Wellington's crumbling seawalls losing the climate change fight - experts

Wellington City Council is spending almost $1 million on strengthening a crumbling seawall on the capital's south coast, but experts claim the walls are losing the fight against climate change.

Scientist James Renwick said that as sea levels rise, land is claimed by Mother Nature and coasts erode.

A natural hazards advisor from Greater Wellington Regional Council added that protecting our coastlines may require looking at solutions other than concrete barriers.

"It might be that it's an interim solution for 20, 30, 50 years. But ultimately we might have to look at other options, rather than relying on seawalls," Iain Dawe said.

Scientists predict the sea will rise 50 centimetres in the next 50 years, which could put thousands of buildings in New Zealand at risk.

Wellington City Council is spending $850,000 strengthening a crumbling seawall in Lyall Bay because it said the heritage-protected wall is worth retaining for now. It's one of 17 walls across the region needing work.

With local authorities strapped for cash, there are questions being asked about whether a new funding system is needed for coastal defences.

Councillor Iona Pannett agreed that the walls aren't a long-term solution, but communities need to get on board with other options.

"Unfortunately, some people have had their heads in the sand. And we need to have deeper conversations with the community about what they value, and what needs to be prioritised for saving," she said.

For some communities, James Renwick said those conversations may include the prospect of moving away from the coast because it's the "best way" to deal with it.

But until then, the sea walls will continue to be their main defence against Mother Nature.