• Media release

02 Nov 2023


The possible effects of climate change on Southland district’s coastal communities will soon be better understood as a result of a study commissioned by Southland District Council.

Chief executive Cameron McIntosh said that as part of its ongoing commitment to understanding the effects of climate change, Council commissioned Great South to prepare a report on spatial modelling of sea level rise.

Great South staff presented summary information about the modelling used in its report, Sea Level Rise and Extreme Sea Level Exposure, to councillors in a workshop in Council chambers yesterday afternoon. The full report is not yet complete. It is expected to be presented to Council later this month.

The sample maps in the summary presentation outline best and worst-case scenarios in year 2090 for six specific locations to the south coast of the Southland district territorial authority and Stewart Island Rakiura: Colac Bay, Curio Bay, Fortrose, Riverton, Oban, and Waikawa.

A best-case scenario for 2090 considers sea level rise, vertical land movement and mean high water spring (spring tides). The worst-case scenario adds to this extreme sea level resulting from a one-in-100-year storm event creating storm surge and wind waves.

The final report will project further scenarios for years 2130 and 2300, and will be peer reviewed before completion.

Great South GM strategic projects Steve Canny said the area of climate change-induced sea level rise was a dynamic and changing area of science.

The methodology was based on interim guidance on the use of new sea-level rise projections provided by the Ministry for the Environment in 2022, and draws on other sources of information including the latest LiDAR data and the New Zealand SeaRise programme.

“It is expected that the guidance from the Ministry for Environment will be updated as climate science knowledge is further refined, and an agreed rate of climate change is confirmed,” Mr Canny said. “Accordingly, the modelling shown may change as updated climate science information becomes available.”

Mr McIntosh said “our communities are already experiencing the effects of sea level rise and changing weather patterns. Council has commissioned this work to provide a basis for better decision-making into the future.

“Council has a responsibility to identify natural hazards, including those that will result from the effects of climate change in the future, and do our best to draw on this information in short, medium and long-term decision-making.

“It is an expectation from the Auditor-General that the potential effects of climate change are reflected in long-term planning.”

The full report and peer review will be made public as soon as they are available.

Council has set up an email address for those who have any questions: coastalhazards@southlanddc.govt.nz

The presentation and a link to the Council workshop livestream are on SDC’s website, here: www.southlanddc.govt.nz/environment/climate-change/coastal-hazards/

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