South Australians in the Murraylands region have been told to evacuate as floodwaters threaten to isolate and damage properties.
The passenger ferry between Cowirra and Mannum was slated to run until 2pm on Wednesday then close indefinitely after the State Emergency Service issued an evacuation warning at 10.45am.
Authorities warned residents of Cowirra, opposite Mannum, to evacuate immediately, with flooding expected to isolate properties by Thursday morning.
The threat follows flooding at East Front Road and Hunter Road at Cowirra.
"Regardless of your property's ability to withstand flood impacts, there is a chance you may also become flooded," the emergency service said.
"If you do not evacuate you may be isolated or flooded. It may be too dangerous for emergency services to assist you."
The service urged people in Cowirra to seek alternative accommodation and if necessary stay in an emergency relief centre set up at Mannum Football Club.
A watch and act alert for Woodlane and Mypolonga, south of Cowirra, remained in effect on Wednesday.
Flood emergency warnings have also been issued for the Bolto shack community near Mannum, the upper Murray River and the lower Murray River in recent days.
Premier Peter Malinauskas was Riverland bound on Wednesday, and said levees around key townships were largely doing their jobs.
"We've now got more water coming across the border than what is consumed by the entirety of South Australia across a whole 12-month period," he told ABC Radio National.
