‘Stay indoors’: Month’s worth of rain dumped on Sydney in a day

In the state’s west, six people were taken to hospital following the collision between a ute and a four-wheel drive on the Castlereagh Highway at Aarons Pass, just south of Mudgee. It was not known if wet conditions were a factor in the crash.

Two children were flown to The Children’s Hospital at Westmead, a man in his 60s was flown to Royal North Shore Hospital and another man, in his 30s, has been taken to a third hospital. A woman in her 30s was also flown to hospital in a critical condition.

On the northern beaches, Wakehurst Parkway was closed due to flooding between the Sydney Academy Of Sport and Recreation and Oxford Falls Road, while in south-west Sydney, Riverside Road at Chipping Norton was also closed during the afternoon.

Reduced train frequencies, from one train every three to four minutes to one every 10, were necessary to stop the network from being clogged after rain damaged signalling equipment at Redfern station.

The ferry wharf at Parramatta was also been inundated, forcing buses to replace ferry services between Rydalmere and Parramatta. Buses were also supplementing train services on the T1 line between Riverstone and Richmond, and on the T8 line between Campbelltown and Macarthur.

The Bureau of Meteorology was forecasting between 100 and 200 millimetres to fall over Sydney from Friday to Saturday morning, warning residents of Sydney, the Illawarra and the Central Tablelands of possible flash flooding.

The bureau said it was particularly concerned about the area between the Blue Mountains and Narooma, where intense rainfall could lead to dangerous and life-threatening flash flooding from into Saturday morning.

Water NSW, the government body responsible for the state’s dam systems, was also preparing for a controlled release from Warragamba Dam, which is Sydney’s main drinking water source, in the coming days.

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The dam was 96.3 per cent full on Friday, but Water NSW chief executive Andrew George said as little as 90 millimetres of rain would be needed for the dam to fill and spill. The Bureau of Meteorology was expecting 100 to 150 millimetres over the dam’s catchment during the current rain event.

“That means the Warragamba will move into a spill, likely Monday morning,” George said. “What’s important about that is that the spill will occur likely when the rainfall event has moved on, so it is very important that the community remain vigilant.”

Elsewhere, Northern Beaches Council workers pre-emptively excavated Narrabeen Lagoon, expecting more water to come from downstream.

“We opened Narrabeen Lagoon last night, but it closed again naturally because the lagoon level was roughly the same as the ocean,” Mayor Sue Heins said.

“The lagoon level needs to be higher to beat the waves. Our contractor is on site again, trying to keep the channel open, to allow water to escape.

“We have also lowered Manly Dam levels, to provide more flood storage, and expect to open Manly Lagoon sometime today.”

Lismore, which experienced horrifying floods in 2022, appeared to have escaped the worst of the system. The Wilsons River peaked lower than expected, at 3.8 metres through Lismore about 3am on Friday.

At 10am on Friday, the bureau removed its flooding warning for the town.

More than 100 domestic flights in and out of Sydney Airport were cancelled, with dozens more delayed.