RNZ's The Detail heads to Matatā to find out how New Zealand's first managed retreat was handled - and what lessons can be learned as communities around the country grapple with the impacts of climate change.

Matatā is a pretty coastal town in Bay of Plenty, just north of Whakatāne. Boulders lie on the grassy reserve that leads to a wildlife refuge and beyond that, there's the beach.

It's like a lot of seaside settlements, with a dairy, a pub and a petrol station.

But a closer look at some of the roadside signs gives a hint of an event that changed the town forever: "Kia mataara. Be aware. This is a high risk debris flow area. Keep clear during and after heavy rainfall".

Beyond the sign are more boulders, overgrown grass and a road that leads to a lone house. It's the last house to be acquired by Whakatāne District Council under its managed retreat programme.

It was bought a couple of months ago, 17 years after torrential rain caused massive landslides that brought a torrent of rock, silt and trees down from the hills. Travelling at a speed of 30km/h, the landslides dumped debris through the town.

The last home to be demolished in Matatā. Photo: The Detail/Sharon Brettkelly.

A total of 34 properties, including 16 homes, were affected, but the drawn-out process that eventually led to the managed retreat left some residents bitter, traumatised and physically and mentally ill.

The Detail looks at the Matatā experience - New Zealand's only managed retreat - as councils and other authorities consider it as an option for managing flood-prone areas and coastal settlements facing the threat of sea level rise.

Whakatāne District Council strategic projects manager Jeff Farrell describes managed retreat as relocating people out of harm's way.

Jeff Farrell. Photo: RNZ.

But the council's handling of the programme has been cited by some affected property owners as a lesson in what not to do - a large sign on the gate of a house on the main road signals that lingering anger: "Whakatane District Council leave our homes alone. Watch out the rest of NZ, you're next".

Farrell tells The Detail why it took the council so long to reach the final decision to acquire the properties, get homeowners permanently off the land, and remove or demolish their homes.

He says he's contacted by other councils regularly about the managed retreat at Matatā.

Among his key points of advice: don't rush in and make promises without fully understanding all the factors at play and work with the community.

Farrell admits things could have been done a lot better.

"Seventeen years from the time of the event to now...it's not a reasonable time period to be subjected to uncertainty, stress about another event happening while they're still living here, uncertainty about funding packages."

He explains the council had nothing to work off: no rules, no funding framework and, until 2017, no formal risk management policy.

"There was no guidance on roles, responsibilities, processes or procedures on how to do it," says Farrell.

Some residents felt betrayed by the council, Farrell says.

"They didn't appreciate that some of the decision-making was beyond the council's ability to control but we were the ones to implement it."

Stuff's Nikki Macdonald has written extensively about the impact of on residents and says Matatā's managed retreat would differ from that of coastal communities threatened by rising seas.

"In this case they didn't have the luxury of time, it's not related to climate change, it's related to a natural hazard and once they'd identified it as 'dangerous', they had to take action, so they had to effectively get them out," she says.

"You didn't have the option of foreseeing this problem."

Councils and the government considering managed retreat should never underestimate people's attachment to their homes and the toll it can take on lives, Macdonald says.

"It is definitely a traumatic process, and I wouldn't want anyone to treat it lightly."

Sharon Brettkelly/RNZ