Five people have died due to major flooding across Queensland and New South Wales caused by ex-Tropical Cyclone Debbie.
Father-of-three Matthew Roser reportedly stopped breathing after suffering a panic attack at his Murwillumbah home in far north NSW about 2am on Friday.
Floodwaters threatening the property are believed to have delayed emergency services from reaching the 46-year-old before he died.
A 36-year-old woman was discovered at a flooded property south of Murwillumbah about 8am on Friday.
Soon after, police divers located a 64-year-old woman in her submerged car, which had been swept off a causeway in the Hunter Valley and into the Worondi Riveulet.
On Saturday afternoon the body of Nelson Raebel was discovered not far from where 77-year-old went missing the day before in Eagleby, south of Brisbane.
A 45-year-old man was also found dead at a South Murwillumbah caravan park, but it is unclear whether his death was flood-related.
Authorities continue to hold grave concerns for three others missing in Queensland - a man in his 60s who went bushwalking at Lamington National Park, 50-year-old Mondure man David Heidemann and 58-year-old John Frost from Mount Pleasant in Mackay.
Some communities in the north of Queensland are still without power and water since Cyclone Debbie made landfall near Airlie Beach on Tuesday, irreversibly damaging at least 650 residences.
Ensuing wild weather down the eastern seaboard prompted the evacuation of 30,000 people in northern NSW and has since isolated 15,000 properties in floodwaters.
"To be honest, it is like a war zone," Lismore Mayor Isaac Smith told AAP.
"There are a lot of health concerns around what may or may not be in the water."
Water levels in Lismore peaked within a metre of the 1974 record of 12.2 metres on Friday.
In southeast Queensland, hundreds remain without power including suburbs such as Beenleigh, Eagleby and Loganlea - after Energex cut supply to stem the threat of electrocution.
Logan mayor Luke Smith said the "unprecedented" impact of the weather meant a ballpark figure on the damage bill was beyond comprehension.
"The sky is the limit," Mr Smith said on Sunday.
While some areas have started the gruelling clean-up, the central Queensland town of Rockhampton is still bracing for the worst flooding since February 1954.
Forecasters are warning flood levels will peak at 9.4m on Wednesday, impacting 5400 properties including 3000 homes.
Army personnel are among the emergency response doorknocking in the area while the Rockhampton Airport is expected to close at midday on Monday as it too is under threat from rising waters.
