Thousands of Australians were Saturday ordered to evacuate their homes in Sydney's northwest and elsewhere in New South Wales state as heavy rainfall flooded rivers and waterways.
State Emergency Service Commissioner Murray Kear said that 3,500 people were subject to evacuation orders as 75 percent of the state, the most populous in the country, was affected by flooding.
Days of heavy rain after a damp summer have seen Sydney's Warragamba Dam, the main source of the city's drinking water, reach capacity for the first time in 14 years - prompting the water to move over its spillways late Friday.
The swollen Hawkesbury and Nepean rivers were now threatening areas around Sydney's northwest.
"This is a moderate flood but it's unusual because we haven't seen water in this river system in a while," Kear said of the waters, which are likely to swamp bridges and close roads.
Further west in New South Wales, the town of Bathurst had been cut in two by floodwaters while across the state some 2,300 people had been left isolated by the surging torrents.
A severe weather warning for flash flooding was in place in large areas of New South Wales and the southern state of Victoria was also bracing for heavy rainfall.