The updated timeline was provided today by Australian Rail Track Corporation after flash flooding in the South Australian outback over a week ago.

The track repairs also involve the rail line heading north to Darwin which was also badly damage by the heavy rain in the Tarcoola area.

Even though three trailers have been allowed to carry fright across the Nullarbor, Perth is suffering depleted grocery stocks with speculation the Australian Navy ships might be called on to help.

RAAF plans have been providing an emergency food airlift to the Coober Pedy Airport this week.

Repairs to the Stuart Highway are also expected to take several weeks.

A spokesman for ARTC today said crews have been working around the clock to repair damage.

"Works have progressed from the initial 18 sites to focussing on the six remaining locations, which were the most severely impacted and will require the most recovery time," he said.

Weather experts now believe the flash flooding was the result of a one in 200 to 300 year event.

"As a result of the volume of water that was recorded, we are required to re-build access roads from the highway to the rail network to enable the movement of heavy machinery to site," the ARTC spokesman said.

"The civil contractors are progressing well on this work.

"ARTC has almost 100 people on the ground working dual shifts. We are utilising accommodation at several regional locations to house the workforce, including Tarcoola, Woomera and Port Augusta, as well as the Mt Gunson mine.

"McMahons, Exact Mining and Bardavcol have reallocated resources from mining and road projects in the region to support the rail recovery efforts and John Holland have brought in specialist rail construction resources from the Eastern States to support.

"This is being supplemented with ARTC work teams from WA (Kalgoorlie), and two SA depots (Adelaide and Port Augusta) as well as ARTC project management and logistics support from across the country.

"Rail equipment from ARTC, Arc Rail and Sydney Trains are being utilised in the recovery efforts.

MORE READING: Ghost town's flash flood cuts the nation in two.

"It is expected that more than 50,000 tonnes of ballast and rock, which is being stockpiled at a number of locations on the network, will be utilised in the repair activity. We are sourcing these materials using both road and rail transport for ballast from WA (Kalgoorlie), Whyalla and Adelaide and general construction material from the nearby Mt Gunson Mine.

"More than 25 units of heavy machinery are in place across the work sites and this has been provided by ARTC, contractors and through local hire arrangements.

"ARTC is also working closely with State and Federal Governments and local authorities on the recovery and repair of damage to infrastructure in the region and we thank them for their support.

"Following an extensive and detailed assessment of all track, ARTC can advise completion of the repair works is expected to occur by mid-February.

"This timeframe is consistent with initial updates provided to customers, stakeholders and the broader community.

"Our focus is to repair the line as quickly as possible, in the safest manner, to ensure operations can commence and freight can get moving."