The authorities in Victoria say a quarter of the state's land mass has now been affected by flooding.
People are still being evacuated from their homes in the town of Dimboola in the state's north-west, while in the north, Kerang has been totally isolated by floodwaters.
The flood threat in north-western Victoria is now shifting to Dimboola, 40km downstream from the towns of Warracknabeal and Kerang.
The ABC reports the Wimmera River in Dimboola was expected to peak on Thursday and as many as 50 homes are at risk of inundation.
State Emergency Service spokesman Lachlan Quick said Dimboola residents had so far cooperated with evacuation orders.
"[There could be] massive amounts of water across massive parts of that territory for probably three days to a week," he said.
Mr Quick said the army had now been deployed to most flood-stricken areas.
The ABC reports the towns of Brim, Beulah and Jeparit could also be swamped over coming days as the waters continue to move downstream.
Volunteers with bobcats have shored up 6km of levees along the Yarriambiack Creek in Warracknabeal and laid 42,000 sandbags. The creek has turned into an inland lake.
A levee in Kerang is also holding firm. The ABC reports the immediate threat there is over. However, residents are being advised to leave while they can.
The Loddon River has stopped rising in Kerang and is expected to remain steady for days.