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  Environment » Environmental Information » Environmental indicators » Rivers and streams: monitoring and reporting » River water quality for ecological health

River water quality for ecological health

Why we monitor river water quality for ecological health

We monitor a representative cross-section of rivers and streams across the region to assess the suitability of water quality for native water plants and animals.

This indicator shows how suitable our water quality is for aquatic plants and animals to live there. We describe the average ‘pass rate’ for seven water quality measures:

  • dissolved oxygen
  • pH
  • turbidity
  • ammonia
  • temperature
  • nitrogen
  • phosphorus.

Sensitive aquatic plants and animals cannot live and thrive when water quality is poor.

Some contaminants (like ammonia and heavy metals) are toxic to aquatic organisms; others use up the dissolved oxygen that aquatic organisms need to breathe. Water that is too warm can stress sensitive fish and animals. Nuisance growths of water plants, algal slimes, and phytoplankton blooms can thrive when there are excessive levels of plant nutrients.

What's happening?

Water quality for ecological health is better in some parts of the region (for example, the Upper Waikato River and the tributaries of Lake Taupō) than in others (for example, Hauraki and the lowland tributaries of the Waikato River). This is mainly because of the greater intensity of land use in the lowland parts of the region.

Waikato Regional Council routinely monitors water quality at sites across the region. View a map of the ten sites on the Waikato River and the 104 sites on other
rivers and streams.

An average ‘pass rate’ for seven water quality measures (dissolved oxygen, pH, turbidity, ammonia, temperature, nitrogen and phosphorus) is determined by comparing results with national and local guidelines for ecological health.

More information

More detail on this indicator, including how and where Waikato Regional Council collects this information, is available in the Technical information page.

Useful links

Documents available from Waikato Regional Council

You can order any of these documents from our library. Most documents will incur a charge.

Tulagi, A. 2014. Waikato River Water Quality Monitoring Programme: Data Report 2013. Waikato Regional Council Technical Report 2014/31. Waikato Regional Council, Hamilton.

Tulagi, A. 2014. Regional Rivers Water Quality Monitoring Programme Data Report 2013. Waikato Regional Council Technical Report 2014/30. Waikato Regional Council, Hamilton.

When this indicator is updated 

This indicator is updated annually

Contact at Waikato Regional Council

Water Quality Scientist - Science and Strategy Directorate 



Updated April 2016

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