Response to lahar "easier than exercises"

An officer sets up a roadblock in response to the lahar.

“It was actually easier than the exercises,” says Sergeant Mike Craig, Ohakune.

“Time went a lot faster. Everyone knew what they had to do. It worked well.”

Ohakune General Duties Constable Andrew Osborn captured these images
showing the increasingly powerful lahar flow and debris coming down the
Whangaehu River valley.

Mike led the Police response to the lahar on Sunday 18 March when an estimated 1.3 million cubic metres of water and volcanic mud broke through Mt Ruapehu’s crater lake rim and headed down the mountain’s eastern side.

When one of the lahar sensors initially went off around 10am, it was thought to be a false alarm due to the foul weather and pouring rain in the area at the time.

However, in keeping with procedure, staff gathered at the Incident Control Point (ICP) at the Ohakune Fire Station. Some 40 minutes later two more alarms went off.

While Mike was on the phone to DoC Duty Scientist Harry Keys, a trip wire was activated and Harry was convinced that “this is it.”

“From there we ramped it all up,” says Mike. “We had sufficient staff to run the ICP and made sure road blocks were in place.

“Initially it sounded like a small part of the dam had collapsed, followed by a bigger breach.

“The police officer on State Highway 1 traveling north could see it and hear it, so we obviously knew we were dealing with the real event.”

Helicopters were despatched to rescue a Genesis power worker who was caught in the rising water and to another person who was separated from their epilepsy medication due to the road blocks.

Mike says the biggest problem was not knowing whether the crater lake had fully emptied.

“Because (the lake) released gradually, it was initially smaller than everyone predicted. Because of the weather conditions, they couldn’t fly up to the crater to have a look.

“Based on that, we maintained everything as long as we could.”

Mike says things were made easier by having fellow Sergeant Graeme Rumble on site on the day. Both Graeme and Mike were trained to deal with the response.

He also praises all the Ohakune staff who assisted, in particular Julie Nation for her help at the ICP, local fire chief, Ben Goddard, the Ruapehu Fire Safety Officer John Hotter, DoC, Ruapehu District Council staff and Fire volunteers who helped police at the road blocks.

“The key people who had always trained for it helped make it the success it was.”

DOC scientist Harry Keys (left) and Senior Constable Barry Shepherd, Taupo,
assess the lahar.

Central District Operations Manager, Inspector Dave White, says lahar planning has been underway for four years and the success of the response was due to the partnerships of all agencies involved.

“It was a major event that used business as usual tools as part of the New Zealand Coordinated Incident Management System (CIMS) – a system all emergency services are now using,” says Dave.

Under this framework, Dave acknowledges the collaborative approach between Police, DoC, GNS, MCDEM and Regional and District councils.