After a night of wet weather woes around Sydney - including several flood rescues - the city is set to be hit by more heavy rain today, with some rivers on flood watch.
The Bureau of Meteorology has again issued a severe weather warning for heavy rain and possible flash flooding in many parts of NSW, including Sydney, the Hunter and the Illawarra.
SES receive hundreds of flood calls
SES crews have answered over a thousand calls for help as a result of flood damage in NSW, with more flash flooding expected in the coming days.
The warning singled out the city, Parramatta and Cronulla as areas where heavy rain could cause flash flooding.
Roads and Maritime Services this morning warned drivers to slow down and look out for hazards and water on the road.
The heavy rain disrupted traffic and public transport during peak hour yesterday, with delayed trains and buses and flooding on some roads in the north and north-west.
Last night State Emergency Service volunteers carried out 15 flood rescues, including of a man who was trapped on the roof of his car at McGraths Hill, in the north-west, and drivers who were caught in flash flooding at Milperra.
NSW SES spokeswoman Becky Gollings said volunteers had 150 calls for help last night and 1040 calls since the heavy rain began falling this week.
"I would dare say that number is going to increase steadily throughout the day, with the extra rain coming through and also people waking up this morning and discovering damage around their homes."
Ms Gollings said about 80mm fell in Sydney overnight, and 126mm fell near Warragamba Dam.
Since yesterday morning 90mm had fallen in Marrickville, 95mm in the city and 104mm in Gosford.
The Georges, Nepean and Hawkesbury rivers are on flood watch with the possibility of minor flooding throughout the day, the bureau said.
Flood watch is not the same as a flood warning, but means that people who live along those rivers should monitor weather conditions and be ready to move to higher ground if floods develop.
The bureau said the weather system causing the heavy rain should move out to sea by tonight, when rainfall will ease.