Toowoomba in the state's south-east is currently in shock after a raging torrent of water swept through the city this afternoon, claiming the lives of at least two people and leaving enormous damage across the city.
Elsewhere in the south-east, emergency services are focused on Dalby and Gympie, which are both on flood alert.
Dalby on the Darling Downs has flooded for the fifth time in three weeks and the water has reached its highest peak so far.
The Myall Creek has reached 3.7 metres and is predicted to peak at 3.8 metres in the next hour or so - higher than the major flood just after Christmas.
Mayor Ray Brown says the damage this time around is worse.
He says 200 homes have been inundated and about 120 people are sheltering in two evacuation centres.
"I don't think anybody has slept here probably in the last nearly 48 hours," he said.
The town is cut in two once again and the only road out is to the west.
Thunderstorms in the area are threatening to make the situation even worse.
Chief Superintendent Alistair Dawson says people are getting frustrated with the ongoing crisis.
"I think a lot of communities are probably thinking 'here we go again', given that we've just been through some fairly significant events over Christmas, and we understand their concerns," he said.
Mother-of-four Dannii Lloyd-Jones says she has only just finished cleaning out her garage after last month's flood.
"They can see mummy's a little bit stressed and they're watching the water," she said.
Chief Superintendent Dawson says the flood recovery effort is now spread across a wide area of the state.
"We've sort of moved from one part of the state to the south-east corner," he said.
"I personally hope, come mid-week, when the sun starts shining and the water starts dropping that we won't get any more for awhile, but I know some of the long range forecasts are predicting still more rain to come."
In Gympie, police say about 65 businesses and 50 homes are at risk of flooding from the rising Mary River.
It is expected to peak at about 20 metres overnight.
The general manager of Gympie's Royal Hotel, Jason Williams, says residents are bracing for a flood like the one in February 1999 - when it reached 21.95 metres and inundated 150 businesses and 20 homes.
"The flood of '99 was 21.95 I believe, which is to the awning of our hotel ... few metres yet to get there, but she's creeping up," he said.
Authorities today advised residents in low-lying areas to move to higher ground as Energex cut power to thousands of homes.
Floodwaters have split the CBD in half and several businesses in the main street, Mary Street, have already been inundated.
Local manager Jessica Philpot says staff and volunteers worked through the night to save as much as they could, but she said fast-rising water started streaming into the pub about 5:45am (AEST).
"We've almost got a metre of water in the back bar," she said.
"They're guaranteeing another three metres and the owners from Sydney, they've just got on the phone now and say they've changed it to 20 metres tonight, which means our roof would be just touching."
Evacuation centres have been set up at the civic centre on the city's northside and the pavilion at the showgrounds on the southside.
The Bruce Highway is closed to the north and south.
Acting Mayor Tony Perrett says about 40 to 50 homes could go under this time.
"We've been out with the police advising residents to take precautionary action. If they need to make alternative arrangements overnight, if the floodwaters are going to affect them, certainly do that," he said.
Next in line
People who live and work along the Brisbane River are also being warned to brace for flooding, as the capital city begins to feel the effects of the big wet.
Authorities fear the swollen river could flood more than 200 homes and businesses as early as Wednesday, and again next Friday.
Heavy rain has already caused some localised flooding in low-lying parts of the city.
Lord Mayor Campbell Newman says the Wivenhoe Dam is the only thing sparing the city from a flood like that of 1974.
"Wivenhoe Dam is actually protecting Brisbane right now and in the coming days from a flood right up there with '74," he said.
Emergency services have been sand-bagging homes in low-lying areas and are worried a big rain cell off the coast could dump more rain on Ipswich tonight.
Premier Anna Bligh says the two major hotspots now in the south-east are Ipswich and Brisbane.