Residents in parts of Queensland smashed by multiple extreme weather events have been warned it will take time to recover.
The state was hit by flooding, tornado-like winds and rain that claimed the lives of seven people in the days after Christmas.
Tens of thousands of homes around the Gold Coast have also endured four days without power as heatwave conditions built.
Federal Emergency Management Minister Murray Watt said some suburbs' power networks had been "completely smashed".
"The scale of the damage we've seen across a pretty big part of southeast Queensland is very large and therefore is going to take some time to work through," Senator Watt said.
Emergency services have been stretched by flooding in Cairns and far north Queensland followed immediately by storms in the southeast.
"When you're dealing with disasters from one end of the state to the other, literally, that is a real test for people and there's incredible work being put in," Senator Watt said.
Port Douglas residents and businesses were told to stop using water immediately on Friday after a landslide halted operations at a treatment plant.
Douglas Shire Council has organised collection points for bottled drinking water with a limit of two litres per person and trucks will supply non-potable water at Port Douglas Community Hall and Mossman State High School.
Acting Inspector Nick Sellars said police were attending 22 road intersections where power had been cut to traffic lights, including near the Gold Coast's major theme parks.
Disaster Recovery Minister Nikki Boyd said five homes had been destroyed across the Gold Coast, Logan and Scenic Rim regions and 27,400 customers were without power.
Ms Boyd said 90 per cent of homes and businesses should have their power restored by New Year's Eve and 80 SES workers were en route to assist.
Federal Nationals leader David Littleproud warned Australia was only at the start of the disaster season, casting doubt on the accuracy of weather warnings.
"We've got a lot of recovery to do in fixing a lot of roads, a lot of infrastructure and helping farmers out who have lost a lot of produce," he said.
"If they haven't provided the right warnings with the right information at the right time, then questions should be asked."
Government Services Minister Bill Shorten said the bureau faced unpredictable circumstances in tracking Cyclone Jasper in far north Queensland.
"The Bureau of Meteorology does, on balance, a pretty good job," he said.
"But this was just an extraordinary set of circumstances and now the focus has got to be helping people."
Temperatures are expected to soar across most of northern Australia.
Parts of Queensland, the Northern Territory and Western Australia face extreme to severe heatwave conditions.
Marble Bar in WA's Pilbara region may reach 49C on Saturday and temperatures up to 45C are expected there for six days.
In the Northern Territory, it's predicted to reach 40C in Katherine and 43C in Tennant Creek, and warm minimums in Darwin are likely to make for uncomfortable nights.
Winton in Queensland's west is expecting 43C, while up to 37C is forecast for Gympie in the storm-ravaged southeast.
Highs of up to 36C are predicted in Brisbane, while Longreach in the state's west is forecast to get to 47C.
People in the worst impacted areas have been urged to stay indoors, close windows and blinds to keep heat out of homes and seek out fans or air-conditioners.
