NZVD2016 and vertical datums

Two layers can line up perfectly on the map and still use different definitions of height.

NZVD2016 is New Zealand's official national vertical datum. LINZ implemented it in June 2016. Its EPSG code is 7839 and its reference surface is NZGeoid2016.

Horizontal CRS is not vertical CRS

EPSG:2193 tells you the NZTM2000 horizontal coordinate system. It does not by itself tell you what Z = 12.4 m means. Record the vertical datum separately for elevation, bathymetry, flood and engineering datasets.

Local vertical datums

New Zealand historically used 13 official local mean-sea-level vertical datums plus other local/city/drainage datums. Their relationship to NZVD2016 varies spatially, so a constant offset is not generally correct.

LINZ publishes vertical datum relationship grids for conversions between the 13 official LVDs and NZVD2016.

GNSS heights

Raw GNSS commonly provides ellipsoidal height relative to the reference ellipsoid. That is not the same as NZVD2016 normal-orthometric height. A geoid/quasigeoid model links the systems.

Why it matters

A one-metre vertical mismatch can completely alter a flood, coastal or drainage interpretation. Before combining terrain with council flood levels, sea-level scenarios or survey levels, confirm the datum of both datasets.

Official source: LINZ NZVD2016.

Last reviewed: 26 August 2026