Part of flood-damaged WA highway reopens

Part of the only sealed road through northern Western Australia has been reopened after unprecedented flooding swept away a major bridge and large sections of the vital transport route.

Motorists are permitted to travel from Friday on a 215km section of the Great Northern Highway between Willare and Fitzroy Crossing, linking the flood-ravaged inland towns with the Port of Derby.

The Kimberley towns were the worst hit during the once-in-a-century flooding that started in early January when ex-tropical cyclone Ellie brought days of torrential rain and wind.

Homes were inundated and a major bridge at Fitzroy Crossing was destroyed along with three kilometres of the highway between Willare and Broome.

Authorities say it will take about two years for the critical road freight link to be completely repaired as they race to find temporary alternatives robust enough to support heavy road trains.

Main Roads WA has previously said it was assessing the viability of a low crossing on the Fitzroy River bed at a nearby site, but this will take at least four months to build and a suitable site won't be chosen until flood levels drop.

Engineers are also in talks with the Australian Defence Force about building a Bailey bridge, a portable pre-fabricated structure, into the damaged bridge to allow lighter vehicles to use the highway.

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.

Authorities are also using barges to transport tonnes of essential goods from Port Hedland to Broome and Derby, and an airlift to cut-off communities continues.

The 290km section of the highway between Fitzroy Crossing and Halls Creek remains closed.