Report finds design flaws and ignored risks at Moa Point
Monday 21 September 2026 · 2 outlets · 2 reports · updated In this story Fire and Emergency New Zealand, Andrew Little, Tiaki Wai
A new report into the Moa Point wastewater treatment plant failure reveals design flaws and unaddressed risks prior to the February disaster. The findings indicate that warnings were left unactioned and high-alert pagers failed to activate as sewage was released into the sea.
Key facts
4 facts
- The Moa Point sewage disaster occurred on February 4
- The Aecom report was released on a Monday following a dispute between Tiaki Wai and insurers
- Repairs for the plant are estimated at $53 million
- The plant is expected to discharge treated wastewater by November
The full story
1 min read · 2 outlets
A newly released Aecom report has detailed design flaws and unaddressed risks that preceded the February 4 Moa Point sewage disaster. The report found that an air blockage risk was identified before UV channel repairs began but was never resolved. One specific risk was recorded in a risk register 'parking lot' and was not assigned to any party for action.
The disaster occurred while a UV channel was out of action for repairs and heavy rain caused increased flows. This led to trapped air which forced rain and wastewater back into the plant. Between the start of the UV channel work in October and the February event, there were five prior inundation events that flooded the offline channel.
During the disaster, 'priority one' alarms failed to reach staff pagers. Operations personnel only became aware of the flooding after being contacted by Fire and Emergency New Zealand, rather than through the plant's SCADA alarm system.
The failure has resulted in seventy million litres of untreated wastewater being discharged daily off the south coast. Repairs are estimated to cost $53 million, with the plant expected to send out treated wastewater by November.
Where reports differ
- Wellington Mayor Andrew Little stated insurers were fighting to keep the report secret, while Tiaki Wai chair Will Peet noted external lawyers were hired to attempt its release
Compiled from reports by NZ Herald and The Post.
