Half of the buildings in South Dunedin remain 'at risk' of flooding

• Half of all South Dunedin buildings remain at risk of rainfall flooding
• This is expected to rise to almost 70 percent by 2100
• Two major reports have been released by the South Dunedin Future programme, a joint initiative led by the Dunedin City Council and the Otago Regional Council
• Seven future plans for climate adaptation have been proposed in a a multi-billion dollar bid to mitigate the growing threat of severe rain events on the South Dunedin basin

Half of the buildings in South Dunedin remain "at risk" from surface flooding with the threat set to increase in coming decades, according to two major reports released by local authorities.

The ominous forecast was outlined in reports released on Friday by the South Dunedin Futures programme, an initiative jointly led by the Dunedin City Council and Otago Regional Council.

Local residents, some of whom remain displaced after the inner city suburb was battered by heavy rain and flooding last October, will be asked for feedback on the best path forward with several future adaptation plans proposed.

Each option is excepted to cost a total ranging between $2 billion and $7.1 billion over the next 75 years.

The South Dunedin risk assessment report analyses the risks presented by a range natural hazards including surface flooding, coastal inundation, and shallow groundwater.

About 49 percent of the 9091 buildings in the area were considered at "high or medium risk" from surface flooding caused by rainfall.

This was expected to increase to almost 70 percent by 2100 without additional intervention.

"Some of the identified present day risks are currently being managed, for example through

existing roading and three waters maintenance schedules," the report said.

"However, this assessment indicates that these maintenance measures will become increasingly inadequate in managing the escalating risks in future scenarios."

South Dunedin is home to more than 13,000 residents, 6000 households and 1000 businesses.

The regional council's natural hazards manager Dr Jean-Luc Payan said the release of the reports follows 15 years of intensive work.

"The risk assessment is a snapshot in time using the best available information.

"It will be updated as new data and information comes to hand. It is primarily intended to support suburb-level adaptation planning, so we can test how effective various adaptation options are at reducing risk."

Whilst the first report evaluates the risk facing South Dunedin, a second report explored seven different "potential adaptation futures".

The options included infrastructure upgrades, land raising, creating space for waterways and wetlands, and moving people out of worst affected areas.

South Dunedin Future programme manager Jonathan Rowe said the report showed there was a range of things that could be done to safeguard the area.

"What the reports do is lift the lid on each of those options and explore them in terms of what are the pros and cons," he said.

"Ultimately there are trade-offs across all of these, there is no quick easy perfect solution.

"It is going to be a balance of how much change are we willing to undergo and at what rate, what can we afford because the dollars matter and what level of risk are we prepared to live with."

Each option is excepted to cost a total ranging between $2 billion and $7.1 billion over the next 75 years.

Both the Dunedin City Council and the Otago Regional Council will formally discuss the reports' findings next week.

Family face another year out of flood-damaged home

Bri Soper and her husband were on holiday further up the motu when heavy rain pounded Dunedin last October.

About 100 residents were forced to evacuate as the city was hammered by 160mm of rain in 48 hours.

Soper said her home on Surrey Street was the lowest lying property on the road.

"When we came back it was just massively damaged," she said.

"We had lost 90 percent of our contents, the walls were ruined, the floors were ruined.

"Because the house was shut it had made a greenhouse effect, so dry clothes hanging up were damp with black water damage."

Since the floods, the family have ping-ponged between rental properties.

Their rental in Brockville is the fourth property they have moved to in five months.

After moving to the city in 2018, she admits the family's future in South Dunedin remains unclear.

"Every time it rains we're quite nervous," she said.

"We always have sandbags out the back and moving forward there's a lot of uncertainty about whether it's worth being in that place with the risk that it could all happen again."

Speaking to RNZ prior to the release of the South Dunedin Future reports, Soper renwed calls for the council to consider buying flood-prone homes in the suburb, as some locals suggested.

The council said there were no plans for a buyout scheme after a previous proposal was rejected by the government.

South Dunedin Community Network manager Kirsten Gibson said it welcomed the release of the South Dunedin Future reports, as it ensured the risks of water issues for peoples' homes were "comprehensively understood".

"The South Dunedin community has continued to experience detrimental impacts of adverse weather events.

"The network are keen to hear people's thoughts from the South Dunedin community about how they'd like South Dunedin to look like and be like to live in the future."

"[We are] also looking forward to hearing how local and national government can support structural solutions in response to water issues and community needs."

Report 'not a major influence' on premiums - insurer

IAG New Zealand said it "commends" local authorities for the work it has done to understand the risk facing South Dunedin.

The company's chief executive Amanda Whiting said some residents would be concerned about what this information means for their coverage.

"We currently insure many homes and businesses in South Dunedin through our brands, State, AMI and NZI.

"While the risk assessment released today by the council shows a challenging future for the community, it does not change our overall view of the risks it faces or our willingness to provide insurance."

While insurers were "moving to reflect risk" at a property level for their premiums across New Zealand, the South Dunedin Future risk assessment would not have a major influence on IAG's pricing decisions for South Dunedin residents, Whiting said.

"The risk assessment and potential adaptation futures reports are a critical step in securing a more resilient and insurable future for South Dunedin and we look forward to being part of that process."

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