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.

A Bureau of Meteorology forecaster, Claire Yeo, said: ''With such heavy rainfall expected on already saturated catchments so soon after the January flood event, riverine flooding is also forecast again.''

Mildura, in the state's north-west, was bracing for more flash floods last night after more than 100 millimetres of rain fell in just two hours yesterday afternoon.

A State Emergency Service spokeswoman said crews responded to 250 calls for help in the riverine community. Three people were rescued from cars and two from their flooded homes.

In south-east Melbourne drenching rain hit Lyndhurst and Narre Warren, where more than 100 calls for help due to flash flooding were made.

Communities named at risk of flooding included Carisbrook, Clunes, Ballarat, Halls Gap and Maryborough in central Victoria.

Parts of the township of Halls Gap in the Grampians were issued with an emergency evacuation order due to possible flash flooding and land slips.

The bureau issued flood warnings for the Wimmera, Loddon, Avoca and Campaspe catchments, which had already been hit by floods in recent weeks.

There was also a flood watch for the greater Melbourne catchments of Werribee, Maribyrnong, Yarra, Dandenong and Bunyip.