Police say New Year's Eve celebrations across the Bay of Plenty last night were a success but aren't saying how many revellers ended up behind bars.

Other centres released details of overnight arrests, but the Bay of Plenty police district has refused to release details about Mt Maunganui, long considered one of the New Year's Eve hot spots.

Instead police suggested a request could be made under the Official Information Act.

"New Year's Eve is just one part of our wider summer policing operation and that doesn't finish until Waitangi weekend in February so if we release our figures at all it won't be until after the entire operation is complete," said police spokeswoman, Jacky James.

She said the figures were not a fair reflection of whether the evening was a success or not.

It was a success, she said.

The second decade of the millennium arrived in relative peace and quiet throughout most of the country and police say it is because widespread liquor bans let them keep drunken troublemakers under tight control.

In Auckland the noisiest part of the New Year's Eve celebration was the $100,000 fireworks display from the top of the Sky Tower in the central city, and from two barges in Waitemata Harbour.

The boom of the fireworks going off was heard on the North Shore and in other parts of Auckland several kilometres from the centre of the city.

Auckland police said it was a relatively quiet night although they conceded the city tended to empty out for New Year, with many people heading for some of the holiday hot spots in the Bay of Plenty and in the Far North.

Ms James said the liquor bans allowed police to kept the troublemakers and drunks out of the areas where people wanted to see the New Year in without the major disorder caused by alcohol.

"They (the liquor bans) are there exactly for that reason so we can police the liquor ban and prevent major disorder.

"We make no apologies for that because it helps prevent problems."

Liquor bans were first introduced in Tauranga in 2004 but amended in 2008 to make the bans permanent 24 hours a day.

In Gisborne the Rhythm and Vines concert attracted about 25,000 people but police reported few incidents.

In the Nelson area 21 people were arrested, including six for disorderly offences and five for being drunk. Three were also arrested for breaching bail conditions, three for assault and two for breaching the liquor ban.

Nelson police said there were also arrests for possession of cannabis and disqualified driving and three drivers were processed for alleged drink driving.

The Maitai Camp in Nelson had about 1400 young people on New Year's Eve. Police said numbers were down from last year but campers and visitors were well behaved and there were no problems.

"We made a point of adopting a high profile, being very visible as we moved around and dealing with the little things before they had a chance of getting out of hand" said Inspector Brian McGurk.

He said careful planning and good organisation produced a quiet night.

In Cathedral Square in Christchurch nearly 12,000 people welcomed in the New Year.

Police said they were pleased with the trouble-free behaviour.

Inspector Derek Erasmus said it was good to see so many families and tourists enjoying the city's night life, the entertainment, and fireworks.

"Overall everyone behaved well, with only a few isolated incidents that police were able to control before they escalated."

There were 69 arrests in the central business district, most for breaches of the liquor ban and disorder.

"Police have been kept busy across the city tonight, however overall once Cathedral Square cleared, it was quieter than the last two years."

Wellington police reported a quiet night in the capital, with 20 arrests, mostly for disorder.

In one of the few Wellington incidents, a 39-year-old woman fell off Glasgow Wharf into Wellington Harbour. She was rescued by two locals, one an employee of Bluebridge Ferry, and was taken to Wellington Hospital.

In Wanaka in Central Otago police said they were also pleased with crowd behaviour.

A large crowd gathered at the waterfront and at pubs and bars in the town but police said it was a family affair and only 13 people were arrested, mostly for minor offences.

Police also stopped more than 1000 motorists but only one was over the legal breath-alcohol limit, said Senior Sergeant Allan Grindell.

"Wanaka is a safe and desirable place to live and visit and this result clearly reinforces this," he said.