The Commerce Commission is considering seeking stronger powers over Wellington’s water services, after a catastrophic failure at the Moa Point wastewater treatment plant.

The economic regulator, which oversees the water sector, has expressed concern over Wellington Water’s performance.

Commission chair Dr John Small said the organisation is assessing whether “additional regulatory oversight” is needed of Tiaki Wai, the new water entity set to replace Wellington Water from July.

“Our immediate priority is to consider whether Tiaki Wai needs stronger rules, beyond the current and planned reporting requirements, to ensure water services are well managed and provide good value for money in the long term” Small said.

Under current rules, Wellington Water is required to publicly disclose key economic information in the name of increased transparency.

The commission is reviewing this information to assess Wellington Water’s performance, to consider whether more power is needed over Tiaki Wai.

Its analysis of earlier disclosures found increasing reactive maintenance costs, low confidence from Wellington Water in the accuracy of its reported data, and room for improvement in its Culture and Value for Money Plan performance.

Raw sewage from the Moa Point wastewater treatment plant washing ashore at Tarakena Bay, Wellington. Photo / Mark Mitchell

“The Commission considers additional, targeted information disclosure requirements on top of information disclosure for Tiaki Wai may be appropriate,” the organisation said in a statement.

Any further regulation would need to be approved by the Minister of Commerce and Consumer Affairs, in consultation with the Minister for Local Government.

The Commerce Commission was first called in to monitor Wellington Water in March last year after revelations it was not getting value for money in its contracts.

Local Government Minister Simon Watts said at the time he had “serious concerns” over Wellington’s water services.

The Commerce Commission took longer than necessary over the Manawa takeover. (Image: NZME)

It comes as untreated sewage continues to flow into the Cook Strait, after a serious failure saw the Moa Point plant flood and become inoperable.

The capital’s South Coast beaches are currently off limits, and are expected to remain so for months as the plant is fixed.

Wellington Mayor Andrew Little has written to Watts outlining his preferred option for an independent inquiry.

In a letter to the minister, provided to the Herald, Little said the unconsented discharge is “very serious” and a Crown Review Team should be established to get answers.

It would establish what the cause of the failure was, what damage it has caused, if it could have been prevented, whether the response was adequate, as well as looking into the governance, management, and contract arrangements in place at the time.

Ethan Manera is a Wellington-based journalist covering Wellington issues, local politics and business in the capital. He can be emailed at ethan.manera@nzme.co.nz.