Interactive online tool – Extreme coastal flood maps

This Extreme coastal flood map dataset comprises 21 coastal flooding scenarios from around Aotearoa New Zealand, representing relative sea-level rise ranging from 0 to 2 metres in 10 cm (0.1 m) increments. 

According to the Ministry for the Environment, 1.0 m of sea-level rise can be expected by the end of this century, or even sooner in places where land is subsiding. 

Rising sea level is already causing more frequent flooding along many coasts and will greatly increase the frequency and consequences of flooding in future. 

Decisions about how we adapt to sea-level rise need to be based on information about our exposure to coastal flooding, both now and in the future after a period of rising sea levels. 

More layers also available

In addition to the 1% AEP (annual exceedance probability) scenario provided here, NIWA has also mapped 39, 18, 10, 5, 2, 1, 0.5, 0.2 and 0.1% AEP scenarios (equivalent to return periods of 2, 5, 10, 20, 50, 100, 200, 500 and 1000-years). All of these scenarios have additional relative sea-level rise increments added up to 2m above present-day mean sea level. GIS polygons of flooding extent and rasters of flooding depth are available.

These additional ARCGIS layers are available on NIWA’s DataHub.