DOC Visitor Facilities
Back Country Hut
Geo-Logic Ltd undertook a geotechnical risk assessment of a back country hut in Nelson Lakes National Park threatened by an avalanche, which carried debris to within 10m of the hut.
A prompt response to a supplied geotechnical brief was supplied and generated a report on our findings and recommendations.
Virtually all back country huts are relatively high risk and subject to various hazards which can be difficult to mitigate. The terrain of much of the Nelson Lakes National Park is steep to very steep, subject to high rain/snowfall and is located within a zone of very high seismic activity. A number of active scree slopes punctuate the slopes of the ranges making up the Park.
The Kaiteriteri track is an easily accessible, high-use walking track in a popular holiday area. A localised area of the Kaiteriteri Walk on DOC reserve was affected by sudden, and in one case dramatic, rockfalls. These rockfalls are understood to have developed following the failure of a large beech tree about 10m up the steep slope above the track. Evidence of active instability in the upper scarp area was observed as ground cracking and soil crevice development several metres upslope of the downed beech tree.
A geotechnical assessment was supplied, including an evaluation of the risk of rockfall to users of the track. Immediate mitigation measures were provided and an ongoing programme of monitoring established.
Fenian Quarry Track, Karamea, Department of Conservation (2001)
Geotechnical investigation of unstable quarry slopes above a high use walking track. A suite of mitigation options and rough order costings were developed ranging from reduction to elimination of the identified geohazards.
Harwoods Hole Viewing Platform, Abel Tasman National Park, Nelson, Department of Conservation (1997)
A geotechnical feasibility assessment for the positioning and design of a proposed visitor viewing platform overlooking the deepest vertical shaft in the southern hemisphere was completed for DOC. The engineering geological mapping of the site included an abseil inspection of the uppermost 15 metres of the 175 metre deep collapsed sink hole in limestone terrain.