The National Institute of Water and Atmospheric Research Ltd (NIWA) has been commissioned by the Ministry for the Environment to estimate 11 components of the national and regional water balance of New Zealand for each of the 20 years from 1 July 1994 to 30 June 2014. This information is for use by Statistics New Zealand in a set of annual national water accounts they are developing, as part of a set of environmental accounts for New Zealand. Specifically, this work is a contribution to the Water Physical Stock Accounts. The data were analysed to summarise the water stock accounts of New Zealand and the 16 regions administered by regional councils or unitary authorities,using a combination of direct measurement and modelled data. The average annual precipitation across the country was 550,000 m3/year (equal to over nine times the volume of Lake Taupo), a reduction from previous years’ calculations. Roughly 20% of this evaporates before reaching the coast, leaving an average of 440,000 million m3/year. There is substantial variation in this water flux from year to year due to a range of climatic factors. Changes in storage – lakes, soil moisture, snow, and ice – represent very small components of the annual water balance. Use of water for hydroelectric power generation represents a significant portion of the nation’s freshwater resource, equating to 36% of the total freshwater flows, but this figure includes multiple use of water within the same catchment. Water fluxes at the regional scale vary depending on the region’s size as well as the spatial variability in the delivery and movement of water. The West Coast receives the largest portion of precipitation – 26% of the national total – and possesses 30% of the nation’s freshwater flow. Nelson City, due to its small size, accounts for the smallest portion in both cases. Canterbury accounts for the greatest portion of hydro-generation water use (mainly for the Waitaki scheme), followed by Waikato. Data are for 11 water balance components: 1. Precipitation 2. Inflows from rivers (regional scale only) 3. Evapotranspiration 4. Abstraction by hydro-generation companies 5. Discharges by hydro-generation companies 6. Outflows to sea from surface water 7. Outflows to other regions (regional scale only) 8. Net change in lakes and reservoirs 9. Net change in soil moisture 10. Net change in snow 11. Net change in ice

Bathymetric contour data set 50m - 12,000m around the New Zealand region.

New Zealand, NZ, regional, bathymetry

Bathymetry vector contour dataset. Compilation of data digitised from published coastal charts, digital soundings archive, navy collector sheets and digital multibeam data. Contour interval 50m in depths greater than 200m and 10m in depths less than 200m (where available). In areas without high resolution data the regional bathymetry data was used to fill gaps.

Bathymetric contour data set 50m - 12,000m around the New Zealand region. Projection: Mercator 41 / EPSG:3994

Bathymetric contour data set 50m - 12,000m around the New Zealand region. Projection: Mercator 41 / EPSG:3994

Bathymetry vector contour dataset. Compilation of data digitised from published coastal charts, digital soundings archive, navy collector sheets and digital multibeam data. Contour interval 50m in depths greater than 200m and 10m in depths less than 200m (where available). In areas without high resolution data the regional bathymetry data was used to fill gaps.Most detailed digital vector contour bathymetry for NZ. Compilation of the coastal bathymetry (high resolution) padded with lower resolution regional data.Projection: Mercator 41 / EPSG:3994