Data

This data set provides an update of New Zealand’s depth to hydrogeological basement map. Depth to hydrogeological basement can be loosely defined as the ‘base of aquifers’; or more strictly as ‘the depth to where primary porosity and permeability of geological material is low enough such that flued volumes and flow rates can be considered negligible’. For more detail on the process and methods, see Westerhoff et al. (2019). New Zealand groundwater atlas: depth to hydrogeological basement. Lower Hutt (NZ): GNS Science. 19 p. Consultancy Report 2019/140

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Cite data as:

GNS Science. (2019). Depth to hydrogeological basement [Data set]. Ministry for the Environment, GNS Science. doi.org/10.21420/FQXD-VY44

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Cite report describing the data as:

Westerhoff et al. (2019). New Zealand groundwater atlas: depth to hydrogeological basement. Lower Hutt (NZ): GNS Science. 19 p. Consultancy Report 2019/140.

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A national model was used to estimate depth to hydrogeological basement. Hydrogeological basement refers to geological material with primary porosity and permeability that is low enough such that fluid volumes and flow rates can be considered negligible.

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.

This dataset includes three “packages” of information, each with multiple variables. The packages include:

1. Load – results on mean annual suspended sediment load reported by REC 2 river reach scale for various model scenario variations.
2. Lakes – results on sediment inflow, outflow, and entrapment in lakes and reservoirs
3. Coastal – results on sediment inflows, trap efficiency, and sedimentation rates in coastal hydrosystems (estuaries)

For further detail on the modelling methods and discussing results, see Hicks, M., Semademi-Davies, A., Haddadchi, A., Shankar, U., Plew, D. (2019) Updated sediment load estimator for New Zealand. NIWA Client Report No. 2018341CH, prepared for Ministry for the Environment. January 2019. Available online: environment.govt.nz/publications/updated-sediment-...

Note that some portions of this dataset refine and update 2011 modelling on suspended sediment loads across New Zealand, whereas other components, especially the coastal package, report new modelling results.

The StockEx LSL 2021 proposed layer identifies proposed areas of "low slope land" where the Resource Management (Stock Exclusion) Regulations 2020 would apply if the low slope land map was updated as proposed in the "Stock exclusion regulations: Proposed changes to the low slope map" (MfE, 2021) discussion document. The layer shows the area of land defined as low slope land. These areas have a local mean slope is less than or equal to 5 degrees and are below 500m in altitude. Areas of lakes and ponds, estuarine open water, built-up areas, transport infrastructure, depleted grass, tall tussock grassland and urban parkland, as defined in Land Cover Database 5, are also excluded.

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Note: The current regulation layer is 'Stock Exclusion Low Slope Land 2020'

data.mfe.govt.nz/layer/104827

The StockEx LSL 2021 proposed layer identifies proposed areas of "low slope land" where the Resource Management (Stock Exclusion) Regulations 2020 would apply if the low slope land map was updated as proposed in the "Stock exclusion regulations: Proposed changes to the low slope map" (MfE, 2021) discussion document. The layer shows the area of land defined as low slope land. These areas have a local mean slope is less than or equal to 5 degrees and are below 500m in altitude. Areas of lakes and ponds, estuarine open water, built-up areas, transport infrastructure, depleted grass, tall tussock grassland and urban parkland, as defined in Land Cover Database 5, are also excluded.