And we have tended to ignore the fact much of it is now contaminated and undrinkable.
“We need good laws and regulations, effective policy options and greater public awareness.”
The NCGRT has made some significant recent contributions toward making this happen and is gaining international attention for its focus on the nexus between science, management and policy – and for some world firsts.
Nationally, it commissioned Deloitte Access Economics to estimate the dollar value of groundwater to Australia, was itself commissioned by the National Water Commission to develop Australian Guidelines for Groundwater Modelling and has been a leader in developing a National Groundwater Strategic Plan.
Internationally, it has been involved with the development of Groundwater Governance – A Global Framework for Action, a major project with such partners as the International Association of Hydrogeologists, the UN’s Food and Agriculture Organisation, UNESCO and the World Bank.
IHP
This is one of the major focus areas of the global framework, which aims to provide policy guidelines and best practice approaches for improved groundwater management at the country and local level.
“Australia plays a valuable role in the Groundwater Governance project,” Professor Simmons said. “Ours is one of the very few countries to have launched a successful bid to reverse a decline in a major groundwater resource when we capped bores in the Great Artesian Basin.
“We are also pioneers in the field of water banking – injecting surface water into underground aquifers during times of plenty, so it can be recovered and used in times of scarcity. And we are international leaders in hydrogeological modelling which is helping us avoid the sort of nasty shocks that have occurred elsewhere when nations have over-extracted water.”
The Deloitte report, which estimates that groundwater directly contributes around $6.8 billion a year to the Australian economy and industries with production worth $34 billion a year directly depend on it, is believed to be the first of its kind in the world.
Similarly, planning for the national strategy – which is due to be finalised during 2014 – was seen as groundbreaking because input was sought from all key stakeholders, including water managers, policymakers and researchers across national, state and territory jurisdictions.
The framework focuses on three priority objectives: sustainable extraction and optimal use, confidence for investment, and planning and managing groundwater for the future.
“To many people, groundwater is all-but invisible, or there as a last resort when surface water runs short,” Professor Simmons said. “In reality, it drives many of our most productive industries – and if carefully managed can be maintained as a sustainable resource.
“Australia is in the fortunate position of being able to plan our increasing reliance by using groundwater sustainably. But to do that we need the world’s best science and technology for measuring and understanding the scale of our resource, how it behaves over time, and how to manage it sustainably.”
Established at Flinders University in 2009, the NCGRT is now one of the largest centres of its kind in the world. It has trained and employed more than 250 staff, including 40 chief investigators and 80 postdoctoral fellows, and welcomed 100 academic visitors.
And it could claim to be quite literally looking high and low in the search for groundwater. In the past year the Centre has mused about water (and life) on Mars and reported the discovery of huge reserves of freshwater kilometres below the sea.
The latter research, which was published in the international scientific journal Nature last December, reveals that as much as half a million cubic kilometres of low-salinity water is buried beneath the seabed on continental shelves off Australia, China, North America and South Africa.
seafloor
The potential of this discovery is obviously enormous, but in practical terms more recent trials on the Colorado River in Mexico and the Coorong in South Australia are even more exciting.
NCGRT researcher Dr Margaret Shanafield is testing new technology that measures how much water is stored underground when big rivers are allowed to flood.
The sophisticated mathematical model, which she developed while completing her PhD, describes what goes on when ephemeral rivers (those that flow only part of the year) flood, by using calculations involving the speed of a flood-wave or advancing streamflow and the rate at which water can flow through the subsurface material.
This can reveal which sections of a riverbed will allow water to seep through the ground and estimate how much water escapes downstream and how much soaks in to be stored underground.
The model can be used in any situation where surface or groundwater removal by industry, agriculture and local communities has the potential to threaten aquifers and dependent ecosystems. It means that instead of making generalisations about groundwater recharge volumes over long stretches of a surface water system, water managers, policy makers and users can have access to quite specific data.
“It provides the sort of information we need to keep the world’s water bank balance in the black, rather than in the red,” Dr Shanafield said.
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