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

Go to the article

Research

Explore

Tools & Services

Explore

Contacts

View contacts

  • 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

    (no image provided)

    Toitoi

    One of the most common species of freshwater fish in Aotearoa is the common bully or toitoi.
    Freshwater quality

  • Link to source page

    (no image provided)

    Water clarity

    Water clarity or turbidity is the cloudiness or haziness in a fluid caused by individual small particles (suspended solids).
    Freshwater quality

  • Link to source page

    Wood processing

    Trees are grown and converted into a range of useful timber and paper products.

  • Link to source page

    Dry stock

    Dry stock farming consists predominantly of pasture grazing beef cattle, sheep, and deer for meat, wool, and velvet production.

  • Link to source page

    What is the proposed activity or industry?

    Various industries and land use activities have the potential to impact on water quality and mahinga kai unless properly managed.

  • Link to source page

    Water dams

    Damming water for urban use, hydro-electric power generation, irrigation, and other industrial and commercial uses.
    Floods

  • Link to source page

    Water abstraction and agriculture

    How do agricultural activities potentially influence water flows?
    Freshwater

  • Link to source page

    (no image provided)

    Mitigation and best practice options

    Some simple steps to minimise the effects of aquaculture activities on water quality and mahinga kai.
    Aquaculture

  • Link to source page

    (no image provided)

    Tuna

    Tuna or freshwater eels are a very significant, widely-valued, heavily-exploited, culturally iconic mahinga kai resource.
    Freshwater
    Freshwater quality

  • Link to source page

    (no image provided)

    Water resources and mining

    How may the activities of the mining industry influence water resources?
    Freshwater

  • Link to source page

    Restoration and enhancement of piharau / kanakana / lamprey

    Research Project
    NIWA is leading a new six-year research project that seeks to increase our understanding of piharau/kanakana/lamprey, using Mātauranga Māori, social science and biophysical science approaches.
    Freshwater
    Freshwater fish
    Taonga species