Proposal for new documentation of tagging for UK boundaries - primarily administrative.
UK Admin Boundaries
Each administrative area should be represented in OSM by a relation of type=boundary. The members of the relation are mostly ways which, when organised as a multipolygon, represent the border of the area.
In addition to the way members for the boundary itself, each boundary relation may optionally contain additional members with specific roles:
- admin_centre: a node representing the place where the council has its principal offices
- label: a node representing the suggested location and text for a label, instead of the centroid of the area and the name of the relation
- subarea: other boundary relations, representing constituent parts of this administrative area; counties can have districts as subareas, districts can have parishes, etc. Note that ceremonial boundaries do not take part in this parent-child hierarchy.
Government Reference Codes
In England, Wales and Scotland, each outer polygon has a code, issued by the Government Statistical Service (GSS). In the majority of cases, this can be seen as an identifier of the local government unit. There are however some special cases to bear in mind:
- an exclave of a parish may have its own code
- "Lands common" areas have their own code
- when a boundary is changed, a new code is issued
- if the name is changed without changing the geometry, the code is not changed
The codes are tagged in ref:gss=* and look like "E07000001".
Note that the codes issued by the Office of National Statistics (ONS) are deprecated and should no longer be used. These codes look like "00AA" or "01AA123"
More information on these coding systems can be found on wikipedia:ONS coding system.
The full title is The United Kingdom of Great Britain and Northern Ireland. Great Britain is a subset of the United Kingdom and consists of England, Scotland and Wales. The United Kingdom is a sovereign state at admin_level=2; the four constituent nations are at admin_level=4.
Local Authority Boundaries
Local authority jurisdiction extends at the coast to Mean Low Water. Certain statutory exceptions have been made to this, extending LA jurisdiction to cover significant areas of sea. Notable examples of these Seaward Extensions include Torbay (the boundary cuts straight across the bay), Brighton Marina (the boundary is at some distance from the marina walls) and Bristol (the area extends part-way across the Severn estuary to some islands).
There are currently 9 regions defined in England. Although they no longer have any administrative role, the Regions are still used for statistical purposes - more information can be found here: wikipedia:NUTS of the United Kingdom The tagging has therefore been changed from boundary=administrative to boundary=statistical
type = boundary boundary = statistical name = South East
Territorial waters beyond LA jurisdiction were controlled by the United Kingdom up to 12nm or more from the coastal baseline. Until recently there has never been much need to distinguish between the territorial waters of the constituent nations. However, devolution of responsibilities and powers to national governments has made it essential, so there are now statutory boundaries between the waters of the nations. In the Severn estuary there is an interesting anomaly where the Seaward Extension of the City of Bristol crosses the line between English and Welsh territorial waters, meaning that a part of Bristol can be said to be in Wales.
I don't know how the EEZ waters (up to 200nm from the coast) are divided between the nations, but this may become clear in the next year or so.
- Governed by a Parish Council or a Parish Meeting for smaller parishes – see parish_type tag.
- All parishes must hold an annual parish meeting.
- A Parish Council can optionally be styled as Community Council, Town Council, Village Council or Neighbourhood Council, at their own discretion.
- A Parish Council can be styled City Council, but only by Royal Decree.
- Can share a joint Parish Council (or a joint Parish Meeting) with adjoining parishes.
- May have exclaves known as a "detached" part
- May share land with adjoining parish – "Lands Common"
"Lands common to parishes" (LCPs) have their own boundary relation, tagged as parish_type=lands_common, with an admin_centre member for each parish sharing the jurisdiction. There will be no council_style or council_name on the LCP as they have no council.
Exclaves are simply additional "outer" rings in the boundary relation of the main area to which they belong.
type = boundary boundary = administrative admin_level = 10 designation = civil_parish name = Bloggsville long_name = Bloggsville Civil Parish parish_type = parish_meeting | parish_council | joint_parish_council | joint_parish_meeting | lands_common council_style = parish | town | city | village | neighbourhood | community council_name = Bloggsville Parish Council
- A Metropolitan District is part of a Metropolitan County. The counties themselves have no council these days.
- A Non-Metropolitan District is part of a Non-Metropolitan County.
- Districts may be awarded Borough status.
- District Councils may also be styled as City or County.
type = boundary boundary = administrative admin_level = 8 designation = non_metropolitan_district | metropolitan_district name = Bloggsville long_name = Bloggsville District council_style = district | borough | city | county council_name = Bloggsville District Council borough = yes | no
- May be awarded Borough status
- May also be styled as City or County
type = boundary boundary = administrative admin_level = 6 designation = unitary_authority name = Bloggsville long_name = Bloggsville District council_style = (nothing) | borough | city | county council_name = Bloggsville Council borough = yes | no
Rutland is a technically a District, which is styled as a County; it is effectively a Unitary Authority.
- The six Metropolitan Counties no longer have a council, although a limited number of functions are carried out through Joint Boards. Therefore they should be tagged as ceremonial rather than administrative.
- Most Non-Metropolitan Counties have a County Council (see below for the exception).
type = boundary boundary = administrative admin_level = 6 designation = non_metropolitan_county name = Bloggsshire long_name = County of Bloggsshire council_name = Bloggsville County Council
Berkshire (a Non-Metropolitan County) has no council. It consists solely of Unitary Authorities.
A number of areas have a Combined Authority, which coordinates certain high-level functions between member authorities. A Combined Authority can have a directly elected Mayor, sometimes referred to as a Metro Mayor, but does not have an elected council.
type = boundary boundary = administrative admin_level = 5 designation = combined_authority name = East Northland
Current CAs are Cambridgeshire and Peterborough, Greater Manchester, Liverpool City Region, North East, North of Tyne, Sheffield City Region, Tees Valley, West Midlands, West of England, and West Yorkshire.
The GLA is the higher level LA for Greater London, including the City of London and the 32 London Boroughs. It is set to admin_level=5 as it includes and governs the City of London which, as a Unitary Authority, has admin_level=6.
There is also a Ceremonial County of Greater London, which excludes the City of London.
type = boundary boundary = administrative admin_level = 5 name = Greater London long_name = Greater London council_name = Greater London Authority
The 32 London Boroughs are divided into 12 Inner London Boroughs and 20 Outer London boroughs. Four of them have special ceremonial names: one City (Westminster) and three Royal Boroughs (Kensington and Chelsea, Kingston upon Thames and Greenwich). Most refer to themselves as "London Borough of ..." but "... Council" is also popular.
type = boundary boundary = administrative admin_level = 8 designation = inner_london_borough|outer_london_borough council_style = borough | (nothing) | city | royal_borough name = Merton long_name = London Borough of Merton council_name = Merton Council
There are two “special case” councils, described as “sui generis” i.e. one of a kind.
City of London
type = boundary boundary = administrative admin_level = 6 designation = sui_generis name = City of London long_name = City of London council_name = City of London Corporation
The Scillies have been largely autonomous from Cornwall for many years, governed by their own council, effectively a County Council since 1890. They are also part of the ceremonial county of Cornwall.
type = boundary boundary = administrative admin_level = 6 designation = sui_generis name = Scilly Isles long_name = Isles of Scilly council_name = Council of the Isles of Scilly
Within the area of the City of London there are two semi-autonomous areas known as Civil Liberties: Inner Temple and Middle Temple. In some ways they function as tiny local authorities, although they have delegated the exercising of some powers “upwards” to the City of London Corporation. I have not found a source of the exact boundaries. Although their theoretical powers approximate to those of a London Borough, an admin level of 9 is probably the best reflection of the practice.
Lower Peover is a cross-border joint parish council. It covers the civil parish of Nether Peover, which is part of Cheshire West and Chester UA, and the civil parish of Peover, which comes under Cheshire East.
Communities are subdivisions of the Principal Areas and equivalent to the Civil Parish in England. As with English Civil Parishes, a council may or may not exist, depending on whether the population justifies the existence of a Community Council. Communities without a council hold Community Meetings instead. Most do not have a council.
A Community Council may style itself "Town Council", and it may be awarded City status by the Crown.
Communities may share a Community Council (analogous to English joint/group parish councils).
type = boundary boundary = administrative admin_level = 10 designation = community council_style = community | town | city name = Aberystwyth name:en = Aberystwyth name:cy = Aberystwyth long_name = Aberystwyth parish_type = community_council | joint_community_council council_name = Cyngor Tref Aberystwyth Town Council council_name:en = Aberystwyth Town Council council_name:cy = Cyngor Tref Aberystwyth
Principal Areas in Wales are usually known as Counties. Some have Borough status, and they are known as County Boroughs.
type = boundary boundary = administrative admin_level = 6 designation = principal_area council_style = county | county_borough | city_and_county name = Cardiff name:en = Cardiff name:cy = Caerdydd long_name = City and County of Cardiff council_name = Cardiff Council council_name:en = Cardiff Council council_name:cy = Cyngor Caerdydd