Midtown wastewater diversion

Project overview

In September 2024, we set up the compounds where three shafts were constructed, on Mayoral Drive, Wellesley Street East and Victoria Street East, plus a storage area on Grey’s Avenue. Our 1.35m-diameter Tunnel Boring Machine (TBM) has now constructed a new 600m long wastewater pipe beneath Queen Street, linking the three shaft sites.

Work is in progress at Victoria Street East where we will shortly connect the new pipeline to the existing Ōrākei main sewer (OMS). From here, wastewater will flow on to Watercare’s Māngere wastewater treatment plant.

Our current timeline to complete all our work and reinstate the roadways and footpaths in April 2026.

Mayoral Drive to Marmion Street extension

Stage 1: Service relocations (March to August 2026)

For some six months, our contractor will relocate a range of services (fibre, gas, electricity and (waste)water supply etc) inside new compounds set up on Queen St (see map below). Work will involve five stages, with each stage in a different location within sites located from opposite Waverley Place down to the corner with Mayoral Drive. For all our sites, we will erect temporary fencing, noise mats and pink way finding signage.

Stage 2: Shaft construction (August 2026 to January 2027)

(We will update these sections before the works begin.)

Key facts:

• Hoarding installation (approximately 60m long and 10m wide) and temporary barrier installation

• Shaft construction: piling, excavation, shotcreting, pipe connections

• Mostly dayshift with some nights for CCTV of manhole and pipes, survey and bringing in equipment

• Shaft approximately 14m deep, 4.9m internal diameter

Stage 3: Pipe jacking (February to March 2027)

Key facts:

• Pipe jacking launched from within the base of the Marmion Street shaft

• Duration of approximately one week only

• Complete the tie-in to a smaller manhole adjacent to the Marmion Street shaft

• Site reinstatement

Stage 4: Mayoral Drive site compound re-establishment (February to March 2027)

We will reoccupy the existing main project compound at the corner Queen Street and Mayoral Drive, for a short time, at approximately two-thirds the size of the current site.

Key facts:

• Pipe-jacking will be received at the Mayoral Drive site

• Asphalt surrounding the Mayoral Drive manhole will be removed to provide more space to manoeuvre. Most of this stage of works is at Marmion Street so there will be minimal noise at Mayoral Drive

• Reinstatement of asphalt around the manhole lid and road and footpath restoration

Stage 4: Permanent Manhole Completion at Marmion Street (April to August 2027)

Key facts:

• Shotcreting internal shaft walls

• Removal of the hoardings (approximately April-May 2027)

• Manhole connections

• Site demobilisation

• Reinstatement of the road including the traffic island

Stage 5: Decommissioning of redundant services along Queen Street (August to September 2027)

Key facts:

• Staged approach to reduce the impact on the traffic along Queen Street

• Three work stages of approximately two weeks each

• Grout filling of redundant pipes and manholes

• Removal of manhole lids under the road surface

• Road reinstatement

Stage 6: Closeout and completion (October 2027)

Map of the works areas

The map shows the areas where the project team will be working.

How will this work affect you?

Work hours

• Between 7.30am and 6pm, Monday to Saturday, including some statutory holidays. Occasionally, nightworks will be necessary and are typically between 8pm and 5am. These works include tying in new infrastructure into existing wastewater systems (we need lower flow levels where our staff members will work) and for hydrovacing, using pressurised water to break up soil, which is then vacuumed up.

Traffic management

• Will be in place 24/7 during construction for the safety of the public, traffic and our workers. Our traffic controllers will be on site to assist anyone who needs it. We will maintain a two-way traffic flow on Queen Street though lane reductions will be in place. Similarly, the footpath will remain open though it too could be narrowed at times.

Noise and vibration

• Construction works generate noise and vibration. We are conscious of the effects noise can have on near neighbours and will work with you to keep noise to a minimum. Construction noise levels will be in accordance with Auckland Council and consent requirements.