A future residential development is planned for a parcel of land at Hobbs Bay Farm (5 Daisy Burrell Drive) at the end of Whangaparaoa Peninsula, Auckland. This proposed subdivision is based on large residential lots with an average size of 1000m2 while working with the topographical and clifftop features of the site.
Due to coastal nature of the site, with cliffs ranging from five metres to 15 metres in height, many geological and geotechnical challenges are present. Multiple small-to-large-scale slope instability features are also evident across the site, with coastal erosion also playing a large role.
The site also contains multiple archeological features such as middens and a pā site, as well as an historic heritage building - the original Hobbs Homestead.
What we did
Although the development is still in its early stage and awaiting construction, geotechnical considerations and recommendations were required to address the instability and coastal regression across the site, whilst preserving the numerous archaeological and heritage features.
This included detailing numerous in-ground (palisade) walls and extensive networks of deep subsoil drainage in targeted areas to remediate slope instability, in addition to appropriate setbacks for future coastal regression and Areas Susceptible to Coastal Erosion and/or Instability (ASCIE).
Findings / Next steps
CMW Geosciences has carried out multiple phases of geotechnical investigations to date. It has been important to build a solid, trusted relationship with our client, as well as the current occupant of the land.
This is an ongoing land development project, with further investigations underway to help address groundwater drawdown and coastal cliff regression queries.