In Sydney, the northern beaches and places such as Bronte and Cronulla beaches were also closed for Friday and Saturday. Clovelly remains open.
Residents of Narrabeen and Collaroy said they are worried a return of menacing surf so soon after their beach lost 25 metres of sand to last week’s tempest would worsen erosion at their beach.
In some parts, the beach is impassable at high tide. Visitors standing on the Collaroy foreshore on Friday could watch waves lapping onto the grass of private lawns as the swell increased.
Mitchell Harley, a researcher with the University of NSW’s Water Research Laboratory, said the return of dangerous surf could cause problems even if it was less intensive than a week ago as much of the sand had been washed out to sea.
“With last week’s erosion and its removal of that protective sand buffer, you could expect some further erosion at vulnerable places like Collaroy and Stockton,” Dr Harley said.
For Collaroy, the main risk was that so-called dune scarps left after last weekend’s storm may erode a few metres further back and expose the buried seawall.
The next period of heightened risk would come with the high tide at 2am on Saturday morning, Mr Harley said.
Collaroy and Narrabeen locals have largely become accustomed to such weather events after storms in 2016 famously swallowed much of the beach, damaging properties along the way.
Vanessa Hill, a Collaroy resident of 10 years, said she was worried about another bout of erosion.
“We’re hoping the seawall will do its job,” she said, watching waves lap against a makeshift rock seawall that protects her property.
Beach-side homeowners along Pittwater Road have been trying for almost four years to win approval and raise the funds for a permanent revetment to protect their land.
Residents are trying to stump up 80 per cent of the cost of the seawall, with the rest split between the local council and the state government. For Ms Hill, her tab would come to a hefty $450,000.
Gary Silk, another resident seeking to secure funding for the wall said some older residents along the strip earmarked for protection did not have the cash to contribute. Those unable to pay should be offered loans otherwise the wall won’t be built, Mr Silk said.
“Why should nine people lose their houses, just because one person can’t do it?” he said.
Northern Beaches Council mayor Michael Regan said the council has “helped identify ways owners can finance the project, including re-financing and cost sharing among neighbours”.
“The council hopes to have commenced works on the seawall by December 2021,” he said.
Despite the dangers, most residents, though, can’t imagine leaving the area. “It’s beautiful and we wouldn’t want it any other way,” Ms Hill said.
Madeleine Bower is an intern at The Sydney Morning Herald
Peter Hannam writes on environment issues for The Sydney Morning Herald and The Age.