Wellington sewage spill: First check of Moa Point damage expected by week’s end
Thursday, 12 February 2026
The first full inspection of damage to the swamped Moa Point sewage treatment plant is expected to start by the end of the week, mayor Andrew Little says.
It comes as questions of blame arise into how the plant last Wednesday flooded, starting a spill of millions of litres of sewage off the south coast that is expected to continue for some time. Wellington Water has already engaged lawyers as an inquiry into the fiasco is signalled.
Little, speaking after a talk at a Wellington Chamber of Commerce breakfast on Thursday, delivered some good news. The plant was severely damaged when it was swamped in 3m of sewage and water and most equipment is thought to be destroyed or damaged.
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But Little understood that the clean-up operation was now far enough along that people would be able to enter the plant by the week’s end to assess the properly damage for the first time.
“We just don't know what the cost is going to be,” Little said.
“We'd have to anticipate this is a major rebuild, at least a re installation of equipment. And that doesn't come cheap.”
That cost could initially be borne by rate payers but insurance and other groups, such as Wellington Water or Veolia, which runs the plant, could be liable when fault was found through an inquiry.
Meanwhile, as the one-week anniversary of the catastrophe passed on Wednesday, Wellington Water refused to answer key questions.
This included when the 1800m long outfall pipe – which somehow sent wastewater gushing in reverse, inundating the Moa Point plant – was last inspected pre-failure.
With heavy rain again possible this weekend, it refused to say if the long outfall pipe had been fully checked for faults and whether there was a chance of the plant flooding again. Wellington Water has confirmed the shorter pipe, which dumped raw sewage 5m off the coast, would likely have to be used again if it rained.
A Wellington Water spokesperson said these questions could not be answered because it had now engaged lawyers due to an upcoming inquiry into the fiasco.
Chief executive Pat Dougherty said Wellington Water supported an inquiry into the incident, and would co-operate fully as it worked to get the plant back up and running.
“Now the inquiry has been signalled, it is important we allow that process to run its course. This means that we are unable to provide any further public statements regarding aspects of the Moa Point incident and response that may be included in the inquiry,” he said.
Wellington Water has been asked to clarify the details of its legal advice.
Along the south coast on Wednesday crews were warning people to stay out of the water and keep off the beaches, where sewage could wash up. Earlier warnings were issued that the water may be off-limit for months. Amid it all, a pod of dolphins swam through the bay.
At one Lyall Bay food outlet, workers said business was down significantly.
“The flies around here have been crazy – big blowflies,” one worker said.
At Queens Drive Dairy, at the other end of Lyall Bay, Jay and Gita Parbhu said business was down about 60% and they had started closing an hour earlier.
“A lot of people are saying fix it as soon as possible,” Jay said. “It looks like a big job.”
MetService meteorologist Mmathapelo Makgabutlane confirmed a low pressure system was looking like forming north of New Zealand and it was “very much in the realm of possibilities” that it would track near Wellington on Sunday and Monday.
It had the potential to reach heavy rain warning levels – up to 100mm of rain in 24 hours hours or 50mm in six hours.
On the night of the initial breach, 33mm fell from 6pm Tuesday to 3am Wednesday,
Wellington Water also failed to answer questions about what precautions it was taking for heavy rain. It previously said that raw sewage may again have to be discharged just off the coast in heavy rain.
“We are proceeding with a high degree of caution, restricting flow to the long outfall with a current capacity of approximately 1300L/s alongside investigating options to increase flow capacity. This is comfortably accommodating the current flows at this stage, and if it rains the additional wastewater will be diverted to the short outfall,” a spokesperson said on Wednesday evening.
“We’re confident the combination of the long and short outfall pipes can continue to handle network flows, even in heavy rainfall, without further impacting the plant.”
In an earlier statement on Wednesday, it said it continued to remove “biological material” from the plant.
“Fresh water is being flushed through the biological treatment areas of the plant to reduce levels of hydrogen sulphide, which makes the interior of the plant hazardous to enter.”
The full impact of the flooding on the plant was still unknown but an extended outage was expected.
“Odour complaints have been received, and odour levels will be more noticeable while the plant odour and ventilation equipment is offline and screening is working in a temporary configuration. Odour will also be present during the removal of sludge from the plant,” the statement said.
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