Officials reported Tuesday that hundreds of homes had been flooded in and around Australia's largest metropolis, affecting 50,000 people.

Ashley Sullivan, manager of the State Emergency Service, reported that emergency response teams rescued 100 people overnight who were stranded in flooded automobiles or residences in the Sydney region.

Days of torrential rain have prompted dams to overflow and waterways to overrun their banks, bringing a fourth flood emergency to parts of the five million-person city in 16 months.

Overnight, the state government of New South Wales declared a disaster in 23 local government areas, activating federal help for flood victims.

Premier of New South Wales, Dominic Perrottet, stated that the number of individuals affected by evacuation orders and warnings to prepare to flee their homes rose to 50,000 from 32,000 on Monday.

"This event has only just begun. Please avoid complacency wherever you may be. Please exercise caution while driving on our roads. Perrottet stated that the state still has a high risk of flash flooding.

On the fourth day of the flooding catastrophe, Emergency Services Minister Steph Cooke complimented the competence and dedication of rescue teams to preventing any deaths or significant injuries.

Jonathan How, a meteorologist with the Bureau of Meteorology, stated that parts of southern Sydney had received more than 20 cm of rain in the preceding 24 hours, which is greater than 17 percent of the city's annual average.

Tuesday, severe weather warnings for heavy rain remained in effect for Sydney's eastern suburbs. Additionally, the warnings stretched north of Sydney along the coast and into Hunter Valley.

The worst flooding occurred along with the Hawkesbury-Nepean river system on Sydney's northern and western outskirts.

"The good news is that it is expected to be mostly dry by tomorrow afternoon," How added. "However, these floodwaters will remain extremely high long after the rain has stopped."

"Overnight, there was an abundance of precipitation, which is causing some rivers to reach a second peak. Therefore, it will take several days, if not a week, before these floodwaters begin to recede," How noted.

Plans to pull a disabled cargo ship with 21 crew members to the safety of open water were hampered by the severe weather and rough seas off the coast of New South Wales.

After leaving port in Wollongong, south of Sydney, the ship lost power on Monday morning and risked being grounded by 8-meter (26-foot) surges and 30-knot winds against cliffs.

An attempt to tow the ship into open water with tugboats failed after a towline snapped in an 11-meter swell late Monday, according to Philip Holliday, chief executive officer of the Port Authority.

Using two anchors and two tugboats, the ship maintained its position on Tuesday further from the coast than it had been on Monday. Holliday stated that the boat would be towed to Sydney as soon as weather and sea conditions improved on Wednesday. The original idea was for the crew to repair the ship's engine at sea.

Holliday stated, "We're in a better position than we were yesterday." We are relatively safe.

Perrottet called the tugboat crews' efforts to save the ship on Monday "heroic."

"I would like to congratulate the men and women who served on those crews last night for their heroism under challenging circumstances. Perrottet remarked that having an 11-meter swell while undertaking and completing this work is astounding.