( CNN ) -- The cost of repairing flood damage in Australia will top AUS $ 5.6 billion ( US $ 5.58 billion ) , according to Prime Minister Julia Gillard , who proposed a one-year tax to help fund the reconstruction . `` The great floods of this summer have been a national tragedy , not just a natural disaster , because of the awful loss of human life , '' Gillard said Thursday . `` The great floods of this summer have destroyed billions of dollars of wealth and robbed us of billions of dollars of income . In time they may prove to be the most expensive disaster in Australian history . '' Gillard said the money will come from $ 2.8 billion ( US $ 2.79 billion ) in spending cuts , $ 1 billion ( US $ 995.6 million ) in delayed infrastructure projects and $ 1.8 billion ( US $ 1.79 billion ) raised through a progressive , one-year income tax on people earning more than $ 50,000 . `` The levy will apply only in the 2011-12 financial year ... '' Gillard said . `` People who were affected by the floods will not pay this levy . '' Flooding in Australia , primarily in the state of Queensland , has affected more than 3 million people , making it one of the most costly disasters in the nation , the federal treasurer said over the weekend . The cost of the damage surpasses past tragedies like major bushfires two years ago and floods in the 1970s , Treasurer Wayne Swan said . The floods have devastated crops , tourism , retail and manufacturing , and have disrupted major urban areas like Brisbane , according to Swan . `` One of the biggest casualties is likely to be our coal exports , with many mines shut down in big coal mining regions like the Bowen Basin , and supply chains severely hampered , '' Swan said . `` While this will be partly offset by higher prices , the loss of production will be hit much harder . '' Swan said the government has already made about $ 227 million in disaster recovery payments to people who have been affected by the floods .
Money to pay for flood damage will come from spending cuts , delayed spending and a tax . Tax would raise $ 1.8 billion and would be levied for a year . More than 3 million people have been affected by recent floods . The government will be investing billions of dollars to help Queensland , national treasurer says .