The South Australian town of Port Augusta has been inundated after a quarter of its annual rainfall fell in a matter of hours overnight.
After a dry day, more than 52mm fell in the space of an hour about 8pm last night.
Another 7mm fell in the next three hours, before stopping altogether.
The town at the very top of the Spencer Gulf is normally known for its arid climate, and typically averages little more than 200mm of rain each year.
The heavy rain flooded the highway and left train lines suspended in the air after the ground washed away beneath it.
Some areas of the town remain underwater now.
Port Augusta Mayor Brett Benbow spoke on the flooding earlier today.
“Unfortunately what occurs with this amount of water that comes at once, the drains struggle,” he said.
“The debris from the trees and the dry areas that built up and created a dam effort to stop the water from running.”
The SES is reminding people to not walk, ride or drive through floodwaters.