Victorians warned to expect one month of rain in one day

Victorian emergency crews and residents are rushing to sandbag as they prepare for further rain and possible flash flooding, with some towns warned to expect more than one months rain in the next 12 hours.

Parts of Victoria and South Australia have been thrashed with heavy rains and flash flooding, along with damaging winds of up to 90km/h.

This photo was taken in Ballarat on Tuesday. Photo: ABC News

The Country Fire Authority (CFA), Victoria Police and the State Emergency Service (SES) have been assisting in the clean-up while preparing for more wild weather as it moves east across the state.

Over the next 24 hours, parts of Victoria are expected to experience rainfall between 20 to 50mm with some areas receiving up to 70mm, the Bureau of Meteorology (BOM) said.

Conditions are expected to ease off at around mid to late morning on Wednesday as the wild weather slowly moves east towards the Tasman Sea.

A severe weather warning has been issued for heavy rain in the Mallee and parts of the Central, South West, Northern Country, North Central, North East and Wimmera regions, including Mildura, Horsham, Ballarat and Bendigo.

The small town of Walpeup has received it's mean September rainfall in 12 hours.

The Mallee region town recorded 32.6mm of rain between 9am and 9pm on Tuesday - it's mean for the entire month, according to the BOM.

From 9am Monday to 9pm Tuesday, the town received 46.4mm of rain.

Flood warnings are also in place for the Glenelg River catchment and the Loddon River catchment.

Mt Emu Creek at Skipton is expected to peak around 5 metres in the early hours of Wednesday morning.

A flood warning has also been set for the Murray River at Corowa and Albury.

Minor flood warnings are in place for several rivers, including the Campaspe and the Werribee River at Ballan.

A tree fell through the roof of a man's house in Victoria. Photo: 7 News

Some parts of Victoria are expected to receive one months worth of rainfall over the next few hours. Photo: ABC News

SES has reportedly received about 100 calls statewide since midnight and have so far rescued four people trapped in cars and floodwaters.

The State Emergency Service has advised people to move their vehicles away from trees, keep clear of fallen power lines, keep clear of creeks and storm drains and to not drive or walk through flood waters.