Residents of a northwest Queensland town are reluctantly leaving their water-logged homes behind, while emergency services warn that power is being cut to Burketown due to the flood risks there.
Police say the last chance to evacuate is during daylight, though several residents have chosen to stay.
Superintendent Tom Armitt told the ABC that emergency services only had a certain window of opportunity to deploy personnel and equipment such as helicopters.
"We don't know how much ground will be left if the water continues to peak and cover all the ground," he said on Saturday.
"If we get to the stage where we are having to shift and move people to rooftops, that makes a whole different level of complexity.
"We don't know when the peak is expected because it has passed any sort of flood modelling at this stage."
Vision filmed from helicopters over the town shows water covering many buildings to their roofs, with only one or two streets in the centre of the town still untouched by the water.
The town is waiting for its worst-ever floods to peak, with multiple communities and outlying cattle properties isolated as heavy rain leaves the state's west and south at risk of flash floods.
The Albert River at Burketown has already surpassed the record 6.78-metre flood of 2011, and the Bureau of Meteorology says waters in the Gulf of Carpentaria community will likely reach their highest by Sunday.
A forecast for severe thunderstorms and rain in southeast Queensland was downgraded on Saturday, but heavy falls are still possible.
"Sewerage to the town has been compromised and power to the town will be cut off today," police said.
"It is not safe for people to remain."
Weeks of torrential rain have overwhelmed the region's rivers, leaving dozens of communities such as Doomadgee, Normanton and Karumba stranded on islands amid a vast inland sea.
Those towns as well as more isolated settlements and outlying cattle stations are relying on food and other supplies being sent by air and on barges.
The danger of the late-season monsoon has moved south but is expected to weaken at the weekend.
It's expected to bring scattered to widespread showers and isolated thunderstorms to the central and southern districts, with a one-in-four chance Brisbane will receive 60mm.
A severe thunderstorm warning in the Capricornia district was cancelled on Saturday morning after Yeppoon copped 100mm in the hour to 4.11am, and 215mm across the night.
Gladstone received 96mm over two hours.
Seqwater said releases from the Somerset Dam into the Wivenhoe Dam on the Upper Brisbane River were possible due to forecast rainfall.
"The Seqwater Flood Operations Centre has moved to the alert activation level due to the weather forecast," the dam operator said.
"If you are downstream of the dam, stay away from fast-flowing or deep water near waterways and floodplains."
Wappa Dam on the South Maroochy River was spilling on Saturday morning.
