Crocodiles have infested floodwater gushing through north east Australia while families stranded on rooftops await rescue.

At least one person was missing on Monday and hundreds of homes were lost in North Queensland after one of the worst floods in Australia’s history.

Following the downpour, rangers warned “lightning fast” crocodiles would be lurking in every waterway in the north of the state until floodwaters recede.

One 9ft-long crocodile was found in a swollen drain in the middle of the town of Ingham, north of Townsville.

Locals told The Telegraph their focus was on rescuing stranded civilians using “tinny boats”, adding: “We’re tough up here on croc country.”

The authorities have come in for criticism for not evacuating homes sooner.

“Had decisions been made earlier on Sunday, then people could have been evacuated before,” Matt Nichols, the editor of Cape York Weekly, told The Telegraph.

“As a result of those delays, people are going to be sleeping rough tonight that shouldn’t be.”

In the remote community of Wujal Wujal, a 7-year-old patient was forced to spend Sunday night on a hospital rooftop as floodwaters rose so high they swallowed an ambulance.

The boy, and eight other evacuees, managed to scale down from the roof about 12 hours later but plans to evacuate them to another hospital were abandoned when severe rain forced the army to ground its helicopters.

Kiley Hanslow, Wujal Wujal council’s CEO, said trapped locals had been given bags of food from a supermarket but it was only enough for a day.

“Tonight may be the last night that we can afford to just wait around,” Ms Hanslow added.

Dan Bateman, from Holloway Beach, was one of potentially thousands of people to lose their homes.

He told the ABC he “had to dodge fridges” as he evacuated by boat to a neighbour’s rooftop.

“At one point, someone said there was a cow coming down the road,” he said.

The mayor of the Shire of Douglas Shire in north east Queensland made an urgent plea for Canberra to send more support, reporting residents in some areas had no clean drinking water and were “flushing toilets with buckets”.

“So many people will be spending Christmas this year hosing out houses, mopping up mud,” Michael Kerr told The Telegraph.

“It’s catastrophic. The Army needs to come and fix this. We are desperate here.”

Anthony Albanese, the prime minister, said two Chinnook helicopters and two AW-139s were involved in the rescue mission.

“Personnel and resources will be made further available as well as requested,” he said, adding images of the flooding was “horrific”.

Communities had initially been told the worst of Cyclone Jasper was over last week. But the relief was short-lived and by the weekend warnings were again upgraded before the storm intensified on Sunday and dumped enough rain to smash century-old records.

The highest December daily total for rainfall in Cooktown had been 195.1mm, recorded in 1907. As of Monday, the new daily record total is 339.8mm.

Some 429mm of rain fell in Port Douglas and Mossman, well above the previous daily record of 283.2mm set in 2007.