This dataset provides boundaries for catchments that drain to the sea (i.e. sea draining catchments).
It is extracted from the Freshwater Ecosystems of New Zealand (FENZ) Geodatabase.
FENZ requires specialist GIS knowledge for its technical operation and biodiversity knowledge for understanding the content. Because of FENZ’s complexity, DOC is providing advice, briefings and training (where possible) to ensure users understand its strengths, limitations and appropriate applications.
If you would like more information about FENZ or access to any FENZ data sets, email firstname.lastname@example.org.
This layer was extracted from FENZ.
The FENZ database grew initially out of work initiated under a whole of government initiative run under the Sustainable Development Programme of Action for Freshwater to identify Waters of National Importance (WONI) for tourism, irrigation, energy generation, industrial uses, recreation, natural heritage and cultural heritage. The Department of Conservation (DOC) was given the task of identifying a candidate list of nationally important aquatic systems for freshwater natural heritage. Following the production of satisfactory results from an initial pilot analysis (Chadderton et al. 2004), the Department commissioned a range of further research (mostly from the National Institute of Water and Atmospheric Research and Landcare Research), to better identify sites with high natural values, with separate projects focussing on lakes, wetlands, and rivers and streams. These sought in particular to develop improved descriptions of biological values, more comprehensive ecosystem classifications, more robust assessments of human impacts, and higher resolution methods for the ranking of sites. This DVD presents many of the data resources and results produced during that research, along with additional relevant data produced for the Department during research on freshwater biodiversity patterns funded under the Terrestrial and Freshwater Biodiversity Information System fund (TFBIS).
Our description of the spatial locations of rivers and streams was drawn directly from the existing River Environment Classification (REC — Snelder & Biggs 2002), i.e., the majority of our riverine spatial data are delivered using the REC network topology, although with substantial numbers of REC flow-lines in lakes removed by overlay against the lake spatial data. We highlight in particular that the REC topology was derived by automatic analysis of digital elevation data based on national 20m contour data, rather than from the topographic map stream lines. While use of this relatively coarse resolution elevation data generally provided good identification of stream flow lines in hill-country, it is less satisfactory at detecting smaller streams in flatter areas, e.g., alluvial flood plains. Users should therefore be wary of over-relying on the positions of small streams in these low-gradient landscapes, using the spatial data with a degree of caution, backed by field knowledge where required.