South D waiting for stormwater justice

South Dunedin on a good day. PHOTO: PETER MCINTOSH
South Dunedin on a good day. PHOTO: PETER MCINTOSH
Julian Doorey has a message for the Dunedin City Council.

Dear Mayor, councillors, and senior staff,

This week marks 10 years since the devastating South Dunedin floods of June 2015.

For many, this was a turning point. Homes and businesses were flooded, the community was shaken, and residents were promised action. Ten years on, South Dunedin is still waiting, remaining at risk and stigmatised.

Despite a decade of meetings, submissions and plans, no physical stormwater flood prevention works have occurred in South Dunedin.

Not one metre of new stormwater pipe, or one new pump has been installed. And yet we have had two major floods — in 2015 and again in 2024 — each initiated by rainfall intensities of only 8mm per hour, well below the national design standard for Dunedin of 18mm per hour for a one-in-10-year event.

The Dunedin City Council has never stated in any public consultation that flooding is due to an undersized stormwater system, for which it is responsible. Rather, since the 2015 flood, DCC has explained recent flooding as somehow climate change related.

While climate change is likely to be a future issue, there is no evidence this has caused flooding over the last 60 years, since the current stormwater system set-up began with the new pumping station in 1964.

There has seemed to be an ideological resistance to engineered solutions to keep South Dunedin dry. In fact, a previous headline stated, "South Dunedin: Poster child for managed retreat".

Prior to the climate change narrative, DCC commissioned several engineering reports. These provided very high quality, workable, conventional, engineered solutions which could (1) solve the current stormwater flooding problem (Opus 2017 report — generally pipes and pumps) and (2) manage the impact of slowly rising sea-level on groundwater as needed in future (Beca 2014 report — dewatering at the sea boundary).

Unfortunately, these engineering solutions were never implemented. About 2018, DCC switched to a longer-term climate change investigation programme, supported by the Otago Regional Council, called South Dunedin Future.

This has produced potentially useful scenarios for 2100. However, it has also resulted in the community enduring a kind of climate change analysis/paralysis, resulting in no actual stormwater flood prevention work. Sadly, this was a contributing factor to the recent October 2024 flooding.

The situation in Surrey St is especially shameful. During both the 2015 and 2024 floods, raw sewage, under pressure, popped the manhole lids, resulting in sewage overflowing into the street and properties. Some houses in wider South Dunedin received contaminated water inside, becoming uninhabitable.

This has nothing to do with climate change, and everything to do with wastewater being diverted from the Kaikorai Valley and western-facing suburbs, including parts of Mornington, Kenmure, Belleknowes, Roslyn and Māori Hill.

These overflows occur every two or three years during heavy rainfall, creating environmental hazards and serious health risks. Why should South Dunedin be flooded with other people’s sewage? This must stop.

This letter is a simple call for stormwater justice for the 13,000 people in 5000 houses who call South Dunedin home and the hundreds of businesses — all ratepayers like everyone else.

Unfairly, they have been left with the social, economic and emotional or psychological issues associated with flood risk or loss of home value.

This letter is not about climate change denial. It is a call to stop using climate change uncertainties as an excuse to delay upgrading stormwater infrastructure which has been undersized for decades.

Long-term climate resilience requires engineered solutions for current stormwater failures — now. Affordable engineered solutions exist — now.

We call on DCC councillors who are standing for re-election this year to state clearly and publicly where they stand with respect to solving the South Dunedin flood risk.

Will you commit to starting urgent, staged, engineered flood prevention works — beginning with pipes and pumps — to make South Dunedin flood-free within five years, and to stop the Surrey St wastewater sewage overflows within 12 months?

The time for plans without action is over. The time for promises without pipes is over.

Julian Doorey is a representative of the South Dunedin Stormwater Justice Group.