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.

  • Freshwater monitoring and reporting

    Research Project
    NIWA's research on freshwater monitoring and reporting is one of three research areas within the 'Values, Monitoring and Outcomes' (VMO) programme led by Landcare Research.
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    What do we measure?

    Research Project
    A range of physical and chemical variables are measured in the NRWQN.
  • 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.
  • 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.
  • 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.
  • Managing water allocation on the West Coast

    Research Project
    This project investigated the capabilities and utility of NIWA’s Cumulative Hydrological Effects Simulator (CHES) tool for facilitating discussions and decision making associated with setting and applying water quantity limits in the Grey River catchment on the South Island’s West Coast.
  • Ngā repo o Maniapoto - Maniapoto wetland inventory

    Research Project
    Through the Te Wai Māori fund Ngā Repo o Maniapoto is a collaborative project between NIWA and the Maniapoto Māori Trust Board (MMTB) Whanake Taiao team that looks to develop an inventory of repo and puna (springs) for the Maniapoto rohe.
  • 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.
  • Mercury biomagnification in three geothermally-influenced lakes differing in chemistry and algal biomass

    Research Project
    This research project aimed to understand the causes behind differences in mercury in trout and other organisms in the Bay of Plenty/Te Arawa lakes—in particular what features of each lake explain why mercury in trout is higher in some lakes than in other lakes.
  • Flow requirements for galaxiid fish spawning

    Research Project
    Many of our iconic native fish species, such as whitebait and eels, rely on river flows to cue key life-cycle stages, including migration and reproduction. As pressures on water resources increase, the risk of disrupting these flow cues, and therefore impacting fish populations, becomes greater.
  • Understanding fish passage in New Zealand

    Research Project
    NIWA scientists have been investigating the different capabilities of our native freshwater fish species in order to help design effective solutions for overcoming barriers to migration