What is cadastral or land surveying?
A land tenure system that provides for private real property rights and interests requires the system to support the establishment and recognition of cadastral boundaries in a physical form i.e. while the interests in a parcel of land are suited to being documented and confirmed as authorative by entry into a register the extent of those interests, or their boundaries, requires some physical or visible presence on the ground to be useful to the holders of those rights.
Plan of actual survey in New Town from 1855
Australia and New Zealand required a whole new boundary framework to be established across the landscape in support of these private property rights and very few of those boundaries are defined by natural features like rivers or cliffs. The vast majority of these property boundaries are "artificial" in that they require humans to "fix" their position using some other method and be described accordingly. Typically this has meant boundaries are initially defined on the ground by some monument or mark and the most common method adopted for describing the physical locations of those marks is by measured directions and distances shown on plan drawn by a land surveyor.The physical element of artificial boundary creation, coupled with the fact most monuments aren't permanent and no survey measurement can ever be error free, means a state guarantee of boundary locations described in a surveyors plan is impractical.
Boundary creation as described above is primarily a legal process rather than a measurement or mathematical one. The combination of specialised legal and measurement knowledge and skills associated with the creation of cadastral boundaries in the physical world resulted in the practice of boundary surveying being regulated in Australia and New Zealand i.e a system of state approved land surveys has been adopted. Since the 19th century only "authorised" or "registered" land surveyors have been legally entitled to re-establish or mark boundaries of land held under the Torrens system.
Land surveyors act in a quasi-judicial fashion by attempting to emulate the decision making process of the courts in re-defining cadastral boundaries. It follows that in attempting to emulate the courts a land surveyors overarching professional responsibility is to the cadastral system and the cadastral boundary fabric - so while a land surveyor has a responsibilty to meet the needs of their immediate client this service must be provided whilst respecting the rights of all parties with an interest in the land including adjoining owners - current and future - and the Crown.
A land surveyor listed in the Register of Surveyors established under the Surveyors Act 2002 is the only person authorised to undertake cadastral surveys in Tasmania, and this includes determining whether improvments such as buildings and fences are, or are not, within boundaries of land.
Cadastral plans, cadastral maps and digital boundary data
Example of current cadastral survey plan
A cadastral plan is simply a description in pictorial form that is intended to describe what happened on the ground at the time boundaries of estates and interests in land were created. Historically, that plan would sometimes be created from a purely verbal description (for example "..then from the bank of the creek along the fence tothe road....") but generally in Tasmania a cadastral plan supporting the description of the location and extent of interests included in the Torrens register has been derived from a field survey by a registered land surveyor where corner marks were actually placed.
At common law, where interests in land are described by reference to a cadastral plan it is treated as though it is actually part of the description and so the plan and the information in it has legal effect i.e. it is a legal document. However, as noted previously a plan is not definitive as to the on-ground location of cadastral boundaries.
Traditionally, cadastral plans were collated into paper cadastral maps with the primary purpose being to show parcels as they relate to one another for use in land administration - in other words an index of the surveys and parcels. It follows that cadastral maps had no purpose in relation to definitively describing the location of property boundaries. The emergence of the digital age has meant that instead of paper maps being used for this purpose the data is now represented in the digital environment and this Land Parcel and Property dataset, commonly referred to as the digital cadastral database or more recently as the spatial cadastre, is a fundamental component of a modern, integrated land and property information system.
Historic Cadastral Map of New Town
Tasmanian cadastral parcels on the LIST
The LIST is Tasmania's integrated land and property information system. It enables both easy public access to property information and the indicative location of land boundaries via the Cadastral Parcels layer on LISTmap. This and other overlays displayed over topographical maps or aerial imagery provide a wealth of spatial context that adds value in land administration. However, it is extremely important to remember that this layer is effectively only a digital version of a cadastral map and the same limitations apply to it as applies to cadastral maps in relation to indicating the absolute location of cadastral boundaries.
A description of those limitations is available here.
Screenshot of some LISTmap cadastral layers plotted with the original cadastral map of New Town
Remember: boundary definition is primarily a legal process and only a land surveyor listed in the Register of Surveyors is authorised to confirm the location of a property title boundary in Tasmania.