Freshwater Data

"River flow refers to the quantity of water passing a point in the river over a certain amount of time. Different rivers have different flow patterns, such as sharp peak flows following rain with low flows in between, or high spring flows from snow melt. These flow characteristics affect how much water is available for irrigation, drinking water, hydro–electric power generation, and recreational activities such as fishing and boating. River flows are also very important for maintaining the health and form of a waterway.

This dataset relates to the "Geographic pattern of natural river flows" measure on the Environmental Indicators, Te taiao Aotearoa website. "

For more information, refer to the March 2015 report: 'Hydrological indices for national environmental reporting' www.mfe.govt.nz/sites/default/files/media/Fresh%20....

River water quality water is valued for many reasons including ecological function and habitat, recreational value, its role in supporting people and industry, and its cultural significance. Nutrients such as nitrogen and phosphorus are essential for plant growth, however too much in rivers can lead to ‘nuisance’ growths of river algae and aquatic plants, degrading habitat. High concentrations in the form of ammoniacal nitrogen and nitrate-nitrogen can be toxic to fish and other aquatic animals. Water clarity is a measure of underwater visibility, and affects habitat of aquatic life such as fish and birds, and can also impact on aesthetic values and recreational use of rivers and streams. Escherichia coli (E.coli) can indicate the presence of pathogens (disease-causing organisms) from animal or human faeces, which can cause illness.

File contains raw data collected at regional council and NIWA monitored sites over the period 1975-2013. Fields are described as follows. Refer to Larned et al. 2015 for further details:
* nemarid ---- Unique NIWA ID
* lawaid ---- Unique LAWA ID
* rcid ---- Collection agency
* srcid ---- Region site is located in
* sflag ---- River (r) or Estuary (e)
* river ---- River name
* location ---- Name of site, assigned by collection agency
* nzmge ---- easting
* nzmgn ---- northing
* nzreach ---- REC1 segment identifier
* sdate ---- Sample date (yyyy-mm-dd)
* Q ---- Flow recorded when sample was taken (if available), cumecs
* npid ---- NIWA parameter ID (as used in Larned et al. 2015)
* lpid ---- LAWA parameter ID
* fdval ---- Parameter value (units are mg/m3, except CLAR (m) and ECOLI (n/100 mL))

For more information please see:
Larned, S, Snelder, T, Unwin, M, McBride, G, Verburg, P, McMillan, H (2015).Analysis of Water Quality in New Zealand lakes and Rivers: data sources, data sets, assumptions, limitations, methods and results. NIWA Client Report no. CHC2015-033. Available at data.mfe.govt.nz/x/Mo8VUY from the Ministry for the Environment dataservice.

This dataset relates to the "River water quality" measures on the Environmental Indicators, Te taiao Aotearoa website.

"Wetlands support unique biodiversity and provide important services. They clean water of nutrients and sediment, help dampen floods, provide habitat, and act as carbon sinks. They are also valued for their spiritual and cultural significance and as important sources of food and materials, such as flax. Draining them for agricultural and urban development has reduced their extent. Understanding this reduction provides insight into the loss of biodiversity and natural function.
This dataset relates to the ""Wetland extent"" measure on the Environmental Indicators, Te taiao Aotearoa website. "

"Wetlands support unique biodiversity and provide important services. They clean water of nutrients and sediment, help dampen floods, provide habitat, and act as carbon sinks. They are also valued for their spiritual and cultural significance and as important sources of food and materials, such as flax. Draining them for agricultural and urban development has reduced their extent. Understanding this reduction provides insight into the loss of biodiversity and natural function.
This dataset relates to the ""Wetland extent"" measure on the Environmental Indicators, Te taiao Aotearoa website. "

Wetlands support high levels of biodiversity. They provide habitat for native invertebrates, plants, fish, and bird species (eg fernbird, kōkopu, and eels), many of which live only in wetlands. Wetlands act as ‘kidneys’ and giant sponges – they clean the water of excess nutrients and sediment, control flood water and pollutants, and act as carbon sinks (removing carbon dioxide from the atmosphere). Wetlands have strong cultural and spiritual importance for Māori. They are a food source (eg eel, whitebait) and provide material for weaving (eg raupō, harakeke (flax)). Draining wetlands for agricultural and urban development over the past 150 years has led to significant wetland loss and deterioration.

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

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.

"A unit of rock or sediment is called an aquifer when it can yield a usable quantity of water.
Aquifers may occur at different depths in the same location. The map shows the areas of New Zealand’s land surface above one or more aquifers. The aquifer boundaries were described by White (2001), and some boundaries were updated by Moreau and Bekele (2015), using information provided by regional councils and from Lovett and Cameron (2015). The map has 153 polygons (aquifer outlines), some of which have more than one aquifer.
Methods for defining aquifer boundaries generally rely on knowing the locations and characteristics of productive wells, and using geological maps to identify water–bearing materials. In many cases, these boundaries are also influenced by management attributes such as regional or property boundaries, and surface water catchments (Lovett & Cameron, 2015).
This dataset relates to the ""Location and area of New Zealand’s aquifers"" measure on the Environmental Indicators, Te taiao Aotearoa website.
"

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:

• trends in concentrations for 10-year (2009–18) and 20-year (1999–2018) periods.

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.

Groundwater is the water stored beneath Earth’s surface in aquifers (layers of water-bearing rock or sand). It is used for human and stock drinking water, irrigation, and industry, and also has a role in sustaining some rivers, lakes, and wetlands, especially during low-flow periods. The health of surface-water ecosystems also depends on groundwater.

Estimated average groundwater volumes by 16 regional councils
* region = Regional Council
* bil_cubicm = Average estimated groundwater volume in billion cubic metres

For more information please see:
Moreau M, & Bekele, M (2015). Groundwater Component of the Water Physical Stock Account (WPSA) GNS Science Consultancy Report 2014/290. 35p. Available at data.mfe.govt.nz/x/Tebsax from the Ministry for the Environment dataservice.

This dataset relates to the "Groundwater physical stocks" measure on the Environmental Indicators, Te taiao Aotearoa website.

"The Lake Trophic Level Index (TLI) characterises the life supporting capacity of a lake based on nutrient enrichment. In general, the higher the TLI score, the poorer the water quality in the lake. Lakes with extremely poor quality are rarely suitable for recreation and provide poor quality habitat for aquatic species.
Care should be taken when interpreting these results. Monitored lakes consist of about 4 percent of all New Zealand lakes, and programmes may focus on those that have poor water quality or are at risk due to the type of land use in their catchment.
After checking for data consistency, the lakes considered suitable for national comparison are sparsely and unevenly distributed, with gaps in the Manawatu, Taranaki, Tasman, Marlborough, Otago, and West Coast regions. The lakes considered in the analysis are located mainly in Northland, Bay of Plenty, Hawke’s Bay, and Canterbury.
This dataset relates to the ""Lake water quality: trophic level index"" measure on the Environmental Indicators, Te taiao Aotearoa website.
"

We report on the conservation status and most recent change in status of indigenous (native), resident (breeds in New Zealand) freshwater fish and invertebrates that have been assessed by New Zealand Threat Classification System (NZTCS) expert panels.
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.