GUEST POST: Trolls under the SH20 Bridge: Is NZTA Attempting to Derail the Light Rail Project?

What is going on with the Mangere Bridge replace, Light Rail and NZTA?

Guest Post from Nicholas Lee

In October 2018, NZTA closed the pedestrian bridge connecting the shore of Onehunga with the Mangere Bridge. At nearly hundred years old and with sinking foundational piles, the bridge had been due for rebuilding or repair since its closure for motor traffic when the SH20 over it was open, in the 1980s. The (scant) publicity at the time of the closure, mostly mourning the loss of this unique human-sized connection across the Manukau Harbour, has quickly died out. That is not surprising: the voices of south Auckland and the Manukau Harbour have been historically ignored. Yet, this Onehunga-Mangere connection should matter to everyone in Auckland, and especially to the advocates of public transport. If the new bridge is designed without the provision for light rail to cross the harbour, this project could be derailed for years to come or even permanently. And there are good reasons to think that this is a realistic scenario.

State Highway 20 over the Manukau Harbour. Source: Nicholas Lee

First, the silence about the tender process is suspicious. The tender for the replacement is (allegedly) due back this month (March) yet there has been no public discussion, or even information, about it:

Official Information Act Request on Mangere Bridge. Source: Nicholas Lee

NZTA have a history of running projects over the summer period which makes public engagement difficult. I have now made an OIA request for the tender documentation, which may or may not add better visibility. And may or may not be received before the tender closes.

Second, and most importantly, according to another recent OIA response, “no work has been undertaken on redesigning the current bridge design to accommodate light rail.”

See the full quote:


Official Information Act Request on Mangere Bridge Ctd. Source: Nicholas Lee.
The Old Mangere Bridge, slated demolition. Source: Nicholas Reid

NZTA at least officially supports light rail, acknowledging it as an important project to increase social equity in Mangere and south Auckland:

Official Information Act Request on Mangere Bridge Ctd. Source: Nicholas Lee.

NZTA also acknowledges it as an important step for Auckland to transition to a climate friendly multi-modal oriented city development:

Official Information Act Request on Mangere Bridge Ctd. Source: Nicholas Lee.

Yet at the same time, proceeding with the current design to tender means that the NZTA has already made a decision: one which excludes light rail . One could argue that the LRT could cross the Manukau Harbour somewhere else. However, even ignoring the extra cost for an additional bridge, getting consent for a third crossing will be difficult and the alignment will not support a good LRT service. With the delays on a city start due to the CRL, America’s Cup and conflicts over Dominion Road, NZTA should be accelerating the project development, starting with the section from Onehunga to the Airport and upgrading the A2B BRT section to LRT, thus creating a complete first stage network. A light rail capable crossing should be a priority.

The inclusion of light rail is not the only issue related to the current design that NZTA has refused to answer. Another one relates to the set of challenges with the Transpower 110kv lines and clearances. Access to the upper harbour is also an area of concern: while the SH20 bridge clearance is very high, the new design has only 4.625m at MHWS, continuing a theme of limited access to the upper harbour. Supposedly a “future lifting section” could provide this access, but why should solving a problem we can foresee now be relegated to some uncertain future?

Furthermore, it is not at all clear how the new bridge will integrate with the port and place making around the port. We do know that NZTA have refused to acknowledge the Master Planning MOU between TOES and Auckland Council.

Official Information Act Request on Mangere Bridge Ctd. Source: Nicholas Lee.

All of these problems can be summarized under two main headings and are characteristic of the approach to infrastructure in New Zealand more generally:

  1. working in silos/lack of integration between different agencies and remits
  2. rushing with projects that have not been thought-through properly, in particular with the regard to the future (human, environmental, economic) challenges

While the “number 8 wire”, “she’ll be right” approach may have worked in small communities of the historical New Zealand, it will not work for Auckland as a big urban centre of the 21st century. What is needed next is not a (new and tidy) replica of the old Mangere Bridge, but a connection for communities built for the future.

Looking out over Mangere Inlet from State Highway 20. To the left is Auckland Isthmus and to the right Southern Auckland. Source: Nicholas Lee.

Bio: Nicholas is a director of several businesses in New Zealand and overseas, with a background in mathematics and statistical modelling (Cambridge, 1999).  Experienced in supply chains, operations and logistics, he has also developed and project managed commercial, residential and industrial builds.  His engagement in sustainable development comes from a long personal interest in cities and urbanism.  An Onehunga resident, the East-West Link EPA BOI have made him realised the importance of citizen advocacy.

One thought on “GUEST POST: Trolls under the SH20 Bridge: Is NZTA Attempting to Derail the Light Rail Project?

  1. Great post. It was an amazingly exciting time when all of these projects were greenlit (LRT City to Airport / Skypath / Botany to Airport, Regional Rapid Rail, etc etc). Wow, I thought. We’re finally getting somewhere. Since then, everything seems to have gone undercover, quiet and is being delayed, with various agencies seemingly acting in not-such-good faith. Really disappointing. Thanks for highlighting this on your blog, Ben and for this post, Nicholas.

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