A report by road transport experts is opposed to shifting Ports of Auckland to Whangārei, saying such a move would be logistically impractical and cost-prohibitive while increasing greenhouse gas emissions.
The report, prepared by TG Enterprises for National Road Carriers Association based on interviews with trucking companies and stakeholders, concluded Auckland's port provided the best value for money and should continue in its current location until it couldn't handle future growth – expected to be at least until 2050.
But big names lobbying for the move to Northport, including former Far North mayor Wayne Brown and Northland Mayoral Forum chairman Jason Smith, say the reasons highlighted by TG Enterprises for the status quo to remain are devoid of logic.
With a focus on road freight, the report said the issue was not port location but the efficiency and safety of road (and rail) access to the upper North Island ports of Northport, Auckland and Tauranga.
It said servicing customers by road freight from Northport would be nearly eight times more expensive, or more than $1 billion annually, than from Ports of Auckland.
An analysis of road freight cost showed a container truck that does five trips a day between Ports of Auckland and South Auckland for $50 would be only able to achieve one from Northport at an estimated price of $230.
"With Auckland's business growth moving south, and Auckland, Waikato and Bay of Plenty dominating the upper North Island's economic growth, Northport was too far away."
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Moving the port to Whangarei, the report said, would add more than 125,000 tonnes of carbon dioxide per year for container road freight, compared with about 27,000 tonnes from Ports of Auckland to South Auckland.
That would seriously undermine New Zealand's efforts to reduce greenhouse gases, it said.
"The decision to move the port from Auckland to Northport is being rushed. We need to stop. Take stock. Reassess."
But Brown said the association has a vested interest to ensure the port didn't move north.
He described as "total and absolute crap" claims about the amount of greenhouse gas emissions, saying goods transported to and from Northport by rail freight would mean less pollution and traffic congestion.
"At the moment, more stuff goes to Auckland from Tauranga which is further away from Northport. Milk from Northland goes to Tauranga for export.
"Auckland is planning 50,000 houses in the south and 86,000 houses north of Auckland. Where are the biggest new commercial businesses like IKEA and Costco going? To West Auckland, not south," Brown said.
He led the Upper North Island Supply Chain (Unisc) working group, whose report promised an economic boom for Northland if the $10b port move went ahead.
"There's nothing that will make Northland do better than shifting the port from Auckland," he said.
Smith said the days of Ports of Auckland were numbered, whereas Northport offered the best deepwater port in the upper North Island.
"Everyone is aware of the growth in Waikato and further south but the next era of growth in New Zealand is, in my view, on the north side of Auckland.
"Ships will be getting bigger in future and the risk for New Zealand is they won't be able to come here. That's where the deepwater port at Northport has an advantage," the Kaipara mayor said.
Regional Economic Development Minister Shane Jones said the report was built around fear and apprehension and he pointed to points of weakness in the state of the trucking industry.
"We'll see more electric trucks in future but for now, we see a significant role for rail and I think the trucking industry is churlish in not acknowledging the $700 million put aside for a four-lane highway out of Whangārei heading south," he said.
Through its Provincial Growth Fund, the Government has provided $300m for work on the existing rail line between Auckland and Whangārei.
The report said with the upper North Island's three ports having limited access and capacity, a superport in the Firth of Thames or Manukau Harbour could be assessed.