Navy ship begins clearing flood debris

Royal Australian navy minehunter the HMAS Huon.

A Royal Australian navy minehunter has started looking for dangerous debris washed down the Brisbane River, and some of it will be blown up.

HMAS Huon has been tasked with clearing two busy shipping routes in and out of Moreton Bay.

With ships carrying food, fuel and other supplies queuing up to enter the port of Brisbane, clearing the Northwest and Spitfire channels is a priority.

Last week's floods washed an enormous amount of debris down the river and it's feared large items including sunken vessels, metal dumpsters and trees could endanger marine traffic.

The naval operation to clear the river will extend upriver to Moggill.

Navy divers plan to raise large objects using inflatable devices, before moving them out to sea and blowing them up.

Other hazards, such as ship masts, may be cut up underwater, the commander of the Maritime Task Force Peter Tedman told AAP.

Navy personnel will also work to identify silt deposits that have affected channel depths.

This morning HMAS Huon was off Caloundra, to Brisbane's north, indicating just how far the debris might have spread.

"There's been so much come out of the Brisbane River that has been unaccounted for," Commander Tedman said.

"We're hopeful that it's not in the main shipping channel.

"But certainly, if it is, our first task will be to identify what it is and the hazard it poses."

Cmdr Tedman warned the task would take some time.

"It's more an open-ended task. There's a lot of water between Caloundra and the upper reaches of the Brisbane River.

"And we really don't know how bad it is."

The naval hydrographic survey ships HMAS Shepparton and HMAS Paluma will join the operation from tomorrow.

The port of Brisbane reopened on Sunday with at least two crude oil tankers having since berthed.

However, Cmdr Tedman said a queue of other supply vessels was sitting outside Moreton Bay waiting to dock.

- AAP