Sewage flows, warning to stay out of sea warning in fallout of Moa Point catastrophe

Friday, 6 February 2026

Wellington is facing a long, sunny Waitangi weekend with millions of litres of raw sewage flowing to the sea, closing south coast beaches and ruling out swimming for months.

At its peak on Wednesday morning, 3300 litres of water and sewage back-flooded into the Moa Point sewage treatment plant, inundating it and shutting down equipment before raw sewage was diverted down another short pipe.

It was expected untreated sewage will be flowing to the south coast at the rate of 70 million litres a day for days. On Thursday evening, Wellington Water said all untreated wastewater was still being discharged through the short outfall pipe, and it was working to divert as much as possible to the 1.8km long outfall pipe as quickly as possible.

MetService is forecasting a mainly fine long weekend with just the chance of showers on Saturday and Sunday.

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Wellington mayor Andrew Little has promised an investigation into the “catastrophic” situation. He pledged to make the findings public – but said the immediate priority had to be stopping the flowing sewage and getting the plant working again.

Local Government Minister Simon Watts has also requested “urgent advice” on the Moa Point wastewater failure “and what options I have as minister to address the issue”.

​The traditional Island Bay blessing of the boats on Sunday, a nod to the suburb's Italian history, has been cancelled due to the outfall.

Wellington Water has, for now, said Wellington Harbour remained safe to swim in but all advisory was based on predicted flows. The first tested sampling from the south coast and harbour was not due back until after deadline on Thursday night.

Greater Wellington Regional Council environment senior advisor Penny Fairbrother said NIWA modelling, showing the harbour was largely immune from the outfall, was based on modelling showing a current was likely to drive the sewage to the west.

Preliminary results on Thursday afternoon indicated fairly little contamination outside of the immediately affected area at Tarakena Bay, where there was obvious visible pollution and a strong odour.

One marine biologist said the sewage spill had the potential to be a large ecological catastrophe that would take many years to reverse.

The worst case scenario involved denudation of the native kelp forest, which the marine life relied on as part of a rich ecosystem, threatening pāua, kina, crayfish and various fin fish.

“The longer that stress is out there, the greater the chances that stress will accumulate and cause ecological harm,” said Victoria University’s senior lecturer in marine biology Dr Christopher Cornwall.

Wellington Water runs the region’s three waters but contracts French multinational Veolia to run its four wastewater plants. Wellington Water on Thursday confirmed all contracts, including Veolia, would roll over to Tiaki Wai when it assumed Wellington Water duties in mid-2026.

Numerous issues over a number of years have been found with Veolia, which promised “international capability” and excellence when it won the work.

A 2021 review, commissioned by Wellington Water, described understaffed plants, inexperienced operators and a lack of executive oversight, leaving frontline teams to deal with complex process failures on their own.

It found Veolia failed to carry out basic asset management, including regular maintenance. But it also condemned the working relationship between Veolia and Wellington Water.

A 2023 report from engineering firm Stantec found issues at Moa Point, which were being fixed when the Wednesday morning fiasco unfolded. It was not yet clear if that work had been damaged in the back-flooding.

And papers to the Wellington Water Committee in December, showed the Moa Point plant has been non-compliant for all but two months since January 2024.