Natural Hazards

Natural hazards are a part of Kaipara’s environment. They are natural occurrences that may have a negative effect on human life, property, or other aspects of the environment. As our climate changes, natural hazards are projected to increase in severity and intensity. Climate change planning and response is also natural hazards planning and response. 

Natural hazards mapping

Natural hazards mapping is an important step in identifying, communicating, and managing natural hazards. Hazards mapping helps us identify places exposed to coastal erosion, coastal flooding, and freshwater flooding, and to determine how that exposure will change as sea levels rise. Both Kaipara District Council and Northland Regional Council map natural hazards, but Northland Regional Council has primary responsibility.

Updated coastal hazards maps

Northland Regional Council has released new coastal flood hazard and coastal erosion hazard maps in April 2021. These maps are in an advisory period for three months. They become final July 2021.  

Here is more information on the updated maps

Read more on the Northland Regional Council coastal maps webpage

Coastal erosion

Coastal erosion is the loss of land due to coastal processes like waves or tidal currents. Coastal erosion can be gradual or sudden. The rate and extent of coastal erosion depends on a variety of coastal processes and on the geology and sediment make-up of the land. Some coastal areas accrete (grow) instead of eroding.

Coastal erosion can cause damage to property and dwellings, infrastructure and transport networks. It can pose risks to life, cause environmental degradation and cause harm to other things valued.

Coastal erosion is projected to get more intense as sea levels rise and as coastal storms grow more severe. Coastal erosion may also be exacerbated by prolonged drought. Visit NRC’s coastal erosion page to learn more about coastal erosion in Northland.

As of April 2021, four sites in Kaipara District have been identified as part of a coastal erosion hazard zone. Mangawhai Heads, Whakapirau, Bayly’s Beach and Glinks Gully. See the natural hazards mapping section above for more information.  

Coastal flooding

Coastal flooding happens when low-lying areas become submerged under sea water, often due to storm surge generated by large storms. Coastal flooding can cause damage to property and dwellings, infrastructure and transport networks. It can pose risks to life, cause environmental degradation and cause harm to other things valued.

Coastal flooding is projected to get more intense as sea levels rise and as coastal storms grow more severe. You can find out more about these coastal hazards on Northland Regional Council’s coastal hazards website. Visit NRC’s coastal flooding page to learn more about coastal flooding. 

As of April 2021, the whole of Kaipara’s coastline is mapped for coastal flooding, including Kaipara Harbour. See the natural hazards mapping section above for more information 

Drought

Drought is an extended dry period, caused by insufficient rainfall, that restricts or prevents human activity such as farming or power generation. Certain areas may have water restrictions put in place during droughts.

Drought itself is not a mapped natural hazard. Northland Regional Council instead has rainfall maps and river and rainfall data available.

Visit our Drought and Water Restrictions page for more information on current water supply, water restrictions and drought response.  

Flooding

Flooding is the covering of normally dry land as the result of extreme rainfall. Flooding is a known and experienced risk for Kaipara communities.

Northland Regional Council has mapped priority rivers, including Kaihu, for 1 in 10 year and 1 in 100 year flood events. To see these maps and learn more, visit their river flooding page.  

Geotechnical hazards

Geotechnical hazards refer to ‘land-related’ hazards like land instability, earthquake and liquefaction, and volcanic activity. Geotechnical hazards also include soil-related hazards like acidic sulphate corrosion. 

Council commissioned geotechnical reports in 2019. Visit the Geotech reports page.  

Tsunami

A tsunami is a series of waves generated when a large volume of water in the sea is rapidly displaced. A tsunami can be caused by large submarine or coastal earthquakes; underwater landslides; or volcanic eruptions beneath or near the sea. A tsunami can violently flood coastlines, causing devastating property damage, injuries and loss of life. Evacuation zones are identified for Civil Defence and Emergency Management purposes.

Visit NRC’s civil defence and natural hazards webpages for more information. 

Fire hazards

Head to the national fire emergency webpage.

Connected services

Hazards mapping informs not only our climate change response, but also our consents services and emergency management services.

Visit our Resource Consents page and Building Consents page to find out how natural hazards impact land-use, development, and building, including information on LIMs and PIMs.

Visit NRC’s Civil Defence page for more information on how you can be prepared for emergency events, including natural disasters.