Cyclone Debbie dumps bull shark in middle of Queensland road

A bull shark has been dumped in the middle of a Queensland road after floodwaters triggered by Cyclone Debbie hit northeast Australia.

Queensland Fire and Emergency tweeted a picture of the shark washed up on a road near the town of Ayr.

It said: "Think it's safe to go back in the water? Think again! A bull shark washed up in Ayr. Stay out of floodwater."

Emergency crews have been forced to rescue dozens of people from floodwaters since the Category 4 storm first hit the coast between Bowen and Airlie Beach on Tuesday.

The region is still being experiencing torrential rain and damaging gusts of wind, which have hampered relief efforts.

"We have a very, very large state here and this is a very, very big weather system that's going to wreak havoc all the way down the coast," Queensland Premier Annastacia Palaszczuk said.

The storm has been downgraded to a tropical low as it heads southeast towards Brisbane.

The city was drenched by a month's worth of rain in a single day, according to meteorologists and theme parks and beaches along the Sunshine Coast and Gold Coast were closed.

Some towns remain cut off by flooding as water levels continue to rise in many areas and have spread to include the neighbouring state of New South Wales.

However, only one significant injury has been reported as a result of the storm, a man crushed by a collapsing wall.

Among the areas worst hit by the storm were the Great Barrier Reef Islands, which experienced winds of more than 160 mph at the height of the cyclone.

Hundreds of residents and tourists are now being evacuated from the Hamilton and Daydream Islands after struggling with no power and toilets not flushing as water ran low.

Around 1,300 soldiers have been mobilised to help with the clean-up and deliver emergency supplies.

Farming is a major industry in the area, with officials saying the economic cost to the area will be huge.

"Producers in the Whitsunday area were planting winter vegetables and they're expected to suffer heavy crop losses as well as infrastructure, crop and irrigation equipment damage," said Queensland's Rural Economic Development Minister Bill Byrne.

"In the Mackay district, it's understood that the cane fields at Proserpine, Mackay and Sarina have been flattened."