30 January 2023

Multiple landslides from extreme rainfall in Auckland, New Zealand

Posted by Dave Petley

Multiple landslides from extreme rainfall in Auckland, New Zealand

In recent days Auckland and the surrounding area of New Zealand have suffered from an atmospheric river rainfall event that has been devastating, with the heaviest rainfall occurring on 27 January 2023.  Met Service New Zealand tweeted about the 36 hour rainfall totals on 28 January:-

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Unsurprisingly, there has been extensive flooding and large numbers of landslides.  Stuff has a really good portfolio of photographs of the landslides and flood that the rainfall triggered, whilst Newstalk ZB has this image of multiple landslides in the Massey neighbourhood of Auckland:-

Multiple landslides in Massey, Auckland.

Multiple landslides in Massey, Auckland. Image by Brett Phibbs via Newstalk ZB.

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Meanwhile at Remeura in Auckland a man was killed by a landslide that knocked a house off its foundationsYahoo News has an image of the aftermath:-

The aftermath of a fatal landslide in Remuera, Auckland. One person was killed at this site.

The aftermath of a fatal landslide in Remuera, Auckland. One person was killed at this site. Image by Getty via Yahoo! News.

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Meanwhile, a large landslide has destroyed State Highway 25A across Coromandel:-

The aftermath of a large landslide that has destroyed SH25A during the extreme rainfall in the Auckland area

The aftermath of a large landslide that has destroyed SH25A during the extreme rainfall in the Auckland area. Image by WAKA KOTAHI via Stuff.

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Repairing this level of damage is going to be time consuming and expensive.

As I write there are warnings of further severe rainfall in the northern part of New Zealand, with a red rainfall warning in place for Auckland, Coromandel and Northland:-

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Further extreme rainfall could occur on Tuesday, with the mayor of Auckland warning that this could be even more dangerous than the rainfall that occurred on Friday.  The challenge is not the rainfall total, which is likely to be considerably lower than on 27 January, but the presence of already saturated ground.  This is a recipe for further landslides.

Already there is considerable soul searching occurring about the preparedness for these increasingly frequent rainfall events.  A detailed review is going to be needed once the rainfall ends.