"Air New Zealand estimates up to 3000 customers will be impacted by cancellations [today] with around 6000 inconvenienced by unexpected schedule changes. In most cases passengers are being accommodated on alternative services and the airline is working through the process of notifying customers. Further disruptions can be expected in coming days."
It has also taken the "unusual" step of restricting ticket sales, including stopping sales on international services.
Efforts were also being made to reduce cargo loads.
Mobil Oil lead country manager Andrew McNaught told Morning Report he's confident there will be no widespread petrol or diesel shortage across the Auckland region, as it is trucked in from other parts of the country.
Good stocks of ground fuels were being brought from other areas, including Mt Maunganui and Marsden Pt.
Auckland Mayor Phil Goff says he is prepared to use specially controlled traffic lights and bus lanes to get tankers through city streets in a bid to solve the fuel crisis.
Goff told the Herald the Auckland Council would do all it could to get fuel to where it was needed, including measures that could worsen the city's already chronic congestion.
"We're the international gateway to New Zealand and that gateway has to stay open," said Goff.
Options for transporting include getting the tankers to travel at night or using bus lanes.
The Northland Regional Council continues to monitor the clean-up operation at the site in Ruakaka.
Council staff have also been sampling groundwater bores to establish existing water quality parameters in the vicinity.
A council spokesman said there still didn't appear to be any significant environmental damage, despite the large volumes - up to 80,000 litres - of fuel spilled.
Public servants were told yesterday not to fly unless it was absolutely essential, and Energy and Resources Minister Judith Collins wants fuel shipped to Wynyard Quarter and trucked through the city, synchronising traffic lights along the way.
Meanwhile, Consumer NZ is reminding travellers of their rights if their flight is cancelled.
The Civil Aviation Act requires an airline to compensate if a domestic flight is cancelled or delayed for reasons within its control. The airline doesn't have to compensate if the delay is caused by uncontrollable factors such as the weather.
"If it's an international flight, travellers' rights differ depending on where you are, where you're heading and where the airline is based," a Consumer spokeswoman said.
If a flight is cancelled in the EU, airlines are required to re-route you to your final destination, a return flight home or a refund; assist with meals, free phone calls and accommodation and compensation proportionate to the distance you're travelling - up to €600 ($1000) for flights further than 3500km."
In Australia passengers' rights to compensation were murkier.
"Choice, the Australian consumer organisation, says most airlines will either carry you on another scheduled service or give you a refund if they're at fault for the cancellation. Some will pay for meals, accommodation and transfers, but it's at their discretion."