A New Zealand adventure company has been charged with four offences relating to the deaths of six students and a teacher during a school trip six months ago.

The group, from Auckland's Elim Christian College, were on an adventure trip in the North Island, when they were swept away in flash flooding.

The Sir Edmund Hillary Outdoor Pursuits centre says it will defend the charges when the case is heard next month and maintains it did not receive weather reports of flash flooding in the area before the trip.

New Zealand's Department of Labour says someone has to be held accountable for not keeping the group safe.

Elim Christian College Principal Murray Burton says the grieving families want to ensure this does not happen again.

"They will have mixed emotions once again," he said. "This news still doesn't bring back a child. But I guess in some ways they might take a little bit of comfort in the fact there will be, potentially there will be changes made."

Mr Burton says he is relieved the school was not charged.