A Capital Letter: Weather and quakes make for inconvenient truths

A large slip threatening houses on and above Woodhouse Avenue in Karori. Photo / Mark Mitchell

OPINION:

In Wellington, we knowingly build and buy houses on fault lines, precarious hillsides and next to rising seas.

I say we knowingly do this because the risks of doing so have been well publicised, yet I think many of us would rather maintain a willful ignorance.

Burying one's head in the sand becomes somewhat more difficult when photographs emerge of houses inches away from massive landslides.

Over the past few miserable soggy weeks in the capital, there have been almost 500 slips.

Some have been minor, a few have closed roads, while others have threatened people's homes.

The most frightening slip was at the southern end of The Terrace, which resulted in the evacuation of a dozen properties.

It has honestly felt like the city is falling to pieces.

These slips have been caused by a long period of wet weather. In July, nearly 300mm of rain was recorded in Kelburn, which is almost double the average amount for that month based on recordings from the past 30 years.

GNS Science experts say it doesn't take as much for a one-off storm to cause landslides when there have been long periods of rain like this saturating the soil.

The slip on The Terrace. Photo / Adam Hendricks

Big cuts have also been made in these slopes to build houses and roads on. Some of this engineering is more than 100 years old and has drastically modified the natural form of the hills over time.

Throw in climate change and a future with more storm events, and it's clear there are going to be more slips in the capital.

We've also seen the sea wash up onto the road in Eastbourne and on Wellington's South Coast.

The beaches and streets seemingly became one in areas where there are no seawalls or sand dunes.

There is literally nothing standing between the ocean and people's homes, yet beachfront property remains desirable.

I doubt the people who are buying these homes are doing so while accepting the trade-offs. The reality is they might only be able to enjoy the house for a finite period of time before it starts getting swamped.

Lowry Bay, Eastbourne. Photo / Mark Mitchell

I wonder if they realise the city council has drawn up new flood risk maps, outlining a proposal of where new housing development will not be allowed in the future.

In lower-risk areas, new housing will be allowed but must include mitigation measures like raised floor levels, relocatable buildings and private pump systems for basement car parks.

The thing about Wellington is that nothing seriously bad has happened in recent memory.

Buildings were demolished as a result of the Kaikōura Earthquake, but it still wasn't our event and it didn't really affect the suburbs.

Unlike Christchurch, where I started university the year after the city experienced a 6.3 magnitude earthquake.

I was insulated from the aftermath of that event being a student living in Ilam.

But I have a clear memory of venturing into the CBD, which was entirely fenced off, and watching the traffic lights flash meaninglessly to the sound of demolition.

One of two slips threatening housing on Eastern Hutt Road in Stokes Valley. Photo / Mark Mitchell

We also drove out to Sumner quite a lot and I'll never forget the houses hanging off the cliffs on the way there.

When you see those things for yourself, in the place where you live, it changes your perspective.

I wonder whether Wellingtonians have really grasped the fact they should be prepared to manage their own toilet waste for a month or more following a major earthquake.

That it's a matter of when not if a big earthquake happens - experts expect the capital will experience a significant seismic event in our lifetime.

Does that phrase sound familiar? That's because it is.

NIWA experts say it's a matter of when, not if, New Zealand will experience the same sweltering conditions described as "absolute hell" in parts of Britain earlier this year.

A "major incident" was declared with several large fires raging across London as 34 weather stations in the country recorded their highest ever temperatures.

Despite this long list of looming resilience issues, I would be the last person to suggest that we up sticks and move Wellington elsewhere.

We can live with these risks so long as we actually meaningfully acknowledge them.

The images of slips tumbling down across the city and several houses being evacuated should serve as a wake-up call.

Admittedly, after seeing the landslide on The Terrace, I did some snooping around our own property to see how close the fence line was to any steep drops.

We need to understand and recognise resilience risks so we don't make the situation any worse going forward.

So that future generations don't have to needlessly deal with properties developed in high-risk hazardous areas and resilience is built into other parts of the city through mitigation measures.

It's time we fronted up to Wellington's inconvenient truths.

• Senior Wellington journalist Georgina Campbell's fortnightly column looks closely at issues in the capital.