The anniversary of the Abbotsford landslip is a reminder emergencies can happen any time, anywhere, Otago's civil defence managers say.
"Terrifying things can happen any time and we can't do anything about that, but we can be prepared," said Peter Taylor, public information manager for the Otago civil defence emergency management group.
Thirty years ago - on Wednesday, August 8, 1979 - New Zealand's biggest urban landslip hit Abbotsford in Dunedin.
It left a 150m-wide, 30m-deep chasm, destroyed 69 houses (more had to be removed from the area) and displaced hundreds of people.
Claims to the Earthquake and War Damage Commission (now EQC) eventually totalled $7.17 million.
Land movement having been obvious for the previous two months, and after engineering and geological reports, the Green Island borough council declared a state of emergency on August 6, 1979, and began a progressive evacuation of the area.
Some people were reluctant to leave their homes.
When the main slip occurred at 9.07pm, 17 people were carried down the slope in their houses and were marooned in the mud and rubble.
Nobody died in the slip.
Landslips were common in New Zealand and authorities were responding to them all the time, Mr Taylor said.
At the end of June this year, the Lake Taupo township of Waihi, the site of previous fatal landslips, was temporarily evacuated after heavy rain, a swarm of earthquakes, and changes observed in the flow of streams and hot springs.
Last month, a landslip derailed a train near Upper Hutt and blocked access to Wellington.
That same evening, other landslips and flooding cut road access to the capital.
What was possibly the world's biggest landslip occurred in Fiordland 13,000 years ago.
Ten kilometres of the southern Hunter mountains collapsed, creating a 26cu km slip.
Most landslips were not on the scale of Abbotsford, and people could take measures to help reduce damage to their homes and businesses and help them survive, Mr Taylor said.
Landslips were caused by various combinations of heavy rain or increased groundwater, earthquakes, weak rock, steep slopes (sometimes created by development or road building) and deforestation.
• What to do
Before a landslip:
Find out from your council if there have been slips in your area before, and where they might occur again.
Check for signs of ground movement.
Signs include. -
Sticking doors and window frames, or gaps where frames are not fitting.
Decks and verandas moving or tilting away from the rest of the house.
New cracks or bulges on the ground, road or footpath.
Leaning trees or fences.
Water springs, seeps or waterlogged ground in areas that are not usually wet.
If a landslip occurs:
Evacuate and take a getaway kit with you.
Contact the civil defence emergency management office.
Warn neighbours.
After a landslip:Do not return to the site until it has been properly inspected.
Take photographs and notes for insurance purposes when it is safe to do so.
