Freshwater Data

11 June 2021: A revised version of this dataset has been published to correct the terminology used to compare nitrate-nitrogen values to the 3 g/m3 guideline value. The field name has been changed from “reference_condition” to “n_n_guideline”, and values in this field will now be either “Does not exceed” or “Exceeds”, instead of “Meets” or “Does not meet”.

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20 July 2020: We corrected the data about drinking water standards for E. coli and nitrate-nitrogen in the key findings for groundwater quality.

For the five-year period 2014‒2018:

• 68 percent of 364 sites failed to meet the E.coli drinking water standards (changed from 98 percent of 145 sites failed to meet the E. coli drinking water standards)
• 19 percent of 433 sites didn’t meet nitrate-nitrogen standards (changed from 28 percent of 403 sites failed to meet the nitrate-nitrogen drinking water standards).

This indicator measures groundwater quality in New Zealand’s aquifers and how it is changing over time, based on measurements made at monitored sites. We report on nitrate-nitrogen, ammoniacal nitrogen, dissolved reactive phosphorus, chloride, conductivity and Escherichia coli (E. coli) including:

• median values for the period 2014–18
• nitrate-nitrogen median values compared to a guideline value of 3 grams per cubic metre (g/m3). This value is defined as a concentration that indicates groundwater has been influenced by industrialised agriculture and is highly likely to have been impacted by human activity (per Morgenstern & Daughney, 2012 and Daughney & Reeves, 2005).
• the proportion of samples from each site that have concentrations of nitrate-nitrogen or E. coli in excess of the Maximum Acceptable Values for protection of human health (Ministry of Health, 2018).

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.

11 June 2021: A revised version of this dataset has been published to correct the terminology used to compare nitrate-nitrogen values to the 3 g/m3 guideline value. The field name has been changed from “ref_meet” to “n_n_guideline”, and values in this field will now be either “Does not exceed” or “Exceeds”, instead of “Meets” or “Does not meet”.

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This dataset measures groundwater quality in New Zealand’s aquifers based on measurements made at monitored sites. Many factors influence the quality of our groundwater. Nitrogen, which occurs naturally in groundwater, can increase in concentrations due to agricultural and urban land use, and infrastructure such as waste treatment plants. High concentrations of nitrate-nitrogen in groundwater can affect human health and the quality of surrounding rivers and lakes that receive inflows from groundwater. Ammoniacal nitrogen can cause an undesirable smell that may make groundwater unsuitable for drinking water. Natural processes in groundwater can convert nitrate-nitrogen into ammoniacal nitrogen or other forms under some chemical conditions. Surplus phosphorus drains (leaches) into groundwater as dissolved reactive phosphorus. Too much nitrate-nitrogen, ammoniacal nitrogen, and phosphorus can lead to excessive plant and algae growth where groundwater flows into surface water. E. coli in groundwater is measured in colony forming units (cfu) and can indicate the presence of pathogens (disease-causing organisms) from animal or human faeces. The pathogens can cause illness for anyone who ingests them.

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.

23 April 2021: A new version of this data set has been published. It includes data on 4 parameters (Ammoniacal nitrogen (adjusted), Escherichia coli, Macroinvertebrate Community Index and Total Phosphorus) that had been missing from the file that was published as part of the Our freshwater 2020 release in April 16 2020. The updated data set also includes data on DRP for all 593,337 REC segments, since the file from April 16 2020 only had data for 255,860 of these segments.

16 April 2020: Subsequent to publication in April 2019 we discovered two small errors with this dataset. These included:

• Errors in the coordinates of some sites and their associated metadata (such as landcover and elevation).
• Errors in our calculation of dominant landcover.

In addition, flow data from TopNet has also been updated.

These changes have a minor impact on overall results. These changes have have been corrected, and are republished here, as part of the Our freshwater 2020 release.

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IMPORTANT INFORMATION

1) The main (cleaned) dataset is structured by each row having a nzsegment and np_id combination. A large dataset (~ 1 GB) has resulted, due to the inclusion of the ANZG/NOF columns and the 10 different np_id values. There are ~ 6 million rows to this dataset, however a 32-bit version of Microsoft Excel will only display/download ~ 1 million rows. __A DBMS, statistical or GIS application is needed to view the entire dataset__.

2) A smaller raw dataset (see attachments) is provided which structures each row relating to a river segment and drops the ANZG/NOF columns.

3) The attached metadata/date quality report provides further information on the NOF, ANZG and the "McDowell meet/doesnt meet" attachment.

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This dataset contains ten parameters of water quality based on measurements made at monitored river sites:

• Nitrate-nitrogen
• Ammoniacal nitrogen
• Ammoniacal nitrogen (adjusted)
• Total nitrogen
• Total phosphorus
• Dissolved reactive phosphorus
• Water clarity
• Turbidity
• Escherichia coli
• Macroinvertebrate community index These parameters are used to measure:
• Modelled median values for all of New Zealand’s river length for the period 2013 to 2017
• For selected indicators, how the modelled values compare to the National Objectives Framework (NOF) (MfE, 2017) bands related to ecosystem health and human health for recreation, and to expected concentrations in natural conditions, as shown by the default guideline values in the Australian and New Zealand guidelines for fresh and marine water quality (ANZG, 2018)

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 www.mfe.govt.nz/publications/fresh-water/spatial-m...

Heavy metals in river waters are an indicator of river water quality. We monitor a subset of rivers and streams in predominantly urban areas in Auckland, Wellington, and Christchurch, and look at how these values are changing over time. This indicator shows:

• trends in concentrations based on measurements made at monitoring sites during the seven-year period from 2011 to 2017

Summary report available at www.mfe.govt.nz/publications/fresh-water/urban-riv....

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.

Heavy metals in river waters are an indicator of river water quality. We monitor a subset of rivers and streams in predominantly urban areas in Auckland, Wellington, and Christchurch, and look at how these values are changing over time. This indicator shows:

• concentrations of dissolved copper and zinc measured at monitoring sites for the three-year period from 2015 to 2017
• how these compare to the default guideline values for the protection of 95 percent of species in the Australian and New Zealand guidelines for fresh and marine water quality (ANZG, 2018)

Summary report available at www.mfe.govt.nz/publications/fresh-water/urban-riv....

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.

This indicator measures the physical habitat condition of New Zealand waterways. We report on 369 sites across six North Island regions and 90 sites in one South Island region (Southland), identifying the overall state of stream habitat at each site based on at least three years of data between 2013/14 and 2018/19. Ten physical habitat components are measured during the assessment, including bank erosion and the diversity and abundance of fish cover (Clapcott et al, 2019).

Summary report available at www.mfe.govt.nz/publications/fresh-water/indicator...

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.

This indicator measures the average percentage of streambed covered by fine sediment for areas of smooth, unbroken water in hard-bottomed, wadeable streams and rivers, at 215 sites across six regions assessed at least bi-monthly for two consecutive years between 2014 and 2019.

Summary report available at www.mfe.govt.nz/publications/fresh-water/indicator....

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.

This dataset summaries backpack electric fishing observations from the New Zealand Freshwater Fish Database for the period 1998 - 2018. It provides the locations and scores for Fish Index of Biotic Integrity (IBI) (including sub-metric scores).

Technical report available at www.mfe.govt.nz/publications/environmental-reporti....

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.

16 April 2020: Subsequent to publication in April 2019 we discovered two small errors with this dataset. These included:

• Errors in the coordinates of some sites and their associated metadata (such as landcover and elevation).
• Errors in our calculation of dominant landcover.

In addition, flow data from TopNet has also been updated.

These changes have a minor impact on overall results. These changes have have been corrected, and are republished here, as part of the Our freshwater 2020 release.

​

This dataset contains ten parameters of water quality based on measurements made at monitored river sites:

• Nitrate-nitrogen
• Ammoniacal nitrogen
• Ammoniacal nitrogen (adjusted)
• Total nitrogen
• Total phosphorus
• Dissolved reactive phosphorus
• Water clarity
• Turbidity
• Escherichia coli
• Macroinvertebrate community index

This dataset includes:

• Median values for the period 2013 to 2017
• for selected indicators, how these values compare to the National Objectives Framework (NOF) (MfE, 2017) bands related to ecosystem health and human health for recreation, and to expected concentrations in natural conditions, as shown by the default guideline values in the Australian and New Zealand guidelines for fresh and marine water quality (ANZG, 2018)

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 www.mfe.govt.nz/publications/fresh-water/water-qua....

16 April 2020: Subsequent to publication in April 2019 we discovered two small errors with this dataset. These included:

• Errors in the coordinates of some sites and their associated metadata (such as landcover and elevation).
• Errors in our calculation of dominant landcover.

In addition, flow data from TopNet has also been updated.

These changes have a minor impact on overall results. These changes have have been corrected, and are republished here, as part of the Our freshwater 2020 release.

​

This dataset measures how water quality in New Zealand’s rivers is changing over time. It contains nine parameters of water quality based on measurements made at monitored river sites in years 1990-2017:

• Nitrate-nitrogen
• Ammoniacal nitrogen
• Total nitrogen
• Total phosphorus
• Dissolved reactive phosphorus
• Water clarity
• Turbidity
• Escherichia coli
• Macroinvertebrate community index

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 www.mfe.govt.nz/publications/fresh-water/water-qua....