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

Rivers

New Zealand has more than 70 river systems. NIWA capability supports the measurement, knowlege and tools need to manage, protect and restore these vital waterways and their ecosystems.

  • Guidelines for sampling freshwater fisheries

    We have prepared a breakdown of the different guidelines that are available for sampling freshwater fisheries. The overview provides links to key documents that explain what should be considered when designing fish monitoring studies and how to implement the various sampling techniques.
  • Stepping into the river

    Feature story
    NIWA discusses, in depth, this year's most asked question—what is happening to our fresh waterways?
  • Nature knows best?

    Feature story
    Returning water to our waterways after we’ve used it in our homes, on farms and in industry is a complex and challenging process.
  • Climate Change Vulnerability Assessment (CCVA)

    Service
    To prepare for changes in climate, our freshwater and oceans decision-makers need information on species vulnerability to climate change.
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    Proud of your plants? 1 June 2017

    News article
    NIWA is doing a nationwide study to discover what makes the best riparian projects. Help us give you the knowledge to make the best riparian management decisions possible by taking our 5 minute survey.
  • Modelling vegetation-impacted morphodynamics in braided rivers

    NIWA is developing numerical models for predicting how the morphology of braided rivers responds to flow regulation and invasive exotic woody vegetation.
  • Modelling vegetation-impacted morphodynamics in braided rivers

    Research Project
    NIWA is developing numerical models for predicting how the morphology of braided rivers responds to flow regulation and invasive exotic woody vegetation.
  • Environmental flow tools

    Tools and software to assist with determining and managing environmental water flows.
  • Ngā Kete o te Wānanga: Mātauranga, Science and Freshwater Management

    Research Project
    New Zealand’s freshwater and estuarine resources provide significant cultural, economic, social, and environmental benefits. Competition for the use of these resources is intensifying, and many rivers, lakes and estuaries are now degraded.
  • Geomorphology influences periphyton abundance

    Research Project
    This research project investigated whether the mechanisms for periphyton removal in rivers relate more directly to hydraulic and geomorphic conditions than flow metrics.
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    Monitoring and maintenance of kōura

    Once you have identified the problem, and applied the necessary tools for restoring kōura to your stream, the next phase of your project is to monitor the site to see whether restoration works.
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    Applying the right tools to restore kōura to lakes and streams

    The tools available for restoring kōura to lakes and streams depend on what is causing kōura to decline.