Work gets underway later this week drilling boreholes in Christchurch's Port Hills.
The work will initially involve drilling at five sites - Clifton Terrace/Kinsey Terrace, Lucas Lane, Deans Head, Richmond Hill and Moa Bone Cave area.
City council city environment general manager Jane Parfitt said the work was expected to take three months to complete.
"It is part of the council's wider programme of geotechnical investigations in the Port Hills.
"The drilling will enable the council to better understand the nature of the soil, bedrock and groundwater conditions, as well as help inform decisions on planning and development in the Port Hills," she said.