Storms have already dumped more than a metre (39 inches) of rain in two days in parts of Queensland, engulfing homes, businesses and roads in muddy waters, authorities said.

Aerial footage showed rural communities surrounded by the floodwaters, cut off from nearby roads.

"We are going to see widespread rain and storms spread across much of northern Queensland," the state's premier, David Crisafulli, warned in a news conference.

"We remain prepared for the ongoing prospect of more rain and the likelihood of more flooding, both flash flooding and riverine flooding," he said.

Emergency services carried out 11 "swift water rescues" overnight, the premier said.

Areas of flood-hit Townsville, a popular coastal tourist destination that lies near the Great Barrier Reef, had been declared a "black zone", he said.

"Our advice to residents in the black zone at the moment is to stay out of that zone and stay safe."

The authorities told 2,100 people in the town to evacuate at the weekend, though about 10 percent refused, emergency services officials said.

- 'Bridge torn in two' -

One woman in her 60s was killed Sunday when the rescue boat she was in flipped over in the flood-hit rural town of Ingham, about 100 kilometres (60 miles) from Townsville, police said.

Her body was recovered later.

The floods swept away a section of a concrete bridge over a creek, cutting off the state's main coastal road, the Bruce Highway, the state premier said.

"It's not every day you see a bridge torn in two. That's what has happened at Ollera Creek, and it is significant," Crisafulli said.

Almost 11,000 properties remained without power across north Queensland, Ergon Energy said, with no timeframe given for when electricity would be restored.

The heavy rain is expected to continue for 24 hours -- with some locations to receive 300 millimetres (12 inches) -- before it begins to ease, the national weather agency said.

Townsville acting mayor Ann-Maree Greaney said the floods were expected to peak on Tuesday morning.

"The roads at the moment are cut off, so communities are isolated," she told AFP.

- Crocodiles -

The town was pressing for power to be restored and working with large supermarket chains to deliver food, the mayor said.

People could expect to see crocodiles moving about in search of calmer waters, the environment department warned this weekend.

One farmer told national broadcaster ABC he saw a "bunch of crocodiles" around his rural property -- 140 kilometres (87 miles) south of Cairns -- sharing a photo of one of the reptiles lit up by a car's headlights as it lurked on a flooded road.

As global temperatures rise because of climate change, scientists have warned that heatwaves and other extreme weather events, will become more frequent and more intense.

Queensland is Australia's most disaster prone state, experiencing major floods in 2019, 2022 and 2023, research from the non-profit Climate Council shows.