Fresh Water Data

This dataset is a result of Random Forest modelling to predict cyanobacterial biovolume in lakes nationally, which included spatial modelling of chlorophyll a, TN, TP, Secchi depth, Trophic Level Index, and Cyanobacterial biovolume.

More information about the methods used to create this dataset can be found here: www.mfe.govt.nz/publications/fresh-water/strategic...

LID - FENZ Lake ID

Name - Name of lake (where available)

RegionalCo - Regional council name

CHLA - Chlorophyll a (mg/L)

TN - Total nitrogen (mg/m3)

TP - Total phosphorus (mg/m3)

SECCHI - Secchi disc depth (m)

TLI3 - Trophic Level Index (unitless)

CyanoBioVo - Cyanobacterial biovolume (mm3/L)

Summary

Water quality for swimming categories for rivers 4th order and above. 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This dataset has now been superseded due to consultation with local authorities, and this is the latest version: data.mfe.govt.nz/layer/95555-river-water-quality-f...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:

NZREACH: NZREACH from the River Environment Classification Version 1

ORDER: Strahler stream order

Category: Water quality for swimming category see www.mfe.govt.nz/fresh-water/national-targets-swimm...

PrGT540: percentage of samples that exceeded 540 E.coli per 100mL

PrGT260: percentage of samples that exceeded 260 E.coli per 100mL

Median: median E.coli per 100mL

Q95: 95th percentile E.coli per 100mL

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

This dataset relates to the March 2018 report National E. coli modelling - Supplementary material to support setting draft regional targets for swimmable rivers.

Scenario 1 represents the level of stock exclusion and riparian planting for the nominal year 2030
when the CWP rules have been implemented assuming that the effects of the measures have been realised and water quality has attained a new attribute state. Scenario 1 also includes the impact of regional committed work (that is, work already committed to by councils in their policy plans, or planned infrastructure investment) in regions that have committed to mitigation beyond the CWP.

The geometries are based off REC1, and the field 'Swimability_band' defines the modelled E. coli attribute state NPS-FM human health for recreation value. The rest of the fields come from the River Environment Classification.

This dataset relates to the March 2018 report National E. coli modelling - Supplementary material to support setting draft regional targets for swimmable rivers.

It represents Scenario 0, baseline (i.e. 2017) including the current level of on-farm fencing and land use - further details available in the above report.

The geometries are based off REC1, and the field 'Swimability_band' defines the modelled E. coli attribute state NPS-FM human health for recreation value. The rest of the fields come from the River Environment Classification.

This layer provides sea-draining river catchments, extracted from the FENZ v1.1 geodatabase.