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“TSUNAMI INUNDATION ZONES", are those that may be affected by tsunami in a maximum credible tsunami event, i.e. they represent the expected worst-case tsunami inundation. These areas represent areas that should be evacuated from in the event of a “long or strong” earthquake, or a tsunami warning. The “TSUNAMI INUNDATION ZONES" were derived differently for the different coastal areas in the Waikato. For the Coromandel Peninsula and the Firth of Thames, the inundation areas are a simplified version of the modelled extent for a maximum credible tsunami event – wave heights vary and there is unlikely to be time for an official tsunami warning. For the West Coast, the inundation areas are areas likely to be susceptible to tsunami, based on preliminary modelling and investigation – wave heights are likely to be relatively small, and there will likely be time for an official tsunami warning. For more information on tsunami evacuation, including Community Response Plans, the Emergency Management staff for the relevant District Council should be contacted. More information on tsunami hazard can be found on the Waikato Regional Council tsunami webpages.

 “SAFE ZONES” are areas that should be evacuated to in the event of a tsunami, if it is possible to do so. Note that for most of the Waikato coastline there is unlikely to be time for an official tsunami warning, thus follow the “Long or Strong: Get Gone” message. The Safe Zones are defined as areas in the vicinity of the coast which are above the 20 m contour line. The 20 m contour line is used, as for the eastern Coromandel (highest tsunami hazard in the Waikato region), this elevation is not predicted to be affected by a maximum credible tsunami event in any coastal communities. The 20 m contour is used for the rest of the Waikato Region for consistency and to be conservative (although tsunami wave heights are predicted to be lower for the Western Coromandel, Firth of Thames and West Coast – as shown by the “Blue is wet” tsunami inundation areas). Note that due to the low-lying nature of the Hauraki Plains, no “Safe zone” exists for this area inland. The messaging is instead to move as far away as possible from the coast and any rivers connected to the coast. For more information on tsunami evacuation, including Community Response Plans, the Emergency Management staff for the relevant District Council should be contacted. More information on tsunami hazard can be found on the Waikato Regional Council tsunami webpages.

 Note data includes changes to Tsunami Inundation Zones at Matarangi as at June 2021.

The Safe zones and Inundation zones data should be considered indicative only. While some areas are based on reasonably accurate LiDAR based contours, in other areas, where no LiDAR data is available, the 20m contour is based on NZTOPO50 data that is less accurate. Some LiDAR data is also old and in need of updating.