Permanent survey marks (PSMs), commonly known as survey marks, are a key component of South Australia’s surveying and spatial framework. They serve as valuable state infrastructure, underpinning the surveying of property boundaries, mapping, development and construction activities. Survey marks contain precise coordinate and height information, providing the stable geodetic reference frame that connects surveys and other spatial datasets.

The Survey Operations Unit maintain:

  • South Australia’s network of permanent survey marks, offers reliable reference points for surveyors to determine property boundaries and establish positioning for construction, mining and mapping
  • An enquiry system for survey mark information, including access to survey mark layers through the South Australian Property and Planning Atlas (SAPPA)

Importance of survey marks

Permanent survey marks support a wide range of activities across South Australia, including:

  • Cadastral (land boundary) surveying and land administration
  • Engineering and construction projects
  • Roads, utilities and public infrastructure
  • Mapping and spatial datasets

The ongoing availability and integrity of these marks is essential for maintaining accurate and reliable survey information.

What do survey marks look like?

Permanent survey marks may appear in different forms, including:

Photo: Large concrete monuments
Large concrete monuments
Photo: Metal plaques or discs
Metal plaques or discs
Photo: Metal rods or pins set into the ground or pavement
Metal rods or pins set into the ground or pavement

They are commonly located in road reserves, roadways, footpaths and other public areas, but may also be located on private land.

In many locations, survey marks are protected or indicated by witnessing, which helps people in identifying the presence of a survey mark. Witnessing is not the survey mark itself, but can include:

Photo: "Photo:Steel or concrete covers installed at ground level, with the actual survey mark located underneath
Steel or concrete covers installed at ground level, with the actual survey mark located underneath
Photo: Witness posts with indicator plates (commonly used in newer developments)
Witness posts with indicator plates (commonly used in newer developments)
Photo: Indicator plate
Indicator plate
Photo: Blue star droppers with red indicator plates (common in rural areas)
Blue star droppers with red indicator plates (common in rural areas)

These witnessing features help protect survey marks and make them easier to locate, especially where the mark sits below ground level or could be obscured by machinery.

Preservation of survey marks

When a survey mark is disturbed or destroyed, property boundaries become more complex to reestablish, creating increased costs for land development and infrastructure.

Preserving survey marks protects the integrity of the state’s spatial reference framework, resulting in better protection for public and private investment.

Under the Survey Act 1992, a permanent survey mark must not be disturbed without prior approval from the Surveyor‑General. The Act provides for fines of up to $2,000 per survey mark that is disturbed, damaged, removed or destroyed.

It is not permitted to:

  • Remove or relocate a survey mark
  • Concrete over or build on top of a survey mark
  • Replace or re-establish survey marks without going through approved processes

These protections apply regardless of whether the survey mark is easy to see or is located below ground level.

Who is responsible for preservation

Any person or organisation carrying out civil works that may affect a survey mark is responsible for ensuring the mark is preserved. This responsibility applies whether the individual was aware that a survey mark was present or not. Responsible parties include:

  • Developers and project managers
  • Contractors and subcontractors
  • Utility providers
  • Local government and public authorities
  • Landowners and occupiers

Before work begins

Before starting any work, you must:

  • Check whether a survey mark is located in or near the work area using the South Australian Property and Planning Atlas (SAPPA). For steps on how to check, visit Steps to locate survey marks.
  • If survey marks are located within or near your works area, contact the Office of the Surveyor‑General early – before civil works commence.

Early identification helps prevents delays, redesign and additional project costs.

Survey marks are not listed on Before you Dig Australia.

Resources

Survey enquiries

For survey mark enquiries or EDM calibration bookings please contact:

Phone: (08) 7133 2300
Email: DHUD.SurveyOperations@sa.gov.au