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.

  • Mahinga kai - what species interests you?

    In Kaitiaki Tools the term mahinga kai generally refers to indigenous freshwater species that have traditionally been used as food, tools, or other resources.
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    Chemical contamination and aquaculture

    What are the potential sources of chemical contamination from aquaculture activities?
  • Chemical contamination and mining

    What are the potential sources of chemical contamination from mining activities?
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    Further reading

    References, further reading, and links to useful websites.
  • Dairy farming activities

    Dairy farms operate to maximise milk production
  • Loss of riparian vegetation

    Plants and trees along the water margins and banks are called riparian vegetation.
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    Stormwater - an introduction

    Stormwater poses risks to NZ’s urban streams & coastal waters, affecting ecological health & the cultural, social, & economic value of these environments.
  • Development of sustainable water supply and treatment systems for a coastal Fijian village

    Research Project
    This collaborative NZaid project worked with coastal Fijian villagers at Votua on the Coral Coast of Viti Levu to develop pragmatic water supply and waste treatment solutions to protect public health and reduce contamination of coastal waters.
  • Sediment

    When soils erode, sediments are washed into waterways.
  • Wastewater Treatment

    Wastewater treatment is the separation and extraction of solid waste from liquid waste, and the removal of nutrients and pathogens.
  • LakeSPI diver

    LakeSPI: Keeping tabs on lake health

    Software Tool/Resource
    The condition of many NZ lakes is under threat from land-use changes and the invasion of alien aquatic plants.
  • Water diversion

    Diverting water away from its natural channel for commercial or private use.