Akaroa wastewater project blowout sparks community backlash

Thursday, 16 April 2026

The Akaroa wastewater scheme expected to cost $175 million - $77 million more than the budget set in the long term plan.

A group of Akaroa residents is accusing the Christchurch City Council of breaking promises and losing control of a wastewater project expected to cost nearly $80 million dollars more than first budgeted for.

At a workshop this week, councillors were presented with a series of money saving options for the Akaroa wastewater treatment scheme, which exceeded the $98 million budget set in the Long Term Plan with an expected bill of $175 million.

Friends of Banks Peninsula (FOBP) deputy chair Suky Thompson said the process had been flawed from the start.

“The community has lost confidence in the council process given the major blunders that have occurred over the years.”

Friends of Banks Peninsula (FOBP) deputy chair Suky Thompson says council broke promisses made for residents.

Last year, the group and mana whenua clashed on the issue, with Rik Tainui, chairperson of mana whenua Ōnuku Rūnanga, urging support for a project that was “urgently needed” to protect Akaroa Harbour.

Council’s Head of Three Waters, Gavin Hutchison, said rising construction costs — an estimated increase of 40% — and new government regulations had forced a rethink.

Senior council engineer Kylie Hills said they assessed more than a dozen alternatives, narrowing them down to five main options.

The four land irrigation options — a process of harnessing the nutrients in wasterwater and spreading on the ground — involved scaling back key parts of the original proposal, including reducing storage, shrinking irrigation capacity, and in some cases relocating the treatment plant across Old Coach Road.

Under the most expensive of these, the system would retain 16,000 cubic metres of wastewater storage and keep the plant in its current location, at an estimated cost of $160 million.

Christchurch City Council Chief Executive Mary Richardson, mayor Phil Mauger and Head of Three Waters Gavin Hutchison will be part of discussions about the Akaroa wastewater treatment scheme next week.

At the lower end, reducing storage to 4,000 cubic metres and relocating the plant could bring costs down to about $136 million.

The fifth option of discharging treated wastewater into the harbour via a 2.7km pipeline would cost an estimated $127 million, making it the cheapest, but it was also the most contentious, leading staff not to recommend it.

Hills acknowledged the difficult decision faced by councillors and said cost saving options were still being looked at.

“One particularly exciting one is, rather than running pipelines down the road … we could lay the pipelines down in the harbour as we do in Lyttelton Harbour … there is certainly a big gain in not having traffic disruption.”

A sign outside the existing Akaroa wastewater plant warns of downstream effects.

Mayor Phil Mauger challenged the size of storage versus financial outlay, also questioning the savings to be made by moving the plant to the other side of the road.

Hills replied that about $10m could be saved by moving.

Councillor Aaron Kew questioned the council’s liability in the event of over-irrigation or a landslide.

“Is there insurance that would cover the cost of it? Would we get our whole $160-odd million back?” he said, with staff saying they did not know the answers but would come back with them soon.

Councillors were expected to consider the options at a meeting next week, but for Thompson the whole situation was a “disaster waiting to happen.”

The proposed savings greatly magnified the environmental risks, she said.

Thompson also criticised the overall cost of the project.

“As there are only 1,200 properties being served, this works out at over $141,000 per property. At a time when the council is increasing rates by 8% per annum, this is a staggering waste of ratepayer funds.”

The Press was unable to contact Rik Tainui to clarify Ōnuku Rūnanga’s position.