The charges cover two periods of alleged offending – between October 2025 and January 2026 and from the failure of the treatment plant in early February 2026 through to subsequent discharges connected to that failure.
Five charges cover unlawful discharges from the plant and five relate to alleged breaches of an abatement notice.
Greater Wellington Director of Strategy, Policy and Regulation Fathima Iftikar said they do not take enforcement against public organisations lightly.
“No matter how important the service, or who owns or operates it, the obligation to comply with environmental law remains the same.
“People should be able to trust that environmental rules protecting the coastal marine area will be upheld by both public and private entities.”
In a statement, Wellington City Council said it “anticipated this was likely” due to the regional council’s responsibility as an independent regulatory body.
A spokesman said the city council will continue to co-operate and engage with the regional council throughout the court process.
Tiaki Wai chief executive Michael Brewster said it was notified of the charges and acknowledged impact on the environment and mana whenua, as well as the community and local businesses.
“We remain resolutely focused on recovering the plant as quickly as possible.”
Porirua Mayor Anita Baker meanwhile has hit out strongly at the choice to prosecute and said this level of financial compensation is unheard of in New Zealand.
Baker supports consequences for the disaster but said the decision “to pit ratepayer dollar against ratepayer dollar is unforgivable”.
“The loser will be our water services, our ratepayers and the credibility of Greater Wellington Regional Council, and by association all of us.”
Moa Point is scheduled to be fully operational again by next February.
Grace Symmans is Wellington-based reporter who covers news in the capital. Grace joined NZME in 2025 as a producer for Wellington Mornings on Newstalk ZB. She can be emailed at grace.symmans@nzme.co.nz.