There are grave fears for a woman missing near Proserpine, after her car was found submerged in cyclone-hit north Queensland as rising dam levels and heavy deluges leave residents stranded and roads cut off.

Two cars were swept away in the surging waters following Cyclone Debbie, with at least one of the vehicles found submerged on the Bruce Highway near Proserpine with its windows down yesterday.

A male driver was found safely at a nearby property, but the search is still on for the woman who was travelling in a white Ford Falcon.

Emergency crews also rescued three people stranded on the roof of another car caught in floodwaters in Sarina.

Almost 100 people - many stranded on the top of houses, cars and verandahs - have been rescued by emergency workers after being trapped by floodwaters.

A palm tree fell behind a motel at Airlie Beach. (AAP)

Cyclone Debbie as seen from the International Space Station. (ISS)

The deluge that hit the northern coastline with Category 4 Cyclone Debbie is now wreaking havoc inland and also in the south of the state.

Overnight and morning flooding has been at its worst in and around low-lying Mackay where the Pioneer River broke its banks, overflowing local dams to exacerbate floodwaters, especially in the Eton and Homebush areas.

Queensland Fire and Emergency Services Commissioner Katarina Carroll said 38 people had been rescued in the Mackay region overnight while about 50 more needed evacuating up until 9am today.

The flooding has stranded residents of north Queensland communities already battered by the ex-tropical cyclone, with the roads connecting Airlie Beach, Bowen and Proserpine cut off.

The Bruce Highway is cut off both north and south of Mackay and residents living downstream from the Kinchant Dam have been urged to self-evacuate or move to higher ground.

Boats wrenched from their moorings at Airlie Beach. (9NEWS)

The Proserpine River spilled over during Cyclone Debbie, all but swallowing road traffic signs and a railway crossing.

Major flood warnings have since been issued for the Connors, Isaac and Pioneer rivers, while lesser warnings applied to Theresa Creek, as well as the Don, Proserpine, Kolan and lower Burdekin rivers.

There had been "phenomenal" rainfall totals over the past few days, with the Pioneer Basin getting more than 1000mm in just 48 hours, the Bureau of Meteorology's hydrology manager Victoria Dodds said.

Proserpine appears to have been the worst affected area, with major damage to a large number of homes.

South Molle Island, to the northwest of Hamilton Island, has been hit hard but it's understood no one was there when it was hammered by the cyclone.

Nearby Hayman Island has also suffered significant damage, while at Daydream Island, water is in demand after town supplies were interrupted by Debbie's destruction.

Hamilton Island's airport reopened last night.

Bottled water is now being handed out to guests and it's understood military assistance has been requested to transport people off the island.

Premier Annastacia Palaszczuk has flown to Bowen alongside Police Commissioner Ian Stewart and Brigadier Chris Field, who will lead efforts to help devastated home and business owners, as well as the battered tourism and agricultural sectors.

For those who have already endured the wrath of the ex-tropical cyclone, there's a long clean up ahead.

Yesterday north Queensland residents woke to fallen power lines, uprooted trees, blocked roads and boats wrenched from their moorings.

The State Emergency Service has so far received more than 800 calls for help, with the number predicted to skyrocket as more people obtain phone connection.

"We don’t want any complacency. If you don’t have to be on the roads until Friday, please stay off the roads," Ms Palaszczuk said.

Whitsunday Regional Council mayor Andrew Willcox described the cyclone-ravaged area of Bowen as "like a war zone".

"The beautiful seaside town is now half-wrecked, but we will rebuild," he told the TODAY Show.

Storm damage in Shute Harbour, near Airlie Beach. (9NEWS)

Video from the town of Shute Harbour have emerged revealing the sheer devastation caused by the storm, with roofs ripped off buildings, countless trees uprooted and debris strewn across roads.

The tiny town of Collinsville also saw roofs torn off homes and off its local pub.

"Collinsville did receive Category 2 winds last night and, as people have been reporting, it was one of the most horrific nights of their life," Ms Palaszczuk said.

The premier said Debbie caused vast losses, particularly in the farming and tourism sectors, with resorts on the Whitsunday Islands suffering severe damage.

"There's substantial, structural damage on Hamilton Island and also damage on Daydream Island, where about 200 guests and 50 to 60 staff are safe but running out of water," she said.

Amid the maelstrom, the premier revealed two babys had been safely born in the Whitsundays.

READ MORE: Healthy baby girl delivered at Proserpine ambulance station

For the latest weather warning, visit the Bureau of Meteorology website.