Premier Dominic Perrottet will visit the devastated northern city of Lismore, with six people dead as a result of the NSW floods disaster and insurance payouts expected to soar into the hundreds of millions.

The cost in NSW alone is now more than $240 million, according to the Insurance Council of Australia, while estimates taking in Queensland claims as well peaked over $1 billion on Friday.

The ICA said it had received 67,537 flood-related claims, 24 per cent from the southern state and 76 per cent from southeast Queensland.

NSW’s most recent fatality was that of a man believed to be in his 40s whose body was found near Terragon, south of Murwillumbah, on Friday afternoon.

The federal government has meanwhile extended one-off relief payments to another 28 local government areas, Emergency Minister Bridget McKenzie and Government Services Minister Linda Reynolds say.

The $1000 payments for adults and $400 for children are available in Bayside, Bega Valley, Blacktown, Blue Mountains, Camden, Campbelltown, Canterbury Bankstown, Central Coast, Eurobodalla, Fairfield, Georges River, Hawkesbury, Inner West, Kiama, Kuring-Gai, Liverpool, Mid-Coast, Newcastle, Northern Beaches, Parramatta, Penrith, Ryde, Shellharbour, Shoalhaven, Sutherland, Wingecarribee, Wollondilly and Wollongong.

“We continue to closely monitor the flood emergency and our hearts go out to those people whose lives are being devastated,” Senator McKenzie said in a statement.

“We have made financial help available now because we know the economic impact of disasters like these are felt long after the flood water recedes.”

NSW Deputy Premier Paul Toole says farmers will also be able to access $15,000 immediately through Commonwealth-State Disaster Recovery Funding Arrangements.

Grants of up to $75,000 are available for primary producers in disaster-declared LAGs.

“We know it’s going to be a long road to recovery for our farmers, however this funding means they’ll have access to immediate support as well as in the crucial period of rebuilding ahead,” he said.

The Westpac Rescue Helicopter carried out five rescues on Friday, including in northern NSW, as the town of Coraki, south of Lismore, remains isolated by floodwaters.

Its crew also assisted people west of Mullumbimby after a landslide.

Concerns have been raised about the depth of the government’s preparation, resourcing and response to the disastrous floods, with Mr Perrottet acknowledging on Friday mistakes were likely made.

Those will be identified when the government conducts its reviews and the premier pledged to “resource every level of government to a level that will provide protection to the people of our state”.

Mr Perrottet also announced Emergency Services Minister Steph Cooke will soon take on the role of flood recovery minister.

Just over 500 Rural Fire Service volunteers, Fire & Rescue NSW crews and 317 Australian Defence Force personnel have also been deployed to help the clean-up effort.

Further south, the SES warned moderate flooding was occurring on the Hawkesbury River on Saturday at Windsor and Sackville, where evacuation orders remain and there are fears of flooding at Wiseman’s Ferry.

Continued rain on Sunday could trigger flood waters to rise from major to moderate levels, the SES warned.

In Penrith, flooding on the Nepean River has eased and levels are below the minor 3.88 metre mark, although the SES warned of possible renewed rises on Sunday.

Some Central Coast residents have been told to evacuate low-lying areas after heavy rain and “abnormally high tides” caused the Wyong River and Tuggerah Lake catchments to rise.

Others were evacuated from Croki on the mid north coast early Saturday morning due to a flood risk on the Manning River.

NSW will continue to be affected by severe thunderstorms and isolated heavy rain on the north coast until Sunday.

-AAP