A high-powered working group has recommended that Ports of Auckland undergoes a managed shut-down and its operations be shifted to Northport.
Northport at Marsden Point is the favoured future site for cargo now going in or out of Auckland, according to the newly released second report from the Government-commissioned Upper North Island Supply Chain Strategy (UNISC) group.
A third report is expected to include formal costs and details about where-to-from-here. Yesterday's report estimates that closing all shipping except cruise liners on Auckland city's prime-site port and moving cargo operations to Marsden Maritime Holdings' Northport could cost $10.3 billion.
That amount, number-crunched by a consortium of economic advisers led by Ernst and Young and based on a variety of supply chain scenarios, includes the cost of the already-promised $94.8 million upgrade of the North Auckland rail line and the as yet unspecified cost of a new line running off it to Marsden Pt, UNISC chairman Wayne Brown said.
• Auckland port to pay $24m for Northland stake
• Northland sells Port Whangarei land
• Government poised to make a call on moving Ports of Auckland to Northland
• Loss-maker drags Northland Port Corporation down
The cost of closing down Ports of Auckland (POAL) wouldn't fall on Auckland ratepayers, or taxpayers, Brown said.
''The ports could probably pay for most of it themselves and, also, there'd be $6b worth of land freed up on Auckland's waterfront.''
A full move to Northport was expected to generate 2000 jobs per year and a net economic benefit of $200m over 30 years.
But while the report has turned all players' eyes to Northland's deep-water facility, its bare hinterland and potentially game-changing regional economic growth, Northport may be getting a decidedly dirty look from Auckland Council which owns that city's port.
Mayor Phil Goff said the UNISC's second interim report does not sufficiently consider the costs and benefits to Auckland of relocating its port.
"Like most Aucklanders I am in favour of moving the port, but we won't simply give away our assets built up by ratepayers over generations.
"Relocation needs to stack up economically and protect the interests of Aucklanders. It will also need to be undertaken with industry support and without imposing additional economic and environmental costs on Auckland businesses and consumers from freight being moved over much longer distances.''
Goff said much more stakeholder engagement is needed to ensure a robust final report by the working group.
That engagement might be what Minister for Infrastructure Shane Jones described as ''the bureaucratic Rubicon yet to be crossed''.
''I would say one of the areas of contention will be the Auckland Council. This report might increase levels of anxiety in Auckland that they might lose something valuable, but the fact is the port is not producing a dividend anyway.''
Jones said the interim report laid out the issues well.
''The first important thing about this report is that it definitely identifies the huge cost of doing nothing to ease Auckland traffic congestion.
''Secondly, it was good to see the [Colmar Brunton] polling data that showed the majority of Aucklanders do not want to see the priceless jewel that is the Waitemata Harbour turned into a river through a need to build the port out further and increased sedimentation.
''Thirdly, it doesn't hide the fact that this will involve a colossal amount of money.
''Taking this project on will not be for the faint-hearted but in the future it means more jobs in the north, better infrastructure, and it will expand the rating base.''
The report recommends activities continue or even expand at Tauranga but doesn't include details about a division of former Auckland operations, said David Pilkington, chairman of the two port companies' combined board.
''We would certainly welcome robust debate about how things might progress. For a long time we've seen Northport as an option to take the pressure of Auckland. There would have to be significant infrastructure put in place and the preferred vector for that is rail.
''In terms of Northport's space and accessibility, we're the best placed of any port in New Zealand.''
Tony Savage, director of the Great Northern Railway Charitable Trust, said the Ernst and Young component of the report backs up everything supporters of a Northland railway have been saying for a long time. He supported the idea of a larger Northport.
''It's so much better than the previous options, such as building an Auckland port in the Firth of Thames or Manukau Harbour.
''Auckland ratepayers are going to benefit. They just have to convince the council to get off a facility which has falling dividends anyway.''
Ernst and Young estimated the capital cost of "the base case" - allowing POAL to continue as is and increase capacity - to be $9.5b. Partially moving to Northport was put at $9.5b, a partial move to Tauranga at $9.5b, and a full move to Tauranga $13b.
It estimated POAL would have to spend more than $1b in the next 30 years to deal with projected freight growth.
The three-stage UNISC study will cost $850,000. Brown said the third and final report was nearing completion.