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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  • Link to source page

    New buoy for Wellington Harbour to boost water quality information

    News article
    10 July 2017
    A buoy with the ability to “phone home” has been deployed in Wellington Harbour today to monitor currents, waves and water quality in the harbour.
    Freshwater quality
    Waves

  • Link to source page

    Hapū joins forces with NIWA in tuna research

    Feature story
    20 June 2017
    Local hapū and NIWA are working together to find out more about juvenile freshwater eels or tuna in streams connecting to the Wairua River in the Wairoa catchment in Northland.
    Fisheries
    Te Kūwaha and Māori

  • Link to source page

    Q&A: Another way to measure river health

    Feature story
    20 June 2017
    There’s another way of measuring the health of rivers – the health of invertebrate populations that need them, says John Quinn, NIWA Chief Scientist, Freshwater
    and Estuaries.
    Freshwater quality

  • Link to source page

    Erica Williams - Where the water is clean

    Feature story
    20 June 2017
    Erica Williams' story starts with the website of Moerewa School, where pupil Tyra-Lee explains her connection to a very special place in her small Far North town.
    Te Kūwaha and Māori
    Freshwater quality

  • Link to source page

    Raising the bar for swimmable rivers

    Feature story
    20 June 2017
    The government has released the ‘Clean Water’ package of proposed reforms, aimed at making more of our rivers swimmable. But how is ‘swimmable’ to be measured, and do these measures stack up?
    Freshwater quality

  • Link to source page

    The Love Bugs

    Freshwater quality

  • Link to source page

    Dairy turns the corner

    Feature story
    11 June 2017
    NIWA's Freshwater and Estuaries Chief Scientist Dr John Quinn believes the dairy industry has been responsive in the tools it has adopted to reduce its impact on waterways.
    Rivers
    Freshwater quality

  • Link to source page

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    Tuna - habitat

    Tuna are found in all sorts of habitats (places), including coastal estuaries, lakes, wetlands, rivers, mountain streams and even alpine tarns.
    Freshwater fish

  • Link to source page

    Stream periphyton monitoring manual

    This manual prescribes a set of sampling and analysis protocols applicable to most of the common stream habitats in New Zealand.
    Environmental Information
    Freshwater
    Ecological monitoring

  • Link to source page

    Nutrient overloading

    Nutrients in waterways are essential for the growth of algae and aquatic plants but too much can destroy an ecosystem.
    Freshwater quality

  • Link to source page

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    Kākahi

    The kākahi or freshwater mussel was a valuable mahinga kai resource for many Māori.
    Freshwater quality

  • Link to source page

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    Temperature changes

    Temperature affects the number and type of animals and plants that live in a waterway.
    Freshwater quality