Building the Waterview Connection in west Auckland involves a number of simultaneous construction projects, ranging from the diversion and upgrading of major services on the motorway route to construction of New Zealand’s longest road tunnels. The overall project employs between 800 and 1000 people in diverse roles on five separate sites including a state-of-the-art precast concrete manufacturing facility in East Tamaki, a managed landfill at Wiri in south Auckland, and the actual motorway route between Owairaka and Waterview.
Construction by zone
There are three distinct construction zones:
- Southern: Above ground works from Maioro Road to tunnels
- Tunnels: Underground works to build the twin tunnels
- Northern: Above ground works from tunnels to State Highway 16, including the Great North Road interchange
Southern construction zone
The Maioro Street to tunnels motorway link under construction.
The Maioro Street to tunnels motorway link under construction.South: the connection to SH20
The existing two-lane motorway between Dominion Road and Maioro Street is being widened to three lanes in the northbound direction
South: expanded Maioro Street interchange
The existing half diamond interchange will become a full diamond interchange. It will include:
- Northbound off-ramp (2 lanes leaving the motorway)
- Northbound on-ramp (2 lanes entering the motorway)
- Southbound off-ramp (1 lane leaving the motorway)
- Southbound on-ramp (2 general traffic lanes and 1 HOV/truck bypass lane entering the motorway)
South: under Richardson Road to the tunnels
State Highway 20 will be extended from Maioro Street interchange, with three lanes in each direction. Construction here includes:
- A new road bridge to take Richardson Road over the motorway (completed)
- A 6-lane bridge to take the motorway over Oakley Creek
- A pedestrian/cycle bridge over the motorway between Hendon Park and Alan Wood Reserve
- A high-sided trench to take the motorway down to the tunnel portals - the Southern Approach Trench
- Realignment of Oakley Creek, the Hendon sewer and major stormwater drainage infrastructure away from the motorway route.
Download the southern construction zone overview map .
Tunnels construction zone
An artist’s impression of the southern tunnel portals.
An artist’s impression of the southern tunnel portals.Two tunnels, each to carry three lanes of traffic, will be built between Owairaka (the Alan Wood Reserve) and Waterview. Construction includes:
- Bored tunnels 2.4km long, with a finished diameter of 13.1m, up to 45m below the surface
- 16 cross passages connecting the tunnels, carrying services and providing a safe refuge for users in case of an emergency
- Ventilation systems connected to ventilation buildings at the tunnel exits and, in turn, connected to ventilation shafts or stacks
- A tunnel operations centre located within the southern ventilation building (insert artist’s impression of the southern ventilation station)
- Monitoring, lighting, communication and fire suppression systems
- Utility service lines and tunnel drainage system accommodated under the roadways
Northern construction zone
The Northern Approach Trench is being constructed as a cut and cover tunnel.
The Northern Approach Trench is being constructed as a cut and cover tunnel.The connection in the north, between the tunnels and Northwestern Motorway will include:
- A trench (called the Northern Approach Trench) to tA ventilation station at the exit to house tunnel services including the fans that draw in air from the tunnel and transfer it to a vent stack approximately 120m away
- The vent stack
- Four new ramps at the Great North Road motorway interchange to provide connections between the tunnels and SH16.ake traffic to and from the tunnel portals, which will be 26 metres below the surface.
Work underway on the new ramps at the Great North Road Interchange.
Work underway on the new ramps at the Great North Road Interchange.The new ramps will be built in phases, crossing over the Northwestern Motorway (SH16) and local roads, as well as archaeological and coastal marine areas.
Construction milestones
These are the ‘big’ milestones of the Waterview Connection construction. Achieving them requires the culmination, on time, of many critical workstreams involving a huge amount of work.
Nearly two years into construction, the main milestones have been achieved on time – no mean achievement considering the diversity of the workstreams and the sheer size of the overall project.
Key milestones are:
| Date | Milestones |
|---|---|
| November 2011 | Agreement signed |
| January 2012 | Start of enabling works in the south |
| July 2012 | Start of construction in the south |
| December 2012 | Start of construction in the north |
| October 2013 | Start of tunnelling, south to north |
| December 2014 | Start of tunnelling, north to south |
| October 2015 | 2 nd tunnel breakthrough |
| Early 2017 | Project opens for traffic |
Building the tunnels
Meet our TBM Alice
Alice has been specifically designed for the Auckland geology by German company Herrenknecht. The 2400 tonnes TBM is the 10th largest machine of its type in the world and the largest ever built for use in Australasia.
She is supported by gantries (1, 2, 3 and culvert) that house all the equipment needed to operate it, place the precast concrete rings that line the tunnels and remove the spoil.
The TBM machine will travel a total of 4.8 kilometres to bore two 2.4 kilometres tunnels.
Alice began her underground journey in November 2013 at southern (Owairaka) end, first heading north to build the southbound tunnel. She reached the northern (Waterview) end of this tunnel on 29 September 2014 before relaunching for her second drive to build the northbound tunnel in January 2015. Alice is expected to breakthrough at Owairaka in mid-Spring.
ALICE TBM QUICK FACTS
14.4m diameter of shield
12m length of shield
87 m total length
15 crew required to operate the TBM
80 mm a minute or 0.0005 km/h is top speed
8400 kW cutting head power
68,220 kN nominal torque
To find out about how Alice works read our TBM Information Sheet .
Keep up to date with all our project news, photos and videos by clicking ‘Like’ on our Alice TBM Facebook (external link) .
Waterview’s tunnel boring machine is the 10th largest ever built.
Over 24,000 ring segments completed
Over 24,000 ring segments were produced at the Segment Precast Facility at East Tamaki by local company Wilson Tunnelling.
The purpose built precast facility was established to manufacture the ring segments that will line the tunnels.
Each concrete segment weighs ten tonnes and when connected together in sets of ten they form one full tunnel ring which is two metres wide and 50cm thick.
The precast facility was built in March 2013 and production of the ring segments commenced in August 2013 before ending in June 2015.
Factory in East Tamaki where over 24,000 tunnel lining segments were manufactured.
Moving the earth
When Alice has finished her job, she will have extracted around 800,000 cubic metres of earth, enough to fill 320 Olympic sized pools.
The spoil is transported by conveyor from the tunnels to a spoil building on the southern construction site.
It sits for 24 hours in “muck” bins to allow surplus water to drain away and is then transported to the dis-used Wiri Quarry 18km away where it is being used as clean fill to rehabilitate the quarry for future industrial and commercial development.
About 6,000 tonnes or 200 truck-loads of spoil are delivered each day, six days a week, to the landfill.
All trucks travel to and from the construction site via a site access point at the Maioro Street interchange with State Highway 20. This means the trucks do not need to use local roads.
Wiri Quarry, where spoil is delivered and spread.
Managing construction effects
The importance of managing construction impacts was recognised by the independent Board of Inquiry appointed by the Government to make the decisions on the NZTA’s applications to undertake the project. The Conditions of Consent set by the Board of Inquiry set out the ‘rules’ the NZTA must follow to manage the effects of construction on neighbours and the natural environment. The Consents also set ‘rules’ for landscaping and the reinstatement of public space; traffic management; heritage protection; communication with affected communities; and operation of the new section of motorway once it has opened.
View our managing the impact of construction information sheet.