Torrential rain boosted by the remnants of tropical cyclones Yasi and Anthony led to flash floods in Victoria, with parts of Melbourne battered by high winds and people rescued from rising waters in Mildura.
Lightning strikes cut power to 30,000 homes when a belt of storms hit late yesterday.
The Melbourne Metropolitan Fire Brigade said it was overwhelmed by calls for help from disabled people.
In one emergency, fire crews helped a wheelchair-bound man who was up to his hips in water inside his home in the suburb of Mulgrave. Firefighters also rescued a girl swept away in a flash flood who managed to grab a tree branch in Ashwood, south-west of Melbourne.
Many roads in regional Victoria were cut, and the Monash Freeway was closed outbound at Toorak Road, with traffic causing long delays last night.
Between 50 and 100 millimetres of further rain was forecast for the weekend.