Huge Wellington waves may return

Yesterday's destructive waves are likely to become a more common occurrence, says a councillor from the worst-hit parts of Wellington.

Climate change would have far-reaching impacts on coastal protection, property, and public spending, Councillor David Lee said today.

Massive waves wrought havoc on Wellington's south coast yesterday, hurling boulders onto roads despite fine weather.

The huge waves didn't even have the company of a powerful southerly, Mr Lee said.

"When you factor in climate change, we're actually going to have more and more of these type of events. So we do actually need to start the conversation around: Do we look at more protection? Do we look at managing or even accommodating these types of events? Or even the big question, which is around managed retreat..."

Waves at Lyall Bay. Photo / Twitter, Simon Baxter

The Southern Ward councillor said the obvious response of "building bigger barriers" would most likely just create a false sense of security.

He said the immediate step was to look at protection, but then perception.

"How big do you keep on building barriers? Do you keep on building up to the point you cannot see the sea?"

Mr Lee said the question of how much money to spend on coastal barriers, protection, or managed retreat would become an increasingly big public spending and policy issue.

Some of the debris left on Wellington roads. Photo / Julia Price

Mr Lee suggested climate change could make coastal properties the preserve of the super-rich, as insurance premiums soared in the wake of sea level rise or freak coastal weather.

He said a "different demographic" who could self-insure would probably still buy waterfront properties if the risk of coastal flooding and erosion intensified.

"It could be people who have so much money that they can actually take a hit of losing their property and then re-building."

High tide in Wellington is expected at 3.41pm today, triggering some nerves.

MetService said more big waves were possible but Mr Lee said a repeat of yesterday's violent condition was unlikely.

Huge chunks of driftwood accompanied stones, pebbles and other detritus on roads around Owhiro Bay and Island Bay, with some roads and footpaths closed yesterday.

Roads around Lyall Bay, near the city's international airport, were blocked off.

Large crowds gathered to watch the unusually high waves and observe the wreckage.

The big waves mesmerised Ingrid Cuttiford, who watched from a restaurant balcony between Owhiro Bay and Island Bay.

She said waves perhaps 15ft (4.5m) high engulfed the pyramid-shaped rocks in the area.

"Rubble and rubbish and debris" were churned up all along the waterfront, she said.

She said the waves were undercutting a local pathway in places.

Yesterday, climate change issues minister Tim Groser said more droughts were likely as the greenhouse effect intensified.

After the Dunedin floods earlier this month, that city's mayor Dave Cull said the event was possibly a prelude to some likely effects of climate change and sea level rises in years to come.