Why Protecting Survey Marks Matters for Developers
In NSW, the State cadastre is the official record of property boundaries. To keep it accurate, surveyors rely on special markers — called Reference Marks and Permanent Survey Marks — to define and re-establish lot boundaries. If these marks are lost or damaged, it can affect the accuracy of boundary records, increase surveying costs, and delay development projects.
To protect these marks, Surveyors General Direction No. 11 was introduced in 2004. In 2022, a new process called the Deposited Plan of Survey Information Only (DPoSIO) was added. This shows the connection between survey marks and nearby physical features, helping surveyors find and replace any marks that may be destroyed during construction — especially after big infrastructure works.
While many people think these surveys only apply to large projects like motorways, they’re now increasingly required for smaller works too — things like footpaths, driveways, and even as a standard condition in Development Applications in the Wollongong, Kiama, and Shoalhaven areas. This is a positive move for protecting the cadastre, but it does mean extra costs and possible delays for developers if it’s not planned for early.
What Developers Need to Do
Before starting work, developers should engage a Registered Land Surveyor to carry out a survey mark audit. This identifies any vulnerable marks and records other survey infrastructure that might be damaged.
The surveyor will then consult with Spatial Services NSW to confirm the process for that specific project. This involves discussing the audit results, agreeing on how to protect or replace marks, and planning a control network strategy. This step is key to ensuring the DPoSIO can be finalised efficiently and cost-effectively after the project finishes.
Replacement Standards and Technology
Spatial Services requires any damaged mark to be replaced on a “like for like” basis. So, if a high-accuracy mark is lost, it must be replaced with one of the same standard. This has led surveying companies, such as Allen Price, to upgrade equipment and processes to meet these requirements.
POSI surveys still use traditional techniques, but with greater precision. Tools like Global Navigation Satellite Systems (GNSS), Digital Levels, and Total Stations have been around for a while, but improvements in techniques, software, and workflows now make the process faster and more cost-effective.
Looking Ahead
POSI surveys are likely to become standard for most projects requiring authority consent. That means it’s in the best interests of both developers and councils to understand their importance and factor them into project planning from the start.
