Three months of deep borehole drilling in the Port Hills begins this week.
The work - part of the Christchurch City Council's wider drilling programme - is aimed at finding out more about soil, bedrock and groundwater conditions.
The council says the information will help guide planning and development in the area.
Boreholes could reach 90 metres and some roads will have to be narrowed to make room for drilling equipment.
The Government announced last week that most homes in the Port Hills with uncertain futures will have to be abandoned.
The fate of 37 properties remains undecided.