"There were a lot of kids under the influence of it."
Inspector Aberahama said three arrests were made in relation to the drug.
"A van was searched in the car park at R&V and three men from Waikato were arrested on drugs charges."
A large quantity of MDMA was seized.
"We are going to get together with the directors of the festival next month and work on a plan around drug use at the festival for next year.
"Drugs issue aside, it was overall an extremely successful event this year from our perspective. The level of alcohol intoxication was more controlled and we saw less of it than last year," Inspector Aberahama said.
"Staff at the site did a great job around alcohol management and the amount of alcohol served to the festival-goers."
As well as the drug arrests, there were several other arrests made during the event. "But they were for minor offences."
Police stopped 4750 cars on New Year's Day as vehicles left the festival venue.
"Ten drivers were over the drink-drive limit. They all had alcohol readings of 250 to 400 micrograms. None were over 400.
"We think that is an outstanding result. It shows that our kids are getting the message around drink-driving. The majority of those vehicles had sober drivers."
St John territory manager Shane Clapperton said it was "business as usual" over the four afternoons and nights on site.
"We saw just over a thousand people for a wide range of medical and accident-related issues across the time we were there."
St John had 30 staff on duty at the site across the four days.
"The number we saw was comparable to last year."
Mr Clapperton said they still looked after a lot of people who were affected in some way by either alcohol or drugs.
"Some of them required significant medical attention."
Mr Clapperton said the impact of the weather on site on Thursday and Friday made their job tougher.
"We had to operate in the wet and muddy conditions and that was difficult at times. But overall we were happy with the role we played in the festival and how we executed that role