The water down under
Box 3 | Research into sustainable groundwater use
The aim of groundwater management is to ensure that there is water for all who need it, that the resource is not exhausted, and that the local environment is protected. The Centre for Groundwater Studies has a series of projects underway looking at these issues.
Although groundwater provides the drinking water supply for many towns across Australia, there is no single definition of what is sustainable yield, with most being guided by recharge rates.
The sustainable use of groundwater resources depends on measuring the balance between the current rate of extraction and the rate of recharge. Recharge rates depend on a number of variables such as the origin of the water, the site of recharge and rainfall. Also of interest is the question of how the recharge rate will be affected by altered rainfall patterns due to climate change.
At present major groundwater resources in Australia such as the Great Artesian Basin and the Murray-Darling Basin, are not being used sustainably, because the rate at which water is extracted is greater than the rate of recharge.
If an aquifer is from an ancient sea or lake, a so-called formation aquifer, then the water can only be withdrawn once, leaving a depleted aquifer. The same applies to aquifers that were charged during much wetter times in Australia's geological past. While water in these aquifers can be used, it cannot be sustained because they are not being recharged.
In addition to measuring recharge rates, water researchers also need to keep an eye on water quality issues – such as pollution from industrial discharges or seawater discharging into an aquifer – and monitoring and licensing of users to assist in assigning water allocations and entitlements.
Prize-wining Australian research
Australian researchers are leading the way in developing better ways of managing groundwater resources. In 2001, researchers from the CSIRO Land and Water and South Australia's Department of Water Resources won the UNESCO Great Man-Made River International Water Prize for their work on managing groundwater in arid areas.
Since 1993, the group has been researching better ways of utilising groundwater, such as topping up aquifers with recycled stormwater or wastewater for storage and improving its quality so it can be used for irrigation. Called aquifer storage and recovery, or water banking, the technology has since been adopted elsewhere in Australia and overseas.
Similar projects are now underway in other states, including Western Australia, which is working with CSIRO researchers on a managed aquifer recharge project in Perth and Mandurah which tops up aquifers with treated wastewater for either irrigation or possible use in Perth's water supply.
Boxes
Box 1. Using science to measure and manage groundwater
Box 2. Our outback oases – groundwater dependent ecosystems
Related sites
Sustainability of groundwater supply – groundwater for the future (Centre for Groundwater Studies, Australia)
Water banking (Connected Water, Australia)
Buried water wins world prize
(CSIRO, Australia)
Water reuse technologies
(CSIRO, Australia)
Posted February 2007.