SYDNEY - Thousands of Australians were evacuated from their homes, several people had to be rescued and a couple was feared swept from a causeway as flooding hit northern NSW and Queensland's Gold Coast today.
One of the areas worst affected by the heavy rain was the northern NSW town of Lismore, where about 3000 residents were told to evacuate their homes to escape rising floodwaters.
Authorities in northern NSW also had to rescue several people trapped by rising water, while several motorists on the Gold Coast called for help after becoming stranded in their cars.
Rescuers were today searching for a man and a woman believed to have been swept from a causeway across a creek at Coomera on the Gold Coast.
A police spokeswoman said the couple was reported missing about midnight, and two hours later a call was received from a driver saying water was pouring into their car on the causeway, the spokeswoman said.
"The mobile then cut out," she said.
There was no immediate sign of a let-up in the conditions, with authorities on the Gold Coast warning conditions were worsening and flood warnings issued around major river systems in northern NSW.
In Lismore, the Wilson River was expected to peak later today, but residents were evacuated this morning as a precaution, State Emergency Service (SES) spokesman Steve Delaney said.
Residents were being sent to an evacuation centre at Southern Cross University, or being told to move to the second storeys of their homes.
"The Director General of the State Emergency Service has authorised a full evacuation of the city," Mr Delaney said.
He said authorities had revised the number of people evacuated in Lismore to 3000, down from an earlier estimate of 6000.
Earlier today, more than 75 elderly residents at a nursing home in Benora, on the Queensland border, were evacuated and about 50 people at a Lismore caravan park were moved to higher ground.
Several people also had to be rescued as heavy rain swamped the region, including a 50-year-old man plucked to safety by rescuers in a front-end loader.
The storm system brought more than 100mm in 24 hours to areas across the border in NSW, including Coffs Harbour, Grafton and Lismore.
Downstream of Lismore, moderate to major flooding was forecast for later today around the Richmond River at Coraki, Bungawalbyn and Woodburn.
Minor flooding was also forecast for the Brunswick River at Mullumbimby and Bellinger River through Bellingen.
Last night, residents in Yamba and Byron Bay were using sandbags to prevent rain entering their houses as flash flooding hit the towns.
The Bureau of Meteorology forecast more rain for NSW today with flash flooding warnings for the Northern Rivers, mid-north coast and the Northern Tablelands.
In south-east Queensland, the SES said most suburbs on the Gold Coast were flooded this morning.
Gold Coast SES controller Peter Lanell said conditions were worsening. Even SES support crews being called in from Brisbane were becoming stranded in some areas.
"My relief crews coming in to back me up are now getting stranded and they can't get through," he told the Nine Network.
The SES had this morning received about 500 calls for help after strong winds and falling trees caused widespread damage on the Gold Coast.
SES volunteers were manning road blocks to stop motorists from braving the worst of the flooding, and people were being advised to stay inside and not to travel.
Jeff Callaghan, a severe weather expert with the Bureau of Meteorology, said the southern end of the Gold Coast had recorded falls of 368mm in the past 24 hours.
Brisbane has also been swamped with heavy rain, with bayside suburbs near Manly copping the heaviest of the falls.
"And there's more to come," Mr Callaghan said.
- AAP
6,000 residents of  in  have been told to evacuate their homes.

A couple is missing on the  in Queensland.  State Emergency Services (SES) workers are currently preparing to evacuate a number of nursing homes in the suburbs of  and .

The  (BOM) have said that South East Queensland has recorded rainfalls of 368mm in the last 24 hours and that the Gold Coast suburb of  has been averaging 80mm per hour for at least two hours.  The Coolangatta airport was closed due to flooding.

Further south the city of Lismore has been inundated.  A recently constructed levy has held back the waters of the , protecting the town's central business district.