SYDNEY: Fresh evacuation orders were issued on Thursday for some residents living near Australia's biggest river in the country's southeast, with warnings of further flooding and forecasts for more rain.

Residents in Echuca, a town of about 15,000 near the Victoria-New South Wales state border, are preparing for the Murray River to peak from late Friday, amid reports of bare supermarket shelves after road closures cut off supplies.

"We are traversing some of those local roads with both supply and emergency services at this point in time, but the next 24 hours is going to be critical," Victoria state emergency service chief officer Tim Wiebusch told ABC television.

Prime Minister Anthony Albanese said up to 500 defence personnel would assist flood recovery, with hundreds already on the ground filling sandbags as military helicopters were deployed on evacuation and resupply missions.

Several layers of sandbags have been placed in front of shops and homes in Echuca, television footage showed.

Up to 100 mm (4 inches) could drench Australia's east, about one-tenth of the annual rainfall for some areas, over the next five days. Though the Bureau of Meteorology on Wednesday downgraded its forecast, any amount of rain raises the risk of flash flooding from the already swollen rivers.

Residents in flood-prone towns across northern Victoria have been warned they could be isolated for up to a week if they don't evacuate soon.

Victoria emergency services also urged Echuca residents to limit water use after flooding damaged sewerage systems.

Police reported one more death from the floods, which began last week, taking the total count to three.

Australia has been battling frequent flooding along its east since early 2021 due to La Nina, which brings more rain. The weather phenomenon is under way for the third year in a row and would likely last into next year, suggesting more flooding likely for the next several months.