9 April 2021

Oxley Highway: multiple landslides in New South Wales, Australia

Posted by Dave Petley

Oxley Highway: multiple landslides in New South Wales, Australia

The Oxley Highway is a rural road orientated east-west in New South Wales, Australia. To the west is the town of Nevertire, to the east it terminates at Port Macquarie on the Tasman Sea coast.

Heavy rainfall in March triggered multiple landslides along the Oxley Highway in a section between Yarras and Walcha.  This is the landscape of the section in question:-

Google Earth image showing the landscape along the Oxley Highway between Yarras and Walcha (just visible in the distance) in New South Wales, Australia

Google Earth image showing the landscape along the Oxley Highway between Yarras and Walcha (just visible in the distance) in New South Wales, Australia

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There is a good helicopter reconnaissance video showing the magnitude of the damage caused by landslides to the highway, posted to Youtube:-

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The level of damage is also clear in some of the images released by Transport for NSW:-

Landslide damage along the Oxley Highway. Image from Transport for NSW.

Landslide damage along the Oxley Highway. Image from Transport for NSW.

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A landslide on the Oxley Highway. Image from Transport for NSW.

A landslide on the Oxley Highway. Image from Transport for NSW.

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There are more than 70 landslide sites along the road.  Transport for NSW has estimated that it will at least two months before the road can reopen with a limited service, and several more months at least before the problems are fully mitigated.  As the two images directly above show, some of the landslides are both large and located below the level of the road bench.  Remediating these sites will be a substantial and expensive challenge.

Meanwhile, also in Australia, 7 Daily News tweeted a video yesterday of a coastal landslide in Queensland:

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I have posted about these retrogressive landslides at Inskip Point previously.  This is another example of a Retrogressive Breach Failure, not a sinkhole.