Natural hazards

Find out what natural hazards are listed for your property and how this affects what you can do on your property.

Natural hazards include:

  • acid sulphate soil
  • coastal hazards
  • flooding
  • land instability
  • mining hazards

First use the hazard layer in our GIS Maps to find what natural hazards your property is at risk from. Then check our District Plan to see how these hazards affect how you can develop your land

What hazards apply to my property?

  1. Open the Hazards map within GIS
  2. Image for the search icon within GIS Maps. Enter your address in the top left hand search box
  3. Image for the layers icon within GIS Maps. Click on 'layers' in the banner
  4. Select hazard layers from the right-hand side bar to what applies to your property. 

District wide rules for hazard areas

The District Plan includes rules for development in flooding, mining subsidence and coastal hazard areas.  These rules may require you to obtain a resource consent, in addition to meeting building consent requirements relating to natural hazards. 

District Plan

Natural hazards - Building consents

We are currently in the drafting stage of the natural hazards plan change.

We have provided draft versions of the District Plan chapters for feedback from all members of the community. This is an opportunity for early engagement before we begin formal consultation.

Have Your Say - Hazards and Esplanades Plan Change package

Types of natural hazards

Acid sulphate soil

Acid sulphate soils are naturally occurring, having been deposited when the sea level was around 5 metres higher than it is at present, 5 to 10 thousand years ago.

While the land was under the sea, salts in the seawater mixed with this land. Now that the sea level has dropped this land which was under the sea and mixed with salty sea water is now available for use. 

Areas that are known to have acid sulphate soil are shown on our GIS maps. You can read more about this phenomenon on the following page:

Acid sulphate soil planning policy page

 

Coastal hazards

Erosion, landslips and sea water flooding are the dominant natural coastal hazards along the District's coastline.

Coastal erosion is either a long-term trend or a significant short-term shoreline fluctuation, especially on sand dune-backed coasts. 

Landslips are directly associated with coastal erosion where the geology is relatively weak and prone to slope failure.

Severe coastal storms or tsunamis produce waves which can temporarily flood low-lying coastal areas. The effects of climate change are likely to increase hazards in the coastal zone.

Coastal hazards reports

Coastal Management Strategy

Review of Coastal Hazard Zones for Eleven Selected Beaches(PDF, 2MB)

Coastal Hazard Risk Zone Assessment for Pataua and Matapouri Bay(PDF, 4MB)

Coastal Erosion Hazards Review - One Tree Point to Waipu Cove(PDF, 597KB)

Projected Sea Level Rise - Ruakaka and Marsden Point(PDF, 2MB)

Coastal Hazard Zone Assessment for One Tree Point and Marsden(PDF, 1MB)

Coastal flooding and coastal erosion

The Northland Regional Council manage the coastal hazard maps for coastal flooding and coastal erosion.  

In April 2021, the Northland Regional Council released a new update to the coastal flooding and coastal erosion maps.   

Update to coastal hazard maps (nrc.govt.nz)

Flooding

Tropical storms and high rainfall intensities  expose many areas to flooding. There are obvious floodway areas plus areas that are susceptible to ponding. 

The flood mapping is used in the assessment of applications for resource consent and / or building consent.

Flood Susceptibility Mapping Report 2001(PDF, 1MB)

Waipu Cove Flood Management (2015)(PDF, 2MB)

Northland Regional Council update to river flood maps 

In November 2021, the Northland Regional Council released a new update to the Northland's region-wide river flood maps. 

Update to river flood maps (nrc.govt.nz)

Region-wide river catchments analysis - technical reports (nrc.govt.nz)

Land instability

Geological characteristics and soil types in the District mean that some areas some areas should be developed carefully, and may require substantial works to avoid, remedy or mitigate land instability hazards. 

Inappropriate earthwork activities and / or the removal of vegetation also contribute to land instability. 

Land stability reports

Urban Land Stability Hazards for Kamo, Maunu, Onerahi, Otaika and Tikipunga(PDF, 386KB)

Urban Land Stability Hazards for Hikurangi, mid-Kensington, Whangarei City Centre and East Kamo(PDF, 836KB)

Urban Land Stability Hazards for Kensington, Morningside and Port(PDF, 203KB)

Coastal Slope Instability Hazards for Oakura to Langs Beach(PDF, 549KB)

Mining hazards

Coal mining was formerly a major industry in Northland and major coalfields were located at Kamo and Hikurangi, both of which are now urbanised. Hazards such as subsidence, sink hole formation and unstable fill restrict development in these areas.

A geotechnical report is required for development withing areas of mining subsidence.

Mine zone reports

Mine Subsidence Hazard - Hikurangi Area(PDF, 242KB)

Mine Subsidence Hazard - Kamo Area (2013)(PDF, 2MB)

Mine Subsidence Hazard - Kamo Area (2005)(PDF, 307KB)

Kamo Mine Zones Map (March 2005)(PDF, 1MB)