Bundaberg, 385km north of Brisbane, has been the hardest-hit, with rescue crews plucking 1000 people to safety after the river that runs through the town broke its banks.
About 1500 residents fled to evacuation centres.
The Langs moved first to the Sunshine Coast last September, before shifting to Bundaberg.
They visited Whangarei for Christmas, and while Mr Lang returned across the ditch to work, his wife stayed back to sort out a few issues.
Raema Lang confirmed that although her husband was stranded, he was safe.
Mr Lang's brother, Trevor, was living in central Bundaberg and was worse affected.
With Bundaberg's roads flooded, all transportation has been cut off to and from the town.
"My husband's working about an hour-and-a-half north of Bundaberg but he stopped working last Wednesday because of the floods and then it [the situation] got worse. He's repairing roads that were damaged in floods two years ago and with the recent rain, they're back to square one,'' she said.
Most districts in Bundaberg received 550mm of rain in two days, while in one area of Childers, a whopping 514mm fell in 24 hours.
The flooding was caused by the remnants of a tropical cyclone called Oswald that also caused severe weather, including tornadoes, and created sea foam that came ashore on the Queensland coast.
Floodwaters in late 2010 and early 2011 left much of Queensland under water in the worst flooding Australia had seen in decades.
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