Australian resort towns along Great Barrier Reef cut-off after flooding from Cyclone Jasper

Heavy rain from a coastal trough linked to ex-Tropical Cyclone Jasper on Monday cut off several tourist towns in Australia's north along the Great Barrier Reef, forcing evacuations as some residents fled to rooftops to escape fast-rising rivers.

Jasper lashed the far north regions of Queensland state last week leaving a trail of destruction before getting downgraded to a tropical low, bringing months worth of rain within a few hours over the weekend, official data showed.

Cairns, the gateway town to the Great Barrier Reef and home to more than 150,000 people, received around 600 mm (24 inches) of rain over 40 hours through early Monday morning. That is more than triple the December mean of 182 mm (7.17 inches).

All international and domestic flights from Cairns airport were cancelled on Monday with footage on social media showing planes partially submerged on the tarmac. "Significant debris" on the runway must be removed and cleaned before resuming operations, Cairns Airport said.

The weather bureau has forecast more rain as Jasper is likely to hover through Monday with some regions expected to pick up around 300 mm of rain in under six hours. Major flood warnings have been issued as rivers remained above danger levels and were expected to break records set in 1977.

A crocodile was spotted in a swollen drain in the town of Ingham, about 250 kilometres (155 miles) south of Cairns, and authorities warned residents not to swim in flood waters. Nine people, including staff and patients, were stranded on the roof of a health clinic.

Dan, a resident just north of Cairns Airport, told ABC Radio he had to shelter on top of his kitchen bench for around four hours before being taken to a house where 30 people were waiting on the roof as they waited for rescue boats.

"Kids, elderly people, dogs and cats on this poor bloke's roof who just had brand new solar panels installed ... it was a very harrowing journey navigating the very fast-flowing water and dodging debris," he said.