Park managers say parents grateful for safe environment they're offering for under-25s to celebrate New Year.
A Tauranga campsite which has banned adults and families in favour of those who are "young, dumb and full of beer" has been criticised by police and an alcohol abuse expert.
Silver Birch Holiday Park has created a "teenage heaven" where more than 210 under-25s have set up tents in what has been nicknamed "Alcohol Alley" to celebrate New Year's Eve.
Park managers Allan Sherson and Richie Robin say they're giving the youngsters a safe environment in which they can enjoy themselves.
They have four security staff working shifts to keep an eye on the revellers, fenced off the camp, and patrol for under-age drinkers. But others are concerned that it's encouraging binge drinking and lacks proper supervision.
"It is grossly irresponsible," said Professor Jennie Connor, head of Preventive and Social Medicine at Otago University in Dunedin.
"Large numbers of very young drinkers, with very little supervision, is saying that they are encouraging drunkenness. It says they are encouraging them to behave in a reckless fashion," she said.
"To explicitly exclude adult supervision just seems outrageous. It's a publicity stunt, it's a money making venture, and it's pathetic really."
A senior sergeant at Tauranga police station said police hadn't heard about the plan but were concerned.
"I saw this today and passed it to my boss who rolled his eyes as much as me. It's the first we've heard of it."
Tauranga and Mt Maunganui are traditional New Year's Eve hotspots.
Tahuna Beach Holiday Park in Nelson welcomed hundreds of youths to the campsite for decades. But management stopped providing "youth sites or heavy drinking sites" to young people, who came from all over the South Island for New Year's celebrations, as it became too much hassle and too expensive.
Tahuna manager Ann Cumpstone was stunned that the Tauranga camp, close to Mt Maunganui, has turned to such a market.
"We haven't had any youth sites, or heavy drinking sites, for six or seven years. It just cost too much in security and in damage. It was just the product of excessive alcohol."
It was also difficult to monitor under-age drinkers, Ms Cumpstone said. "I wish them well and hope it all goes all right. They will have to make sure that no under-18s are getting alcohol, or else they better watch out. I bet they don't do it again next year."
Ms Robin accepted that her Tauranga campsite always gets "the odd idiot", but people were generally well-behaved and she didn't expect any hassles tonight.
She rejected criticisms of the youth policy. "We get parents all the time saying, 'Thank you, at least we know our kids are safe and that you're being responsible and looking after them'."
Safe drinking tips
* How to start 2014 without a hangover:
* Set limits for yourself and stick to them.
* Alternate between non-alcoholic and alcoholic drinks.
* Drink slowly.
* Choose drinks with a lower alcohol content.
* If you participate in rounds of drinks, try to include non-alcoholic drinks.
Source: Australian Medical Association (AMA).