However, incident controller Ray Jasper said a second peak in the river level was not expected.
Mr Jasper said on Tuesday he was confident that based on advice from water authorities, catchment authorities and special technicians the Goulburn River would hold above the major flood level height of 11 metres at Shepparton and Mooroopna “for potentially 24 to 36 hours longer than we would have hoped”.
“But there will not be a second peak ... (however), if we get thunderstorms across our whole catchment, which is very unlikely, we may see that,” he said.
“But the modelling clearly shows for Shepparton, Mooroopna and other areas that it will hold its height for another 24 to 48 hours, but we’ll not see another peak.
“So 12.06m, the peak we had (on Monday) is the peak. It is going down.
“But it will go down very slowly. This is a very unfortunate slow-moving flood going down, but we will not see a second peak based on the rain predicted at this stage.”
Mr Jasper said authorities thought the river would remain at between 11m and 11.4m for a few days.
“Potentially we might have 11m on Friday but it will stay 11m on Saturday and Sunday and start going down to the moderate flood level,” Mr Jasper said.
This means water will stay around a lot of properties because Shepparton needs to get to a moderate level before the water will dissipate from flooded areas.
Mr Jasper, however, urged residents who had evacuated not to return to their homes until a ‘safe to return’ order was made at the incident control centre.
Mr Jasper said authorities were resupplying people with urgent essential goods, both at the evacuation centres and by going by boat to people who had stayed in their homes.
“But we don't want people moving in that area, so those evacuation orders, ‘do not move’, will be on for the protection of the people in there but also so we don't have other people going in there that shouldn’t be,” he said.
A Victorian Incident Control Centre media spokesperson said residents should continue to monitor the VicEmergency app for any changes to warnings and advice for their area.
“They need to see the warnings for their particular area and should be vigilant,” the spokesperson said.
She said 20 to 50mm of rain was forecast to fall over northern Victoria on Wednesday, Thursday and Friday, while 150 to 200mm was forecast in the upper Goulburn and Campapse river catchments.