A report has found that ports in the upper North Island will have to boost their efficiency by around 2% over the next 30 years to cope with demand.
The findings come from a report by PricewaterhouseCoopers, commissioned by a number of councils.
It found the Ports of Auckland, Port of Tauranga, and NorthPort in Northland, will mostly cope with demand over the next 30 years without any major changes.
But it said they will need to become faster at moving containers, and finish minor improvements.
Ports of Auckland will need to do this faster than its competitors, with the report warning it will face capacity constraints in the near future.