The purpose of this document is to explain what are Statute and Administrative Boundaries, when they were enacted, how we show them on Ordnance Survey Ireland (OSi) plans and why they are important.


The Ordnance Survey was established in 1824 to carry out a large scale survey of Ireland at a scale of 1:10,560 (6”). It was also to record Townland, Parish, Barony and County names, and set down the Boundaries of each. The Government passed a statutory law, the 1825 Boundary Survey (Ireland) Act which allowed the survey and the recording of Place names and areas to be carried out. This, consequently, had the effect of making the Boundaries shown on OSi plans statute Boundaries.


Early in the nineteenth century it became obvious that the local taxes which were based on townland units in Ireland were inequitable. On the recommendation of the Spring Rice Committee, a survey of all Ireland at a scale of six inches to one mile was authorised by Parliament in 1824.

PRE 1824.

One of the earliest known maps of Ireland was produced by Baptista Boazio in 1599. This predates the establishment of the Ordnance Survey by more than 200 years. At the end of the Cromwellian Wars in Ireland, the victorious soldiers had to be paid, so it was decided to pay them with the land confiscated from the rebels. William Petty undertook the survey of the forfeited land and this became known as the “Down Survey” because it was plotted down and reproduced on paper. Grand Juries who were the forerunners of the County Council also commissioned maps of their areas. So, it can be seen that Ireland was very well mapped before the establishment of the Ordnance Survey.


A new boundary department was established by Act of Parliament in July 1825. Richard Griffith was appointed head of the new department and he was directly responsible to the Lord Lieutenant in Dublin Castle. This department was given the task of ascertaining the boundaries of parishes and townlands in Ireland.


Griffith produced boundary descriptions and sketch maps of all the townlands and parishes in Ireland. He also provided the acreage and the valuations required for an equitable tax system.


The vast majority of the place names were originally in the Irish language and the standardised forms were to be anglicized. O’Donovan, who had no difficulty in drawing information from all levels of society, was given this task. The forms thus provided by the Ordnance Survey have served as the official Government orthography in the English language.


The Government in Great Britain at the time was fearful that Ireland would become a burden on the British tax payer, so, in order to remedy this, it passed the Poor Law Act of 1838. This allowed for the setting up of Unions in each county for the relief of the poor. This would be paid for by the local gentry. Each county would be broken up into Unions and each Union would be made up of District Electoral Division known as DEDs. They are now known as EDs. Each DED would be made up of townlands.

FAMINE 1845-1849

After the potato famine, many Irish landlords were forced by economic pressure to sell their properties and an “Encumbered Estates Court” was established in 1844 to deal with the flood of land transactions. The Judges found the six inch map too small for the precise area calculations required and eventually the Ordnance Survey was asked to supply estate maps which were re-plotted at 1:2,500 from the six inch field books and then field revised. In 1863, Griffith requested that Dublin be resurveyed at a scale of 1:2,500. Subsequently, all of Ireland was resurveyed at this scale.


Following the completion of the six inch survey of Ireland in 1846, the 1854 Boundary Ireland Act provided additional powers to the Ordnance Survey to revise boundaries affected by recent alterations of the course of rivers and other such changes. Provisions were made for appeals to “Quarter Sessions” and for the Boundary Surveyor to submit proposed amendments to the Grand Jury (Co. Council).

Following approval by the Grand Jury, they were then submitted for approval by the Assizes court. On completion of this process, the proposals were then submitted to the Lord Lieutenant and Privy Council for ratification by order in council. The Act of 1857 gave additional powers to the Boundary surveyor to correct errors made in earlier surveys provided that the land owners involved initiated the process by application to the Boundary Surveyor. The Act also provided the survey with powers to mark out the boundaries of any land reclamation from the sea, tidal river or lake.

The Act of 1859 gave the Boundary Surveyor the power to change the names of townlands and also dispensed with the necessity for Privy Council involvement. The Boundary Survey Act 1872 allowed for the Government to change county boundaries. It allowed for an order to be made under this Act and for a map to be made from this order. The existence of this map was proof of the new County boundary.

This map would then be accepted by the Courts or other bodies. The 1898 Act set up a Local Government administration system for Ireland. Each area was to be responsible for its own health services and local government. It also abolished the Grand Juries, which up to then ran each county. This Act imposed further responsibilities on the Boundary Surveyor who had to ensure that the newly defined administrative boundaries were shown correctly on Ordnance Survey maps. The Boundary Surveyor however, had no responsibility for the determining of any change in the administrative boundaries which include; county borough, borough, urban district or town. This situation still pertains today.

Note: The Boundary Surveyor mentioned in the Acts is today, by custom and practice, known as the Chief Boundary Surveyor.


The Chief Boundary Surveyor appears to have stopped signing supplementary boundary sheets in 1912. With the outbreak of the First World War in 1914, the uprising in 1916 followed by the war of Independence little mapping was carried out. The Government of Ireland Act 1920 set up the Parliament for Ireland one for the North, the other for the South. It states that the Parliamentary boundaries of Antrim, Down, Fermanagh, Londonderry, Armagh and Tyrone are the areas for Northern Ireland and the remaining counties are the South.

This is how the land frontier evolved. In 1924 the Ordnance Survey was transferred from the Department of Agriculture to the Department of Finance. At this time there was little mapping carried out due to limited resources. The Foreshore Act was enacted in 1933. In this Act the word “foreshore” means the bed and shore below the line of high water of ordinary or medium tides of the sea and of every tidal river and tidal estuary and of every channel, creek and bay of the sea or any such river or estuary.

1:1,000 mapping was started in the early 1960’s Boundaries were transferred from the 25” county services. N.P.S. mapping was started in the early 1990’s Boundaries were transferred from the 25” county series.


The Ordnance Survey was set up to (a) Map Ireland (b) Show statute boundaries on its maps Each townland boundary has a written description and a signed boundary sheet that can be produced in court in the event of any dispute. As previously mentioned an “Area Book” exists for each county. It is divided into rural district, electoral district, barony and townland. These are also put on the signed boundary sheet. So, if we change a townland boundary in any way for whatever reason, we then change the area of the townland too. This will then affect the Land Registry registrations and maybe the Valuation Office.


Originally set out in the 1825 Boundary Survey (Ireland) Act County, Barony, Parish and Townland boundaries are statute boundaries which means that they have been enacted by Parliament and therefore cannot be altered except by reference to: 1854 Boundary Survey (Ireland) Act 1857 Boundary Survey (Ireland) Act 1859 Boundary Survey (Ireland) Act Any changes made to the original boundaries by the Chief Boundary Surveyor due to changes in high water, incorrect spelling or erroneously marked out areas by reference to the 1854, 1887 and 1859 Acts means that these revised boundaries become the new statute boundaries.


(“description attached to a boundary”) Under the 1825 Boundary Survey (Ireland) Act, Ireland was surveyed at a scale of 1:10,560 (6”) on a Parish by Parish basis. These Parish maps are known as “Fair Plans”. As well as the Parish and townland boundaries being plotted on maps a description was written for each boundary. These are known as the “Boundary Survey Register”, – name of Parish and these are available in the National Archives.


The Ordnance Survey also kept “county area books”. These divided up rural district, division electoral district, townland and barony. Each place was given a specific area, so that each townland has an area which when combined together make up a barony and then a county. Areas for each townland appear on the signed supplementary boundary sheet. The area also includes water and indicates whether it is tidal. When the townland boundary was originally plotted it was usually on a feature e.g. fence or a wall, so the mereing was then added to the boundary to become C.F. or C.W. In the Pale, the mereing usually is 6ft. (1.83m) from the boundary. This allowed for the land owner to maintain his fence and still be on his own property. If the feature changes e.g. the fence is removed, the boundary then becomes undefined.

Examples of mereing are:

  • E.R. Edge of river
  • T.B. Top of bank S.D.
  • Side of drain


As stated previously Ireland was mapped mainly for taxation purposes but with Ireland now mapped on a large scale of 1:10,560, the Government used Ordnance Survey maps to show Administrative boundaries. From the 1898 Local Government Act, when the Co. Councils were set up and Grand Juries were abolished, the Chief Boundary Surveyor had to ensure that newly defined Administrative boundaries were shown correctly on Ordnance Survey maps. This practice has continued with the passing of new Local Government Acts.

2001 Local Government Act In 2001 the Government passed the 2001 Local Government Act which replaced the 1898 Act. The system of Local Gov. in Ireland has fallen into disrepute amid many scandals. The Act set out to remedy some of the deficiencies of the 1898 Act but it is where it affects the Administrative Boundaries where we must focus.

The main changes are the renaming of;

  • County Borough to City Council.
  • Borough to Borough Council.
  • Urban District to Town Council.
  • Towns under 1854 Town Improvements Act to Town Council.
  • Tipperary North Riding to North Tipperary County Council.
  • Tipperary South Riding to South Tipperary County Council.

These became law on 1st January 2002.

Under the 1898 Act, an order was made incorporating the 1872 Boundary Surveys Act to change county Boundaries. The OSi plan quoted in the order was evidence of the change being made. The 2001 Local Government Act has simplified this procedure. Therefore, instead of a written statutory instrument, the Act now allows for an OSi plan to be submitted by the Council to the Dept. of the Environment and with the Minister’s approval and signature the extension becomes law.

Tidal Water Ordnance Survey Ireland shows the low and high water mark on large scale maps. As already stated, the area between high and low water is the Foreshore. Under the 1933 Foreshore Act, the Foreshore belongs to the state. Foreshore can occur in both baronial waters and maritime waters. By baronial waters we mean tidal water within a barony, which is also within the administrative area of a county, for example The Shannon Estuary.

Maritime water, which we usually refer to as the Maritime boundary (level shown is County, Barony and Townland) is shown as open sea. Dublin Port Large portions of land were reclaimed from the sea (maritime boundary) in Dublin Port between 1950 and 1980. As this land was outside any statutory boundary it could not be registered in Land Registry or valued by the Valuation Office. A committee was set up in 1969 comprising of the Department of the Environment, the Chief State Solicitor, Dublin Corporation and the Ordnance Survey.

They reached a conclusion in 1983 and agreed a procedure for the reclamation of land from maritime waters. Since 1984, this procedure has been applied in Malahide, Dun Laoghaire, Cork, Wexford, Kerry and Donegal. This procedure is recorded in the Boundary Section and the Valuation office.


Boundaries have many uses including: Census The Central Statistics Office uses both administrative boundaries and statute boundaries for calculating the population for each province, county, county borough, urban district, rural district, E.D. and towns under the 1854 Towns Improvement Act. They also supply the population of Civil Parishes on request.


The country is divided into 8 health regions. The areas for each Health Authority outside Dublin follows country boundaries, inside the Eastern Regional Health Authority they follow E.D’s.


Under the terms of the Electoral Act, 1997, a commission was set up to issue a report that reviewed both Dáil and European constituencies. In its final report it used 15 small scale Ordnance Survey Ireland maps and for the first time used 1:1,000 plans to set our constituency boundaries.


The GeoDirectory is a collaboration between An Post and Ordnance Survey Ireland. The purpose of the project is to identify every address in the Republic of Ireland and to assign to them accurate postal and geographic addresses. For the first time the GeoDirectory combines accurate postal and geographic addresses for the Republic of Ireland in one database. It will provide a basic infrastructure, which will become invaluable across all industrial sectors.


As already stated county, barony, parish and townland boundaries are statute boundaries and Ordnance Survey Ireland is called on to prove these facts in court. For example; High Water and Low Water form the extent of the Foreshore under the 1933 Foreshore Act, and disputes may arise in the issuing of a Foreshore Licence. Under the 1920 Government of Ireland Act (which the Free State did not accept) which set up the Parliament in 26 counties in the South and 6 counties in the north, the border between north and south became known as the Land Frontier.

Ordnance Survey Ireland appears in court to identify in which jurisdiction a crime took place i.e. north or south of the Land Frontier (1976 Jurisdiction Act). In property disputes i.e. land where both parties claim ownership, the courts look to Ordnance Survey Ireland to help. In all cases the signed 6” Boundary Sheet is accepted in Court as a legal map.

Land Registry

The Land Registry Department is one of the largest users of Ordnance Survey Ireland maps in the state as they use Townlands to register all property boundaries using folio numbers or deeds. Section 84 of the Registration of Title Act, 1964 provides that the latest available Ordnance Survey maps for the State are to be kept in the Land Registry.


As stated in OSi Act 2001, it is the duty of OSi “to provide the necessary technical support to the Chief Boundary Surveyor in the performance of his/her duties in delimiting statutory boundaries and the delineation of such boundaries on maps”. The duty of the Chief Boundary Surveyor is to ensure that new statutory and administrative boundaries are shown on Ordnance Survey Ireland maps, and to supply and make a report to the Government on new maritime boundaries, e.g. Dublin Port, Rosslare etc.