Households and businesses will help pay for Victoria’s largest desalination order, with authorities concerned about water levels in the long term.
The state government said, on average, households would pay an extra $10 to meet the $100 million 125-gigalitre order.
For the past six years, Melbourne has used more water than is being collected by the state’s dams.
This year the deficit is 137 gigalitres, or enough to fill the MCG 87 times.
Melbourne water storages are currently at 54.7 per cent capacity, the lowest since 2011.
The government is resisting increasing water restrictions because of the impact on business and sporting clubs.
Water Minister Lisa Neville said Victoria has had below-average rainfall and inflows into water storages in 18 of the past 20 years.
“At the end of the day, the only thing that is going to be able to increase significantly our water storages is the desalination order,” she said.
The government has also made the record order because of fire run-off fears following bushfires at Melbourne’s largest water supply, the Thomson Reservoir in Gippsland.
Reviving target of 155 litres a day
During the millennium drought between 1997 and 2009, Victoria established a personal water usage target of 155 litres per person, per day.
Melburnians are using 161 litres a day.
Ms Neville said the government would boost campaigning to convince the public to return to the 155-litres-per-person target.
From 2006, Melbourne’s storages dropped 30 per cent over 18 months, down to 24 per cent.
The Thomson dropped to 16 per cent.
With population growth, Melbourne’s annual usage has risen to above 450 gigalitres.
At full operation the desalination plant can produce 150 gigalitres.
‘Water security under threat’: Government
The State Opposition questioned the strategy to use the desal plant and slug consumers.
“I think there is a real concern that base living costs have increased drastically in the last few years and I think the government should be doing everything it can to avoid putting people under more pressure for basic utilities,” Shadow Water Minister Steph Ryan said.
But Ms Neville said it was essential.
“They may want to do the rain dance and hope it rains. I’ve tried that. It doesn’t work,” she said.
“What I do know is that our water security is under threat without the desal plant.”
Melbourne Water’s Craig Dixon said water supply was secure, but the order avoided a panicked situation.
He said water inflows to dams over the past five years were 36 per cent below the long-term average.
“Autumn is projected to be certainly another dry spout. We’ve come out of an unusually dry summer,” Mr Dixon said.