Cyclone-battered Mackay won't know until after high tide if it has escaped the threat of flooding from rising river levels.
Cyclone Debbie, which is now a rain depression, has dumped vast amounts of water over coastal and inland catchments in north Queensland, and the region is on alert for flooding.
The Pioneer River in the Mackay region is rising but authorities are confident no homes in the town are under immediate threat.
The Clark Range in the Pioneer River catchment area has recorded over 340mm of rainfall in the past 24 hours.
Mackay Regional Council mayor Greg Williamson said some streets in the township of Mirani, on the upper reaches of the Pioneer River, had flooded.
Mr Williamson said water level monitors along the river were being carefully watched and while serious flooding isn't anticipated, residents will be alerted and evacuations ordered if it was necessary.
"We've got a really good system of early warnings along the river system so if the waters are rising to a dangerous level we should know very quickly," Mr Williamson told AAP.
"We're as prepared as we can be."
Mr Williamson said the key time for Mackay would be Wednesday's high tide at 1.30pm AEST.
"The high tide's going to be a little test," he said.
"The good thing with the Pioneer River is it is a short river system, so if we do get floods they tend to be short-lived."
At 8.10am the Pioneer River was at 6.6m and rising.
The river is expected to rise towards 8m and a moderate flood level later on Wednesday but isn't forecast to reach 9m - the level which would flood homes in the town.
Authorities are also watching the Fitzroy River at Rockhampton, with a vast amount of water flowing into the Connors and Isaac rivers that feed it.
The latest warning from the Bureau of Meteorology (BoM) showed the Isaac River at Yatton was at 7.31m at 8.20am AEST and rising.
Authorities expect the river to exceed the major flood level of 16.50m at that point sometime between Wednesday night and Thursday morning.
At this moment the BoM doesn't believe the Fitzroy will break its banks at Rockhampton although heavy forecasted rainfall will have to be monitored.
"The system is starting to move south, bringing a lot of rain with it and that's heading towards the Rockhampton area now, and their catchments," meteorologist Adam Blazak told AAP.
"I'd expect those catchments are going to take a bit of a deluge today."
Moderate flood warnings are also in place for the Don and Proserpine Rivers, and the lower Burdekin River.
The Don River, which flows through Bowen and was only a trickle early on Tuesday, has now broken its banks but is not believed to have affected any homes.
And a flood watch is current for coastal catchments between Ayr and the NSW border, extending inland to parts of the Central Highlands and Coalfields, Central West, Maranoa and Warrego, and Darling Downs and Granite Belt districts.
