River water quality: Nitrogen, modelled, 2016 - 2020

Adapted by Ministry for the Environment and Statistics New Zealand to provide for environmental reporting transparency. Dataset used to develop the “River water quality: Nitrogen” indicator, (available at River water quality: nitrogen | Stats NZ ).

Nitrogen in river waters is one of five parameters that provide an overview of New Zealand’s river water quality and how it is changing over time. Nitrogen is an essential nutrient for plants and algae. Some nutrient supply is a natural component of healthy rivers, but agricultural and urban land use, and infrastructure such as wastewater treatment plants, can add more nitrogen to waterways. Too much nitrogen can lead to excessive growth of algae, which can deteriorate river habitats. In very high concentrations, some forms of nitrogen, including nitrate-nitrogen and ammoniacal nitrogen, can be toxic to aquatic life.

This dataset shows:

concentrations of total nitrogen (TN), nitrate-nitrite-nitrogen (NNN) and ammoniacal nitrogen (NH4N) modelled for New Zealand’s river length, expressed as percentiles for the period 2016–2020

More information on this dataset and how it relates to our environmental reporting indicators and topics can be found in the attached data quality pdf.

Summary report available at https://environment.govt.nz/publications/environment-aotearoa-2022/.