Manawatu's rivers changed colour as earthquake-shaken gravel and dust enveloped them, with some residents close to being caught in the cliff landslips.
At least four cliff collapses were reported in the aftermath of yesterday's quake, with the biggest of them on the papa cliffs of the Rangitikei River near Mangaweka.
Smaller cliff falls also occurred near Anzac Cliffs at Palmerston North on the Manawatu River, on the Pohangina River near Ashhurst and on the Pohangina River near Pohangina.
Mangaweka Adventure Company guide Anna Kasparova said dust and gravel could be seen from the Mangaweka Campground falling from the top of the cliffs into the river.
It had not been large enough to alter the way the river was flowing but it had caused it to turn milky-grey, she said.
Civil Defence issued an advisory on its Facebook page advising Mangaweka locals to stay out of the river area.
Near Ashhurst Charlotte Robertson and Zaria Hemara had decided to go to the Saddle Rd Bridge over the Pohangina River, near Ashhurst, to look for blackberries at the popular swimming hole by the cliffs.
Instead they found themselves facing a cliff collapse.
"While we were walking upstream along the riverbed we heard a low rumbling sound, followed by the horrible screeching of metal [from the bridge]," Ms Hemara said.
"The cliff itself began rumbling. We clicked that it was an earthquake, grabbed each other and ran across the rocks. When we were in an open area of the river bed, we glanced and saw the Saddle Bridge twisting and screaming.
"I heard my friend yelling ‘landslide!' I turned and looked where she was staring.
"I was horrified to see a huge dust cloud spreading across the river as part of the cliff gave way. As the shaking subsided I grabbed my phone and tried to take photos of the dust cloud and the scarred cliff."
The landslide occurred less than 150 metres away from where she was walking.
"It was absolutely terrifying to think that if it had happened a minute later we could have been under it.
"I watched as the river changed from clear to a murky brown. Then all sorts of debris started floating down in mats. In all honesty it was the most terrifying moment of our lives."
Firefighters were yesterday out checking Anzac Cliffs after a flurry of reports about a collapse along the Summerhill border of the Manawatu River. The rockfall did not appear to be serious.
- Manawatu Standard
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