Received

Heavy rain has caused a flood levee breach in Lismore along with the forced evacuation of residents in the northern NSW city.

The levee height was exceeded mid-morning on Wednesday as the Wilson River peaked over 10.65m and flood waters and mud began to spill into the CBD again, the Bureau of Meteorology said.

Mayor Steve Krieg told AAP he had heard reports the river had begun to tip over the top of the levee shortly before the confirmation.

"Everyone's exhausted," he said.

"Evacuation orders started at four o'clock yesterday afternoon and then got cancelled before the phones started ringing again.

"(People are) running on no sleep at the moment.

"It's hard to put into words. You're feeling angry as well because the messaging hasn't been what it should have been."

Mr Krieg said frustration in Lismore had grown after an evacuation order was cancelled half an hour after being issued on Tuesday.

The order to evacuate was then re-issued late Tuesday night, with the Wilson expected to burst its levee on Wednesday, peaking over major flood levels of 10.6 metres, up to 11 metres and higher, BoM said.

The worst might still be to come, with even higher readings at Lismore possible on Wednesday afternoon.

Like many Lismore locals, Mr Krieg has been sleeping at a friend's home for the past month and says he will be bunking with others for months to come.

He says the silver lining about the renewed flooding is most people lost the bulk of their valuables in the first inundation.

"The hardest thing for these people is they have spent weeks and weeks cleaning and getting rid of all the flood mud, sanitising and addressing the mould issue.

"Now you've got to virtually start all of that process from the start again."

City centre residents along with those in surrounding Lismore Basin, East Lismore and Girards Hill were urged early Wednesday to leave immediately.

Byron, the owner of a petrol station in Murwillumbah, said his business had been flooded in the most recent catastrophic event in the Northern Rivers.

"It came up to like two metres (high) in the shop and we've lost everything," he told the Nine Network.

The recent floods had broken the business' petrol pumps, ovens and fridges which had all since been replaced.

Flash flooding in the CBD has again inundated roads and an evacuation centre has been set up at Southern Cross University.

Further south, heavy falls and thunderstorms which could lead to flash floods with the possibility of dangerous and life-threatening conditions is forecast for parts of the Mid North Coast and Northern Tablelands.

Six evacuation orders are in place across NSW for areas including the Lismore CBD, Lismore Basin, low-lying areas of East Lismore, North Lismore and Girards Hill, Riverside Caravan Park Coraki, Tumbulgum, low-lying parts of Kyogle, parts of South Lismore, and Bellinger River Tourist Park on the north coast.

Six-hour rainfall totals between 80mm and 140mm are possible, while up to 300mm may fall over mountainous coastal areas.

Locations in the warning zone include Grafton, Coffs Harbour, Port Macquarie, Taree and Dorrigo.

© AAP 2022

A dozen flood evacuation orders have been issued across NSW as politicians warn severe weather conditions are expected to continue for several weeks.

The city of Lismore had its flood levee breached for the second time in weeks on Wednesday, as the Wilsons River peaked above 10.65 metres, with flood waters and mud spilling into the city centre.

"When you have a look at the rainfall, no one could have predicted some of the amounts we have seen," NSW Acting Premier Paul Toole said.

"Four weeks ago these communities were impacted ... no one could have predicted that we would be back here again."

The acting premier said renewed flooding had come just as many people were returning to their homes and businesses.

The areas suffering the most impact were Lismore, Ballina, Byron, Coraki and Woodburn, he said.

Mr Toole said harsh, wet conditions were expected to continue, with a very wet April in prospect.

"We may be in this situation, coming back in a week's time," he said. "When you have a look at the ground it is saturated.

"You only have to see a small amount of rainfall landing in these areas (for further flooding)."

Flood Recovery Minister Steph Cooke said the state had faced many natural disasters over recent years.

"Whether it's droughts or bushfires, and now floods," she said.

"We know this wet weather is likely to continue for quite some time, right throughout April and potentially beyond that.

"I know for many of you it must feel that this flooding emergency will never end, but I can assure you that there is light at the end of the tunnel."

Lismore Mayor Steve Krieg told AAP he had heard reports the Wilsons River had begun to tip over the top of the levee shortly before confirmation arrived from the Bureau of Meteorology.

"Everyone's exhausted," he said. "Evacuation orders started at four o'clock yesterday afternoon and then got cancelled before the phones started ringing again.

"(People are) running on no sleep at the moment.

"It's hard to put into words. You're feeling angry as well because the messaging hasn't been what it should have been."

Mr Krieg said most people in the area had lost the bulk of their valuables in the first inundation.

"The hardest thing for these people is they have spent weeks and weeks cleaning and getting rid of all the flood mud, sanitising and addressing the mould issue.

"Now you've got to virtually start all of that process from the start again."

A small but intense low off the coast of Evans Head produced intense thunderstorms and remarkably heavy rainfall on Tuesday night, Dean Narramore from the Bureau of Meteorology said.

Communities from Evans Head to Byron Bay were hit with 200 to 300mm of rain within a few hours, causing significant and destructive flash-flooding, Mr Narramore said.

Numerous rivers in the Lismore area are experiencing major flooding, including the Wilsons - which continues to rise after breahing its levee on Wednesday morning.

In Coffs Harbour, Dorrigo and Bellingen, falls between 200 and 300mm were recorded overnight and major flooding is also occurring on the Bellinger River.

The NSW SES has undertaken more than 40 flood rescues in the last 24 hours, many of which were for people attempting to drive through flood waters, NSW SES Acting Commissioner Daniel Austin said.

"We ask for people not to drive through flood waters and to stay away from these environments," he said.

Some 12 evacuation orders are in place across NSW, with an additional six issued on Wednesday morning.

The new orders are for Urunga CBD and Bellinger Keys, East Bellingen, Coraki and New Italy, Broadwater, Wardell and Cabbage Tree Island, and Newry Island.

© AAP 2022

One of the wettest summers on record continues, with heavy rain forcing a new evacuation order for Lismore in northern NSW amid fears the city is headed for further inundation.

"Everything's falling apart in Lismore at the moment," the city's Mayor Steve Krieg told the Nine Network on Wednesday morning.

"Our river is normally about eight metres lower ... We're estimating in about half an hour to an hour that's going to come up over the levee and the Lismore CBD ... will be inundated with water again.

"So, second time in a month.

"I'm going to jump in my car and get to higher ground."

The Wilsons River is expected to burst its levee on Wednesday morning, peaking over major flood levels of 10.6 metres, up to 11 metres and higher, the Bureau of Meteorology said.

The worst could be yet to come, with further river rises at Lismore still possible on Wednesday afternoon.

City centre residents along with those in surrounding Lismore Basin, East Lismore and Girards Hill have been urged to leave immediately.

Byron, the owner of a petrol station in Murwillumbah, said his business had been flooded in the most recent catastrophic event in the Northern Rivers.

"It came up to like two metres (high) in the shop and we've lost everything," he said.

The recent floods had broken the business' petrol pumps, ovens and fridges which had all since been replaced.

The evacuation order is the second for the city in 24 hours after an all-clear was issued to return with caution on Tuesday afternoon.

Six evacuation orders are in place across NSW for areas including the Lismore CBD, Lismore Basin, low-lying areas of East Lismore, North Lismore and Girards Hill, Riverside Caravan Park Coraki, Tumbulgum, low-lying parts of Kyogle, parts of South Lismore, and Bellinger River Tourist Park on the north coast.

Flash flooding in the CBD as a result of heavy rainfall has inundated roads and an evacuation centre has again been set up at Southern Cross University.

Further south, heavy rainfall and thunderstorms which could lead to flash floods with the possibility of dangerous and life-threatening conditions is forecast for parts of the the Mid North Coast and the Northern Tablelands.

Six-hour rainfall totals between 80mm and 140mm are possible, while up to 300mm may fall over mountainous coastal areas.

Locations in the warning zone include Grafton, Coffs Harbour, Port Macquarie, Taree and Dorrigo.

Alstonville recorded 355mm of rain from 9am on Tuesday, while Bellingen received 276mm, Dorrigo 262mm and Coffs Harbour 207mm.

© AAP 2022