Five hundred rescues have been made in northern New South Wales as residents battle rising floodwaters, NSW Premier Dominic Perrottet says.
There have also been 972 calls for assistance, with the premier warning conditions are likely to worsen.
There are currently 12 evacuation orders in place, affecting close to 16,000 people in northern NSW.
"Can I ask those people who are isolated at the moment to please be patient?" Mr Perrottet said in a press conference on Monday.
"Please be patient but be assured we are doing everything we can to help you."
NSW Minister for Emergency Services Steph Cooke said the situation was an unprecedented disaster and people should be prepared to leave their homes at very short notice.
"The last record flood along the Wilson at Lismore was set in 1954 and it peaked at 12.17m," she said.
"The river is presently at 14.36m and continuing to rise."
A rescue worker comforts a woman during the floods in Lismore, northeastern NSW earlier this year. Source: AAP / JASON O’BRIEN/AAPIMAGE
People were caught unaware by the speed of the rapidly rising waters, with some forced to take refuge on the roof of their homes overnight.
The ADF arrived in Lismore on Monday morning to help the stretched emergency response crews which include the RFS, NSW Fire and Rescue, police and ambulance, and State Emergency Services volunteers.
The town recorded 181mm of rain in 30 minutes on Monday and a severe thunderstorm warning is current for intense rainfall across the northern rivers.
The Bureau of Meteorology issued a major flood warning at 9.42am on Monday for the Tweed River, adding to major warnings already in place for the Wilson and Clarence rivers as large swathes of the northern rivers grappled with the crisis.
Near the Tweed River, the BOM said major flooding was occurring at Tumbulgum, Mueillumbah and Chinderah, with further rain forecast for Monday, stoking fears waters could rise even higher.
"This has caused major flooding at Tumbulgum and Murwillumbah, with further rises possible during Monday. At Chinderah, major flooding is occurring on the high tide," it said.
People being rescued from the extreme floods in the NSW town of Lismore on Monday, 28 February, 2022. Source: AAP / JASON O’BRIEN/AAPIMAGE
Dangerous and rapid river-level rises have been observed along the tributaries upstream of Lismore, with heavy rain falling over the Wilsons River catchment and forecast to continue during the remainder of Monday morning.
The floods at Lismore were "worsening", with hundreds of calls for assistance from the area, and the search for a man missing in floodwaters suspended until conditions allow it to resume, NSW police told AAP on Monday.
'Unprecedented situation'
Lismore Mayor Steve Krieg described the situation as "unprecedented", "very dangerous and life-threatening".
"This really is a catastrophic event for the city of Lismore. We have broken records, flood records dating back to 1854 already ... The rain has set in and there is another forecast of another 200mm of rain today," Mr Krieg told the Nine Network.
Twenty kilometres north of Lismore, at Rocky Creek Dam, the SES is directing people below the dam to evacuate to higher ground as "uncontrolled water is spilling over", amid fears it could burst its banks.
"If you remain in the area you will be trapped without power, water and other essential services and it may be too dangerous to rescue you," the SES said.
NSW Emergency Services Minister Stephanie Cooke said Lismore's situation was much more severe than forecast on Sunday, straining the resources of SES.
Flooding occurs in the town of Lismore, northeastern New South Wales. A severe weather warning is in place for southeast Queensland and areas in northern NSW as wild weather and dangerous flooding continues to severely impact large swathes of both states. Source: AAP / JASON O’BRIEN/AAPIMAGE
"We are putting every single available emergency services personnel and resources in place to support the community," Ms Cooke told Sydney radio 2GB.
The government was "throwing everything" it had at the crisis with a "multi-agency response", she said.
Many roads are cut and the SES is warning people to heed warnings and avoid entering floodwaters.
South Murwillumbah has also been evacuated as roads are cut and the only way out is by boat.
The SES ordered the town of Mullumbimby to evacuate on Monday morning, with the area threatened by rapidly rising floodwaters from the Brunswick River.
Fire and Rescue and the SES have been door knocking to ensure people evacuate.
One man died when his LandCruiser was carried away by floodwaters on the Central Coast, north of Sydney, on Friday and another remains missing in floodwaters in Lismore.
