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Waiwhakaiho River at Constance Street

The Waiwhakaiho River is a large ringplain river arising in the Egmont National Park and flowing through agricultural and industrial land to the sea. This lower reach site is in an industrial area of New Plymouth and is 27 kilometres from the National Park boundary at an altitude of 20 metres above sea level. This site is also monitored as part of the lower Waiwhakaiho River industrial monitoring programme. 

Macroinvertebrate data for Taranaki shown on LAWA may vary from some data reported elsewhere by the Taranaki Regional Council. This variation is because the level of macroinvertebrate identification used by the TRC has some minor differences from that used by other Councils and LAWA, affecting the taxonomic richness and % EPT taxa scores. Taranaki Regional Council also uses Macroinvertebrate Community Index (MCI) scores which have been modified to reflect the conditions experienced in Taranaki, while the scores shown here are based on the National MCI scores. For more details, the full state of the environment report is available at

Ecological data for this site

This dashboard shows the result of macroinvertebrate sampling at this site.  It displays three measures, macroinvertebrate community index, taxanomic richness and percent EPT

If 'N/A' is showing, there are not enough data to calculate a 5-year median.  You can select the 'Show more information+' box under each measure to see the available historic data.

  • MCI

    Quality class based on MCI score
    The median of the last 5 years of data

    {{MciText | uppercase}}

    The Macroinvertebrate Community Index uses aquatic macroinvertebrates to assess the health of streams in New Zealand.
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    MCI sample history at this site

    MCI for Waiwhakaiho River at Constance Street
    MCI score

    What do the icons mean?

    MCI score of more than 119. Streams in excellent ecological condition. Indicative of excellent water quality and/or habitat conditions.
    MCI between 100 and 119. Streams in good ecological condition. Indicative of good water quality and/or habitat conditions.
    MCI between 80 and 99. Streams in fair ecological condition. Indicative of only fair water quality and/or habitat condition.
    MCI less than 80. Streams in poor ecological condition. Indicative of poor water quality and/or poor habitat conditions.
  • Taxonomic richness

    The median of the last 5 years of data

    {{medians.TaxaMedian || 'N/A'}}
    Taxonomic richness is the number of different taxa present in an ecological community identified to the best possible level.
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    Taxa richness history at this site

    Taxa richness for Waiwhakaiho River at Constance Street
    Number of taxa
  • Percent EPT richness

    The median of the last 5 years of data

    {{medians.EptMedian || 'N/A'}}
    EPT are macroinvertebrates that are sensitive to water pollution. These are Ephemeroptera (mayfly), Plecoptera (stonefly) and Trichoptera (caddisfly).
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    EPT history at this site

    Percent EPT richness for Waiwhakaiho River at Constance Street
    EPT %
Can I trust this data?

The Cawthron Institute has worked alongside regional councils to verify the processes and methods used for macroinvertebrate data collection, processing of the data in the laboratory, quality control in the field and laboratory and the statistical analysis and interpretation of the results presented.

For more details on each tick, see our 'Can I Trust this Data' Factsheet.

Can I trust the data for this site?
Data Collection

Macroinvertebrates are sampled at this site as part of council's stream health monitoring programme, as recommended by proposed national guidelines.

Sampling - Frequency

Macroinvertebrate sampling is done annually or more frequently at this site as recommended by proposed national guidelines. Therefore, data shown here follow current best practice guidelines.

Sampling - Protocols

This site is a hard-bottomed site and appropriate sampling protocols have been applied.  Data shown here have been collected using current best-practice.

Sampling - Habitat

Macroinvertebrate sampling is done in riffle habitat at this site. Data shown here are therefore following best practice.

Sampling - Stand-down period

Macroinvertebrate samples are collected within the first two weeks after a flood greater than three times the median flow at this site. Proposed national guidelines suggest a minimum of two weeks 'stand-down' period after a flood greater than three times the median flow. Therefore, data shown here is not following best practice and conclusions based on this data need to be treated with caution.

Processing - Protocol

Samples at this site have been processed following sampling protocol P1 (semi-quantitative - coded abundance). Data shown here is not following best practice, but are still robust.

Quality Control - Field

Field data collected at this site had no quality control applied to it.

Quality Control - Lab

Data processed at this site has had one of the three Laboratory Quality Control Protocols (i.e., QC1, QC2,Q C3) applied. Data shown here is more robust than data with no laboratory QC applied.

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