People in parts of Sydney’s northwest were ordered to flee their houses in the middle of the night as heavy rains continued to batter Australia’s east coast on Sunday with fast-moving waters causing widespread destruction throughout the region.

Flooding risk and evacuation warnings were in place for about 12 areas in New South Wales (NSW), Australia’s most populous state with 8 million people, with rivers swelling and rain accumulation posing danger.

“It’s not just the rain which is causing the devastation,” Jonathan How, senior meteorologist with the Bureau of Meteorology, told the ABC News state broadcaster. “It’s strong winds as well.”

How added that the heavy downpour is set to continue for the rest of Sunday in Sydney and throughout the state, with some areas expected to get up to 200 millimetres (7.9 inches) of rain.

Emergency services said they had received about 600 calls overnight asking for help; more than 60 of those were pleas for rescue from floods.

Television and social media footage showed fast-moving water unmooring houses, engulfing roads, breaking trees and damaging road infrastructure.

The extreme weather was affecting Australia’s COVID-19 vaccine delivery to Sydney and throughout the state and disrupting the country’s plans to deliver the first vaccine doses to almost 6 million people over the next few weeks. [

NSW Premier Gladys Berejiklian, who is expected to hold a briefing later on Sunday, said the weather system moving through the state could be a one-in-25-year rain event.

“This will be a deep-seated, extreme weather event,” she said on Saturday.