MEDIA RELEASE 19 June: The preferred location, consenting approach and treatment standards for a new wastewater treatment plant have been confirmed, marking a major step forward for the project.
The Southern Wastewater Treatment Plant will support a fast-growing region, strengthen the resilience of the wastewater network, and help protect the long-term health of the Waikato River.
IAWAI – Flowing Waters board members made several key decisions on the project yesterday (18 June 2026), including selecting 131 and 139 Raynes Road in Rukuhia as the preferred site for the new Plant and confirming the project would be submitted for fast-track referral.
The board also confirmed:
- the Waikato River as the preferred re-entry environment for highly treated water from the Plant
- three potential locations for re-entry for further investigation in partnership with the Kaitiaki Roopuu, and
- the minimum wastewater treatment standards to be adopted for all IAWAI wastewater plants in the future.
IAWAI Chief Executive Peter Winder said the decisions were a significant milestone.
“The new wastewater treatment plant is critical to future‑proofing our wastewater network and managing the rapid growth we are seeing across the region,” he said.
“It’s not only about managing growth, but also about improving the resilience of the network, which is currently under pressure, and delivering better environmental outcomes.”
Winder said the new Plant represented a “best for river” approach to wastewater management and gives effect to Te Ture Whaimana o Te Awa o Waikato.
“Te Ture Whaimana sets a simple but powerful vision, to restore and protect the health and wellbeing of the Waikato River for generations to come. As a living entity, the awa’s wellbeing is central to the wellbeing of us all.”
“The new Plant will contribute to this by using leading treatment technology to clean wastewater to a much higher standard than we have today.”
The new wastewater treatment standards are consistent with the high treatment performance now in place at the upgraded Cambridge and Raglan plants, and align with IAWAI’s commitments and obligations to Te Ture Whaimana.
IAWAI General Manager Growth and Delivery Andrew Parsons said the organisation is working in partnership with a dedicated Kaitiaki Roopuu to ensure mana whenua and iwi are represented at all levels of project decision‑making.
“This is a significant project in many ways, including the partnership approach we have taken with mana whenua, who have been involved at all stages of the project including identifying a preferred site and shaping environmental outcomes.”
Parsons said the next step for the project included sharing the draft Plant design and information about the re-entry pathway for water from the Plant back to the environment with the community.
“We will be taking a proactive and no surprises approach to speaking with and working alongside the community as we progress with this important piece of work.
“This will include seeking feedback on what the buffer area surrounding the Plant should be used for. This is a large area and there are plenty of opportunities for things like native planting, wetland restoration, and community amenities such as walking and cycling networks.”
The decisions provide certainty on core elements of the project – location, treatment standards and consenting approach. Future decisions will be made on construction phases and timing. The project supports a new, boundaryless approach to managing wastewater across Hamilton, Waikato, and Waipaa, and is a key part of IAWAI’s $3 billion 10-year capital works programme.
