Parts of the Australian city of Brisbane are under water after heavy rain brought record flooding to some east coast areas and killed eight people.

The flooding in the city of 2.6 million people and its surrounding area is the worst since 2011, when it was inundated by what was described as a once-in-a-century event.

The latest fatality was a man in his 50s who drowned on Monday after driving his car into floodwater before dawn at Gold Coast city, south of Brisbane, Queensland state police said.

The bodies of the man and his dog were retrieved hours later from a submerged car which had been washed from the road, a police statement said.

Queensland emergency services warned life-threatening flash flooding was occurring in parts of Gold Coast.

Emergency crews made more than 130 swift-water rescues in 24 hours, officials said.

All eight flood deaths have been in Queensland state, of which Brisbane is the capital.

A search continues for a solo sailor, aged in his 70s, who fell overboard from his vessel in the Brisbane River near the city centre on Saturday.

Police are also searching for a man missing from Goodna, west of Brisbane and another Esk, north-west of Brisbane.

South of the Queensland border, police on Monday were searching for man after officers heard him calling for help on Sunday in floodwaters in the New South Wales town of Lismore.

Police warned businesses along the river waterfront to evacuate after a pontoon carrying a crane broke from its moorings upstream and began riding the floodwaters toward them.

Multiple emergency flood alerts were in place for Brisbane suburbs, where 2,145 homes and 2,356 businesses were submerged on Monday. Another 10,827 properties were partially flooded above the floorboards.

The Brisbane River peaked on Monday at 3.85 meters (12ft 3in), officials said.

That was 61 centimetres (2ft) below the 4.46 metre (14ft 3in) flood level reached in 2011, officials said.

Queensland’s premier Annastacia Palaszczuk said the rainfall over Brisbane had been extraordinary since November when authorities were considering water use restrictions due to a shortage.

“It is still a significant event, and I think everyone would agree no one has seen this amount of rain in such a short period of time,” in the south-eastern area, Ms Palaszczuk said.

Brisbane Lord Mayor Adrian Schrinner said the floods are “very different” to 2011 because the rain pummelled the region for five days.

In 2011, the rain had stopped days before the Brisbane River peaked and authorities had warned for several days of flooding downstream.

Queensland transport minister Mark Bailey said major roads had been cut off. Train and ferry services across Brisbane have also been halted, he said.

“We’re going to have localised flooding in a lot of areas for a couple of days yet,” Mr Bailey said.

Lismore is braced for its worst flooding on record, with the city centre inundated on Monday after days of unrelenting rain. Some 15,000 people have been evacuated.