Australian authorities have asked tens of thousands of people to evacuate their homes due to heavy rains and flooding.

According to the authorities, at least eight people have died since the storm began on the east coast of Australia almost a week ago.

Most recently, a 50-year-old man died on Monday when his car was swept away by the floods in the state of Queensland.

The city of Lismore in the state of New South Wales experienced the worst flooding in its history.

More than 400 millimeters of rain fell in the Lismore area in 24 hours.

With the city's levees breaching, the 43,000 residents have been ordered to leave the city.

The emergency services received numerous calls for help.

Mayor Steve Krieg has therefore already asked for help via the online networks for residents stuck on their roofs.

"If anyone has a boat and can come to Engine Street, there's a pregnant woman sitting on her roof.

Please help," he wrote on Facebook on Monday.

The Australian Meteorological Service has warned that "life-threatening flash floods" are threatening much of the coast due to more severe thunderstorms and heavy rainfall.

In total, millions of Australians have been asked to stay at home.

Almost 1,000 schools in Queensland remained closed due to the floods.

A 70-year-old man miraculously survived the storm.

His houseboat was swept away by the Brisbane River, crashed into a ferry dock and sank.

According to a report by ABC broadcaster, several eyewitnesses managed to save the man unharmed from the river with the help of a human chain.

After several years of drought and climate-related bushfires, eastern Australia is currently experiencing an exceptionally wet summer due to the La Niña weather phenomenon.

Queensland Prime Minister Annastacia Palaszczuk said on Monday that in some regions of her state it had rained as much in the past few days as it normally does in a whole year.