Tauranga has a long history of landslides due to its combination of steep slopes and sensitive soils.
What is a landslide?
A landslide is the downward movement of rock, soil, or debris. Landslides can vary dramatically in both speed and size. From very slow (a few metres per year) to extremely fast (up to 80km per hour during major events) and from a single boulder rolling down a bank to massive debris flows covering many kilometres.
The stability of any slope depends on factors like soil type, water levels, and the steepness of the land. However, what makes landslides particularly concerning is that even slopes that appear stable may be slowly moving or close to failure. Even small environmental changes can trigger landslides leading to significant impacts. Most often landslides are the result of heavy rain, earthquakes, or slope modification by human activity.
You may also see terms such as "landslip", "slippage", "slip", and "falling debris" to refer to landslides.
Landslides in Tauranga
The combination of steep terrain and unstable soils in Tauranga creates ongoing landslide risk. The city has experienced significant landslide events for over a century, with documented damage dating back to 1907. More recent storms in March 1979, May 1995, May 2005, April 2017, and January 2023 have caused widespread landsliding across the city.
Management of landslide risk is a key consideration for Tauranga City Council. To help residents and developers understand landslide risk, Tauranga City Council maintains three types of hazard maps:
- Landslide susceptibility maps - show how likely different areas are to experience landslides
- Slope hazard zones - identify areas where slopes may be unstable
- Relic slips - show where historical landslides have occurred
These maps serve as a broad-scale tool that help determine when expert geotechnical advice is required for building consents, subdivisions, or land use changes. They provide a broad overview, but professional assessment is still needed when developing on specific properties.
Further information on how the maps were produced and what they show, as well as links to technical reports can be found on our city-wide landslide mapping page.
City-wide landslide mapping
Landslides on the Maungatapu Peninsula
Landslide mapping viewers