Northwestern Motorway Causeway Progress


Developments today on NZTA’s Northwestern motorway causeway upgrade.

It is calling for registrations of interest to upgrade the Northwestern Motorway’s causeway across the Waitemata harbour – a $270m project to widen and raise 4.2 kilometres of the causeway.

The NZTA also announced today that it will start preliminary work on the project in January when it builds a trial causeway parallel to the existing motorway in order to measure the impact the project will have on an important marine reserve.

The motorway, and the 50 metre-long temporary causeway, are located inside the Motu Manawa – Pollen Island Marine Reserve.

The NZTA’s State Highways Manager for Auckland and Northland, Tommy Parker, says the temporary causeway will provide valuable information to ensure that the construction footprint inside the reserve will be as environmentally light as possible. .

“We will be working in a sensitive environment and building the temporary causeway is important for the overall success of the project,” says Mr Parker. “The trial will ensure that we’ve got the right approach and the right methodology in place when we are ready to start construction.”

NZTA contractors will focus on monitoring plants and wildlife in the marine area to minimise the impact of building the improved motorway. Work on the trial causeway is scheduled to be completed in June

Interested parties have until December 21 to submit their registrations of interest for the project to deliver the design and construction required to upgrade the causeway and the Rosebank and Patiki interchanges, widen bridges and improve pedestrian and cycle facilities.

Mr Parker says a competitive alliance procurement model – involving a consortium of companies submitting a tender together - has proven successful on other NZTA projects including the Manukau Harbour Crossing and the recently awarded Waterview Connection project.

“We’re adopting the same model for the Causeway upgrade project to enable the NZTA to get the best value for money and deliver Auckland drivers an operational Western Ring Route by 2021. We expect to receive registrations of interest from industry experts from here and overseas, to take forward into the next stage,” says Mr Parker.

Early next year, after registered parties have submitted their design and construction records and skills, the NZTA will shortlist three consortia and start a rigorous investigation of their bids before announcing the successful one in September 2012.

Construction is expected to start in early 2013, with completion earmarked for 2017 to match the extra capacity provided by the Waterview tunnels and Great North Road Interchange.




  1. BD says:

    With all this work starting soon and no mention of a North-West Busway being brought up by any of the councillors.

  2. ingolfson says:

    BD, that ship has sailed, and the election has sunk any rowboats trying to catch up with it.

  3. Geoff Houtman says:

    Causeway or “seawall”?

  4. rtc says:

    I hope the work on this causeway also includes improvements to the flow of water, the tidal movement of water in the estuary has been severely impeded since the NW went in meaning the upper reaches of the area are slowing filling up with mud.

  5. damian says:

    rtc - the work will not include any improvements to the flow of the water. Not in the above contract at least

  6. rtc says:

    @damian - yeah it’s NZTA, what was I thinking they’d do something other than widen the road.

  7. Mike F says:

    Always wondered why they are raising the causeway (at a considerable cost) when decent stopbanks either side would control the higher high tides at a fraction of the cost. Stopbanks would also contain runoff from the motorway into the marine reserve.

  8. damage says:

    Mike - I would suggest its because of the ecological impact that stop banks would do.
    H’apperently its quite a sensitive area…

  9. ingolfson says:

    If you widen the existing motorway, due to the camber down, your outer lanes would be even more at risk of flooding w/o stopbanks.

    Also, the existing bridges are crappy in some regards (including for cyclists), plus, as noted, stopbanks would just extend the footprint even further.

    I do believe that improving in- and out-flow from the estuary formed a big discussion during the Board of Inquriy process. I do not know whether this ended up in improved mitigation being required. As noted, this testbed certainly will not affect that.

  10. Owen Thompson says:

    Great to see that a Marine Reserve is protected from everything, except motorway construction.


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