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.

Rachel Crawford and Paul Franklin inspecting a fish passage on the Waikato River.

Freshwater and Estuaries Update

A seasonal review and outlook for New Zealand's water resources, and an update on NIWA's freshwater research

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Research

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Tools & Services

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  • Link to source page

    Biosecurity tools

    Software Tool/Resource
    Our biosecurity management tools include: assessment models, field surveys, management advice and the testing of control methods.
    Freshwater
    Freshwater fish

  • Link to source page

    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.

  • Link to source page

    catfish

    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.
    Invasive species
    Fish
    Freshwater fish

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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.

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    Sediment tools

    More information about our sediment tools.

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    Restoration tools

    More about our restoration tools.

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    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
    18 June 2012
    Freshwater quality

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

    News article
    10 April 2012

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    Waikato River Independent Scoping Study (WRISS)

    Research Project
    NIWA is involved in research and consultation' aimed at improving the health of our freshwater systems.
    Freshwater quality

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    Flyathalon - NIWA gives aquatic insects an obstacle course

    News article
    23 March 2012