The New Zealand Vertical Datum 2016 (NZVD2016) was introduced in June 2016, to replace the various height surfaces used across the country. It allows for the consistent collection and seamless exchange of heights across New Zealand.
Prior to GNSS technology it was difficult to define a national height system and this lead to various localised datums, usually based on some sea level reference. These are often one of the 13 official Local Vertical Datums (LVD), a secondary datum, or city/drainage datum.
NZVD2016 has some significant benefits over these localised datums, which will reduce time, costs and risks, while increasing resilience and ability to support our communities.
Example of LVD limitations
Usually when heights are used in planning and monitoring, the most important factor is the relative heights. These projects are completed with a local RL (reduce level) and as long as all heights are measured in terms of that RL the heights are consistent and can easily be used to assist decision making.
However, problems can quickly occur, for example:
- If a neighbouring site has used a different RL.
- If a reference mark has slumped or moved.
- If the area of interest is large, such as in LiDAR surveys or roading projects.
- If there are no reliable reference marks near the site.
In these cases, it can be difficult to compare heighted data in a consistent manner. Additional time and resources may be spent on either resolving data management issues or dealing with the consequences of decisions based on incorrect information.
NZVD2016 heights can be established anywhere and are easily recoverable if the reference marks are moved or destroyed. Furthermore, as NZVD2016 is nationally consistent, NZVD2016 RL values can be easily be combined across projects.
NZVD2016 is now well established and will remain the New Zealand’s national vertical datum for the foreseeable future.
LINZ engagement with Councils
In November 2018 LINZ, with support of Survey and Spatial New Zealand (S+SNZ), completed the first of a series of meetings with local and regional authorities to discuss the benefits of adopting NZVD2016, the limitations of LVDs and obstacles they may be facing with their heighting systems.
The slides from the meeting with council and the subsequent technical meeting are available in the Attachments section at the bottom of the page.
The remainder of this meeting series will take place from February 2019.
For additional information please contact Rachelle Winefield: firstname.lastname@example.org