Motorway Expansion and Motu Manawa Marine Reserve/Pollen & Traherne Islands

Recently it was officially announced by press conference that the Northwestern Motorway will be widened significantly where its passes through the Motu Manawa (Pollen Island) Marine Reserve, which is within Forest and Bird Central Auckland’s region. Within the marine reserve lie Pollen Island, a scientific reserve, and Traherne Island, presently owned by Land Information New Zealand (LINZ) for motorway development purposes.

In collaboration with Waitakere and Auckland City Councils, the New Zealand Transport Agency (NZTA) is proposing to:

  • Add lanes to the motorway to increase capacity
  • Raise the causeway and the adjacent cycleway to reduce flooding
  • Widen and improve interchanges
  • Construct new bus priority lanes on the motorway shoulders
  • Improve access across the motorway for pedestrians and cyclists

These works are set to begin in 2011. Resource consent applications were lodged in Oct 2010 and a submission made by Forest and Bird to help ensure the unique conservation values of the marine reserve and the islands it encloses are respected and enhanced as part of the motorway widening plans.


Traherne Island is set to lose up to 3m where it borders the motorway, but a lot of work has been started to compensate, including weed control, pest control, lizard surveying, moth surveying, and salinity monitoring. As well, a regionally uncommon plant, Mimulus repens (pictured below) is being translocated and then re-introduced following motorway works.


More information is available here at

Forest and Bird has now made a submission about these works. Click here to see a copy.

M. repens (photos Kent Xie)