Flood water is spilling over the levee bank and Ulupna Island residents or campers should leave immediately, authorities said on Saturday.
The river island is bound by the Murray River and Ulupna Creek.
People who have left their homes should go to the relief centre at Numurkah Showgrounds, or a friend's place that is in a safer location.
Meanwhile, residents on Parfitt Road in Wangaratta have been allowed to return home on Saturday after concerns about a leaking levee on the Ovens River eased overnight.
Properties along Parfitt Road were evacuated on Friday, with residents initially advised to take enough supplies for three days.
As towns along the Victoria-NSW border prepare for floods, wild winds are also expected to lash parts of Victoria.
Strong winds are expected to move through the state on Sunday with gusts predicted to reach 100 km/h in parts, including Melbourne.
Moderate flood warnings remain in place for a handful of rivers, including the Avoca, Loddon and Mitchell rivers.
Areas along the Murray River at Albury and Corowa are also experiencing moderate flooding.
