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.

  • How do clouds modify the response of mountain glaciers to climate change?

    Research Project
    While we know that glaciers are sensitive to changes in their local climate, our understanding of exactly how mountain glaciers will respond to climate change is incomplete.
  • Upper Rakaia weather station

    Snow and Ice Network

    Research Project
    NIWA has established a network of high elevation electronic weather stations to provide a solid basis to understand seasonal patterns and long-term changes to seasonal snow and ice in alpine regions of New Zealand.
  • Flood-harvesting effects on braided river geomorphology

    Research Project
    The alp-fed braided rivers of Canterbury are treasured for their landscape, recreational amenities, salmon- and trout-fishing, and unique riverine environments – which provide habitat to a host of endangered birds – but they are under threat from land-use intensification and a growing demand for irrigation water.
  • Weed Management

    Research Project
    Of the more than 70 aquatic plant species naturalised in New Zealand, more than 75% have become problem weeds or have been assessed as having the potential to become future problem weeds. Most of our lakes, rivers and streams are affected by at least one of these species.
  • Braided river morphodynamics and invasive exotic vegetation

    Research Project
    Braided rivers are an arena where woody weeds and floods are in constant competition with each other.
    Braided rivers naturally flood frequently, repeatedly mobilising their bed sediments and shifting their multiple channels.
  • Plastic pollution processes in rivers

    Research Project
    Most of the plastic in the ocean originates on land, being carried to the estuaries and coasts by rivers.
  • River forecasting: capabilities versus user requirements

    Research Project
    Currently there are gaps in understanding of user decision making processes and public needs and requirements for river forecasting in New Zealand. This project aims to bridge NIWA river forecasting aspirations and capabilities with both the public and decision makers’ requirements.
  • NZ Water Model - Hydrology

    Research Project
    Bringing together leading scientific organisations and regional councils, this project aims to develop a sophisticated computer modelling framework that will enable users to accurately predict how much freshwater is available, where it has come from, and how quickly it moves through New Zealand catchments.
  • The New Zealand Estuary Trophic Index

    Research Project
    Excessive nutrient input (eutrophication) threatens many New Zealand estuaries causing ecological problems, such as algal blooms and poor physical and chemical conditions for estuarine life.
  • National riparian restoration database project

    Research Project
    NIWA is undertaking a five-year nationwide study to find out how different approaches to riparian planting influence water quality improvements and to provide better guidance to the people and groups undertaking stream restoration.
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    Water Quality Monitoring Capabilities

    Research Project
    NIWA provides national capabilities in Water Quality Monitoring.
  • Landscape

    On-Site Household Sanitation Guidelines for Fiji

    Research Project
    A participatory project empowering communities with self-help tools to improve water, sanitation and hygiene.