This includes the river lines, watersheds, and a layer for each river order showing catchment boundaries. 

2. What are the system requirements for the REC?

The REC is delivered as GIS layers in ESRI shapefile format. As a minimum you would need a GIS capable of reading and manipulating shapefiles and hardware capable of supporting the GIS.

3. What information comes on the REC CD?

The REC CD contains classified rivers, associated catchments, an electronic copy (PDF) of the manual and two utilities to assist in the use of the REC. The river classifications and catchments are broken up by region (more or less – see question 4).

4. Why do the REC regional boundaries not match the political boundaries?

The REC is built along catchment boundaries. In most cases political regional boundaries align with catchment boundaries, but there are some exceptions. For the REC we decided that rivers that end in a political region will form part of that region even if politically a tributary belongs in another region.

5. Why is there an overlap between the Auckland and Waikato RECs?

There are a few rivers near the Auckland/Waikato border that flow into Waikato (and so must form part of the Waikato REC), but which were identified by Auckland Regional Council staff as being important for Auckland (as water is diverted north). So it was decided to include those rivers in both of the classifications.

6. What is ‘Tracer’?

Tracer is an ESRI ArcView extension developed by NIWA to allow network based selection of river lines (for example, all rivers upstream from a point). For more information see Section II of the user guide.

7. What is ‘Grouper’?

Grouper is a specialised tool developed by NIWA to allow users to produce simplified versions of the REC for particular planning and management purposes. For more information see Section II of the user guide.

8. Who do I contact with REC problems or errors?

All REC questions should be sent to: rec@niwa.co.nz. Errors in the REC will be logged for correction if/when the REC is updated.

9. Why do the REC lines not match my river lines?

The REC is a synthetic river network generated by GIS procedures and based on a 30-metre digital elevation model of New Zealand. While every attempt has been made to ensure that the REC river lines are spatially accurate, there will be numerous errors in the position of the lines. It is important to remember that the REC is designed as a strategic management tool and not as a map of New Zealand rivers. However, information on any major errors can be emailed to rec@niwa.co.nz and will be logged for correction if/when the REC is updated.

10. Why are there no river names associated with the REC river lines?

Labelling every river in New Zealand with its correct name is a very difficult problem, and one that was not part of the scope for the REC project. While there are a number of sources of information about the names of rivers at particular points, the propagation of the names upstream/downstream is complicated, prone to error, and virtually impossible to check. At this stage addition of names to the REC is something to be addressed ‘at some future point’.

11. What is the map projection of the REC?

The REC is in New Zealand Map Grid projection.

Contact

For further information or to ask other questions about the REC send email to rec@niwa.co.nz or post to NIWA, PO Box 8602, Christchurch.