Transit NZ has withdrawn an application to pull down the old Mangere Bridge while it considers "heritage options", but denies this will hold up plans for a duplicate harbour crossing.
The agency, which hopes to lodge a new application for a resource consent before the end of the year, acknowledged yesterday that its rethink over the 92-year-old structure followed concerns raised by the local community and the Historic Places Trust.
It had planned to dismantle the concrete bridge - closed to motor traffic in the 1970s but retained for pedestrians, cyclists and fishing enthusiasts - as part of a $265 million project to duplicate the Southwestern Motorway's crossing of the Manukau Harbour.
In its recent plans, Transit intended to replace the old structure with a narrower footbridge and a row of piles to protect it from being struck by ships using the Onehunga Wharf.
That would have been in addition to the existing motorway bridge and a new twin structure, which would each carry four lanes of traffic but without being "future-proofed" for a rail crossing, which has been sought by the Auckland Regional Council.
But Transit now describes the old bridge as a historic structure of high architectural, cultural and social significance, requiring further assessment and consultation with the community and organisations such as the Historic Places Trust.
It will ask consultants to prepare a conservation report, in consultation with the trust, to consider whether some of the old bridge's "key heritage values" can be retained, or its material used in building a replacement walkway.
Transit was already having to reconsider details of a proposed new motorway interchange on the Onehunga side of the harbour, after Auckland City Council consultants raised concerns about potential impacts on the community and a volcanic crater in Gloucester Park.
But it is not withdrawing its resource application for that part of the project, which Transit promises to "substantially" complete in time for the 2011 Rugby World Cup as part of Auckland's western bypass.
All resource consent applications for the projects were lodged in June with the regional council and Auckland and Manukau city councils.
That followed a preliminary assessment by Transit consultants of sites of potential heritage and pre-1900 archaeological interest.
The old bridge was built in 1914 by the same engineer who was in charge of constructing Grafton Bridge, a Mr R.F. Moore of the Ferro-Concrete Company of Australasia.
Historic Places Trust heritage planning adviser Megan Patrick acknowledged yesterday that the old Mangere Bridge may not compare with the Grafton Bridge on aesthetic grounds, but said it was "still part of our heritage" and valued by many local residents who enjoyed fishing from it.
She said the trust hoped a way could be found not only to retain the bridge, but also to keep the even older Aotea Sea Scouts Hall at its existing location on the Onehunga foreshore.
Transit says it is committed to retaining and protecting the hall, built in 1911, but wants to move it about 70m to the northwest to make room for the Onehunga motorway interchange and the development of Orpheus Drive as a pedestrian boulevard.
The agency also faces difficult heritage and archaeological challenges to another critical component of the western bypass, a motorway extension through Waterview.
It has promised to skirt around historic sites and has delayed applying for land designations for the project while considering extensive tunnelling options which could push construction costs well above $1 billion.