Historically in New Zealand, heights have been defined in terms of 13 local vertical datums referenced to local mean sea level (MSL).

The 13 local vertical  datums were established by determining mean sea level at a tide-gauge and then transferring this level to benchmarks in a network. The majority of observations in these long and often poorly constrained networks, were made using precise levelling.

To account for changes in the Earth's gravity field an approximate orthometric correction was applied to the levelling observations to give normal-orthometric heights in relation to the tide-gauge MSL.

Sea level is known to vary around the coast of New Zealand. This means that the level of MSL determined each datum's tide-gauge will be different and that heights measured between adjacent datums will not agree. It is therefore important that the vertical datum of a height is checked before it is used.

In most cases the level of MSL for the vertical datums was determined prior to 1960 and has not been updated since then, even though MSL has changed by unknown but measureable amount.

Read about tidal level information for surveyors about relating the local datums to mean high water springs (MHWS).

Heights in terms of the local datums can be related to the NZVD2016 or NZGD2000 by using the NZGeoid2016 geoid model and the appropriate Vertical Datum Relationship Grid. The conversion of heights between the different datums is described on the height conversion pages.

Mean sea level vertical datum locations
Mean sea level vertical datum locations

NZVD2016 heights are also published on the Geodetic Database for all geodetic marks included in the National Geodetic Adjustment. The table below compares the height of the reference mark for each local vertical datum with the NZVD2016 height as computed using the relationship grid, and as published from the National Geodetic Adjustment. 

LVD

Datum Code

Reference Mark

Reference mark height in terms of local datum (metres)

Reference mark height in terms of NZVD2016 (metres)

Determined by relationship grid (HA+OA)

Reference mark height in terms of NZVD2016 (metres)

From National Geodetic Adjustment 9-11-2016

One Tree Point 1964

ONTPHT1964

RNZN BM (DJM9)

3.138

3.053

3.066

Auckland 1946

AUCKHT1946

98-21 SO 69501 (DD1N)

3.488

3.156

3.128

Moturiki 1953

MOTUHT1953

BC 84 (B309)

3.137

2.938

2.945

Gisborne 1926

GISBHT1926

GB 01 (ACVP)

3.036

2.699

2.698

Napier 1962

NAPIHT1962

H 40 (B3XM)

3.906

3.713

3.720

Taranaki 1970

TARAHT1970

New Plymouth Fundamental (AGMH)

4.897

4.599

4.608

Wellington 1953

WELLHT1953

K 80/1 (ABPB)

2.060

1.672

1.741

Nelson 1955

NELSHT1955

N 1 (AC4T)

3.511

3.182

3.161

Lyttelton 1937

LYTTHT1937

UD 40 (B40V)

3.237

2.848

2.830

Dunedin 1958

DUNEHT1958

WW 83 (AFEQ)

2.732

2.355

2.368

Dunedin-Bluff 1960

DUBLHT1960

Z 41 (B3R8)

112.696

112.390

112.438

Bluff 1955

BLUFHT1955

Bluff Fundamental (ABCC)

7.009

6.695

6.689

Stewart Island 1977

STISHT1977

N (Paterson SD) (A017)

44.1

43.8

n/a

Last Updated: 22 March 2018