Pipes, pumps insufficient, manager says

"[Climate change is] going to be transformational, so everything is accelerating at an accelerating rate" — South Dunedin Future Programme manager Jonathan Rowe. Photo: supplied

Seven proposed climate adaptation plans for the low-lying suburb have been narrowed to a shortlist of three, following multi-criteria assessment through the Dunedin City and Otago Regional Councils’ joint South Dunedin Future Programme.

Dunedin city councillors considered the shortlist in a report to Tuesday’s council meeting.

Each of the plans shortlisted included a different mix of infrastructure and nature-based solutions, and discussed the need for managed retreat due to flooding and climate change.

Cr Lee Vandervis asked why the longlisted pipes and pumps plan was not considered a suitable long-term option when it had been used successfully in the low-lying Netherlands for 800 years.

Programme manager Jonathan Rowe said the situation might be different if the council had started work 800 years ago.

"Climate change is not having an incremental impact.

"It’s going to be transformational, so everything is accelerating at an accelerating rate.

"If we started that approach now, it would be very difficult to catch up and it would require an enormous amount of investment."

Pipes and pumps were key to managing water in South Dunedin over the next 25 years, as part of a balanced approach, Mr Rowe said.

"What this assessment is saying is that that’s not the best sole focus over the long-term."

Status quo was also unsuitable in the long-term, although elements may be used in short-term work.

Relocation to raised land and large-scale retreat remained under consideration, but were considered more relevant in "very long timeframes beyond 2100".

Cr Vandervis said he was "appalled" the report discussed relocation to raised land and large-scale retreat from South Dunedin.

"The fact that the report considers options which I consider to be completely unpalatable is the main reason that I’ll be voting against noting this report."

Cr Steve Walker said Cr Vandervis was misrepresenting the matter and the report did not suggest large-scale retreat from South Dunedin.

"There is no silver bullet for climate change across the world generally, for the infrastructure that may have existed hundreds of years ago and exists in a different world now," Cr Walker said.

"There will be a multifaceted approach to creating solutions, and that’s just normal."

Councillors accepted Mr Rowe’s report, Cr Vandervis recording his vote against.

Next steps include further technical and economic work on the three shortlisted plans to determine the right balance of infrastructure, nature-based solutions and managed retreat required to "manage risk to acceptable levels".

The Otago Regional Council endorsed the South Dunedin Futures programme yesterday at a meeting with caution decisions will come down to funding.

Chief executive Richard Saunders said funding was the big question and something that will continue to be a challenge. — Additional reporting Steve Hepburn

ruby.shaw@odt.co.nz