Councillors demand review after Wellington sludge plant budget blow-out

Wednesday, 20 August 2025

Some Wellington city councillors are demanding immediate independent reviews to understand the $83 million cost blow-out at the Moa Point sludge minimisation plant, and avoid making “the same mistake again”.

But with a review scheduledfollowing the project’s completion in 2027, staff say council needs to “get on and deliver” the project, and the overrun was a risk that was part of delivering “big, complex projects”.

Councillors were told last week that the project, originally slated to cost $200m in 2021, would now cost between $478m and $511m.

Councillor Ben McNulty and Diane Calvert’s amendment is similar to the independent review Calvert called for when the Town Hall jumped by $140m in a single year, ultimately voted down following then chief executive Barbara McKerrow’s advice.

But councillor Rebecca Matthews said the move was a “knee jerk political response,” with two Treasury Gateway reviews done and another planned this November, as well as the governance review after its completion.

The council will meet on Wednesday to vote through the additional funding to the Moa Point sludge plant, and also approve the Water Services Delivery Plan for the region’s new water company.

McNulty said waiting years to commission a review was “simply not a serious option”, and if council wanted to continue with projects such as the Golden Mile there needed to be every assurance lessons had been learnt.

“Council's current fiscal situation means that every dollar a project goes over budget requires that a dollar is pulled from something else. We learnt this lesson the hard way with the Town Hall whereby funding its completion we deferred replacing pipes.”

Calvert said if the Town Hall review had gone through, there would likely have had better advice on risk management and governance.

“We cannot afford to repeat the same mistake again.”

Calvert said council chief executive Matt Prosser promised a review after the closed session where news of the overrun emerged, but gave no time frame.

Chief infrastructure officer Jenny Chetwynd told councillors in a briefing on Tuesday the purpose of any more reviews needed to be “very careful and clear,” and council was covering all bases.

She said the fundamental drivers of costs could not be avoided. “You took the risk on … they’ve just come to fruition, they’ve just happened and that is just part of delivering big, complex projects.”

But there were “big learnings,” such as the importance of having business owners identified at the start of costings.

Councillor Tim Brown is also calling for an independent Consumer Advocacy Group on water costs, financially supported by council to represent Wellington consumers and residents.

At present, an in-house advocacy group will be set up to financially assist low income households, monitor adverse impacts of the move to a user pays system on water, and scrutinise the group.

But Brown said the structure for the group largely replicated what was already in place, where rising costs, poor service delivery, and inefficiency had been a hallmark of the past decade, with water rates more than doubling in that time and forecast to almost triple over the next eight years.

The proposed group would look into Metro Water’s plans and activities and provide independent reporting and advice; ensure that consumers’ interests were well and clearly represented; and protect council from being blamed for charges and activities council had “next to no influence”.