Eruption warning system needs replacing - Green

Ruapehu Bulletin, Volume 13, Issue 597, 1 August 1995, Page 3

Eruption warning system needs replacing - Green

Skiers on Whakapapa were threatened by a lahar (volcanic mud flow) which swept down the northern slopes of Mt Ruapehu on Wednesday last week, taking out two bridges and isolating the ski field and Whakapapa Village. That was the scenario behind a Civil Defence and Department of Conservation exercise designed to test and evaluate DoC' s lahar response plan as well as to practise evacuating the Whakapapa Village and ski field. Exercise organisers also wanted to raise public awareness regarding lahars and to familiarise staff and village residents of the threat. A number of minor issues had been highlighted by the exercise and were dis-

cussed at the debriefing. These included a need to upgrade the sound alarm systems as well as parts of the early warning system and the involvement of more village residents in the Lahar Response Plan. The early warning system, now 13 years old, could need replacing, said district conservator Paul Green "Considering the elements the equipment is exposed to, it works very well. However, technology has improved enormously in the ensuing years and our knowledge of possible lahar paths has also increased," he told the debriefing. "It may be time to extend and upgrade the early warning system on Mt Ruapehu Turn to Page 7

Eruption warning needs replacing

From page 3 and replace it with more up-to-date technology." Under the scenario presented to DoC and ski field staff, an eruption on Mt Ruapehu sent a lahar from the Crater Lake down the ski field and Whakapapanui Stream, destroying the two road bridges on the Bruce Road. Some 200 skiers were evacuated from valleys on the ski field to the safety of high ground. They were alerted to the simulated emergency by ski field staff directing them to move to high ground. Sirens and a taped voice announcement were also activated. Because of bad weather there were few skiers on the field and the upper slopes were closed. However, DoC spokesperson Lianne Fraser said that it was realistic to assume that up to 5000 people would have to be evacuated some days if an emergency occurred. Exercise observers were impressed with the speed at which ski field staff moved into action. People on the ski field have between three and eight minutes to respond in the event of a lahar and skifield staff reported that the evacuation took place within the allowed time. A fault on the Waterfall Chairlift had added an extra degree of reality to the exercise. At Whakapapa Village 152 people including school children, members of the public, accommodation staff and other village operational personnel were evacuated to high ground at the Skotel.