WA floods destroy dozens of homes

Dozens of families in Western Australia's flood-ravaged Kimberley are homeless, with authorities warning it could take years to rebuild the remote region.

Damage assessment teams are combing through sodden communities along the Fitzroy River after record flooding earlier in the month.

Emergency Services Minister Stephen Dawson says 38 homes and 37 businesses have been destroyed.

Another 121 homes have some damage, with ongoing assessments likely to push numbers higher.

"It has been a challenging couple of weeks. The weather we saw up there was unprecedented. We've seen nothing like this before," he told reporters on Wednesday.

"For those people that have a damaged house, it will be a tough time over the next few months."

Mr Dawson did not know many people were homeless but said some houses were likely to have been home to more than one family or extended families.

He said authorities were working to find temporary accommodation for displaced residents, which could include transporting dongas into the region.

Talks are also underway to use a Rio Tinto mining camp and an Australian Defence Force facility.

Flooding also caused "significant" damage to infrastructure and the Great Northern Highway, including a major bridge in Fitzroy Crossing.

"We have a lot of work ahead of us. This won't be days or weeks this will be months and potentially years," Mr Dawson said.

Main Roads crews are working to temporarily reopen one lane of a three kilometre stretch of the Great Northern Highway, which was swept away between Broome and Willare.

Diesel generators are being transported to Derby and Fitzroy Crossing to supply electricity and take over from the towns' gas-fired generators, which will run out of liquid natural gas in the coming days and can longer be supplied due to the damaged highway.

Authorities are also continuing their hunt for a temporary and long-term replacement for the damaged bridge so WA's only sealed road into the north of the state can be reopened.

Mr Dawson declined to provide a timeline other than to say "Main Roads are estimating it could take a long time".

"It's stuffed basically and it was a really important piece of infrastructure," he said.

Whatever solution is found will need to be longer than the original bridge after the flooding "created new parts of the river".

Mr Dawson also said it was too early to say how much the recovery effort would cost, highlighting that the wet season still had months to run.

"Bridges are expensive. Rebuilding houses are expensive," he said.

In the meantime, road trains with freight for Kununurra and the Northern Territory have been diverted into South Australia to travel up the Stuart Highway through central Australia.

Barges are also being used to transport essential goods into Broome and Derby, and an airlift continues to fly food to cut-off communities and pastoral stations.