Permanent survey marks
They are an integral part of Queensland’s surveying infrastructure. Each PM is individually identified with a unique number. The provision of a modern accurate survey system requires the protection of these important survey marks.
PMs complement the use of global navigation satellite systems (such as GPS) by surveyors and may provide accurate longitude and latitude as well as height information.
You can be fined up to a maximum of $10,000 if you interfere with or damage a Permanent Survey Mark. So, if you are planning to do any construction work or landscaping, no matter how small, please read on.
What do they look like?
figure 1 - brass plaque
figure 2 - bolt in concrete with numbered disc
In urban areas, older PMs are brass plaques (figure 1) set in concrete. Often, new PMs are bolts in concrete with a numbered disc (figure 2).
Some PMs in urban areas are positioned below ground level and are not visible unless they have been marked with a concrete or metal cover at ground level.
In rural areas, many PMs are star pickets driven to near ground level, and have a surrounding concrete collar. Witness posts, which are placed to help locate PMs, are often painted red and white.
Where are they placed?
There is no definite rule as to exactly where surveyors should place PMs because a consideration is to protect them from construction activities.
In urban areas, PMs are usually placed in the footpath near street corners or bends. In new subdivisions, there is now a trend to place PMs in the back of the kerb.
In rural areas, PMs are most often placed at prominent road bends, road intersections or near property boundaries in the road reserve. Occasionally, on large rural surveys, PMs are placed on private property.
How can you protect them?
If you are doing any construction work, no matter how small, it is vital that you check whether there are any PMs which could be damaged.
Some of the more common causes of destruction are the building of fences and driveways and also landscaping. There have been instances of individuals mistaking a witness post for a PM, preserving it and then actually destroying the PM it was identifying.
If a driveway or landscaping is placed over a survey mark, and a surveyor needs to measure to it, the surveyor has the right to break the surface to access the mark.
So, before commencing any construction work such as new driveways and landscaping, find out if any Permanent Survey Marks will be affected.
What if you are going to affect a PM?
If you find out that there is a PM that might be affected by construction or excavation work, you can request permission to interfere with a PM. This gives the department an opportunity to minimise the effects if the mark is removed or destroyed.
An application to interfere with a PM should be made to the surveying contact at one of the department's business centres.
If you happen to accidentally disturb a PM, even by a few millimetres, please tell us, so that we can update our records. You should never attempt to put the mark back where it was, as this can lead to errors.
How to locate them?
Contact one of the department's business centres.
Just one phone call could save you $10,000 - so, heed the warning and save our Permanent Survey Marks.
Last updated 28 February 2012