Nearly 50,000 people are isolated in the worst flood disaster the NSW Mid North Coast has ever seen. 

Dramatic vision has emerged of multiple rescues, including a man who waited behind while his wife was winched to safety and a woman seen wading out of her house in thigh-deep water.

The town of Taree, about 130 kilometres north-east of Newcastle, is the epicentre of the floods, with dozens of residents rescued from their rooftops and hundreds more fleeing their homes.

ALERTS: All of the latest warnings from the NSW SES

More than 100 flood warnings were in place this morning, including more than 20 emergency warnings for residents to evacuate.

"If you are under an emergency warning currently and it is safe to do so, I need you to evacuate now," NSW SES Commissioner Mike Wassing said.

"I cannot stress enough that it is important to heed the warnings of evacuations.

"We've already seen over the past few nights rescue conditions being difficult and dangerous, particularly at nightfall.

READ MORE: 'We really need to get rescued': NSW residents stranded as floods rage

"I cannot guarantee that our crews will be able to immediately rescue people if you do not evacuate and heed the warnings."

One resident, Keith, has lived in Taree more than 20 years and gave an emotional interview to 9News.

"It's coming in the back door, it's going into the front door, the water's pushing all up through the floorboards."

He said it was the worst he'd ever seen.

"It's destroyed everything."

AS IT HAPPENED: Almost 50,000 isolated as 'one-in-500-year' flood crisis escalates

After a series of social media posts asking for help to evacuate, Taree man Sam Halloran yesterday said his family and two dogs were safe.

Halloran shared a video showing his partner being winched to safety while he said he would stay behind to rescue the dogs.

In another rescue at Pampoolah, near Taree, a woman was winched to safety as floodwaters lapped at her house, almost up to the windows. 

Natural Hazards Research Australia chief executive Andrew Gissing said the flooding was the biggest on record for the area, describing the deluge as a one-in-500-year event.

Volunteers have carried out almost 300 flood rescues since midnight.

There have been more than 40 rescue teams active between the Hunter and Coffs Harbour.

"Our volunteers and partner agencies are working around the clock, prioritising rescues and getting help to those who need it most," SES Assistant Commissioner Storey said.

"We've seen a large number of calls for assistance, and we are doing everything we can to reach people as quickly and safely as possible."

There were still 19 high priority flood rescues being carried out last night, including in south Taree and in the Glenthorn area.

The following evacuation centres were open yesterday:

• Dungog RSL Club
• Club Gloucester
• Club Taree
• Manning Point Bowling Club
• Wingham RSL
• Bulahdelah Golf Club
• Tuncurry Beach Bowling Club
• Kempsey Showground
• Panthers Port Macquarie

Woolworths said all stores from Newcastle to Port Macquarie were open for now.

North of Port Macquarie, the Kempsey Woolworths and Big W were closed after the town was ordered to evacuate.

"With a number of communities along the Mid North Coast remaining on flood watch, we're continuing to closely monitor conditions and the advice of authorities to ensure the safety of our team and customers," a Woolworths spokesperson said.

The state and federal governments activated disaster assistance to communities in 16 local government areas.

That includes: Bellingen, Central Coast, Cessnock, Clarence Valley, Coffs Harbour, Dungog, Kempsey, Lake Macquarie, Maitland, MidCoast, Nambucca, Newcastle, Port Macquarie, Port Stephens, Singleton and the Upper Hunter.

The funding will cover emergency accommodation and essential items for evacuation centres.

It will also give grants for low-income, uninsured residents to replace basic home items for their standard of living, and to do structural repairs for their homes.

Councils will get money to help clean up and restore public assets.

Small businesses and producers will get funding to replace goods and property, and freight costs for primary producers will get subsidies to replace livestock and fodder.

Drenching not over yet

The Mid North Coast is bracing for more flash flooding with heavy rainfall continuing this morning.

Rainfall totals of between 100 and 150 millimetres were expected today in much of the state's north-east, with totals of 200 to 300 millimetres in some parts.

Due to the ongoing weather situation, Port Macquarie Airport has been closed.

As the situation is constantly changing, visit the NSW SES website for the latest warnings and advice.