Whangārei coastal residents watch land disappear into sea at Waikaraka

The row of pohutukawa trees were once set back from the water's edge - now they are not far from being taken by the ocean. Photo / Michael Cunningham

For the past 20 years, Waikaraka waterfront resident Paul Frische has enjoyed sitting under the pohutukawa trees lining the shore in front of his house.

But from his house, he's also watched those pohutukawa trees become one with the ocean.

Many residents of Waikaraka, on the northern side of Whangārei Harbour, a few kilometres from Onerahi, are concerned about their surrounds as they've witnessed the ocean creep closer, the beachfront grass verge disappearing as it collapses onto the once sandy beach, turning it to mud.

The pohutukawa, once set back from the water's edge, are now practically half-suspended with roots exposed.

Fellow resident John Calder has only lived in the area five years but said he has witnessed the foreshore eroding at an alarming rate of at least 50cm a year in places.

"I've noticed it even more than the residents as I've spent time overseas and every time I've returned, I would notice. Everyone I've spoken to is concerned, not just about the erosion, but all the land slipping into the beach basically turning it into mud and clay. We feel that a few truckloads of rocks would slow this erosion considerably and is a simple and effective solution in the interim."

However, he said pleas to Whangārei District Council (WDC) were falling on deaf ears. But the council says the residents' concerns are unfounded.

"I've been writing to the council about this for over two years and keep getting fobbed off. What's insulting is that we see a barge go down the harbour every three days and it's full of rocks going to Napier [for foreshore and wave protection], which is a bit ironic when we have this problem here. It's not that it would fix it, but it would certainly slow it down by around 60 years. We've even offered if they dumped the rocks, we'd do the labour [of building the sea wall]."

The council says the land is road reserve and, although no houses were in immediate danger, the residents were concerned about the environment and a nearby wastewater system.

"Those pohutukawa trees are all but in the water and the sewerage plant about 12-15ft [3.6-4.5m] from where the erosion is. It's not a case of if it will happen, but when it will happen," said Calder. "I estimate 30 years there's going to be serious problems but if they put up a concrete wall, you're talking about 100 years' time. It beggars belief as to why nothing has been done."

Waikaraka residents have watched the grass verge disappear as it collapses onto the beach turning the sand to mud. Photo / Michael Cunningham

However, WDC strategic asset coordinator Shaun Dixon said a thorough investigation had found no risk, including to the wastewater system.

"The assets are 4 and 8m from the high water line, elevated from the beach and will not be affected by sea level rise for a considerable period. Both have been inspected and are operating as intended."

He said that although the council owns land and infrastructure that may be affected by coastal erosion along kilometres of coastline, with limited funds, its policy is to prioritise erosion protection works where it is necessary to protect life or community infrastructure, where there is a significant public benefit, where any intervention is supported by national and regional policy statements, where a coastal hazard assessment supports intervention and identifies practical solutions, and when all necessary consents are obtained.

"In this case, several property owners over time have carried out a range of ad-hoc protection works. Council has been asked to fund rock so that property owners can undertake further protection works.

"At this stage there is no benefit to the wider community for erosion protection work to be carried at this site. However, we do take planning for sea level rise seriously and do build it into our planning when building and renewing infrastructure and assets. With the sea level rising at about 3.5mm per year, coastal erosion and flooding is increasingly affecting council-owned property."

WDC was working on a model to help understand where the highest risk sites are and what approach best suits the district's long-term needs.

"These decisions can be complicated. Before we have a good understanding of the risks across the district, our approach is to avoid the construction of new coastal protection structures unless absolutely necessary."

As well as enjoying the shade of the pohutukawa tress, one of the attractions for Frische was taking his 3.9m tinny out for a fish in front of his house. But, he said, it was getting harder to launch where sand had now turned to silt.

He pointed out a patch of rocks residents had paid for and put in themselves around 12 years ago. "You can see that it's worked – you can't deny that."

WDC would be developing a climate change adaptation strategy to address existing gaps in their understanding about what council assets are at risk from climate change. This would guide planning and decision-making about assets and help make decisions about whether to provide and maintain coastal protection structures based on long-term planning.

Said Calder: "But isn't our land an asset? Where do you draw a line in the sand? New Zealand is a treasured asset and it's washing out to sea. They can word it how they like – it's just bureaucracy gone silly."