Restoring electricity and essential services will be the focus of the clean-up effort in central Queensland today in the wake of ex-Tropical Cyclone Marcia.
About 300 soldiers and State Emergency Services (SES) personnel were expected to take to the streets of Yeppoon and Rockhampton over the next 48 hours, where 550 homes suffered serious damage, including torn roofs and power lines down.
With about 1,400 power lines down, many residents could remain blacked out for a number of weeks.
The category five cyclone battered the region after making landfall about 7:30am (AEST) near Shoalwater Bay, between St Lawrence and Yeppoon, on Friday.
It was a category three system when it reached Rockhampton, about 40 kilometres inland from Yeppoon.
At Biloela, south of Rockhampton, 200 homes were inundated by floodwaters from the nearby Callide Dam, where the flood gates opened automatically on Friday night when the dam reached 90 per cent of capacity.
The town remains isolated on Sunday, with the Dawson and Burnett highways cut in all directions.
The flooding in Biloela was described by Banana Shire Mayor Ron Carige as the worst they had ever seen.
Councillor Carige said telephone and internet access was almost non-existent in Biloela and the local disaster centre could not reach state emergency authorities to provide updates.
River in Gympie expected to peak
In southern Queensland, the flooded Mary River has isolated residents in the town of Gympie.
The river is expected to peak at about 17 metres this morning, according to Dimitri Scordalides from Gympie Regional Council.
He said flooding had closed the Bruce Highway and the town's major bridges.
There had also been a number of incident where residents had ignored warning signs by trying to drive on flooded roads or bridges.
"People are disobeying flood signs and the like and finding themselves in difficult situations," he said.
"From the normal flooding point of view it is very much what we're used to so our normal flood plans and responses are all in place," he said.
Thousands still without power in central Queensland
At the height of the disaster, up to 100,000 properties were blacked out across the networks run by Energex and Ergon Energy, Queensland's Fire and Emergency Services said.
Ergon said the damage to infrastructure in central Queensland meant many people could be blacked out for several weeks.
About 50,000 customers were still without power by Sunday morning and the SES received more than 6,000 calls for assistance.
Queensland Premier Annastacia Palaszczuk said the damage to towns and communities in and around Rockhampton and Yeppoon was far worse than she expected.
She said the Army would fly into central Queensland today to help repair infrastructure and essential services such as power, water and sewerage.
She said the Government would do everything possible to get life back to normal.
"That's what we have to do we need to make sure that we do that as quickly and as thoughtful as possible," she said.
Communities not prepared for Cyclone Lam
People in areas of the Northern Territory hardest hit by Cyclone Lam say they were not ready for the storm and are struggling to cope in the aftermath.
Disaster response crews have reached small communities along the Arnhem Land coast that felt the full force of the category 4 system as it made landfall on Friday night.
State officials say there were just two reports of injuries.
But residents say the health of people in the cyclone-hit areas will be an issue in coming days as they have no running water or electricity.