Freshwater Data

NZ regional council freshwater nutrient and biomass measurements 2012-2020.

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Used to derive nitrogen and phosphorus concentrations and exceedance criteria for managing periphyton in fresh water.

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Creative Commons 4.0 International by Ministry for the Environment and Statistics New Zealand

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Variables:

• Site (the number of the data point itself)
• RC (Regional Council that collected the measurement)
• RCSiteID (the identifier used by that specific council)
• SiteName (the Site where the measurement was collected)
• DateChla (date the chlorophyll-a measurement was collected)
• Year (Year of collection)
• Month (Month of collection)
• Chla ( mg chlorophyll-a per square meter)
• NOxppb (Nitrous oxide parts per billion)
• NH4ppb (Ammonia parts per billion)
• DRPppb (Dissolved Reactive Phosphorus parts per billion)
• TNppb (Total Nitrogen parts per billion)
• TPppb (Total Phosphorus parts per billion)
• DINppb (Dissolved Inorganic Nitrogen parts per billion)
• EC (Electrical Conductivity)
• pH (acidity/basicness of the water at the sample location)
• Temp (water temperature in degrees Celsius at time of measurement)
• Turbidity (turbidity of the water at time of measurement)
• Clarity_m (water clarity, in metres, at the time of measurement)

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N/A values in the data set refer to an absence of measurement for that specific variable.

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Report:

environment.govt.nz/publications/derivation-of-nut...

Snelder T, Kilroy C, Booker D (2021) Derivation of Nutrient Criteria for Periphyton Biomass Objectives. Using regional council monitoring data. LWP and NIWA Ltd, Christchurch, New Zealand

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For subject matter questions please contact freshwater@me.govt.nz.

Water quality for swimming categories for lakes with perimeters over 1.5 km. This dataset was used to compose the current state for water quality for swimming.

Note this data is under review and will be updated in due course. This information is based on modelled and measured data using the approach outlined at
www.mfe.govt.nz/fresh-water/freshwater-management-...

The modelling methods used are outlined in Snelder et al. (2016) Strategic assessment of New Zealand’s freshwaters for recreational use: a human health perspective. LWP Client Report 2016-011 www.mfe.govt.nz/publications/fresh-water/strategic...

Versions

This dataset is the geometric version of this: data.mfe.govt.nz/table/53620-river-water-quality-f...

This dataset has now been superseded due to consultation with local authorities, and this is the latest version: data.mfe.govt.nz/layer/95555-river-water-quality-f...

Column headings:

LID: FENZ Lake ID

Name: Name of lake (where available

RC: Regional council name

CHLA: Chlorophyll a (mg/L)

SECCHI: Secchi disc depth (m)

TLI3: Trophic Level Index (unitless)

TN: Total nitrogen (mg/m3)

TP: Total phosphorus (mg/m3)

CyanBVl: Cyanobacterial biovolume (mm3/L)

Cy_cat: Water quality for swimming category see www.mfe.govt.nz/fresh-water/what-government-doing/...

Note: blank cells are reaches where a prediction was not possible because of missing predictor variables.