Prime Minister Anthony Albanese said the "one-in-100-year" flood event in Western Australia's Kimberley region will come with a significant price tag but the government is committed to rebuilding as quickly as possible.

Albanese and Premier Mark McGowan visited the flood-stricken region to hear from residents and farmers who are counting the cost of the emergency which has caused severe damage to homes and infrastructure.

"This is at least a one-in-100-year event. They haven't seen anything like this, certainly that anyone can ever recall," Albanese told Nine radio station 6PR.

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"We know that the bill will be substantial and my government is committed to providing whatever support that we can in partnership with the WA government."

It comes as the prime minister announced a major relief package to support people forced into temporary housing, for housing repairs and essential item replacement.

"There are a couple of hundred people at one stage were staying in the emergency accommodation that has been established here at the community centre," he said.

"This is a devastating impact."

The shires of Derby West Kimberley, Broome, Wyndham East Kimberley and Halls Creek are eligible for assistance measures through the Commonwealth-State Disaster Recovery Funding Arrangements.

The measures include financial aid for individuals and families, businesses, farmers, non-profit organisations and local and state governments.

Key infrastructure has been destroyed in the region, including the Great Northern Highway, which has been cut off by floodwaters, and the collapsed Fitzroy Crossing Bridge.

"We know the Great Northern Highway has been cut as well and there'll be a substantial investment required there," he said.

"That is the major artery heading north in the great state of Western Australia, but also across to the Northern Territory."

Ex-tropical cyclone Ellie crossed into Western Australia from the Northern Territory on December 28.

Since December 30, widespread rainfall totals between 200mm and 500mm have been recorded across the Kimberley region.

Major flooding has occurred along the Fitzroy River to Fitzroy Crossing, reaching record levels of 15.81m.

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Roads and associated infrastructure have been damaged and floodwaters have isolated towns including Fitzroy Crossing and many remote Indigenous communities along the Fitzroy River.

Albanese's visit comes after Western Australia's biggest mercy mission began rolling into the Kimberley.

Road trains have been loaded onto barges bound for Broome to resupply bare supermarket shelves in the town.

The Australian Defence Force has been deployed to help isolated communities.

Three Royal Australian Air Force transport aircraft are being used to help evacuate residents and provide essential supplies to those who are cut off.

ADF crews will also be on the ground to help with cleaning up the damage.

The clean-up is beginning, with SES crews cutting down trees and clearing roadways.

Kimberley locals are starting to wrap their heads around the destruction caused by the floods.

More than 230 people have so far been pulled from the danger zone.

"It's an absolute national disaster, it's come from completely left field," cattle farmer Lachy McClymont said.

"We haven't had much to think about it, there'll be an emotional shock at some point I'm sure."

Farmers are also preparing to survey the damage and are literally counting the cost.

Cattle stations are relying on expensive food airdrops from helicopters to keep stock alive.

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Lauren Bell from the Kimberley Cattle Association said it was going to be a hard year.

"We are really concerned about the long-term mental health and emotional toll of this. It's only January, it's going to be a really long year for people," she said.

But the message for some isn't sinking in.

Authorities rescued three children playing in floodwaters near Broome on Saturday.

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An ADF aircraft has dropped off medical supplies to Derby and soon evacuees could be flown from the town to Broome.

Those left homeless could call the dormant Bullsbrook quarantine hub in Perth home.

Work is underway to turn the facility into temporary accommodation as the region rebuilds.

Visit the Emergency WA website to stay up to date with the latest warnings and information.