On 1 July 2025, NIWA merged with GNS Science to become Earth Sciences New Zealand.

Freshwater

We provide public information on river, lake, and groundwater conditions across New Zealand including freshwater quantity and quality.

  • Identifying New Zealand freshwater fishes

    NIWA has a series of identification guides available to help you identify New Zealand fish species both in the field and in the laboratory. The quick-guides are great for use in the field and the formal keys provide a greater level of detail.
  • NZFFD publications and catchment number directory

    Access commonly cited references for the NZFFD and the Catchments of New Zealand publication.
  • Biosecurity tools

    Software Tool/Resource
    Our biosecurity management tools include: assessment models, field surveys, management advice and the testing of control methods.
  • Controlling water weeds with grass carp

    Research Project
    A Ministry for Primary Industries-funded study has shown that grass carp, in enclosures, can be used as an effective means of controlling invasive plant species in our waterways.
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    Freshwater pest species

    This is a user guide on non-native fish, reptile, invertebrate, algal and plant species that are recorded in New Zealand freshwaters.
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    Publications for water managers

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    Fish risk assessment model

    FRAM is powerful and simple to use - series of straight-forward questions about the biology and behaviour of any alien species lead to it being ranked and categorised as a high, intermediate, or low ecological risk.
  • Sediment tools

    More information about our sediment tools.
  • Restoration tools

    More about our restoration tools.
  • Catchment modelling

    We offer a range of catchment modelling services.
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    Float your boat! Scientists use hi-tech miniature Q-boat to measure river flows

    News article
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    Robot spies make new science discoveries in Fiordland’s World Heritage Park

    News article