Statute Boundaries

In 1824, the Spring Rice Committee recommended to the British House of Commons that a survey of Ireland at the scale of six inches to the mile was required to provide a definitive indication of acreages and rateable values for the purposes of establishing local taxes in Ireland. Borne of this need for accurate land measurement for valuation purposes, the Irish Ordnance Survey under Lt Col Colby began this work on the 22 June 1824 and completed the world’s first large scale mapping of an entire country by 1846.

The Boundary Survey was initially carried out under the Act 6 Geo IV c 99, the Boundary Survey (Ireland) Act, 1825 in order to demarcate the boundaries of townlands, parishes, baronies and counties henceforth known as Statute Boundaries in preparation for the work of the Ordnance Survey and the Valuation. Richard Griffith was appointed the first Boundary Surveyor (also known as Chief Boundary Surveyor) in 1825 and in 1829 he also became the Commissioner of Valuation, a dual responsibility practice which has continued to this day.

Much of the archive material relating to the historical first survey may be found in the National Archives, Dublin.

Chief Boundary Surveyor

The role of the Chief Boundary Surveyor is to fix maritime and internal boundaries for public purposes in accordance with the provisions of the Boundary Survey (Ireland) Acts, 1854, 1857 and 1859. In the case of maritime boundaries, he revises the land boundaries of counties and their constituent denominations, such as baronies, parishes and townlands, following the reclamation of land from the sea and in the case of internal boundaries, he revises land boundaries requiring to be surveyed and determined arising from changes to administrative boundaries under Local Government legislation.

In his statutory role, under the Boundary Survey Acts, the Chief Boundary Surveyor receives the necessary technical support of Ordnance Survey Ireland in the performance of his duties in determining statutory boundaries and in the delineation of such boundaries on maps. As the State mapping agency, the primary function of Ordnance Survey Ireland (OSI), under its founding legislation – Ordnance Survey Ireland Act, 2001 – is to create and maintain the definitive national mapping and related geographic records of the State. Its role does not include the defining of legal land and maritime boundaries, that being the statutory prerogative of the Chief Boundary Surveyor.

Administrative Boundaries

Since the 1898 Local Government Act, all mapping requirements of any necessary administrative boundary changes must be pursued through the Commissioner of Valuation or Chief Boundary Surveyor

Official Maps

The official maps produced pursuant to the Boundary Survey Acts or a map referred to in a Government Order directing the alteration of a statutory boundary pursuant to section 11 of the 1854 Act are the “relevant ordnance maps” to which reference was made in the Supreme Court decision, Justice J Henchy, in Brown V Donegal Co Council 1980 where he observed

“Therefore it will be seen that the true definition or delineation of a county boundary is to be found in the relevant ordnance map”.

For further clarification the term “ordnance map” means a map made under the powers conferred by the Boundary Survey (Ireland) Acts 1825 to 1872 (Interpretation Act 2005) . In addition to County boundaries, the same interpretation will also apply to Barony, Parish and Townland

The Boundary Survey (Ireland) Act 1872 also clarifies that a duly certified copy of such a map “shall be conclusive evidence of the original map for all purposes”

These maps are also those contemplated in the Local Government Act 2001 as amended by section 12(1) of the Local Government Reform Act 2014 where the map is treated as the definitive record.

Conclusion relating to Statutory and Administrative Boundaries

Whilst Ordnance Survey Ireland maps and mapping services continue to represent Statutory and Administrative Boundaries, their true definition or delineation may only be found on the “relevant ordnance map”. Users of Ordnance Survey mapping are consequentially advised to exercise due diligence and undertake appropriate research when reliance on the position of a Statutory or Administrative Boundary is required.

Ordnance Survey Ireland is fully engaged with in the Open Data Initiative as led by the Department of Public Expenditure and Reform. Part of this initiative is for various data creators such as OSi to release significant data for  public use.  This data is  free from any licencing limitations and allows the  users of that date to freely use it as they see fit. To date, Ordnance Survey Ireland has made available over 100 boundary datasets as Open Data.

Property Boundaries

Ordnance Survey Ireland is the national mapping agency of Ireland. It is the State Agency responsible for the official, definitive surveying and topographic mapping of the Republic of Ireland. As this mapping is topographic, it only represents the physical features on the ground at the time of survey.

OSI maps never indicate legal property boundaries, nor do they show ownership of physical features. Although some property boundaries may be coincident with surveyed map features, no assumptions should be made in these instances and consequently it is not possible to identify the position of a legal property boundary from an OSi map.

Ordnance Survey Ireland can supply a mapping product known as a Land Registry Compliant Map that will act as the base map element to meet the Property Registration Authority mapping requirements. However please note the details of ” Mapping Guidelines-Appendix 1, Basic Requirement for Acceptance of Maps in the Land Registry 2017” on the Property Registration Authority of Ireland website

Statistical Boundaries

Small Areas are a national statistical boundary dataset which subdivides the existing Electoral Districts (EDs) into substantially smaller units with each small area having a general coverage of between 18-120 households. They offer a substantially better level of detail in terms of analysing data spatially whilst avoiding problems of confidentiality. They were originally developed by the National Centre of Geocomputation at NUI Maynooth for Ordnance Survey Ireland in 2010. They were first used in the 2011 Census Analysis and continue to be used and modified in consultation with Central Statistics Office. The Small Area Population Statistics (SAPS) from Census 2016 are easily accessible and freely available for all to use on the SAPMAP website