Warnings for wild surf and damaging winds remain for the NSW coastline as the ‘bomb cyclone’ that has battered the state weakens.

Thousands of people are still without power, trees have been uprooted and beaches eroded after the wild weather system battered large parts of Australia’s east coast.

The weather bureau said a series of low-pressure systems remained in the Tasman Sea on Thursday morning (AEST).

A secondary low that was moving north just offshore from the NSW coast had begun to weaken.

The departing system was still creating damaging surf conditions along the entire NSW coastline, with people told to “stay well away” from the surf and surf-exposed areas.

The extreme seas could cause coastal erosion and localised damage to coastal infrastructure, after earlier forcing evacuations from beachfront homes at Wamberal.

People have been warned to stay away from the dangerous NSW coastline. Photo: BOM

“These conditions are expected to begin easing during the day,” the Bureau of Meteorology warned.

“Initially [that will be] for southern coastlines later during Thursday morning, and [they] may ease throughout the warning area by late Thursday afternoon.

“Beach conditions in these areas could be dangerous.”

Strong to damaging winds peaking at about 100km/h were likely for parts of the NSW Northern Tablelands, the mid-north coast hinterland and about areas on the border with Victoria.

However, they were expected to ease later on Thursday morning.

Warragamba Dam, west of Sydney, was expected to begin a “moderate spill” on Thursday after days of heavy rain, WaterNSW said.

“The duration and volume of the spill will ultimately be determined by rainfall received across the catchment,” it said.

State regulations do not allow water to be released at Warragamba Dam before predicted rainfall or to mitigate floods as it supplies 80 per cent of Sydney’s drinking water.

Spills at the dam are not uncommon. The last was in May, and there were three in 2024.

Warragamba flows into the Hawkesbury-Nepean river catchment, where the bureau has warned of possible flooding on Thursday.

Other, smaller dams are also spilling after reaching capacity following days of heavy rain. The downpours formed part of a “vigorous” east coast low the Bureau of Meteorology predicted would move into the Tasman Sea.

Lord Howe Island residents were warned to prepare for increased winds and elevated seas, with waves up above five metres.

More than 3400 incidents were reported to the SES during the storm, which began on Monday. There were 10 flood rescues.

Additional crews from the ACT joined response and recovery efforts late on Wednesday.

About 8000 Endeavour Energy customers were without electricity as crews worked to restore power on Wednesday night, down from a peak of 30,000.

Dozens of properties were under evacuation warnings due to flooding at Burrill Lake and Sanctuary Point near Jervis Bay.

In nearby Sussex Inlet, Fay Brown was stranded when roads approaching the Badgee Bridge flooded.

Without a four-wheel drive, Brown would have used a flood access road, but the local council continued a long-standing practice of blocking the road rather than allowing residential access.

“This happens every time we have heavy days of rain. I’ve lived here 11 years and been stuck on at least five occasions,” she said.

“Once we were stuck there for four days.”

-with AAP