Maungawhau / Mount Eden trig beacon to be removed

The trig beacon at the summit of Maungawhau / Mount Eden is set to be removed next week due to health and safety concerns.

Toitū Te Whenua Land Information New Zealand is responsible for managing and maintaining trig stations as part of New Zealand’s ‘geodetic’ measurement system. The system allows surveyors to accurately map and measure properties.

Acting Surveyor General Jeff Needham says the trig beacon is over 40 years old and has reached the end of its usable life.

'Modern survey methods mean there is less of a reliance on traditional trig beacons in surveying, so we won’t be rebuilding any structure in its place.  The raised platform and survey mark underneath the beacon will stay, and visitors will be able to continue to access the site.

'Surveying is no longer heavily reliant on these purpose-built structures which are expensive to maintain. The Sky Tower is an example of a modern alternative surveying reference point in common use,' says Jeff.

Tūpuna Maunga Authority supports the removal of the trig beacon, prioritising the health and safety of manuhiri. The Authority’s Integrated Management Plan (IMP) acknowledges that the tihi (summit) is the most sacred part of the maunga and special consideration should be paid to what structures are erected there. 

Work is expected to take one to two days to complete. During this time there will be no public access to the raised platform the trig beacon stands on, however walking tracks will be open as usual.

Note for media on land surveying 

Surveyors use survey marks as fixed points to measure from when determining property boundaries. They are also used for engineering projects, roading, mapping and measuring the position of land, sea and infrastructure. For example, surveyors can tell how much land has moved following an earthquake by measuring between survey marks.  

A trig beacon is a structure used to make a survey mark visible from a distance and to provide a well-defined reference point. Due to advancements in technology and adaptation of methods, there is less of a reliance on trig beacons when undertaking surveys.