Repairs from the floods and Cyclone Yasi in Queensland last summer are costing $A1 billion more than expected.
The ABC reports the latest costs have climbed to $A6.8 billion, $A1 billion higher than the state government's February estimate.
Treasurer Andrew Fraser says the increase is largely due to new estimates from councils on repairs.
He says the additional costs place pressure on the state budget, which will be delivered later this month.
Meanwhile, Premier Anna Bligh has set a timeline for most of the funds from the state's disaster relief appeal, to be paid.
She says more than $A265 million will be given to 30,000 flood and cyclone victims by the end of August.