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  Environment » Natural Resources » Water » Rivers » Water quality monitoring - rivers and streams

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WAIKATO RIVER: 10 sites along the Waikato River.

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WAIPĀ RIVER: 5 sites along the Waipā River.


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LAKE TAUPŌ: 13 sites in and around Lake Taupō.


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OTHER RIVERS: 100 river and stream sites with the region, including the Waipā, Piako, Waihou and Mokau rivers and their tributaries.

Waikato Regional Council measures water quality every month at 115 river and stream sites throughout the region. These include the Waikato, Waipā, Waihou and Piako rivers and the many streams that flow into them. We also monitor sites at Lake Taupō and at the streams that flow into it.  

Water quality in rivers and streams is influenced by the surrounding land uses and land management practices. So, here in the Waikato, we find that water quality is generally excellent in our upland bush areas, but it deteriorates markedly in the urban and lowland farming areas.

You can click on an image and link above to locate a site you're interested in, and find out more about its water quality. 

For an overall summary of these results and a snapshot of how we're tracking regionally, check out our environmental indicators.



The Ministry for the Environment (MfE) has introduced new categories to report on the suitability of rivers and lakes for human contact recreation puroses ("swimmabiilty") at national and regional levels.

However, the monitoring work carried out by Waikato Regional Council, and the resulting information presented on this site, is assessed using established guidelines and categories. 

This difference in reporting categories means that there will be a difference between Ministry for the Environment and Waikato Regional Council's swimmable standards at some locations. 

In some cases it will mean that a river or stream we say doesn't meet the acceptable state for swimming will now be categorised by the Ministry as "swimmable, under certain circumstances”. Have a look at the chart below, with the coloured flags, to help you understand the differences.

The key point is that Waikato Regional Council's standards are the more stringent. The new categories are less stringent than those established, and used under the National Policy Statement for Freshwater Management. The original, more stringent categories are what Waikato Regional Council measures by when reporting on whether a river or lake is swimmable. 

Also, remember there are many other factors that affect safety for swimming, including access and flow rates. The maps and our monitoring reports do not provide advice on these.

You can see a lot more information, including maps showing the Ministry for the Environment's suitability of rivers and lakes for swimming by checking out these links:


Water quality swimmability - Ministry for the Environment (MfE) categories vs Waikato Regional Council's standards

MfE categories Waikato Regional Council's standards
Blue rivers – Excellent water quality. It is OK to swim Meets Waikato Regional Council's standards for excellent or satisfactory water quality. It is OK to swim.
Green rivers –  Good water quality. It is OK to swim most of the time. Doesn't meet Waikato Regional Council's swimmability standards.
Yellow rivers – Fair water quality. It is OK to swim some of the time. Check LAWA or regional council first. Doesn't meet Waikato Regional Council's swimmability standards.
Orange rivers – Intermittent water quality. It is OK to swim now and then. Check LAWA or regional council first. Doesn't meet Waikato Regional Council's swimmability standards.
Red rivers – Poor water quality. It is not OK to swim.

Doesn't meet Waikato Regional Council's swimmability standards.


A bit more explanation on the difference

Currently Waikato Regional Council says that about a third (34 per cent) of Waikato waterways are swimmable. This is based on national e. coli bacteria and regional clarity criteria at measured sites.

But the Ministry for the Environment maps, which model water quality everywhere in the region, will now indicate where swimming is also

  • OK either 12 months of the year (blue)
  • most of the time (green)
  • some of the time (yellow)
  • OK now and then (orange). This is purely from an e.coli and cyanobacteria perspective, not clarity. (If clarity is poor a waterway can’t be assumed to be safe for swimming even if other factors are OK.)
  • The lowest category is red.

About 48 per cent of Waikato waterways will now fit into Ministry for the Environment categories as safe - or may be safe - for swimming (blue, green and yellow).

Want to learn more about our water quality monitoring?

Find out more about how we measure water quality.

Check out our publications for reports, science and information about our regional rivers, their water quality, and Waikato Regional Council's monitoring programmes. 

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