New Zealand / Weather

Councillor suggests Dunedin could be world leader in flood risk response

19:00 pm on 5 December 2023

The South Dunedin basin, home to 13,000 people, was swamped by floodwaters in 2015. Photo: RNZ / Ian Telfer

Dunedin residents will soon be able to have their say on how a low lying and vulnerable community should adapt to the many hazards it faces.

Local councils have been working together to respond to flooding and climate change predicted to impact densely populated South Dunedin areas.

As part of this work, 16 potential adaptation approaches were unveiled last week with options ranging from managed retreat, ground strengthening, creating more water storage, more restrictive building standards, to changes to individual properties including being raised, waterproofed, having flood barriers or rain tanks installed.

The Dunedin City Council voted to endorse the list for community engagement during a meeting on Tuesday along with starting work to develop a city-wide climate adaptation plan.

Jules Radich Photo: Supplied

Mayor Jules Radich - who moved the item - said it was important work for the city.

"This speaks completely to the resilience of our city in the face of climate change and it has a huge impact on the economic resilience of the city as well," Radich said.

Programme manager Jonathan Rowe said it was a milestone for their work that focused on moving forward.

The next round of consultation would kick off properly in the new year.

Rowe said they would use feedback as they underwent more technical work focused on what solutions different areas might need and how they should be prioritised.

"Part of that next phase of the risk assessment is going to quantify risk to identify what are the impacts, what are the consequences, how does that rate relative to other risks, which ones are we going to prioritise and focus on and then that will feed into the adaptation approach."

The programme has fixed government funding until June 2025 which Rowe said would support the bulk of the technical work.

Councillor Steve Walker questioned how the complex and technical work could be made more accessible to people who might be after a silver bullet, single approach.

Rowe said there was not a single approach that would solve all of the issues, but they would ensure they shared the information using plain language so people could come to grips with what the different approaches meant.

"It's an inconvenient truth ... but one of the things we wanted to do with this process and particularly the long list of approaches is to open people's minds to the different ways that different potential solutions you have for fixing a range of problems," he said.

Councillor Walker wanted the council to lead the way in helping the community to adapt.

"Be a place where people from across the motu and in fact from across the world visit us to see how we managed to face this ... and adapt and accomplish some mitigation measures."

Councillor Carmen Houlahan was pleased with the work, saying when it came time to approach the government for support, they could present a range of evidence and reports to back them up.

"Rather than being victims, we're being proactive," she said.

Councillor Christine Garey said she knew a family who chose to move to South Dunedin after the 2015 flood, and had a positive view of the future of the area, speaking highly of the consultation to date.

She described the different approaches - some of which were noted as not standalone solutions - as puzzle pieces that could be combined and staged over time.

Concern on residents' mental health

Councillor Kevin Gilbert asked how mental health would be factored into the plan.

Rowe said it was a theme that would run throughout the programme, which was vital as there would ultimately be trade offs they would have to grapple with.

They would be put in a position where they could not choose everything they wanted to do and might have to decide with the community among options that might not be preferred or best, and they would need to understand what residents wanted to prioritise, he said.

Councillor Mandy Mayhem said this was a once in a lifetime opportunity to create something future-proof and amazing for the city.

Only councillor Lee Vandervis opposed the plan, saying he did not believe the evidence that had been provided and it was catastrophising.

In response, Radich detailed the catastrophes and near misses that had been experienced including hundreds of South Dunedin homes being flooded in 2015, water reaching from house to house but not entering them two years ago, as well as those faced by communities in Auckland, Hawke's Bay and Gisborne this year.

He wanted the work to continue in order to help communities to prepare and adapt.