The bill for the worst floods in 40 years in northern NSW is already in the millions and will rise, the state government says.
Premier Gladys Berejiklian was in Tweed Heads area on Monday to get an update from the State Emegency Service.
"Millions have been spent supporting the effort in the last three days," she told reporters in Banora Point. "There will absolutely be more to come."
Ms Berejiklian warned insurance companies they were on notice.
"They are on notice. No-one is to drag their feet," she said.
"They'll be answerable to me. They'll be answerable to every person in the community. We want people to be treated fairly. That's exactly what I'll insist."
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The clean-up is being in earnest on Monday after a number of communities in Lismore and Murwillumbah were allowed back to their homes to access the damage. Others are expected to get the all-clear on Monday.
Ms Berejiklian also had something to say to people who ignored SES evacuation warnings and stayed in their homes as the flooding began in the aftermath heavy rainfalls driven by former-Cyclone Debbie.
"This was a one-in-40-year event, if not longer. Unfortunately, these freak weather incidents are going to increase," she said.
"One big learning point everybody has been telling me about here is people not being inclined to listen to warnings and having to have search and rescue operations afterwards."
The premier also asked everyone to spare a thought for residents returning to their damaged homes.
"This is when it becomes very confronting. A lot of people will be stressed about what they might find when they go back," she said.
Since Thursday, the SES has dealt with more than 2600 jobs and 480 flood rescues.
The focus now is on helping people move back to their properties and get on with the clean-up.
Prime Minister Malcolm Turnbull and NSW Premier Gladys Berejiklian are seeing firsthand the damage in flood-hit regions of northern NSW such as Lismore and Murwillumbah.
The SES gave residents the all-clear to return to homes in Tweed Heads and Lismore's south, north and CBD on Sunday afternoon.
Mr Turnbull will meet locals in both Lismore and Murwillumbah, and is likely to meet Ms Berejiklian at Murwillumbah on Monday.
At least three people are dead after floodwaters swept through northern NSW, and three men remain missing in Queensland after continued wild weather.
Meanwhile, residents in low-lying parts of Rockhampton are being evacuated from their homes as the central Queensland city braces for the worst flood in over 60 years.
The full cost of near-record flooding won't be known for some time, with many residents not yet allowed to return to homes or businesses.
The NSW Premier has pledged her government will do whatever it can to help flood-hit communities in the state, and it's understood she is likely to make an announcement on flood assistance during her visit.
The NSW SES has urged locals to turn off electricity and gas before re-entering properties and advised people to be aware of snakes and wildlife which may have taken refuge in properties.
“The affects of the clean up can be just as dangerous as the floods themselves and we are appealing to the communities impacted by the floods to take all precautions and listen to advice of the emergency service agencies,” SES Acting Assistant Commissioner Stewart said.
Ms Berejiklian said emergency services were on standby with equipment to drain water and hose down buildings.
"We know it's very frustrating and people want to get back to their homes," she said on Sunday.
"In some places the water has receded, but please heed the warnings."
NSW Labor has criticised the time it took for Ms Berejiklian to visit flood-hit regions, and questioned whether the areas had been properly prepared for the floods.
"The NSW Liberals and Nationals were clearly caught off guard by the looming flooding - and the north coast got smashed," opposition North Coast spokesman Walt Secord said in a statement.
Watch: Floodwaters near Murwillumbah
Aftermath in NSW, Queensland
Lismore local Christine Devine returned home to assess the damage – water came close to entering the second storey of her home.
Furniture is upturned, a sink has fallen, and gardens are in complete disarray at the house.
A stone fountain is now lodged in a spa bath, about ten metres from where it was previously located.
After being forced to evacuate, Ms Devine ended up in hospital after collapsing on her friend's floor.
"I just couldn't move and I was shaking," she said, “[My emotions] just exploded, like a volcano.”
Casualties in NSW and Queensland have continued to mount over days of wild weather.
Two women, aged 36 and 64, were swept away by floodwaters in NSW, while a 46-year-old man died in Murwillumbah from a heart attack when paramedics couldn't reach him.
A 45-year-old man was discovered dead at a South Murwillumbah caravan park, although the cause of death is yet to be confirmed.
On Saturday afternoon the body of 77-year-old Nelson Raebel was found in floodwaters in
southeast Queensland.
Police will on Monday resume searching for three men 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.
