The Port Hills Geotechnical Group (PHGG) was established in Christchurch, New Zealand, as part of the response and recovery to the 22 February 2011 Christchurch earthquake.[1] It was formed from several local and international engineering consultancies.[2] The group consisted of specialist slope stability experts, engineering geologists and geotechnical engineers from Aurecon, Geotech Consulting, GHD Group, Opus and URS Corporation, and it was supported by the University of Canterbury and GNS Science.[3] The group's initial function was to manage the response to geotechnical issues caused by the earthquakes in the Port Hills, including the southern suburbs of Christchurch, as well as Lyttelton, Te Rāpaki-o-Te Rakiwhakaputa, Governors Bay and other settlements around Lyttelton Harbour and the Banks Peninsula.
PHGG was subsequently contracted by Christchurch City Council and Canterbury Earthquake Recovery Authority to map and define the locations of mass movement hazards, such as rockfall and landslide, and to collate geospatial information for use in the rezoning of the city.[4] This information was subsequently used by PHGG in the assessment and mitigation of risks from these types of hazard, where they affected roads, property and infrastructure throughout the region. The information continues to be used in regional and local geotechnical risk assessments.[5]