Note: this guideline is issued by the Surveyor-General under section 7(1)(ga) of the Cadastral Survey Act 2002 about the Rules for Cadastral Survey 2010 and is not legally binding.

The following information relates to rule 3.6 and the accuracy requirements that apply between witnessed boundary points and non-boundary marks on a cadastral survey.

Boundary witness accuracy applies to boundary points and stratum boundaries

The horizontal and vertical accuracy between a witnessed boundary point and all old and new non-boundary marks within the distances specified in rule 7.3.2 must not exceed the tolerances in rule 3.6.

The accuracy tolerances apply to boundary points that define both the horizontal extent of primary parcels and the vertical extent of primary and non-primary parcels in the case of a stratum boundary.

Boundary witness accuracy applies to all close non-boundary marks

The accuracy of boundary witnessing [r 3.6] applies between a boundary point and all non-boundary marks fixed in the field that are within the distances specified by rule 7.3.2.

This includes those marks without a direct connection to the boundary point and in some cases does not include the mark used to set out or tie to the boundary mark.

Figure 1: Distance (radius) and tolerance depend on accuracy class of boundary point

Boundary witness accuracy and primary parcels less than 0.4 ha

In the case of a class A primary parcel being subdivided, for a resultant parcel less than 0.4 ha the accuracy of boundary witnessing standard applies to new boundary points (as indicated in blue in the diagram below) and also to the existing boundary points (as indicated in red) where the larger parcel is less than 90% of the extinguished parcel. This is because rule 7.3.1(a) requires every boundary point on a primary parcel that is being defined by survey, to be witnessed, and all boundary points for a parcel less than 0.4 ha to be defined by survey [r 6.2(a)(iv)].

Diagram showing accuracy standard applies to new and existing boundary points
Figure 2: Accuracy standard applies to new and existing boundary points for new class A parcels less than 0.4 ha

Effect of boundary witness accuracy standards

The Rules emphasise the accuracy of a boundary position in relation to both witness marks and other non-boundary marks within the specified distances in rule 7.3.2.  This enables the boundary point to be confidently reinstated from any one of these marks in the future.

Note the CSD is required to include sufficient vectors to ascertain and verify the relationships between the non-boundary marks and the boundary point [r 8.1(d)(iii)].

Figure 3: The boundary point is able to be reinstated from any of the non-boundary marks
Last Updated: 29 March 2017
Authority: Surveyor-General - Section 7(1)(ga) of the Cadastral Survey Act 2002
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