This article relates to recording the survey and boundary vector information required to be included in a CSD.
Under rules 8 and 9, CSDs must include vector information that describes the survey relationship between all marks and points. This enables the points and marks to be correctly located in the cadastre and for users to set out and relocate these positions in the future.
The components of a vector are a bearing and distance.
A vector may be either adopted from an existing survey or measured or calculated.
The Rules do not specify that measured vectors must be provided in a CSD.
Figure 1 below illustrates two ways of using measured vectors and calculated vectors to ascertain the relationship between four marks. Both methods achieve the same result.
Surveyors may wish to distinguish between calculated and measured vectors in a CSD to indicate to future users how they undertook the survey and how the vector was determined. The interpretation of what constitutes a measured vector and a calculated vector is left to the surveyor. Rule 9.3(c) requires that the CSD indicates whether the vector is calculated, measured, or adopted, and rule 12.3 specifies the appropriate line style where the vector is depicted on a diagram.
Number of vectors required to each survey point in CSD and CSD Plan
To ascertain the relationship between any two marks or points, they must be connected by a vector or a series of vectors.
To verify the relationship between these points, additional vectors are needed (ie by forming a closed circuit). Rule 8.1(d) requires that a CSD (but not necessarily the CSD Plan or Diagram of Survey) must include sufficient vectors to both ascertain and verify the relationships.
The CSD Plan must include sufficient vectors to ascertain the relationships.
Note that in most cases, vectors required by the Rules to be included in the CSD in order to ascertain and verify the relationships between points must be captured [Standard for lodgement of cadastral survey datasets (LINZS70000) – standard 4.2(a)].
Vectors between marks and points in a CSD
A CSD must include sufficient vectors to enable the relationship between all points and marks to be ascertained and verified in accordance with the accuracy standards [r 8.1(d)], except for boundaries accepted under rule 6.3 (refer to Accepted boundaries).
This applies to:
- new and old PRMs and witness marks
- new and old non-boundary (traverse) marks and points. Note that rule 8.1(d)(i) includes non-boundary points (in addition to non-boundary marks). Non boundary points are locations where a physical mark was not placed in the ground
- boundary marks and points
- points on water boundaries and irregular boundaries (refer below to Vectors for water boundary or irregular boundary in a CSD).
Number of vectors to each mark or point in a CSD
At least two vectors are required for all boundary points (except those accepted under rule 6.3), and each new survey mark (boundary mark, non-boundary mark, PRM and witness mark) [r 8.1(e)]. These marks must not be left hanging. The second vector may be measured, calculated, or adopted.
For old non-boundary marks, while a single vector is necessary to ascertain the relationship, a second vector may not be necessary to verify this relationship. This will depend on how this old mark is held in the cadastre (Landonline):
- The positions of marks that are survey-accurate (eg by their SDC status or coordinate order), can be used to provide verification, but
- where the position of a mark in the cadastre is not survey accurate, additional vectors may be required to verify the accuracy between that mark and other marks and points.
Where a vector to a control mark that is a long way from the parcel under survey is included in the CSD for the purpose of ascertaining or verifying a position, determining or confirming orientation, or to satisfy the requirement to connect to the control network, refer to Capturing remote trig observations.
Vectors for water boundary or irregular boundary in a CSD
The requirement that there must be a minimum of two vectors for each boundary point [r 8.1(e)] also applies between the end points of a water boundary or an irregular boundary and other boundary points, unless those boundary points have been accepted under rule 6.3.
On the Diagram of Survey only one of these vectors is required to be shown to each point [r 9.6.13(c)].
These vectors can be directly between each end point or, alternatively, to other boundary points or other non-boundary marks.
The Rules do not require intermediary points along a water boundary resulting from, for example, field ties, to be included in the CSD. However if such points are included, then two vectors to each point are required in the CSD [r 8.1(e)] although only one is required on the Diagram of Survey. (Refer to Capture of connections to water or irregular boundaries).
A Diagram of Survey must include sufficient vectors to enable the survey relationship between all points and marks to be ascertained in accordance with the relevant accuracy standards [r 9.6.13(a)]. The vectors in the CSD that verify these relationships are not required on the diagram.
This means a Diagram of Survey must depict at least one vector to each mark and point, and every point must be connected to every other point by one or more vectors. This applies whether the points or marks are new, old, or adopted.
The requirement to depict sufficient vectors on a Diagram of Survey to ascertain the relationship between boundary marks and points does not apply to an existing non-primary parcel (eg an easement parcel) not severed by the creation of a new underlying parcel boundary [r 9.6.13(b)(i)].
Vectors for accepted boundaries on a Diagram of Survey
The requirement to depict sufficient vectors on a Diagram of Survey to ascertain the relationship between boundary marks and points does not apply in the case of accepted boundaries and boundary points [r 9.6.13(b)(ii)]. One example is residue parcels.
A Diagram of Survey must include sufficient vectors to enable the points and marks at the end of water and irregular boundaries to be related to other boundary points [r 9.6.13(c)], unless those boundaries have been accepted.
Historically, the practice was to include a 'scaled' distance extending from a boundary mark or point to the water boundary.
To comply with rule 9.6.13(c), this vector must meet the boundary accuracy standards. A suitable computed value will satisfy this requirement.
These requirements also apply to irregular boundaries.
Adopted vectors on a Diagram of Survey
Adopted vectors used for the purposes of boundary definition, must be depicted on a Diagram of Survey [r 9.6.13(d)] unless they cannot be clearly shown (refer to Where impractical to show vectors on a Diagram of Survey below).
This includes poor quality traverse vectors and abutting boundary vectors used as the best evidence of a boundary location.
Note: the practice of not electronically capturing these vectors in the CSD and recording them on a calculation sheet is not appropriate.
Where the vectors that the Rules require to be depicted are numerous or extend beyond the parcel under survey, the historical practice of only including the vectors in a traverse sheet, rather than on the Diagram of Survey, is not permitted.
Where it is impractical to clearly show the vector dimensions (bearing and distance) on a Diagram of Survey, the line-work for the vector must still be depicted [r 9.6.13(e)]. The vector dimension must be included in the CSD Plan clearly referenced back to the related line-work on the diagram [r 9.6.15(a)].
Historically, boundary dimensions were sometimes not required to be depicted when a parcel was a Class IV Parcel Diagram or a balance parcel in terms of rule 19(2A) SG Rules 2002/2. These exceptions no longer apply.
Boundary dimensions must be shown on a Diagram of Survey [r 9.6.14] and boundary distances on Diagram of Parcels [r 10.4.9].
Exception for recording boundary dimensions for existing easements
Boundary dimensions are not required to be depicted on a Diagram of Survey and Diagram of Parcels where an existing non-primary parcel (eg. an easement parcel) is to be retained and its boundaries are not severed by the creation of a new underlying parcel boundary [r 9.6.14(b)(i) and r 10.4.9(a)(i)].
Exception for recording missing bearings or distances or magnetic bearings
In the case of accepted boundaries:
- When there are missing bearings or distances, a Diagram of Survey must depict the bearings or distances that exist in the cadastral record [r 9.6.14(b)(ii)]. The boundary must be annotated 'bearing unknown' or 'distance unknown', as appropriate [r 9.6.12].
- A magnetic bearing is not required to be depicted, but the boundary must be annotated 'magnetic bearing' [r 9.6.12].
- A Diagram of Parcels must depict the boundary distance where that distance exists [r 10.4.9(a)(ii)]. No boundary annotation is required.
Exception for recording residue parcel boundary dimensions
Boundary dimensions are not required to be depicted on a Diagram of Survey and a Diagram of Parcels where the vectors for accepted boundaries are not common with a new parcel [r 9.6.14(b)(iii) and r 10.4.9(a)(iii)].
Exception for recording dimensions of existing boundaries on parcels over 100 ha
In the case of existing boundaries on parcels over 100 ha that are accepted under rule 6.3(c), boundary dimensions are not required to be depicted on a Diagram of Survey or a Diagram of Parcels [r 9.6.14(b)(iv) and r 10.4.9(a)(iii)]. Note that annotations are required on the Diagram of Survey and Diagram of Parcels.