Te mahere aituā ao tūroa Natural hazard maps

Natural hazard maps show where different types of hazards, such as flooding, landslides, earthquake shaking, or tsunami, could occur across an area. They are built from scientific data and modelling to help answer one important question: What natural hazards could affect this location?

Natural hazard maps are not predictions. They show the possible scenarios and patterns of what could happen, not certainty of an event. A location appearing on a hazard map does not mean a hazard event will happen there, or that your property will be damaged if one does.

The Natural Hazards Portal currently shows hazard maps for the Bay of Plenty region, as part of a pilot to test how regional hazard information can best be displayed and used. We plan to expand hazard maps to other regions over time.

Knowing that a hazard could affect your area is useful, but it's only part of the picture.

Whether a property is damaged in a natural hazard event depends on more than location alone. It also depends on how a home is built, where and how it sits on the land, and how it has been maintained.

Two homes in the same flood area could experience very different outcomes depending on floor height, drainage, and construction. Two properties on similar slopes can perform differently based on ground conditions and site management. Earthquake damage varies significantly depending on how a home was built and how it has been cared for.

This is why hazard maps, on their own, cannot tell you:

• how likely damage to your home is
• how severe that damage might be
• what you can do to reduce it

The Portal is working towards bringing this fuller picture to users — bringing together hazard information and what we know about how buildings perform.

See what the Portal does today, and what comes next.

Seeing your home on a natural hazard map can feel confronting. You may feel surprised, worried, or even unfairly labelled—especially if you haven't experienced a natural hazard event before.

It's important to know that these maps are not a judgement about your home, and they are not a prediction of what will happen. They show where natural hazards could occur, based on the best available information. They do not capture every detail, such as how your home is built or any steps you may have taken to reduce any potential risk.

Being in a hazard-prone area does not mean your home will be damaged. But it is worth understanding what hazards exist in your area, and what that means for your situation.

If you want to understand more, a good starting point is your local council, a licensed building practitioner, or the resources available on this Portal.

Every natural hazard map is different, so it's important to always check three things:

The title: what hazard is being shown, and for what area.

The legend: what the colours, lines, or symbols mean. Shading or zones that look similar across different maps can mean very different things.

The scale: whether the map covers the whole country, a region, or a local area. This matters because hazard maps are created for a specific scale and should only be used at that scale. A regional map is not designed to assess an individual property.

If you need a site-specific assessment of a property, the right step is to consult your local council or a qualified professional. Links to local hazard information sources are available on each property page.

The following sections provide support on interpreting specific natural hazards maps on the Natural Hazards Portal. These maps are currently only available for the Bay of Plenty region.

Active faults

Active faults can rupture the Earth's surface where movement has occurred at least once in the past 125,000 years (25,000 years in the Taupō Rift). These faults are often seen as as potential sources of future earthquakes.

The lines on the active fault map represent fault traces at or near the surface of the ground. Each fault is grouped by how likely it is to rupture and cause an earthquake, this is known as its recurrence interval.

• Red = less than 2,000 years between earthquakes (more frequent) 
• Blue = more than 2,000 years between earthquakes (less frequent) 
• Dark grey = not enough data to determine 

The direction of most active faults in the Bay of Plenty run north–south within the Taupō Volcanic Zone, including the Whakatāne, Waiōhau, Edgecumbe, Waimana, and Paeroa faults.

Recurrence intervals are statistical averages, not predictions. This data does not tell you when or where an earthquake will occur. Faults outside the "active" definition can still generate earthquakes, and earthquakes can affect the region from faults beyond the map area. There are also unknown, unmapped faults that are likely to exist across the country.

Learn more about the NZ Active Faults Database (Earth Sciences New Zealand). open_in_new

Earthquake shaking map

This map shows how strong earthquake shaking could be across the Bay of Plenty region.

The colours represent the strength of shaking that has a 10% chance of being exceeded in 50 years, based on the 2022 National Seismic Hazard Modelopen_in_new. 

• Purple (darker) = weaker modelled shaking 
• Red (brighter) = stronger modelled shaking 

The eastern Bay of Plenty and areas south of Rotorua have higher modelled shaking. Western areas have lower modelled shaking. Shaking strength varies according to how often earthquakes occur nearby and the types of earthquakes that could happen.

Each grid square shows an average shaking value for that area, not a value for a specific property. 

Shaking is measured on how fast the ground moves during an earthquake. This is called Peak Ground Acceleration (PGA). In the Bay of Plenty, modelled PGA values range from around 0.18g (weaker shaking) to 0.57g (strong shaking, where it can be difficult to stand upright).

This is modelled hazard, not a forecast. It does not show damage or risk and does not account for a building's strength. The model outputs assume that most ground conditions are firm, however this is not the case in many places. Actual shaking at a specific location may be higher or lower depending on local soil and rock type. 

Learn more about the National Seismic Hazard Model (Earth Sciences New Zealand).open_in_new

Liquefaction

This map shows how susceptible different areas of the Bay of Plenty are to liquefaction.

Liquefaction is a natural process that occurs when partially saturated soils are disturbed by intense shaking and therefore lose their strength and stiffness. The most vulnerable areas are typically low-lying estuaries, dune systems, and flat flood plains.

The colours show liquefaction vulnerability (how likely the area is to liquefy) for a large earthquake scenario:

• Warm colours (red/orange) = higher vulnerability 
• Cool colours (blue/green) = lower vulnerability 
• Grey = not assessed 

Vulnerability categories range from Very Low (more than 99% chance of no significant ground damage) to High (more than 50% chance of moderate to severe ground damage). Some areas are marked 'Undetermined' where there was not enough data to assess, or 'Unlikely/Possible' where data was not precise enough to assign a specific vulnerability level.

This is modelled vulnerability, not a forecast. It does not show damage or risk and does not account for building strength or performance. The data comes from work commissioned by Bay of Plenty Regional Council and Tauranga City Council. The Tauranga City Council data was mapped at a higher precision than the rest of the region, so you may notice more detail in that area.

Learn more about liquefaction (Tauranga City Council).open_in_new

Tsunami

This map shows the different scenarios of where tsunami inundation (how far in land a tsunami may travel) could reach along the Bay of Plenty coast.

The modelling these maps are based on assess tsunamis generated by earthquakes very close to the Bay or Plenty coast (along the Tonga-Kermadec Trench, north of East Cape). Low-lying and coastal areas along the entire Bay of Plenty coastline are shown as exposed to tsunami inundation.

The two colours shown on the map represent different tsunami scenarios:

• Darker blue = inundation from a 5m tsunami (estimated once every 1,000 years on average) 
• Lighter blue = inundation from an 8m to 15m tsunami (estimated once every 2,500 years on average)

This is modelled hazard, not a forecast. The area inundated by an actual tsunami would differ from what is shown here, this is because we cannot predict the characteristics of how and why a tsunami is generated. This map shows how far inland a tsunami may travel. It does not show potential damage or risk, and does not show the tsunami evacuation zones. The modelling was carried out by Earth Sciences New Zealand for Bay of Plenty Regional Council. 

Learn more, including methodology and limitations (Bay of Plenty Regional Council). open_in_new

Volcanic activity

This map shows areas exposed to volcanic hazards in the Bay of Plenty region. 

The Bay of Plenty contains four active volcanic areas that are monitored by GeoNet: Ōkataina Volcanic Centre, Tūhua/Mayor Island, Whakaari/White Island, and Pūtauaki/Mount Edgecumbe. These sit within the larger Taupō Volcanic Zone, which stretches 350 km from Mount Ruapehu to Whakaari.

The points on the map show monitored volcanoes. The coloured areas show hazard zones for the Ōkataina and Pūtauaki volcanic systems only:

• Orange = closer to previous vents (higher hazard) 
• Yellow = further from vents (lower hazard)

These zones cover hazards such as sudden explosions, pyroclastic flows, lava flows, and ballistics. They do not cover ashfall, gases, lahars, or volcanic unrest.

This is modelled hazard, not a forecast. Volcanic hazards could affect areas outside the zones shown, including from volcanoes beyond the map area such as Taupō and Ruapehu. Hazard areas are not currently shown for Whakaari/White Island or Tūhua/Mayor Island.

The volcanic hazard areas are adapted from Scott & Nairn (1998); monitored volcanoes are provided by GeoNet. 

Learn more about volcanic hazards in the Bay of Plenty (Bay of Plenty Regional Council).open_in_new

Geothermal activity

This map shows indicative areas where geothermal activity is known or likely to occur in the Bay of Plenty region.

Geothermal activity in the region is associated with areas of active or recently active geological activity beneath the ground. Most geothermal systems lie within the Taupō Volcanic Zone, which extends south into the Waikato region and offshore to Whakaari/White Island.

While geothermal features are valued for energy, tourism, and cultural heritage, some can pose hazards. Not all geothermal systems present a hazard, and the presence of a geothermal system on this map does not necessarily mean there is a risk to people or property.

Most geothermal hazards in New Zealand (around 97%) are hydrothermal, meaning they involve heated water or steam. This includes features such as hot springs, geysers, mud pools, and ground collapse. The map shows the broader geothermal system areas, which include where hydrothermal hazards are most likely to occur.

• Teal = known or likely geothermal activity zones 

These are indicative extents only. Geothermal activity may occur outside the areas shown. This is not a forecast and does not show damage or risk.

Learn more about geothermal activity in the Bay of Plenty (Bay of Plenty Regional Council).open_in_new

Maps on the Natural Hazards Portal come from a variety of organisations (such as councils or research agencies). Follow the links to the original data sources to learn how each map was created, how it should and shouldn't be used, and any possible limitations associated with it.

Visit our Portal Data Sources page to learn more.

The Portal currently shows where natural hazards could occur, alongside settled EQC/NHC claims since 1997. This is a great good starting point, but we know it's not the complete picture of risk.

Over time, we plan to add more tools and information that help you understand not just where natural hazards exist, but what they could mean for your home or community. This will include more natural hazard map coverage, integrating hazard models and providing assessments and information on how homes with similar characteristics typically perform in different natural hazard events, and what practical steps can help to reduce risk and improve resilience. This might be improving drainage, adjusting floor levels, or strengthening key structural building elements.

Our focus will continue to be on helping you understand your options and take practical action to reduce your risk from natural hazards.

In the meantime, there are steps you can take now:

• Learn about the natural hazards that may affect your area
• Consider how your home is built and how it sits on the land
• Talk to your local council, a builder, or an engineer if you want more specific advice
• Look for opportunities to reduce risk over time, particularly when renovating or maintaining your property