Hamilton City Council
Te kaunihera o Kirikiriroa
The proposed wastewater treatment plant, south of Hamilton, is part of a new way of delivering long-term wastewater services across the territorial boundaries of Hamilton and Waipaa.
Suburb City-wide
Status Underway
Programme City wide waters
The Southern Wastewater Treatment Plant is part of a new, boundaryless approach to managing wastewater across Hamilton, Waikato, and Waipā. By focusing on the awa (river) as a whole and planning for our region’s future growth, this project puts what’s best for the river at the heart of every decision.
It’s one of five projects endorsed through the Southern Metro Wastewater Detailed Business Case (the DBC). Hamilton City Council is the lead council for this project and is working in close collaboration with iwi, mana whenua and Waikato and Waipā councils.
The Waikato region has seen and is forecast to continue seeing tremendous growth and development in residential, commercial, and industrial areas.
This is placing pressure on existing wastewater services at Hamilton’s only wastewater treatment facility in Pukete and creating further demand for wastewater treatment and management services in the sub-region.
Over the past five years, Hamilton City Council, Waikato District Council, Waipā District Council, Waikato-Tainui and mana whenua have looked at the future wastewater servicing needs across the Waikato Metro area (from Taupiri in the north through to Cambridge and Te Awamutu in the South). That work has delivered an agreed servicing strategy including major investments at the Cambridge and Pukete (Hamilton) wastewater treatment plants. This has also confirmed the need for a new plant in the south of Hamilton.
By delivering a “best for river” wastewater management solution for the region, this new Plant will directly contribute to achieving the vision and objectives set out in Te Ture Whaimana o Te Awa o Waikato – the Vision and Strategy for the Waikato River.
This project recognises and provides for the unique relationship that tangata whenua have with the awa and is underpinned by a partnership approach. We’ll uphold treaty-based partnerships through ongoing collaboration, co-design and joint decision making by council and mana whenua representatives.
IAWAI - Flowing Waters is leading the delivery of the Southern Wastewater Treatment Plant project on behalf of the project partners. IAWAI is collaborating with mana whenua, iwi, Hamilton City Council, Waikato District Council and Waipā District Council to develop and deliver the project.
Hamilton City Council is the lead council for the Southern Wastewater Treatment Plant project. The successful delivery of the project relies on the existing budgets, systems, and human resources from Hamilton City Council. From 1 July 2026, IAWAI – Flowing Waters will be fully responsible for delivering the project alongside the project partners. This project forms part of a significant long-term infrastructure investment programme being managed by IAWAI, the new water services entity serving Hamilton and Waikato communities.
To uphold commitments under Te Tiriti o Waitangi, the Joint Management Agreements (JMA) with Waikato-Tainui, and to advance Te Ture Whaimana o Te Awa o Waikato, a shared governance approach has been adopted for the delivery of this once-in-a-generation infrastructure project.
This approach ensures mana whenua and iwi are represented at all levels of project decision-making through a dedicated Kaitiaki Roopuu. The Roopuu has played a pivotal role throughout the project, including the selection of the preferred site for the treatment plant and the identification of a shortlist of discharge options for further consideration.
The Southern WWTP project is located within the Waipaa District, where Waipā District Council is the relevant Territorial Authority. As a partner in the Metro Wastewater Detailed Business Case, Waipā District Council is leading several key initiatives from the DBC, including the upgrade of the Cambridge Wastewater Treatment Plant. The Southern WWTP is expected to serve areas of Waipā, Hamilton and Waikato in the future. Waipā District Council, together with Waikato Waters Limited, continues to work alongside IAWAI, Hamilton City Council, mana whenua, Waikato-Tainui, and Waikato District Council to support the development and delivery of the Southern WWTP project.
Waikato Regional Council is the regulator and will be processing the regional resource consents (in particular discharge to land / air / water).
Focussed investigations for the new Southern Wastewater Treatment Plant started in 2022. This built on early site selection work undertaken to support the detailed business case in 2020/21. As part of this, a site selection assessment was undertaken to determine the best location for the Plant . Through this process, eight potential site options across Hamilton City, Waikato District and the Waipā District were considered, with four sites taken forward to the shortlist.
Site selection was thorough and involved both technical and cultural investigations. Some of the key criteria included:
Proximity to Hamilton airport and the Waikato River
Proximity to the future servicing area (south Hamilton, Tamahere and Maatangi villages, Tauwhare Paa)
Any existing utilities infrastructure
The size of the site, with a minimum requirement of 20 hectares and a desire to ensure a significant buffer between the Plant and neighbouring properties.
The site topography, with flatter terrain preferred
The existence of waterways (as a possible discharge method)
Whether there are culturally significant areas or findings on a site.
Through that process a preferred site was identified. The preferred site is Council-owned land at 131 Raynes Rd. It is a large site, 34 hectares, and was chosen through a process of elimination from seven other potential sites. The preferred site is in an ideal location for future development areas, is large enough to provide a significant buffer between neighbouring properties, has access to power and communication services, and good topography with no significant natural features or known archaeological sites.
The timing of construction of the new Plant is not confirmed but could be expected in the next decade. What we are doing at this stage is protecting the land for future use and providing more certainty to the community as to where the Plant and its associated treated wastewater discharge will be located.
This includes creating a concept design for the new Plant which will determine its exact location, layout and appearance and incorporating features to manage concerns such as potential odour and noise. We will also create a master plan for the whole site which will consider what we use the land surrounding the Plant for.
Once these steps have been completed, we will be lodging a notice of requirement for a designation and the related consents under the Resource Management Act 1991. It may take up to two years for us to reach this point of lodging the notice and resource consent applications.
A future where a healthy Waikato River sustains abundant life and prosperous communities who, in turn, are all responsible for restoring and protecting the health and wellbeing of the Waikato River, and all it embraces for generations to come.
2022 - 2024
Project set up and site selection2025-2027
Planning and consentingTBC
Design and buildThere are many ways that wastewater treatment processes can be set up.
Yes, there are plenty of examples of wastewater treatment plants around the country.
Three examples of wastewater treatment plants include:
Click on the links to find out more about these plants, what they look like and how they operate.
There are a number of potential impacts we consider when designing a new wastewater treatment plant. These include but are not limited to:
Visual impacts
To understand and mitigate visual impacts on surrounding properties:
Odour
To understand and mitigate the effects of odour on surrounding properties:
Noise and vibration
To understand and mitigate the potential effects of noise and vibration on surrounding properties:
Traffic
To understand and mitigate the potential effects of traffic on surrounding properties:
Click on the PDF to see other effects that are considered during the design process.
To identify and then manage any potential effects from the new Plant, we’ll:
Step 1: carry out baseline environmental assessments to understand the current condition of the site and the surrounding environment before any development happens. This includes looking at things like noise, landscape, odour, traffic, cultural effects, ecology and archaeology. This assessment creates a starting point or “baseline” so that future changes can be measured and managed responsibly.
Step 2: start designing the wastewater treatment plant (plant design) and the surrounding area (master plan), looking at how the plant could be built and developed over time. These draft plans will go through multiple revisions as part of an ongoing process. You’ll have the chance to share your thoughts and help shape the master plan in mid-2026.
Step 3: once we have an initial design, we’ll go back and carry out further assessments to understand potential impacts that design may have on the surrounding environment and look at measures to avoid or reduce them. These could include things like plants, thoughtful building design, odour controls and noise management. An important part of this step is reconnecting with landowners to hear their views and understand what matters most to them.
Step 4: once we have a draft design and master plan, we will share this with the wider community and seek their input into the master plan (surrounding area). We’ll also reconnect with landowners to share how their feedback has helped shape our plans.
Step 5: once we have a finalised design and master plan, we then prepare and lodge a Notice of Requirement which will allow us to designate the site - this means earmarking it for future use for the wastewater treatment plant. This is a formal planning step that helps provide certainty to landowners and the wider community around the location of the Plant and sets out rules for how it can be used. We will share this with the community when it is lodged.
Yes, these include:
Ecology and biodiversity: there will be opportunities to plant natives and encourage wildlife to the area, especially along the Nukuhau Stream and its small tributaries. This could include planting along the stream (riparian planting), helping fish move more freely, creating or enhancing wetlands, and adding natural features such as logs, rocks, and roosts for wildlife and birds. We’ll explore planting options that not only look good but also support biodiversity.
Cultural restoration: Cultural restoration opportunities will be identified with mana whenua through a Tāngata Whenua Effects Assessment process (TWEAR). This provides a meaningful way to share cultural values and stories connected to the land, waterways, airspace, sacred sites, and people. This tikanga-informed design approach builds cultural narratives, and kaitiaki (guardian) roles in monitoring and beyond for the project.
Buffer zone: There is also an exciting opportunity to shape the area surrounding the Plant. The extent of this area is not confirmed yet and will be determined through the design process. While some of this space will be used for planting and ecological restoration, we’re keen to hear from the community and taangata whenua about other potential uses. Ideas like walking and cycling paths could help make this area a valuable and enjoyable space for everyone.
One of the key areas our technical team are considering is how highly treated wastewater will be discharged from the Plant.
Our team, together with the Kaitiaki Roopuu, recently held an optioneering workshop to review and assess shortlisted discharge methods and locations. No decision has been made yet, but the three options currently being considered include:
While these broad options have been short-listed, the feasibility of each option, potential location and what they might look like has yet to be developed. The final approach may involve one or a combination of these options.
We’ll be coming back to the community in 2026 to share our progress in this space.
The Southern Metro Wastewater Detailed Business Case (DBC), completed with partners Waikato Tainui, Waikato, Waipā, and Hamilton councils, identified the Southern Wastewater Treatment Plant as part of the preferred servicing strategy.
Building on the previous site selection assessment in the DBC, four locations were shortlisted with partners, including mana whenua. Ecological, cultural, archaeological, and geotechnical investigations were completed. Discharge options were evaluated, with a short list selected for further review.
Funding approved in Hamilton City Council’s 2024-2034 Long-Term Plan to progress the concept design, site master plan, designation and consenting for the project.
131 Raynes Road was formally selected as the location for the new plant in collaboration with project partners.
Beca Limited appointed as the consultant team to lead the concept design, site master plan, designation and consenting for the project.
An initial outreach to landowners living near the project site and to stakeholders was carried out to share information about the project.
IAWAI – Flowing Waters established and contracted to act as agent for Hamilton City Council and Waikato District Council on Major Transferred Projects including the Southern WWTP.
Ongoing conversations with mana whenua, landowners and stakeholders.
Community information sessions held on 5 and 6 November 2025 at the JetPark Hamilton Airport Hotel and Conference Centre, giving the community a chance to meet the project team, learn more about modern wastewater treatment, and the process of designing and consenting a wastewater treatment plant.
The community will have an opportunity to share their views on what the site surrounding the plant could be used for.
Feedback received during the consultation period will be reviewed and used to inform the design.
The concept designs for the site will be finalised and shared with the community.
Ownership of the project will pass to IAWAI. Hamilton City Council will continue to be involved in the project.
IAWAI will lodge a notice of requirement to designate the land for the future construction of the plant. Consenting and planning approvals will also be submitted.
Post-lodgment, IAWAI will continue to provide regular updates on the project.
We're looking at a new way of delivering water services across the Waikato Metro Area. Hamilton City Council and Waikato District Council have just approved forming a joint waters Council Controlled Organisation (CCO). From 1 July 2026, the CCO will be responsible for delivering drinking water and wastewater services. They will also manage projects including the Southern Wastewater Treatment Plant. You can find out more here.
We looked at several different locations as potential sites for the new Plant in the east and south of Hamilton and around the Airport precinct.
After assessing each site against a range of technical requirements, as well as a comprehensive cultural assessment, we have a preferred option – parcel of Council-owned land, south of the city boundary, at 131 Raynes Rd.
You may be aware that Hamilton City Council purchased land in 2022, which is now the preferred site for the project. This land purchase was an opportunity for Council to obtain property in a strategic growth area. The property was purchased to enable broad community outcomes, with several possible uses for the land, including the Southern Wastewater Treatment Plant. In March 2025, after thorough investigations, the property was determined to be the preferred site for the plant.
The next step in the project is to develop a concept design which will determine what the Plant looks like and what features will be included to manage concerns such as noise and odour.
What we do know is:
Information on the design, layout, and how potential impacts will be managed will be shared through regular project updates as the project progresses. Sign up to receive regular updates or check the webpage for updates.
We've started engaging with nearby landowners and key stakeholders on our preferred option for the site. There will be an opportunity for the wider community to have their say when we begin the process to designate the land. We’ll also ask for community feedback on other aspects of the project, including the design and layout.
The concept of a new wastewater treatment plant south of the city is not new, but until recently, we haven’t had funding to progress it. We have only recently selected a preferred site after extensive investigations into a number of possible locations.
Southern Metro Wastewater – Detailed Business Case Summary
Southern Metro Wastewater DBC – Preferred Option Report
Southern Metro Wastewater DBC – Site Selection Options Report
Southern Metro Wastewater DBC – Short List Options Report
Southern Metro Wastewater DBC – Long List Options Report
Southern Metro Wastewater DBC – Benefits Realisation Plan
Southern Metro Wastewater DBC – Consenting Strategy
Southern Metro Wastewater DBC – Conveyance Options Report
Southern Metro Wastewater DBC – Wastewater Treatment Shortlist Options Report
Last updated 18 November 2025