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.

  • Wastewater Treatment

    Wastewater treatment is the separation and extraction of solid waste from liquid waste, and the removal of nutrients and pathogens.
  • What is Kaitiaki Tools?

    Kaitiaki Tools is a guide to teach people (especially hapū and iwi groups) who manage the resource consent process.
  • 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.
  • Dairy farming activities

    Dairy farms operate to maximise milk production
  • (no image provided)

    Tau kōura sample collection and processing protocol

    Tau kōura is a traditional Māori fishing method commonly used to harvest kōura or freshwater crayfish in areas where they are abundant.
  • (no image provided)

    Stormwater - an introduction

    Stormwater is a major concern for New Zealand because of its potential effects on the ecological health of our urban streams and coastal waters, as well as on the economic, social and cultural value of these environments.
  • (no image provided)

    Kanae

    Grey mullet have a worldwide distribution and Aotearoa is at the southern limit of their range.
  • (no image provided)

    Wastewater treatment activities

    Rural, urban, and suburban wastewater treatment methods.
  • (no image provided)

    Sediment and mining

    How can mining activities influence sediments in waterways?
  • 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.
  • Wood processing

    Trees are grown and converted into a range of useful timber and paper products.
  • Water diversion

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