There are grave fears for a delivery driver who is missing after his truck was found submerged in floodwaters in Sydney's west.
The Isuzu Pantech was found at Greendale about 9pm on Tuesday by the truck's owner, who told police his driver had failed to make a drop off at 6am after leaving just after midnight.
The missing driver has been named as Xianbin Liu, 50, from Beverly Hills.
Police entered the floodwaters to search for the man but he was not inside the truck or in the surrounding area.
The death toll from the state's flood crisis stands at eight after the bodies of a man and a woman were found in a western Sydney stormwater canal on Tuesday.
Authorities are warning about widespread disruptions and dangers on the state's roads, with many closed due to flooding and storm damage.
Commuters are being advised to avoid unnecessary travel and Sydney Trains also warned of significant disruption and delays.
Sydney has had its wettest-ever start to a year after being drenched with average rainfall totals close to what is usually reported in 12 months.
The Bureau of Meteorology's Dean Narramore says 872mm of rain has fallen in Sydney since January 1, the highest tally since records began. The previous record was 815.8mm in 1956.
"That is the wettest start to Sydney so far," he said.
In the past 24 hours parts of Sydney copped more than 100mm of rain.
A sunny day is expected on Thursday, but the state's flood crisis isn't over.
Major flooding is continuing in western Sydney's Hawkesbury and Nepean Rivers, and the Wollombi Brook in central west NSW.
The Hawkesbury River at Windsor reached 14 metres on Wednesday, about a metre above river levels seen during devastating floods a year ago.
"Numerous other communities on the Hawkesbury are likely to see the flood levels peak sometime today and only slowly recede in the coming days," Mr Narramore said.
No major rainfall events are forecast in the coming days, including next week.
There is a chance of "isolated, severe storms" in the Northern Rivers which could see large hail, damaging winds and heavy rainfall in localised areas.
The State Emergency Service received 2000 calls for help and completed 71 rescues in the 24 hours to 10am, Sydney Metro Zone Commander Greg Swindells said.
With forecast winds of up to 90km/h and saturated soil, the SES is bracing for an increase in fallen trees and powerlines.
Some $238.9 million worth of grants have been handed out to 205,700 people affected by floods in NSW, Government Services Minister Linda Reynolds said.
"The sheer scale of this disaster and the huge number of communities impacted is the largest in recent Australian history," she said.
Some 1635 ADF personnel were deployed to clean up efforts on Tuesday, growing to 3139 by the end of Wednesday, the majority of them in the flood hit Northern Rivers.
A long list of Sydney roads and bridges have been impacted by flooding on the city's northern beaches, the Hawkesbury, Wiseman's Ferry, the northwest suburbs, Windsor and the Blue Mountains, Craig Moran from Transport for NSW said.
In the Northern Rivers, a fifth flood-recovery centre has opened at Casino, joining others already operating at Mullumbimby, Murwillumbah, Kyogle and Lismore.
Prime Minister Scott Morrison and NSW Premier Dominic Perrottet are expected to give an update at flood-ravaged Lismore on Wednesday.
Grants of $1 million have been extended to an additional 28 local government areas declared disaster zones, with some 45 councils now eligible.
"Each of the 45 flood-affected councils have now received a $1 million grant which can be used to cover operational costs or begin to restore damaged public infrastructure," Mr Perrottet said.
NSW small businesses and not-for-profits affected by the floods can now apply for up to $50,000 in government support to cover the cost of clean-up and repairs or to restock and reopen.
