PM pledges help for flooded graziers 'doing it tough'

Struggling outback graziers impacted by devastating cattle losses from severe flooding have been given further financial support.

Prime Minister Anthony Albanese travelled to the outback Queensland town of Clermont on Thursday to announce an additional $26 million in aid for farmers "doing it tough".

It brings the joint federal and state financial support package to $66 million.

Communities across outback Queensland remain under threat as major river systems continue to rise.

Roads to Burketown, Normanton, Karumba, Doomadgee, Julia Creek, Duchess and Kajabbi in the state's north are cut, leaving thousands of residents stranded.

Stock losses have soared past 64,000, more than 3000km of fencing has been damaged and almost 5000km of private roads impacted in the wake of ex-Tropical Cyclone Koji.

Clermont, west of Mackay, was one of the worst-hit areas, with more than 70 homes inundated by flash flooding following record rainfall.

"This is a difficult period that we are going through - Australia is experiencing more extreme weather events, and they're occurring more often and with greater intensity," the prime minister said on Thursday.

"They're dealing with bushfires in Victoria at the same time as we're dealing with floods here in Queensland, and our thoughts are with those communities.

"They're already doing it tough with massive losses of cattle."

The support package includes $11 million toward impacted primary producers and $10 million in disaster recovery grants for small businesses.

More than $4 million has been allocated to a mental health program, along with a relief fund to support clean-up and immediate recovery efforts.

"You see the best of the Australian character, and here in regional Queensland, you see it in spades," Mr Albanese said.

"Every level of government will be working together ... to make sure that this community can recover."

While reconstruction costs are expected to soar, authorities say the true impact of Koji might not be known for months.

The Bureau of Meteorology warns there is a slim chance Koji could make an unwelcome return.

"At the moment, it's most likely to dissipate by the weekend," senior meteorologist Sarah Scully told AAP on Thursday.

"However, it could potentially move out over the Gulf of Carpentaria or even into the Coral Sea, where there's a low risk of developing into a tropical cyclone."

For now, the torrential rain has eased to isolated showers and thunderstorms.

Flooding continues to threaten regional Queensland, with the Mackenzie River placed on major alert as flood levels looked set to exceed 2010 records.

"The latest alert is to leave now. So for all of the properties along the Mackenzie River, we're asking those property owners to leave immediately," Central Highlands Mayor Janice Moriarty told AAP.

"There has been inundation to the low lying areas, with more flooding expected."

Properties in the region are expected to be isolated for weeks.

The water will continue to carve its way through the catchment with the Mackenzie feeding into central Queensland's Fitzroy River, which will be the next hit by major flooding.

A flood watch is also current for the Gulf Country and parts of western Queensland and Cape York Peninsula, which includes the Flinders and Cloncurry catchments.

Major flooding is possible along the Georgina River at Marion Downs, southwest of Boulia, from Thursday as water levels steadily rise.

"It's a Catch-22," Boulia mayor Rick Britton told AAP.

"If you talk to ... the bottom half of Queensland, they're probably still waiting for their wet season to break and start, and the top end, they are probably wanting it to bloody stop."

Without decent rain by Anzac Day, Mr Britton said most of the graziers across Boulia Shire would have to start selling off cattle.

"We're all in the hands of Mother Nature," he said.

"She's a hard, hard beast to deal with at times."