Melbourn, March 6: Victorian Government in Australia places largest-ever water order from a desalination plant in dry conditions. The largest water order in Victorian history will be made from the multi-billion-dollar Wonthaggi desalination plant as the state continues to grapple with dry conditions and plunging water storages.
The city's largest water source, the Thomson Dam in Gippsland, has been affected by fires on its banks which continue to burn. Every year Melbourne uses 175 gigalitres of water from the dam.
Officials had been worried that run-off from the fires in the dam's catchment would contaminate water, but Ms Neville said that threat had eased.
"We feel quite confident around the Thomson that we have been able to do everything we needed to stop silt run-off and quality issues in the Thomson,'' she said.
Last year the state ordered 46 gigalitres from the Wonthaggi plant, which the minister said had helped keep storages above 50 per cent capacity. "We can't take any risks here around our storage levels. We have got a hot, dry autumn ahead unfortunately what the bureau is telling us, so I think that we will see one of our biggest orders,'' Ms Neville said. The desalination plant can produce up to 150 gigalitres a year.
What is desalination?
Desalination refers to the removal of salts and minerals from a target substance, as in soil desalination, which is an issue for agriculture. Saltwater is desalinated to produce water suitable for human consumption or irrigation.
What is the purpose of such orders?
Fires over the weekend in the Armstrong Creek catchment, which feeds the Upper Yarra dam, Melbourne's second-largest reservoir, have also caused some concern, as have spot fires at the northern reaches of the dam.
There are also long-term risks to water supply from bushfires in water catchments, because regrowing bush sucks up more water from the ground, stopping flows into dams.
Dr Chris Taylor from the Australian National University said the fire in the Armstrong Creek area was of particular concern because the area was also burnt by the Black Saturday fires.
"Fires in these forests were historically infrequent, with return intervals spanning decades or even centuries,'' Dr Taylor said. Some catchment areas can also be logged, further reducing flows into dams.