More than 230,000 households and businesses are without power and flash flooding alerts have been issued for coastal areas in the aftermath of ex-tropical cyclone Alfred.
The warnings follow heavy rain across southeast Queensland overnight and are clustered around the Brisbane, Gold Coast, Logan and Ipswich council areas.
Residents have been told to move to higher ground away from the water or get ready to leave immediately if the threat worsens.
“If you are near flood waters get up as high as you can where you are,” Queensland Police said on Monday.
In northern NSW, where one person has died, rain is falling, roads remain closed and people are warned not to drive through high water.
Some 1800 people have been isolated by the deluge and other 18,500 have been told they could be isolated.
Across the northeast, 20,300 people have been told to evacuate.
Over the weekend, some residents were allowed to return to their homes in places such as Lismore as conditions eased.
“We’re not out of the woods just yet,” NSW SES Assistant Commissioner Sean Kearns said on Monday
“The predicted risk of heavy rain to continue throughout Monday and possibly into Tuesday will only exacerbate this risk.”
The prime minister flew into Brisbane on Sunday as flooding shut down a Queensland community and falling trees destroyed homes and cars.
Residents at Hervey Bay north of Brisbane were told to stay inside under an emergency declaration after almost 250mm of rain fell in hours, triggering flash flooding.
Parts of Gold Coast received an emergency warning late on Sunday, with communities told to “take action now” and stay off the roads.
About 30 rescues took place across Queensland’s southeast and northern NSW on the weekend.
But some were not so fortunate. The body of a 61-year-old man was found after his ute was swept into floodwaters at Megan, near Dorrigo, NSW, on Friday.
Thirteen soldiers were injured, and two remain in serious condition in hospital, after a truck rolled near Lismore on Saturday.
After the former cyclone made landfall just north of Brisbane as a tropical low on Saturday night, the Bureau of Meteorology predicted up to 700mm of rain could hit the region through to Monday.
Conditions on Sunday forced evacuations in Hervey Bay, where a public safety declaration meant police had extra powers to carry out emergency operations. Almost 250mm of rain fell in a matter of hours, triggering flash flooding. Officers performed nine rescues from houses and seven from cars. An emergency alert was in place for the Fraser coast.
The bureau warned of swollen rivers and flash flooding, with more rain looming.
Speaking on Sunday afternoon, a meteorologist, Sue Oates, said the impact of ex-Cyclone Alfred had been “reduced to one hazard – and that’s the rainfall”.
Isolated rainfalls of between 200mm to 400mm were expected on Sunday, with another trough from central Australia dragging the low-pressure system inland over northern NSW.
Insurance customers have lodged about 3,000 claims over two days.
The Insurance Council of Australia chief executive, Andrew Hall, said it was too early to estimate the total insurance bill. “Insurers have received around 3,000 claims in the past two days and expect many more thousands of claims as residents return to their homes and understand the full extent of the damage,” he said.
SEQwater advised that two water treatment plants were out of action – one in Dayboro and one in Canungra – but both had full reservoirs, so they would be able to provide water to those communities while work went on to get the plants back online.
The company’s chief executive, Emma Thomas, said there were no plans to release water from the dam in Wivenhoe at this stage and residents downstream would be given as much possible notice if that were to change.
Lismore’s deputy mayor, Jeri Hall, said about 600 people had sought shelter in evacuation centres.
Some residents have been without power and water for days.
Showers are not set to become isolated until Tuesday. But even after the rain does ease, flooding can continue for several days to come, the bureau has warned.
Twelve ADF soldiers remained in hospital on Sunday evening, two in a serious condition, after a crash on Saturday involving two military trucks near Lismore. Each truck was carrying 16 soldiers.
The first truck rolled, then the second did the same as it swerved in an attempt to avoid the first, officials said.
Of the 32 Brisbane-based soldiers onboard, 13 were injured.
Read more of Guardian Australia’s Tropical Cyclone Alfred coverage:
