In some areas of the state of Queensland, parents have been urged to pick up their children at schools, in order to avoid the children getting stuck there, when nearby roads are no longer navigable due to the water masses.
"No one wants their children to spend the night at school without their families," state Attorney General Grace Grace told ABC News.
In the state of New South Wales (NSW), 200,000 have been ordered to leave their homes and another half a million people have been warned that they may be evacuated.
In the western outskirts of NSW's capital Sydney, several areas have been evacuated, including the same areas in the northwest that were hit hard by floods a year ago.
On Thursday morning, local time, the state's Prime Minister Dominic Perrottet urged those affected by the warnings to take them seriously.
- We believe that the situation will worsen before it improves, he said, according to SBS.
Large parts of eastern Australia have had several weeks of persistent rain, which has led to rivers flooding over their beds and ponds being filled to bursting point.
In the past week, 13 people have died in Australia's floods and the country's fleet has, among other things, rescued stranded people by helicopter from rooftops.