Emergency workers are using boats, choppers and tip-trucks to rescue residents from Townsville's flooded suburbs.
The army, police and emergency crews helped more than 1100 people evacuate their homes on Sunday night.
Those efforts continued on Monday, with the aid of every available boat, helicopters and even tip trucks repurposed by resourceful council staff to carry people.
Dangerous and unpredictable conditions with the potential for more flash flooding are expected to continue for at least the next 24 hours.
About 1000 people are holed up in six evacuation centres as they wait to see what lies ahead.
Authorities are monitoring rainfall at sites across the city every five minutes so they can issue new alerts if there's a new threat to public safety but so far no lives have been lost.
"It's very difficult for us to predict what's going to happen over the next 24 hours," Townsville Mayor Jenny Hill warned.
She tried to reassure rattled residents, saying: "We will protect you as much as
we can."
Thousands of Townsville residents are facing "unprecedented flooding", after relentless downpours forced the Ross River Dam to be fully opened on Sunday.
The floodgates have been opened to their maximum setting, releasing almost 2000 cubic metres of water per second.
A rapid rise in the water level followed, with soldiers deployed to help about 400 people leave their homes overnight.
The Bureau of Meteorology said "dangerous and high-velocity flows will occur in the Ross River Sunday night into Monday, adding that there was a "risk to life and property".
Hundreds of homes have already been left without power and cut off by flooded roads, and there are warnings up to 20,000 homes are at risk of being inundated if the rains continue.
Townsville Airport announced that it will re-open on Monday afternoon at 2pm, however.
Emergency crews overwhelmed
Emergency crews have been stretched to the limit, with more than 1000 calls for help logged by the State Emergency Service and Queensland Fire and Emergency Services in the past 24 hours, most in Townsville.
SES Regional Manager Daryl Camp says boats and choppers are extracting people from their homes, with no clear estimate yet on just how many properties have gone under.
The Townsville City Council estimates it could be up to 2000, but with floodwaters still swamping parts of the city there's no real way to know.
Crews tasked with getting people out are on alert after crocodiles were spotted near suburban homes and flood waters are also teeming with snakes.
The Bureau of Meteorology has also warned that tornadoes could form, with gale-force winds seen in Townsville overnight.
Schools in Townsville remain closed and a decision will be made early on Monday about whether to reopen the city's airport after all flights were cancelled late on Sunday.
The monsoon trough that's been dumping vast amounts of rain on the state's north for a week has rewritten Townsville's record books.
