The six students and their teacher, from Auckland's Elim Christian College died, when they were hit by a torrent of water while canyoning near Turangi on April 15 this year.
"The Department considers that there were steps OPC should have taken to better ensure the safety of the group on the day," said Mike Munnelly, the Department of Labour's Central Region Manager of Health and Safety Services.
OPC chairman Rupert Wilson told the Stuff website that the tragedy had been a "terrible time for everyone" and safety was the centre's "paramount consideration".
"We believe that our risk analysis, safety and staff training systems are up to ... world best practice for the outdoor education industry.
"Losing seven lives is a tragedy beyond belief and the Department of Labour is doing what it thinks is right," Mr Wilson said.
The Department is required to investigate when people are seriously injured or killed in the workplace.
Four charges were laid yesterday under the Health and Safety in Employment Act 1992.
Two charges related to OPC's obligations to protect the instructor who went into the gorge with the students and teacher.
The third related to OPC's obligation to ensure that its employee's actions didn't expose others to avoidable risks.
The fourth charge relates to OPC's obligation to appropriately ensure the safety of other people in the place of work.
The charges were laid in the Wellington District Court, but will be filed in the Taumarunui District Court - the closest court to OPC's registered head office and the scene of the incident. The first hearing is likely to be in four to six weeks.
No other charges will be laid.
Mr Munnelly said the department wanted to acknowledge the tremendous dignity and strength shown by the victims' families and friends, and by the survivors, despite the trauma they had suffered. "Prosecution action is not commenced lightly by the Department, and we appreciate that this is a difficult time for everyone involved in this tragic event."
"But seven people lost their lives that day and several others were put in serious danger. So it is important that someone is required to answer what the Department says were failures to better ensure the safety of the group. Our hope is that this prosecution may help prevent others from suffering a similar loss in future."
As this matter is now before the court no interviews or further comment will be provided.
