Kinds of Boundaries
Boundaries can be classified at many levels: they may be international (between countries), national (between states of a country), regional (between regions of a state), local (between localities of a region or local government area) or – as in the context of this paper – individual boundaries separating parcels of subdivided land.
Boundaries between countries and states are more commonly referred to as borders, and may be either natural (eg. seas, rivers, lakes) or artificial (eg defined by geographic lines of latitude and longitude). Borders serve political, legal and economic purposes in separation of the jurisdictions of abutting areas.
Other kinds of boundaries include maritime boundaries, which define the exclusive rights of a country or state over the resources of oceans adjoining the land of that country or state: In Australia, "a 3 nautical mile limit of coastal waters; a 12 nautical mile limit of the territorial sea, 24 nautical mile Contiguous Zone and a 200 nautical mile limit of the Australian Exclusive Economic Zone" (Geoscience Australia, 2011). Maritime boundaries may also exist for specific purposes, such as marine parks and fishing zones and ‘administrative boundaries’, which are based on cadastral maps and used for political and governmental administrative purposes (eg. electoral boundary divisions, censuses taken periodically for planning and development purposes at a national or regional level).
Definition of Boundaries of Land Parcels
Boundary lines (commonly called property lines) define the extent of the legal limits of ownership of any parcel of land.
At common law, the rule of ‘marks (monuments) before measurements’ prevail in the definition of a boundary. There is also a presumption at common law that where land is described as being bounded by a road, ownership extends to the middle of the road (the ad medium filum viae rule), unless there is a clearly defined intent to the contrary (which is usually the case).
If the description of a boundary is ambiguous, otherwise uncertain or in conflict with the occupations, Courts may settle the position of the disputed boundary. Courts have established precedents granting priorities of weight where any two or more of the following boundary features present conflicting evidence in the determination of a true boundary position, in order of priority:
- "Natural boundaries (eg rivers, cliffs)
- Monumented lines (boundaries marked by survey or other defining marks, natural or artificial)
- Old occupations, long undisputed (for example an old wall or fence)
- Abuttals (a described ‘bound’ of the property eg a natural or artificial feature such as a street or road)
- Statements of length, bearing or direction (‘metes’ or measurements in a described direction)
This ranking order is not rigidly adhered to; special circumstances may lead a court at times to give greater weight than normal to a feature of lower rank" (Hallmann 1994, 13.13).
Subject to any evidence to the contrary, Courts have consistently ruled in favour of long, acquiescent and undisturbed occupation dating to the time of survey as the most convincing evidence of a boundary between properties.
Further, it is a fact of law that where a property is described by ‘metes and bounds’, that is both measurements and a feature which describes the extent of ownership, the described bounds (abuttals) take priority over the stated measurements.
Strata title boundaries are specifically defined by the strata title plan and, commonly, are the centre of the walls, floor and ceilings enclosing a lot.
The actual location of any boundary is subject to evidence of an on-ground assessment of the facts pertaining to the matter, and is best undertaken by a registered (or licensed) land surveyor. (Refer also Boundary Disputes and Judicial Determination.)
The Nature of Boundaries
Boundaries of land are generally fixed and do not move, although the interpretation of the location of the boundary can be difficult and professional judgements may vary in the interpretation of evidence of the location.
Where ‘natural’ boundaries are formed by seas, lakes, rivers etc the situation is more complex: such boundaries are said to be ‘ambulatory’. Ambulatory boundaries cannot be marked on the ground and are not fixed in one place, but can change position over time through slow and imperceptible accretion or erosion of the described feature.
Different rules of interpretation of the definition of natural boundaries apply, depending upon:
- whether the boundary adjoins tidal or non-tidal waters
- the existence or otherwise of Crown reserves
- the determination of high or low water mark, or the water’s edge
- the definition of a river bank and, perhaps more importantly
- whether or not changes in the situation were slow and imperceptible over time, or sudden as in the change of course of a river caused by flooding or deviation.
In future years, there will no doubt be great interest in the impact of climate change on sea level and the subsequent effect on boundaries bordering those waters.
It should also be noted that there is a presumption at common law that where land is described as being bounded by a non–tidal river or stream, ownership extends to the middle line of the water (the ad medium filum acquae rule), unless there is a clearly defined intent to the contrary.
The extent of the boundaries of home ownership is subject to the same rules described in the Definition of boundaries of land parcels.
Where a new subdivision is under development, the primary indicators of land boundaries are the survey marks placed by a registered land surveyor for that purpose.
In a developed subdivision, the primary indicator of boundaries is most likely to be fences, however caution should be taken to confirm that fences are truly located and not subject to encroachment by the owners of adjoining lands.
Caution is advised when checking measurements of land on the ground, as distances shown on survey plans and land titles are always stated as horizontal distances, which are always subject to adjustment for any slope of the land itself.
It is not safe to rely on results from hand–held Global Positioning System (GPS) devices (also referred to as Global Navigation Satellite Systems (GNSS)), as these do not necessarily give the same coordinates and may vary in accuracy and repeatability of measurements, nor should digitised coordinates derived from Digital Cadastral DataBases be relied upon as the best evidence of the location of boundaries.
The only sure way of establishing where a property’s true boundaries lie is to engage the services of a registered land surveyor.
Boundary Disputes and Judicial Determination
Boundary disputes can occur at many different levels: international border disputes (often leading to wars between nations); national border determinations between states; regional boundaries between the localities of a region; or — as in the context of this paper — disputes between owners of adjoining lands.
Boundary disputes generally arise because of one landowner’s lack of consideration for the owners of neighbouring land. It is apparent that far more boundary disputes arise between the owners of urban residential properties than between commercial or agricultural neighbours.
Disputes between residential neighbours are likely to involve access issues and the location and/or type of boundary separating the land parcels, potentially causing much angst (and considerable expense) for the aggrieved parties.
As previously indicated, where a dispute exists, a land surveyor is not the final arbiter of any boundaries under dispute: this role falls to the Courts.
The surveyor’s role in these matters is one of fact-finder and expert witness, providing the evidence of what has gone on before, upon which the Courts will make judgement.