South-west wastewater upgrade

Project overview

As the south-west of Auckland develops we need to expand our wastewater treatment infrastructure to support population growth in Waiuku, Glenbrook Beach, Clarks Beach and Kingseat. The treatment plants currently serving these communities are coming to the end of their operational life and the area is growing. We are developing a long-term solution that will support growth through to 2050. By then 30,000 people are expected to live in the area. We are committed to improving the Manukau Harbour and to do this we will be using state of the art technology to significantly advance the quality of treated wastewater. Some of this technology is currently being installed at Clarks Beach where we are delivering an upgrade project while we wait for a long-term solution to be delivered.

History

Our plan has previously been to replace these plants with one larger facility that can meet the needs of 30,000 people. In 2023, we purchased land in Glenbrook and lodged a Notice of Requirement with Auckland Council to designate it for wastewater treatment purposes. Council referred it to a panel of independent commissioners for review.

In late May 2024, the independent panel of commissioners recommended we withdraw our Notice of Requirement. After reviewing the commissioners’ feedback, we decided not to pursue the designation of our land in Glenbrook for wastewater treatment purposes at the time.

Long-term solution

We are currently seeking to find a sustainable, affordable and appropriate long-term solution that can deliver environmental benefits while allowing for growth. Alternative options, including our Waiuku, Clarks Beach and Glenbrook sites are being considered as we revisit the planning/feasibility stage.

Short list options

We now have four proposed short list options thanks to your initial feedback and a multi-criteria analysis (MCA). A MCA looks at the pros and cons of each option against a wide range of criteria, such as: heritage, social and community, natural environment, landscape/visual, highly productive land, constructability, operability, greenhouse gases, resue of treated effluent.

The results from each MCA get combined with feedback from the community which help to inform the decisions made by our project team.

Long list options

Our team identified eight potential options. These included:

• Four centralised options at our current Waiuku site or adjacent land

• One centralised option at the Glenbrook Beach Road site (372 Glenbrook Beach Road)

• Three decentralised options treating wastewater at more than one location - a combination of Waiuku, Glenbrook Beach, Clarks Beach

Each option includes the treatment plant location as well as the conveyance (via pipelines and pump stations) of raw and treated wastewater from the community to the treatment plant and ultimately to the outfall in the Manukau Harbour that is currently being constructed at Clarks Beach.