Authorities in the Australian state of Queensland had rescued several people from floodwaters by Sunday afternoon, with parts of the region receiving more than 400 millimetres of rain.
The torrential rain claimed one life and a severe weather warning for between Brisbane and the New South Wales border was issued as the downpour caused flash flooding and swollen rivers.
The ABC reports areas around Brisbane had more than 100mm from Friday to Sunday afternoon, while some parts of the Gold Coast received more than 400mm of rain.
A 14-year-old disabled boy was killed near Toowoomba in Queensland when the vehicle he was in was washed away in floodwaters.
Several major roads were cut on the Gold Coast and many parked cars were submerged up to their roofs.
Queensland Fire and Rescue Service Acting Inspector Scott Beasley said crews had performed nine rescues, five of them people trying to drive across flooded roads.
In New South Wales, there was flash flooding around the Tweed River at Murwillumbah.
There was also flash flooding in parts of Sydney overnight on Saturday, prompting more than 1,000 calls for assistance.