When police warned Gino Barbisan that they'd lock him up if he tried to enter his severely damaged home in the NSW Illawarra on Sunday, he nearly took them up on the offer.

"At least I'd have a roof over my head and a hot meal - that's more than I've got now," the 72-year-old  Kiama man said.

"Three-quarters of my roof has gone, the windows and sliding doors are not only shattered, they're all on the ground.

"I don't know what's left inside."

Residents of 20 homes in the area remain unable to access their properties due to the threat posed by asbestos contamination caused by Saturday night's storm, and may not be able to return to their homes for a week.

Premier Barry O'Farrell visited the region on Monday and described the scene as 'extraordinary'.

"It was extraordinary flying over, seeing the roof of the fire station missing, seeing from the air mature trees that look as though they've been through a mix-master, seeing blue tarpaulins along a defined corridor.

"This is the sort of event that you associate with a tornado going through parts of those areas of America, not usually what you'd see going along our coastline."

Mr O'Farrell said the declaration of a natural disaster would give residents and business owners access to a number of disaster assistance schemes.

A similar declaration has been made for flood victims in the Hastings and Macleay valleys, clearing the way for grants and low-interest loans.

Flood waters have yet to completely recede in the region, leaving residents with an anxious wait to discover the extent of damage to their properties.

VIDEO, PHOTOS: Floods bring the foam to northern NSW beaches

Despite the devastation in Kiama, Mr Barbisan considers himself "lucky" because he was at a party in Wollongong on Saturday night and so wasn't home when the violent storm struck around 3am on Sunday morning.

He got a call from a neighbour soon after and reached the street about 4am, but was not allowed access to his home, or the street, for safety reasons.

"I came back at at 7am [on Sunday] and was allowed to walk up the street to my house. I got a shock when I saw it, but what can you do?" he said.

"I tried to get some stuff out, but the cop kicked me out and told me I'd be put in jail if I went in again.

"So now it's up to the engineers and the insurers to decide; I'll either get money to fix it or I'll have to get a new one.

"At my age you just have to deal with what comes your way."

Minnamurra Street was the worst affected after the extreme weather event tore through the town.

Yesterday the street was cordoned off again, not just for the clean-up of corrugated iron, clumps of insulation, shattered glass and tiles and other wreckage that lay strewn about, but because of the added threat of asbestos.

Asbestos removal crews, dressed in white protective clothing and masks, moved in to monitor the clean-up and ensure no traces of the deadly building material were left exposed.

Residents of the worst-struck streets were issued with notices to vacate in the afternoon due to concerns over asbestos, while nearby residents were advised to keep windows closed and wear masks if they had concerns.

Experts seeking tornado evidence

Storm investigators will study a narrow path of destruction at Kiama today for proof a tornado was present.

Experts from the Bureau of Meteorology believe it "highly likely" a tornado is responsible for some of the damage delivered on the seaside holiday town during a severe weather event overnight Saturday.

The visiting bureau team will apply the Fujita scale, a measure of tornado intensity based on the amount of damage to homes and other structures.

Julie Evans, a meteorologist with the bureau, said it had been difficult to be certain of a tornado because the storm occurred at night.

"While some of the damage appears to be associated with very strong winds funnelling around the local hills and headlands, there is also a narrow path of damage consistent with a tornado," she said.

"It would appear that small-scale circulation formed within the sharp trough that was moving down the coast, bringing very heavy rain to the NSW coastal districts.

"It was dark - without visual observation of a funnel we cannot be conclusive, but it is highly likely that a tornado formed within that circulation."