South Dunedin Future programme manager Jonathan Rowe said a risk assessment for the suburb, due in a matter of weeks, could have wide-ranging implications for council services, infrastructure, mana whenua, residents, schools, public housing and utilities companies.
Mr Rowe said the five-year South Dunedin Future work programme under way was on track to produce a climate adaptation plan for the low-lying suburb by 2026.
Work was now moving on from the previous high-level conceptual stage, he said.
A new risk assessment for the suburb was due in September and a report on adaptation options was due in November.
The assessment would examine how much of a risk high groundwater, coastal erosion and surface flooding would pose to people, places and "assets" in the suburb.
It would detail how these natural hazards might be affected by more frequent and severe storms, higher groundwater and rising sea levels brought about by climate change.
It would be the first time the risks faced by the area were formally assessed, quantified, and put together in a single report.
"Over the next six months, the [South Dunedin Future] programme will undertake a major transition by producing more detailed, location-specific, and time-bound assessments of risks, more developed adaptation options for managing and mitigating those risks, and in doing so provide an initial picture of the future of South Dunedin", Mr Rowe said.
"While the risk assessment will be based on information that is predominantly already available to the public, the analysis of this information — ‘putting all the pieces together’ — will represent a new and significant step forward in our understanding of risk for South Dunedin.
"In this sense, it may present a concerning or unwelcome picture for some stakeholders but should reduce long-term uncertainty for many."
However, it would not answer every question for home and business owners, asset managers, service providers, residents and others.
It would principally focus on risk at "a suburb and city block level"; more finely detailed assessments would require significantly more information, time and cost, he said.
South Dunedin Future is a joint Otago Regional Council and Dunedin City Council work programme that began two years ago.
In a report due to presented at the ORC meeting in Cromwell tomorrow, Mr Rowe said the work covered natural hazards, strategy and programme management, communications and community engagement, risk assessment and adaptation approaches.
The forthcoming "spatial adaptation options" for South Dunedin would build on 16 generic approaches released late last year, and consulted on early this year.
Four distinct "cells", or areas, had now been identified within South Dunedin based on "geography, hazards, risks, infrastructure, value and other measures".
The boundaries of each cell were not yet finalised, but they generally separated the flats of South Dunedin, the slightly elevated areas around the flats and surrounding hills, the elevated reclaimed land on the harbour edge, and the St Clair and St Kilda coastal areas.
The previously released generic adaptation approaches would be tailored to these cells over specific timeframes.
The spatial adaptation approaches report due in November would "essentially provide the first high-level outline for the future of South Dunedin", Mr Rowe said.
"It will identify how and where risks might be managed or mitigated, including through additional infrastructure investment, property-based interventions, planning rule changes, intensification, de-intensification or relocation, and other potential land use change over the next 50 to 100 years."
Mr Rowe said over the the next six months, the South Dunedin Future work programme would take "a necessary, but potentially challenging, step" towards a climate-resilient South Dunedin.
