The NSW State Emergency Service (SES) has responded to over 4,200 requests for help as rain continues to pound Greater Sydney and its surrounds.
About 30,000 people have been impacted by the flooding event across Sydney, the Hunter and Illawarra, with dozens of evacuation orders in place.
The Hawkesbury, Nepean, Georges and Colo rivers have flooded due to the persistent rain.
Most of the communities inundated are on Sydney's south-western and north-western outskirts, but just before 7.30pm yesterday, the Bureau of Meteorology (BoM) warned major flooding was possible at the more suburban areas of Liverpool and Milperra on Monday night and throughout Tuesday.
About 9.30pm, the SES ordered people in parts of Chipping Norton, about 30km from Sydney's CBD, to evacuate.
While the east coast low which sparked the deluge weakened, the BoM still recorded more than 120mm of rain between 9am and 6pm yesterday at Horsley Park, in the city's south-western suburbs.
SES Commissioner Carlene York said there had been an "enormous" demand for help with the organisation dealing with about 4,297 requests and 141 rescues taking place since the start of the event.
With rain easing in some parts of Greater Sydney, Commissioner York warned "it's still dangerous out there".
"It can change quite dramatically. Just because it's not raining doesn't mean the catchments aren't filling up," she said.
Commissioner York said while it was still expected to rain in Sydney today, it would "not be in the amounts that have been seen over the last 72 hours".
Minister for Flood Recovery Steph Cooke warned Sydneysiders to be vigilant.
"Sydney so far has missed out on the worst but it doesn't mean it's out of the woods yet. We still have broad warnings from just south of Nowra all the way up to just south of Newcastle at the moment," Ms Cooke said.
She said there had been 184 registrations at evacuation centres, with 68 people in emergency accommodation.
Premier Dominic Perrottet said he had requested 100 more Australian Defence Force officers, with 100 currently assisting rescues across north-west Sydney.
Greater Sydney residents have been warned to avoid travel and check the SES website for evacuation orders.
Camden resident of 42 years, Stephen Rae, said it had been "horrendous" weather this year.
"The trouble with this flood now is the other flood filled everything up with water, even the groundwater is full, there's nowhere for it to go," Mr Rae said.
"The house is damp, the pets are damp all the time [and] it's very hard to keep things dry."
Windsor resident Tracey moved her animals to Blacktown when water began inundating her property.
She said insurers had only recently been assessing damage in the area from the last flood, in March.
"We're so over it, four times in three months is a bit much for all of us," she said.
"A lot of us aren't coping, there's a lot of people in the area who are elderly with illness and stuff like that and basically we're stuck, we're stranded."
On Monday, the SES told people in low-lying areas near the Hawkesbury River downstream of Wisemans Ferry, north west of Sydney, to evacuate by 10am.
Warragamba Dam, Sydney's main water source, began spilling about 2am on Sunday and, on Monday morning, WaterNSW said "all major dams in the Sydney network continue to spill".
Some rivers have exceeded the major flood levels reached in March.
Major flooding is continuing along the Nepean River at Menangle where river levels peaked at 16.61 metres on Sunday morning, exceeding the March flood peak of 15.92m, but below the April 2022 flood peak of 16.83m.
The Hawksbury River at North Richmond peaked at 14.18m on Monday morning, above the March peak of 14.08m and below the March 2021 level of 14.38m.
A severe weather warning for heavy rainfall is current for the Metropolitan, Illawarra, parts of Hunter and Central Tablelands Forecast Districts.
It's the third time this year many of the areas being inundated, including parts of Sydney's north-west and south-west, have flooded.
The downpour became deadly on Sunday when a man drowned in the Parramatta River at Abbotsford.
SES deputy state commander Ashley Sullivan said people in Greater Sydney should "bunker down".
"This is a developing flood and severe weather situation and we do ask residents to really consider your movements over the next couple of days," Mr Sullivan said.