Australia Weather News

About 20,000 people have been evacuated, while 10,000 are without power and safe water supply after northern New South Wales was inundated by severe flooding today.

The main areas affected are around Murwillumbah, where residents have sought refuge in ceiling cavities and on the roofs of their homes, and in Lismore, where the Wilsons River has reached 11.6m.

The New South Wales State Emergency Service has made about 330 flood rescues in the past 36 hours.

Between 500 and 740mm of rain was recorded in the Tweed River valley in the 24 hours to 2:00am today, although it began to ease after that.

State Emergency Service deputy commissioner Mark Morrow said floodwaters were not a playground.

"To tell you the truth, I have seen disgusting footage today of people being dragged around behind vehicles on wakeboards thinking it is fun. It is not, it is serious," he said.

"For our volunteers, it is too much of a risk."

'There's a chance it could get a lot worse'

The heights of the Tweed River at Murwillumbah and Chinderah are the major concerns for emergency services and are expected to peak about midnight with a high tide.

"With that high tide coming in, there's a chance that it could get a lot worse," Lindy Alston from the SES.

Authorities said the Wilsons River was "approaching a peak" at 11.6m.

However, that will be cold comfort to people in Lismore, where the flood levy that was built in 2005 was breached.

"To the layman who hears that, what it really means is that there is about two metres above floor level in the Lismore CBD, upwards to two metres, so that's a significant amount of water," Mr Morrow said.

"By any stretch, most of those businesses will have significant damage or all of the properties in fact that were subject to that evacuation order, and it will probably be 12-24 hours before the water is receded enough to even get in and have a look at just how bad it is."

Residents taken by surprise by rapidly rising fast water

The SES said the situation was extremely serious and warned residents to act with extreme caution.

The SES assistant commissioner Kaylene Jones said there were concerns some people may have been swept away by the floodwaters.

"Some people potentially have been washed downstream and there's a potential that some of those flood rescues may indeed result in tragedies," she said.

SES spokesman Ian Leckie said many people were trapped across the region because of the rapidly rising water.

"We have everything happening — we have people on rooftops, we have people stuck in vans, it is an utter disaster," he said.

"This is the fastest event we have seen in this area for a long, long time. The rate of rise has caught people unaware and they are trapped.

'The water just raced in'

The speed at which the water from the Tweed River moved took many residents by surprise.

Shane Twomey is not insured.

"The water just raced in. Before you even had a chance to turn around it was here," he said.

"There's probably a good 50 or 100mm inside [the house] at the moment."

By the afternoon, residents were clambering to find higher ground.

"I'm more worried about how much clean-up is going to happen, given that there's silt and all the mud," Brett Lesslie.

"You can see all the debris coming down the river. It's a mess, there's stuff everywhere."

Problem will move south

While waters in Lismore are expected to begin receding overnight, the problem will move south down the Richmond River.

"Friday evening into Saturday the water is expected to head downstream," Justin Robinson, from the BOM, said.

"Water will continue to Coraki, Bungawalbin and Woodburn, and there is a major flood warning for that area."

Over 20,000 people have been evacuated from areas around Lismore, Murwillumbah, Ocean Shores, Kyogle and Kingscliff and another 20,000 people are subject to an evacuation order, mainly on the Tweed River but also on the Wilsons River at Lismore.

People who need assistance are advised to go to an evacuation centre at Southern Cross University on Military Road in East Lismore.

All schools from Grafton to Tweed Heads are closed today.

Flooding has forced the closure of a number of roads including the Pacific Motorway and the Summerland Way near Kyogle.