Multi-million dollar beachside homes in Sydney's north are still at risk of collapse due to storm erosion.
SES crews and hundreds of volunteers worked into the night piling up thousands of sandbags to fortify the dozen or so homes and two unit blocks in Collaroy that are on the verge of sliding into the sea.
The properties survived Tuesday night's high tide that hit just after 10pm, with SES crews still at the scene on Wednesday.
The Collaroy homes are still in danger of collapsing and residents are not allowed to return home, the SES spokesman said.
Boulders will be brought in on Wednesday to strengthen sea defences.
Meanwhile, as hundreds of NSW residents continue the mop up from the weekend's monster storms, the SES is concerned gales, due to hit coastal regions on Wednesday afternoon, could cause more damage.
Extremely strong winds are expected to hit the NSW coast just after midday and will continue until midnight, an SES spokesman told AAP.
The winds could send debris flying and also lead to fallen trees already loosened by all the recent rain, the SES has warned.
"The cold winds are coming off the Alpine region," the spokesman said.
SES crews continue to assist residents in the state's storm-hit communities including around Lismore in the north, areas in Sydney's southwest including Picton, Milperra and Chipping Norton and in the city's northern beaches.
During visits to Sydney on Tuesday Malcolm Turnbull and Bill Shorten agreed on an open-ended support package for victims as an insurance catastrophe area was expanded to cover the east coast of Victoria and Tasmania's northern and eastern coastlines.
The storms have claimed the lives of two NSW men, while the search continues off Sydney's Bondi Beach for an American university student who was seen diving into the churning ocean on Monday afternoon.
