NSW flood emergency response scrutinised

A rebuffed early offer by the Australian Defence Force to help in the days before the flood crisis hit northern NSW will be examined in an independent investigation of the response to the disaster.

State Emergency Services Commissioner Carlene York has defended the decision, saying the organisation was prepared and resourced to deal with the minor to moderate flooding that was forecast.

Emergency Services Minister Steph Cooke says the investigation will scrutinise the emergency response to the catastrophic floods.

"I think we can always do better next time," Ms Cooke told 2GB on Monday.

While some 8000 ADF personnel are now involved in the clean-up effort, there has been heated criticism of how long it took to deploy troops, and questions have been asked over whether the state or federal government is to blame.

Ms York says the unprecedented flooding was much worse than forecast, which also meant helicopters were sent to regions where floods never eventuated.

Responders relied on the Bureau of Meteorology forecast when allocating resources, with only minor to moderate flooding expected in the Northern Rivers region.

"We resourced appropriately on those levels," Ms York said.

Instead, towns were hit with record floods, including in Lismore where waters were two metres above any previous event.

Helicopters were deployed to areas like Cooma, near the Snowy Mountains, to be on standby for floods that never arrived.

Ms York said the worst of the floods in the Northern Rivers had hit at night when rescue crews were restricted.

Former NSW fire commissioner Greg Mullins said the federal government was warned by its own agencies, such as the Bureau of Meteorology, that flood disasters were forecast.

However, he said the government failed to heed the warnings.

"The Morrison government was missing in action - not listening," he told ABC TV.

"It's their job to prevent this getting worse and into the future, while the emergency services get on with the response."

Head of federal body Emergency Management Australia, Joe Buffone insisted an earlier national emergency declaration would not have made an impact in sending in additional defence personnel.

"The way this declaration is right at the moment, it actually wouldn't have changed our posture at all," Mr Buffone told reporters in Canberra on Monday.

"The Commonwealth does not have the legal authority to take over or respond without authority from the state," he said.

Opposition Leader Chris Minns said it looked like the federal and state government were "fighting like schoolkids" while towns were flooding.

"You can't leave somebody standing on a street corner pointing the finger about who did what," he said on Monday.

"The truth is no one did enough."

"This squabbling between the federal and state government needs to be put to one side, they need to stop pointing the finger at each other ... these guys are all supposed to be from the same political party."

The SES has determined 3396 homes are uninhabitable and 6708 were inundated as 120 motor homes are sent to the Northern Rivers to deal with the shortage of accommodation.

Some 1100 people are in emergency accommodation and 134 remain in evacuation centres.

Flood recovery co-ordinator Deputy Police Commissioner Mal Lanyon says it's "devastating and heartbreaking to see what people have lost" in Lismore.

Infrastructure Minister Rob Stokes says people who live on flood plains in uninsurable houses are now considered a vulnerable class who need protecting.

"Where the market is unable to look after their interests then government does have a role to step in and address issues of market failure," he told a parliamentary hearing on Monday.

The loss of people's homes and all their belongings was a cost "being borne by everybody else in society".

The minister said he was looking to extend flood protection to people living on flood plains, in a similar scheme extended to people whose homes were damaged by cyclones.

Australian Associated Press