Grey Lynn tunnel

The tunnel will connect Orākei main and Grey Lynn sewers.
Start-finish: Late 2022 – 2024
Location: Western Springs to Tawariki Street, Grey Lynn
Status: Planning

What’s happening?

The works at the Tawariki Street site will commence in 2023 as part of the Central Interceptor project. The tunnel will be created (by machine) 15-60 metres underground from an existing site at Western Springs.

A new construction site will be required at Tawariki site, where we will create a shaft to extract the machine once tunnelling is complete, and connect into local sewers which are at capacity when it rains. The main works at this site will be the shaft construction which is expected to take eight months to complete. The total construction will take approximately two and a half years to complete which will include, operational structures, removal of the tunnelling machine, closing the shaft and  commissioning the tunnel.

Details of the works will be confirmed closer to the time of construction.

What are the benefits?

  • A reduction in diluted wastewater overflows in the Grey Lynn area, resulting in better water quality and surrounding environment

  • It will help cater for the growing Auckland population, now and for the next 100 years

  • To enable future connections and continued improvements to the wastewater system in the area

  • The tunnel will be constructed by tunnel boring machine underground to limit effects on residents along the pipeline route.

How will this work affect you?

Tawariki Street construction site

  • Work hours at the shaft sites will be between 7am-6pm Monday to Friday, and 8am-6pm Saturday.

  • At the Tawariki site, works will involve up to five truck movements an hour during peak construction specifically during the creation of the shaft.
  • There will be some noise and traffic around construction sites, however, we will ensure this is kept within Auckland Council consent requirements.

  • Traffic management will be in place at the site and on truck routes to minimise safety risks to road users. The works may at times affect street parking.

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  • Due to the tunnel being built deep underground (between 15 -60m deep), there are no effects on properties above the tunnel route. Vibration from tunnelling is unlikely to be felt by residents above the tunnel when the machine passes beneath.

Any questions?

Please contact:
Jennifer Charteris
Stakeholder advisor
Phone: 021979803

Supporting documents

Grey Lynn tunnel - Notice of requirement, resource consent application and assessment of environmental effects
Appendix A: Land requirements plan
Appendix B: Certificates of title
Appendix C: Schedule of properties on tunnel route
Appendix D: Tunnel long section
Appendix E: Tawariki Street shaft site layout plans
Appendix F: Assessment of alternatives report
Appendix G: Objectives and policies assessment
Appendix H: Proposed conditions
Appendix J: Archaeological heritage assessment
Appendix K: Traffic impact assessment
Appendix K: Traffic impact assessment with updated parking plan
Appendix K: Updated parking plan
Appendix L: Noise assessment
Appendix M: Vibration assessment
Appendix N: Groundwater assessment
Appendix O: Settlement assessment
Appendix P: Air quality assessment
Appendix Q: Contamination report
Appendix R: Visual impact landscape assessment
Appendix S: Arborist report
Appendix U: Flyer to landowners
Grey Lynn Tunnel wastewater upgrades flyer (February 2018)