Posted 24 January 2007
Using bore water on ovals and parks may seem prudent in a time of drought, but unregulated use of underground aquifers could lead to environmental disaster, according to a leading group of Australian groundwater experts.
A group of seven senior professionals from public and private sectors, including Flinders University hydrogeologist Professor Craig Simmons, is urging Australian governments to take swift action to control and manage groundwater use.
"Unlike surface water, groundwater often suffers from being out of sight and out of mind," Professor Simmons said.
"Bore water also seems to be regarded by many people as an inexhaustible resource, and that is an attitude that has to change.
"Significantly, our recent water restrictions only deal with the mains water supply, and there has been no discussion whatever on groundwater.
"As you restrict use of the surface water supply, you can naturally expect pressure on groundwater to increase as people seek alternative sources that are not subject to the same restrictions. Any water debate must feature both groundwater and surfacewater."
In a recent position paper presented to State and Federal governments, the group makes several recommendations to encourage urgent change in addressing national groundwater issues.
The recommendations include:
According to official statistics, some 20 per cent of Australia's current water usage derives from groundwater and demands are growing.
"It is a vital resource because of its broad scale availability, its interaction with surface waters, and availability during droughts," Professor Simmons said.
"Groundwater is and will continue to be a valuable resource, but it is not a bottomless well.
"Like a bank account, if you continue to take more money out than you put in, you know you will eventually go bankrupt.. In many cases we still do not even know what the environmental water requirements of important ecosystems are and how groundwater extraction affects them."
He said that above average rainfall in the two to three decades prior to the 1980's has led to false sense of security, and warned that if rainfall patterns return to those of the early part of the 20th century, the consequences would be dire.
"Groundwater is recharged by rainfall and we urgently need to understand the wider implications of climate change" he said.
With the ability to recharge aquifers affected both by declining levels of rainfall and urban sprawl, aquifers are also facing degradation from factors such as uncontrolled pollutant discharges and the intensification of agricultural use.
Professor Simmons said the effects of poor management will be drastic, and in some areas are already evident in the form of falling water-tables, the reduction of groundwater flow to sustain wetlands, springs and rivers, irrevocably salinised or polluted groundwater and land subsidence.
"Our water management issues are complex," he said. "We need to identify the best mix of options for meeting not only water demands but also critical environmental objectives."
The existing systems of water allocation are contributing to the issue - in some cases, Professor Simmons said, entitlements exceed the sustainable yields, and the same drop of river water is effectively allocated twice over. He said State governments were "robbing Peter to pay Paul" by restricting the use of water in rivers and creeks, but not properly controlling the amount of water extracted from underground aquifers.
"The only answer is better management of the resource, backed up by education and further research," he said.
"There has been a serious deskilling in many water agencies and we need a strategic and nationally co-ordinated approach for safeguarding the ongoing collection of knowledge about the resource.
"We also face a serious shortage of hydrogeology capacity in this country at a time when we desperately need it.
"Groundwater systems are highly complex, and since our future survival and prosperity are reliant on a reliable water supply, it is vital that we maximise our understanding of the resource and that those with appropriate knowledge of long-term environmental effects are given a major role in critical decision making."
Source: Flinders University
Links:
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