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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    Setting maximum turbidity levels for riverine fish (DSS)

    NIWA research has established turbidity limits to protect fish in New Zealand rivers.

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    Models to help manage erosion

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    Freshwater management tools

    Some of the useful methods, guidelines and modelling tools we've developed to assist with management of freshwaters.

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    Freshwater species and habitat management

    Find out how we can help you with freshwater species and habitat management.

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    Flow assessment and management

    We offer a range of flow assessment and management services.

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    Wastewater treatment

    We can help with wastewater treatment and ecotoxicology.

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    Water quality monitoring and advice

    More information about our water quality monitoring and advice services.

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    Specialist analytical services

    Service
    Find out more about our specialist analytical services.
    Algae
    Ecotoxicology

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    Impacts of meat and dairy processing

    What are the impacts of meat and dairy processing activities on water quality and mahinga kai?

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    Timber

    A range of wood products are produced in Aotearoa.

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    Mitigation

    Here are some simple steps to minimise the effects of riparian vegetation loss on water quality and mahinga kai.

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    Mitigation

    Simple steps to minimise the effects of chemical contamination on water quality and mahinga kai.
    Freshwater quality