Police have praised the courageous efforts of an officer who entered crocodile-filled waters in far north Queensland after a man drowned in monsoonal floods.

Dozens of roads remained closed and communities were isolated as flood waters continued to rise in outback Queensland late on Wednesday.

A man in his 70s was found dead in a submerged vehicle in the far northern town of Normanton on Tuesday.

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Mount Isa District Acting Supt Paul Austin praised the efforts of emergency services who responded.

“The SES operator was able to align their vessel [with the submerged car], and one of the police officers entered into a significant depth, and was able to get into the vehicle and recover the deceased male,” he said.

“If he hadn’t done what he did, it certainly would have made it a very difficult operation to try and retrieve that vehicle with the deceased in it.

“There’s some really big crocs in the Norman River … what he did was very courageous.”

The Queensland premier, David Crisafulli, said the loss of the local man was “a deep tragedy for the North West community”.

“Our big focus remains on infrastructure … it’s the roads, it’s the bridges. We have to make sure that people remain connected.”

The mayor of McKinlay shire in north-west Queensland, Janene Fegan, said it could be weeks before the full extent of the damage and stock losses was known.

After days of severe rain, conditions did not clear until Wednesday, allowing graziers to launch helicopters.

“We just don’t know officially yet – it’s just sitting and waiting but it doesn’t look good in parts of the north-west of our shire,” Fegan said.

“We’ve been told that the water level is quite high, and there’s places that could be higher than 2019.”

The Bureau of Meteorology warned that isolated heavy falls of 100mm were possible in parts of the Northern Goldfields and Upper Flinders, North West and Central West districts.

The bureau’s Miriam Bradbury said rain and thunderstorm activity would continue “but we should start to see more of an easing across more widespread areas late in the weekend into early next week”.

Disaster relief has been activated for five north Queensland councils after the widespread flooding caused by monsoonal rainfall over the Christmas period.

In Western Australia, emergency services were assessing the damage caused by ex-tropical cyclone Hayley, which crossed the Kimberley coast as a category three storm over the Dampier Peninsula on Tuesday.

Winds up to 158km/h were recorded along with 132mm of rain.

There were no reports of major damage or injuries.