Herne Bay wastewater trunk sewer upgrade

A project aimed at delivering cleaner waterways and beaches by 2028.

Start-finish: 2024 – 2026
Location: Herne Bay
Status: Planning
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Latest project update

Herne Bay resource consent application  

The resource consent application for the construction of the Herne Bay wastewater trunk sewer was submitted on Friday 30 June 2023 to Auckland Council for assessment.  The resource consent application was publicly notified on 5 September and was open for submissions until 3 October 2023. Thank you to everyone who made a submission on the resource consent application.

Please click the links below to view the resource consent documents for the project:

Background of the original St Marys Bay/Herne Bay separation projects  

The original proposal focused on separating the old, combined stormwater and wastewater pipes directing stormwater to the environment and wastewater to the Māngere Wastewater Treatment Plant via the Orakei main. The project included a new public wastewater network, storage and a new pump station at Point Erin as well as private drainage separation and connections. 

We had to unfortunately defer this project due to an unaffordable escalation in costs. The work has been heavily impacted by geotechnical design issues and escalating material, labour, and traffic management costs. The result has been a doubling in the original forecast.  

We remain committed to delivering a solution for the ongoing wastewater overflow challenges and have been working closely with Auckland Council to find an alternative which will allow us to deliver cleaner beaches and waterways by 2028 while remaining committed to separation in the longer term.

The proposal

Read our frequently asked questions

The proposed Herne Bay trunk sewer will support the extension of the Central Interceptor (CI) wastewater conveyance and storage tunnel from Tawariki Street in Grey Lynn to a new drop shaft in Point Erin.  

In parallel with the CI extension, the Herne Bay trunk sewer will ensure combined overflows are picked up and conveyed to Māngere Wastewater Treatment Plant for safe treatment, reducing overflows to the environment and improving the quality of waterways and swimmable beaches by 2028.  

An overview of the Herne Bay wastewater trunk sewer is as follows:  

  • The proposed new pipelines are primarily 2.1 metres in diameter and will be constructed via a tunnel boring machine underneath the road. Approximately 8 shaft locations are required for this trenchless construction method. Please refer to map below showing the exact location of the proposed works.

  • For small diameter pipelines as part of the proposal along Marine Parade (600mm in diameter) and local connections to the existing engineering overflow points (between 200mm to 450mm in diameter), these pipelines will be constructed via open trenching.

  • Construction will occur sequentially over different road sections. The total construction period will take approximately 18 months. We will provide more specific details closer to construction.

  • The map below shows the proposed work area:

Herne Bay wastewater trunk sewer map

What is the timeline for the proposed works?

The Herne Bay wastewater trunk sewer will be constructed between 2024 to 2026. Closer to the construction dates we will provide more specific dates. Please refer to timeline below. Please note, these dates are only an estimate and are subject to change.

Herne Bay wastewater trunk sewer upgrade timeline

Point Erin Central Interceptor extension: Park infrastructure works

We are proposing new works in Point Erin Park to help reduce wastewater overflows onto local beaches. Find out more about the works here.

Point Erin CI extension timeline

Any questions?

Please email [email protected]


Herne Bay newsletter August 2023

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