Western Australia should move towards ‘sustainable functionality’ through a restructuring of its agricultural industry and adaptation to the changing climate, according to an internationally renowned water expert.
Western Australia should move towards ‘sustainable functionality’ through a restructuring of its agricultural industry and adaptation to the changing climate, according to an internationally renowned water expert.
Professor Jorg Imberger, director of the Centre for Water Research at the University of Western Australia, said farmers should be subsidised to relocate to areas with better access to water, for example near the Ord River irrigation area, and be encouraged to plant native vegetation.
The South West, once among the most biodiverse regions anywhere in the world, would continue to suffer from decreasing rainfall patterns and soil moisture as the biodiversity moves north.
The warming climate had also contributed to the lowering of the Gnangara Mound through evaporation, he said.
“There is no shortage of water in WA, only the resources have shifted,” Professor Imberger said.
He commended the Water Corporation for its ‘security through diversity’ vision, and has identified the use of re-cycled water as having enormous potential.
The issue of natural resource management, particularly the emotionally charged debate surrounding the state’s water supplies, presented a challenge in a boom economy.
Professor Imberger said there was a conflict between an economy centred around growth and consumption, and the preservation of the natural environment,
“This last year, everyone’s become familiar with the words ‘environmental sustainability’. Business is seeing an opportunity to make more money. Those two are incompatible,” he said.
Agriculture remains the largest water consumer in the state, using 535 gigalitres, or around 40 per cent of the total volume, in 2004-05, according the Australian Bureau of Statistics’ water account.
Households are the second biggest water consumers at 362GL per year, with the mining industry also a significant water consumer at 183GL, fuelled by the state’s resources boom.
The Water Corporation says that, of the 265GL of water in the public scheme, about 50GL, or 20 per cent, is used by the industrial-commercial sector,
In the industrial sector, the mining and energy companies dominate the list of biggest water users in the state.
Some major players in those sectors have been working towards greater water efficiency and reductions in consumption.
Rio Tinto Iron Ore, which drew more than 40GL of water from various sources, uses about half of this in iron ore production, an amount it has reduced despite increasing output, and discharges the rest.
Water is used at the operations predominantly for dust suppression, to add moisture to ore before and during processing and for human consumption on site.
Excess water from dewatering is returned to the environment or recycled.
Rio Tinto Iron Ore’s water spokesman said the company had been active in reducing total water usage by maximising water recycling and implementing water saving technologies.
The spokesman said the company had also raised awareness on-site by conducting specific workshops targeted to improve water use and by focusing employees on the issue.
The mine sites use purely groundwater, which is extracted at the site, with some scheme water used around the Karratha area at operations located near the port.
The company’s ‘water effectiveness manager’ heads its water efficiency measures, with role created in November 2004 to focus solely on the sustainable use of water.
Since then, its water efficiency has risen from 215.4L per tonne in 2003 to 154L/t li in 2006.
Alcoa’s WA mining operations have also reduced their potable water usage, which is down 42 per cent.
About 26 per cent of the water used by Alcoa is sourced from the Water Corporation.
Alcoa’s Pinjarra refinery also sources 241ML of tertiary treated sewage effluent annually from the town’s sewage treatment plant.
Verve Energy’s Peter Winner said the utility needed about 21GL of water a year for its Muja and Collie Power Stations, and had a licence for a further 1.6GL for its Kwinana and Cockburn Power Stations. The bulk of the water, about 90 per cent, is needed for cooling.
Cooling water is taken from Cockburn Sound.
This week, Water Resources Minister John Kobelke launched his State Water Plan 2007, establishing a target for 30 per cent of all waste water to be reused or recycled by 2030, adding to the current target of 20 per cent by 2012.
Mr Kobelke said the government would work closely with the agricultural and mining sectors to help them improve their water use efficiency by 20 per cent.
