Wetland identification

Wetlands are determined by:

  • Hydrology (‘wetness’)
  • Soils
  • Plants and animals


Wetlands do not have to be saturated with water all year round… but they do have to be saturated intermittently. The hydrology needs to be monitored over at least a year which makes it impractical for most assessments.


Wetland (hydric) soils are defined by the water saturation. Soils are useful in defining a wetland because spot samples are definitive. However, the Resource Management Act definition is silent about soils.

Plants and Animals

Various plants and animals that are adapted to wet conditions are good indicators of wetlands. There is a national protocol for defining wetlands based on vegetation (Clarkson, 2014). All plants have been given ratings on a scale of 1-5 for how much they need wet conditions. Some plants have a specialized need for a wet root zone.

Wetland habitat classes
Determining a wetland
Wetland mapping process
What if I don't agree with the outcome of the mapping process

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