Emergency measures have been activated in South Australia as the state braces for more inland flooding after recent rains cut food supply lines to the Northern Territory and Western Australia.
Roads and rail lines to both states remain underwater in parts leading to diminishing stocks of fresh food and meat in the NT and some processed foods in WA.
Tropical weather systems across the state last weekend dumped record rains in some regional centres and State Emergency Service Chief Officer Chris Beattie said more was on the way.
He said further storms bringing severe weather were expected to impact the northern pastoral districts, the Eyre Peninsula and the Flinders Ranges across the weekend with heavy rain to persist through to Wednesday.
The situation prompted SA to declare a 14-day major emergency giving Police Commissioner Grant Stevens increased power to direct the movement of freight, ensure food security and coordinate relief efforts.
Mr Beattie said the Stuart Highway, the main link between Adelaide and Darwin, remained submerged in places with no estimate of when it might reopen.
Authorities are giving consideration to establishing an alternative route to Darwin through Burra and Mt Isa, but that would add about two days to the journey.
SA's major rail freight line remains cut east of Tarcoola, restricting access to both WA and the NT, with 14 areas where tracks have been washed away.
Repairs are expected to take about 18 days but that could increase if further rain causes more damage.
Supplies to some SA outback towns have also been cut, including Coober Pedy while other centres have reported widespread flood damage to roads and other infrastructure.
Northern Territory Police Commissioner Jamie Chalker said while the road and rail closures had impacted local supermarkets, supply lines through alternative routes should be established by early next week.
He said ample stocks of most critical goods remained as he urged locals to only buy what they needed.
"Our supply chain from South Australia has been impacted, there's no denying that," he said.
"But many of our stores up here and our supermarkets, in particular, have significant holdings, particularly around non-perishables.
"The short-term impact is people have surged and taken beyond what they genuinely require."
Mr Chalker said the situation could be escalated to an emergency response if more severe weather also impacted supply lines through Queensland.
Mr Stevens said his role would involve coordinating relief efforts across local, state and the federal governments.
"To make sure we prioritise the right efforts to restore those services as quickly as possible and so that no individual community suffers adversely," he said.