Tongariro National Park

• Increase of the possom population and use of poison (issue resolved)
• Volcanic eruption having caused a large build-up of ash - risk of a lahar

Previous deliberations:
25th extraordinary session of the Bureau, December 2001 (Paragraphs, III.152 - III.154)
25th session of the Committee (Paragraphs VIII.105 - 109)

Main issues:

The eruption of Mt. Ruapehu in 1995 and 1996 caused a large build-up of ash that blocked the outlet of Crater Lake.  There is concern that when the Lake refills (estimated to be sometime between late 2002 and 2005), a rapid collapse of the ash dam could occur followed by a major lahar (ash flow).  Options to manage this risk and address issues of public safety need to take account of the protection of both the natural and the cultural values, as interference with the summit area and Crater Lake has implications for the protection of spiritual, traditional and cultural values to the Maori people.

New information:

Following the request of the Committee at its 25th session (Helsinki, 2001) the State Party has provided a report following completion of a review of the management decisions taken to date to minimise the risks to safety associated with the impending Ruapehu Crater Lake lahar.

The Minister of Conservation announced that the installation of a state of the art alarm and warning system, and the construction of a bank alongside the Whangaehu River are sufficient to address risks to public safety from an expected lahar.

In addition to these measures, the Department of Conservation is working closely with the Police and the Ministry of Civil Defence and Emergency Management to develop an appropriate emergency response plan.  Furthermore, the Ministry is helping organisations with assets in the predicted lahar path to review their individual civil defence response plans.

The Minister has decided against undertaking engineering work at the Ruapehu Crater Lake to reduce the impact of a lahar.  Such works had been opposed by environmental and recreational groups, the Tongariro/Taupo Conservation Board, the New Zealand Conservation Authority and by local iwi (Maori tribes). The decision was based on assessment of potential risks to staff working on the engineering works versus the risk to the public and infrastructure without engineering, and the public concerns about the impact on national park values that would occur by bulldozing into the summit of the mountain.

The decision followed a lengthy period of consultation with technical experts, the community and other stakeholders as well as input from other Government Ministers with portfolios that would be affected by a lahar. In making the announcement the Minister stated that an engineering intervention at the Crater Lake would be inconsistent with the provisions of the National Parks Act, the Tongariro National Park Management Plan and the World Heritage Convention. "This area is of outstanding international significance for its natural values. Given the high natural values of the crater and the intense interest in the area," she said, "intervention would have been highly controversial and there would have been considerable uncertainty as to whether the required consents could have been obtained."

Both ICOMOS and IUCN have expressed their support for this decision.

The Bureau commends the State Party on its decision concerning the management of the ash build-up that has blocked the outlet of Crater Lake following the eruptions of Mount Ruapehu in 1995 and 1996.

The Bureau considers that the decision to install a state of the art alarm and warning system and to construct a bank alongside the Wangaehu River rather than undertake engineering work at the Ruapehu Crater lake will maintain the outstanding natural and cultural values of the site whilst giving due regard to public safety issues. The Bureau expresses its hope that all parties will accept the decision.