Australia Weather News

Record rainfall swept away parts of the Great Northern Highway at the end of January. - ABC

The repair bill for a section of the Great Northern Highway in WA's Kimberley badly damaged in recent flooding is expected to exceed $16 million, with water still inundating the road almost a month after Tropical Cyclone Kelvin passed over the region.

A 120-kilometre stretch of highway north of Broome between Roebuck and Willare has already cost Main Roads $1 million in emergency temporary repairs, with permanent repairs expected to cost $15 million once the water has finally receded.

Repairs further south on the same road are expected to be in the region of $200,000.

Less than three weeks before Kelvin arrived in mid-February, a storm flooded an area of the Kimberley larger than the state of Victoria.

Tropical Cyclone Joyce had dumped hundreds of millimetres of rain not long before that.

When Kelvin crossed the Kimberley coast, it brought huge rains to already saturated ground, causing major flooding in Broome and across the region.

Main Roads regional manager Gerry Zoetelef said the Great Northern Highway had been reopened, but sections of the road to the north and south of Broome were still underwater.

"On Roebuck plains the water is still about 50 millimetres on the road in a few spots, and between Roebuck and Willare, there's still floodwater crossing in a number of places." Mr Zoetelef said.

"Most of that has receded now, but there's still a fair bit of water on each side of the road, which is causing us the problems at the moment because it's soaking into the road."

He said people driving in floodwaters or on damaged road should exercise caution and be patient.

"People should reduce their speed and drive to the conditions," he said.

"When you see people approaching, slow down and be careful."

Main Roads said the conditions it had been dealing with this wet season have been exceptional, even for the Kimberley, which is used to heavy rain at this time of year.

The authority said water had risen over the top of the Logue River Bridge near Willare three times this year — something which has never happened before.

It said the only recent flooding event to cause similar damage in the region was in the East Kimberley in 2011 at Big McPhee Bridge, 100km south of Kununurra.

Main Roads said it was looking to initiate permanent repairs at the end of April, as long as there were no major rainfall events between now and then.

But those plans could be dashed as soon as this weekend, with a tropical low developing in the Timor Sea over the Northern Territory.

The Bureau of Meteorology said if it became a cyclone, there was a chance the system would move close to the north Kimberley coast by Saturday.

The Shire of Broome said it was working to repair damage to a number of local roads, some of which remain underwater, and it would have a better idea of how much it would cost to fix once flood waters had receded.

It said the shire would receive natural disaster relief from State and Federal governments to cover the costs of the clean-up.

ABC