10 Aug 2022

Residents surprised as large slip falls on part of Karori

6:49 pm on 10 August 2022

Another massive chunk of land has fallen away in a hilly Wellington suburb, after days of heavy rain.

The latest slip in Woodhouse Avenue in Karori. Photo: RNZ / Kevin McCarthy

The city has had its wettest July on record and a number of banks have given way in the last week - keeping contractors and engineers on their toes.

This morning the latest victim was Karori.

Many residents on Woodhouse Avenue did not hear the rumble of land sliding down this morning - but they soon woke up and saw the rubble close to their front yards.

Peter who lives nearby said he heard something but he didn't know what.

"I just thought it was somebody dropping something upstairs, you know, being downstairs" he told RNZ.

He got a text from his landlord shortly afterwards to tell him what had happened a few metres down the street.

"I thought, wow ok, looks like I'm walking up the hill from the bus this morning."

While the slip was edging on the backyard of the property on Ramsey Place, there were no concerns for the house up top.

Neighbour Carey said the bank that gave way had seen small slips before - but nothing like today.

"Very rarely have I seen slips on Woodhouse Ave, they've only been minor ones," he said, noting today's slip was the biggest he had seen.

Porirua's Paekakariki Hill Road was taken out in the early hours of this morning after a large tree fell.

A motorist had a lucky escape after driving through the cordoned off area and colliding with the debris.

Back in Wellington a cleanup began on the large slip on The Terrace. Two homes are still evacuated and will likely be for some time.

Slip blocks The Terrace in Wellington

The slip that has been blocking The Terrace for several days. Photo: RNZ / Charlotte Cook

Seatoun's main thoroughfare tunnel reopened after being closed overnight due to a tree falling down the bank.

While it has been a busy few days of land giving way, the council's chief infrastructure officer Siobhan Proctor said it was not uncommon.

"We've had several weeks of very heavy rain, so no extreme one-off events, but just persistently heavy rain so it has been busy," she told RNZ

There have been about 50 slips in the last two weeks around Wellington city.

A slip has fallen into the backyard of a Wellington home due to an intense storm

A run of wet weather has brought down dozens of slips in the capital. Photo: RNZ / Angus Dreaver

Proctor said there tended to be a lot of slips at this time of year and history showed that some compromised residential properties in Wellington on occasion.

"Anywhere where we've had to cut into ground, so whether we're putting in a road ... anywhere you've cut that ground there's an increased risk of slippage," Proctor said.

"I think if we're expecting more extreme weather events, which for all intents and purposes we are, we're going to see more of these events in the future."

Climate change's impact

Climate change will likely create a further headache for areas prone to landslips if severe weather events increase.

Cushla Loomb heads the climate change and resilience team at consultancy company Beca.

She said to build resilience people needed to firstly understand the risk and then consider the options.

The first option was keeping the status quo - accepting the risk and cleaning up the slips.

"Of course, that is quite costly to do and with the increasing frequency we're seeing with some of these events it may not be a viable option," Loomb said.

"The other options are to protect, which is to produce engineering outcomes that would reduce the potential likelihood of landslips in the future."

The third option would be in areas of extreme instability to look at retreating.

Wellington's councils are undertaking a regional climate change risk assessment with the help of Beca, NIWA and GNS and other experts to inform future planning.

Get the RNZ app

for ad-free news and current affairs