Ōrākei Main Sewer repair and relining

Project overview

The current works on the Ōrākei Main Sewer’s rehabilitation involves the construction of a deep shaft in the northern section of Alberon Reserve and relining of the sewer between manholes 14 and 15 (refer map above) with glass reinforced plastic liner. This technology will enable the sewer to continue in service for another 100 years.

Current updates

• The construction of our shaft down to an approximate depth of 13 metres in Alberon Reserve to access the sewer was completed in early 2025. The construction involved completing the shaft in sections, with timber poles and large steel beams used to provide structural support.

• Unfortunately, due to the heavy rain fall we have experienced this winter our crew have not been able to progress our grouting works as much as possible.
• As of late July, we estimate that our crew has approximately 28 more night shifts to complete the remaining grouting work on site.
• Once we complete the grouting we will then move on to final reinstatement works in Alberon Reserve.

• Parking restrictions are currently in place on the corners of Alberon Street, between 10am and 3pm, Monday to Friday. This is required to allow heavy vehicles to deliver equipment. Please refer to map below.

Alberon Reserve walkways and access

During construction, Alberon Reserve walkways will remain open, however, there will be sections of the reserve that will be fenced off for health and safety reasons. Access between Alberon Street and Saint Georges Bay Road will remain, as well as the pathway between Alberon Place and Havana Coffee. The southern section of the reserve will remain open for normal recreational use.

Future works - update on the Ōrākei main sewer relining programme

When the Ōrākei Main Sewer collapsed in Parnell in late 2023, we quickly implemented a solution involving relining the existing pipe. This innovative approach allowed us to stabilise the pipe and prevent further collapses.

After completing these initial emergency works, we began relining an adjacent section of pipe that needed preventative maintenance. This was between manholes 14 and 15 by Alberon Reserve in Parnell (the work highlighted above).

We intended to continue using this methodology to rehabilitate further sections of the sewer – from Auckland Domain to Hobson Bay, as well as a section by Queen Street which was to be relined as part of our Midtown Wastewater Diversion project.

However, despite the initial success, the relining solution has not proven to be the easy fix we had hoped for. The team has identified several challenges, including working in a live sewer, manoeuvring the lining material around bends, and the sewer's depth (which can reach 40 to 50 metres below ground in some locations).

Given these challenges, our Board has approved a change in approach. We are now reevaluating our options for rehabilitating or replacing this part of the sewer, including a potential new tunnel alignment.

In reconsidering the approach we are:

• Addressing the complexity of the work and developing the best solution to continue providing wastewater servicing for the next 100 years.

• Aiming to identify options that will decrease impacts and disruption to the local community.

We will carry out regular monitoring and maintenance of the sewer while a solution is planned and commissioned, and will keep the community informed as the project progresses.