Climate change and the associated rise in sea level is likely to increase the risk of coastal hazards such as coastal flooding, coastal erosion and rising groundwater. This is a challenge facing low-lying inland and coastal communities in Ōtautahi Christchurch, and all around the world.
Christchurch City Council has created the Christchurch Coastal Hazards Viewer for visualising the potential future risks of coastal hazards. The information presented in the Viewer comes from the 2021 Coastal Hazard Assessment, which was carried out for the Council by the environmental and engineering consultancy Tonkin + Taylor.
Check out the Christchurch Coastal Hazards Viewer
The Viewer presents results from the 2021 Coastal Hazard Assessment, showing how hazards may change over time with sea level rise. You can explore:
- Coastal Flooding – how flood depth and extent might change with different sea level rise scenarios.
- Coastal Erosion – how much land may become prone to erosion over time.
- Groundwater – where sea level rise could cause elevated groundwater or surface ponding.
How to use the Viewer:
- Choose a hazard: Click on one of the tabs at the top (Coastal Flooding, Coastal Erosion, or Groundwater).
- Zoom to your area: Enter a property address in the search bar at the top right.
- Select a location: Use the dropdown on the left to choose either Christchurch Coast or Banks Peninsula.
- Adjust the scenarios: Use the vertical slider bars on the left to change the time period and sea level rise amount. As you move the sliders, the map will update automatically.
- Explore further options: You can also tweak assumptions around flood event frequency or long-term erosion processes for a more detailed look.
This tool offers a clear, visual way to understand how different areas could be affected by coastal hazards over time. While it’s not designed to assess risks to individual properties, it does give a neighbourhood-scale view.
For more information about coastal hazards and adapting to sea level rise, see the Council website page for coastal hazard adaptation planning. The ‘Coastal hazards’ section of the website includes the 2021 Coastal Hazard Assessment report, as well as many other technical reports on coastal hazards.