Australia's most populous state of New South Wales on Sunday issued more evacuation orders following the worst flooding in decades. The New South Wales State Emergency Services responded to 640 calls for help on Saturday night, including 66 for flood rescues.

New South Wales Premier Gladys Berejiklian said that hundreds of people have been rescued from the waters.

Evacuation orders have been issued at multiple locations on the Mid North Coast in the northeast of the state, which Berejiklian said was experiencing a one-in-a-100-year event, and "whilst we don't think things will worsen on the Mid North Coast, definitely conditions will continue, so the rainfall will continue across the parts that have already been affected."

Berejiklian also said that parts of Western Sydney are being hit by a one-in-50-year weather event, with some locations recorded more than 11.8 inches of rain since Friday morning, breaking records.

The Warragamba dam, west of Sydney, started overflowing on Sunday and so far, 13 evacuation centers have been opened across the state. More evacuations are expected as the bad weather is forecast to last into the middle of the week.

Local authorities are urging people not to drive through flooded areas as they could get easily swept away by the strong currents.