Residents of three storm-hit suburbs in Melbourne's east have been told not to drink tap water until further notice.
The Department of Health issued an urgent warning on Wednesday morning to people who live, work or are in Kallista, Sherbrooke or The Patch not to drink tap water, even if it is boiled, due to contamination.
It is expected the warning will stay in place for at least three days.
"This advice has been issued following an equipment failure at Yarra Valley Water drinking water tank due to recent severe weather," the warning reads.
"This may result in potentially unsafe water entering the drinking water system and customer taps."
The department said special care should be taken to not ingest the water when bathing or showering.
Emergency drinking water will be available at the Patch Hall and Kallista Public Hall, though people will need to bring their own bottles, pots and kettles to fill up.
It comes as about 17,000 homes in eastern Victoria remain without power following storms last week.
Two people died in the dangerous conditions.
Minor flood warnings remain for the Latrobe, Thomson and Yarra rivers.
But forecast rain on Friday in the flood-affected Gippsland region is not expected to dramatically affect local river levels.
East Gippsland will have 25-40mm, which could lead to minor flooding in the Snowy River, and 5-15mm is expected to fall in the west.
"It's probably not enough to result in significant impacts," said Christopher Arvier from the Bureau of Meteorology.
Wind strength is also not expected to reach last week's destructive levels.
The BOM also reported much-needed rain in the northwest and west of Victoria after a dry autumn, with more forecast in the Wimmera.
Australian Associated Press