Water Link

A network representation of the general alignment and connectivity of permanent water, including rivers, lakes, and canals.

Diagram showing what a Water Link feature looks like in OS NGD data.

Temporal filtering

The earliest date on which you can request a one-off snapshot of a date in the past for data in this feature type is 29 September 2022.

Any data temporally filtered earlier than the specified earliest date noted above for the data schema version may contain data inconsistencies.

Feature type attributes

The following sub-sections provide details about the attributes included with this feature type, their data types in the different output formats, and other important metadata about them.

Loading OS NGD CSV files into databases

Comma-separated values (CSV) file format is universally supported for easy ingestion into all major database products. Before loading OS NGD data contained in CSV files into a database, it is necessary to create relevant tables. Data definition language (DDL) statements for PostgreSQL, SQL Server and Oracle can be accessed in our OS NGD Resources GitHub repository.

For instructions on loading CSV files, see the Getting Started with CSV guide.

osid

Primary identifier for the feature. The OSID is a Globally Unique Identifier (GUID) and requires no centralised authority to ensure uniqueness. Note that the same OSID can occur in more than one feature type when a single feature is represented multiple times in the OS NGD.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: false

• Max Length: 36

• OS NGD API – Features Filterable: Yes

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

toid

Topographic identifier (TOID) of the feature, as published in the OS MasterMap suite of products.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Max Length: 20

• OS NGD API – Features Filterable: Yes

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

versiondate

Date when the version was last updated.

• Data Types: String (GeoJSON), Date (GPKG), Date (CSV)

• Nullable: false

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

versionavailablefromdate

The date this version of the feature became the latest version.

• Data Types: String (GeoJSON), DateTime (GPKG), DateTime (CSV)

• Nullable: false

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

versionavailabletodate

The date this version of the feature was superseded by an update or ceased to exist.

• Data Types: String (GeoJSON), DateTime (GPKG), DateTime (CSV)

• Nullable: true

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

changetype

The type of change that generated a new version of the feature.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: false

• Code List Name: changetypevalue
• Max Length: 50

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

geometry

3D geometry for the feature.

• Data Types: Geometry (GeoJSON), Geometry (GPKG), WKT (CSV)

• Nullable: false

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

• Geometry Type: LineString

geometry_length

The measured length of the geometry in metres.

• Data Types: Number (GeoJSON), Float (GPKG), Real (CSV)

• Nullable: false

• Precision: 15

• Scale: 6

• OS NGD API – Features Filterable: Yes

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

geometry_evidencedate

The date on which the latest evidence was gathered to make an update if required. For example the date of collection by a surveyor or third party information received.

• Data Types: String (GeoJSON), Date (GPKG), Date (CSV)

• Nullable: true

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

geometry_updatedate

Date when the attribute was last updated.

• Data Types: String (GeoJSON), Date (GPKG), Date (CSV)

• Nullable: false

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

geometry_source

The source organisation who provided the data.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Code List Name: waterlinkgeometrysourcevalue
• Max Length: 50

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

theme

The OS NGD theme to which this feature belongs.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: false

• Code List Name: themevalue
• Max Length: 40

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

description

A single descriptive value intended for a quick understanding of what the feature represents.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: false

• Code List Name: waterlinkdescriptionvalue
• Max Length: 12

• OS NGD API – Features Filterable: Yes

• OS Select+Build Filterable: Yes

• Data Schema Version: 1.0

description_evidencedate

The date on which the latest evidence was gathered to make an update if required. For example the date of collection by a surveyor or third party information received.

• Data Types: String (GeoJSON), Date (GPKG), Date (CSV)

• Nullable: true

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

description_updatedate

Date when the attribute was last updated.

• Data Types: String (GeoJSON), Date (GPKG), Date (CSV)

• Nullable: false

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

description_source

The source organisation who provided the data.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Max Length: 50

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

primacy

Value indicating the relative importance of the water network link within any larger watercourse it is part of.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: false

• Code List Name: waterlinkprimacyvalue
• Max Length: 1

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

watertype

Expresses whether the water network link represents inland or tidal water.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: false

• Code List Name: waterlinkwatertypevalue
• Max Length: 6

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

physicallevel

The physical level of the feature, for example 'Surface Level' or 'Level 1' if it is on a supported structure.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: false

• Code List Name: physicallevelvalue
• Max Length: 15

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

physicalcontainment

Value indicating whether the water network link in contained in a culvert, tunnel or natural subterranean passage.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: false

• Code List Name: waterlinkphysicalcontainmentvalue
• Max Length: 31

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

flowdirection

Direction of water flow in the segment relative to digitisation of segment geometry.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: false

• Code List Name: waterlinkflowdirectionvalue
• Max Length: 12

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

permanence

Describes if the watercourse contains water year round (in normal conditions) or only contains water intermittently. For example, a flood relief channel would be considered to be Intermittent.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: false

• Code List Name: waterlinkpermanencevalue
• Max Length: 12

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

capturespecification

Indicates the capture specification used by OS when capturing the feature. This could either be Urban, Rural or Moorland.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Code List Name: capturespecificationvalue
• Max Length: 10

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

levelofdetail

A calculated value indicating the relative cartographic importance of a Water Link to aid selection and depiction when styling the data.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Code List Name: waterlinklevelofdetailvalue
• Max Length: 8

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

catchmentname

The name of the catchment area where the WaterLink falls, assigned by a responsible body. The responsible bodies are Environment Agency for England, Scottish Environmental Protection Agency for Scotland, and Natural Resources Wales for Wales. In rare cases where the WaterLink falls inside more than one catchment or is not inside any catchment (for example in the sea), the catchmentName is set to null.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Max Length: 254

• OS NGD API – Features Filterable: Yes

• OS Select+Build Filterable: Yes

• Data Schema Version: 1.0

catchmentid

The code of the catchment area where the WaterLink falls, assigned by a responsible body. The responsible bodies are Environment Agency for England. Scottish Environmental Protection Agency for Scotland and Natural Resources Wales for Wales. In rare cases where the WaterLink is in more than one catchment or is not inside any catchment (for example in the sea), the catchmentID is set to null.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Max Length: 20

• OS NGD API – Features Filterable: Yes

• OS Select+Build Filterable: Yes

• Data Schema Version: 1.0

width

The average width of the watercourse along the WaterLink expressed in metres. For WaterLink features derived from Ordnance Survey large scale single line features, the width is currently set to null.

• Data Types: Number (GeoJSON), Float (GPKG), Real (CSV)

• Nullable: true

• Precision: 7

• Scale: 2

• OS NGD API – Features Filterable: Yes

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

gradient

A calculated percentage value that indicates the rate of descent of the surface of the water. The gradient is derived by dividing the Vertical Drop by the Length of the link and multiplying by 100. NOTE: where the gradient does not correlate with the flow, this value is set to null.

• Data Types: Number (GeoJSON), Float (GPKG), Real (CSV)

• Nullable: true

• Precision: 5

• Scale: 2

• OS NGD API – Features Filterable: Yes

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

startnode

The Water Node coincident with the first vertex for this Water Link.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: false

• Max Length: 36

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

endnode

The Water Node coincident with the last vertex for this Water Link.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: false

• Max Length: 36

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

nameid

The identifier of the name of the Water Link. Used to differentiate between features with the same name.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Max Length: 36

• OS NGD API – Features Filterable: Yes

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

name1_text

Name assigned to identify the feature.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Max Length: 254

• OS NGD API – Features Filterable: Yes

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

name1_language

The language of name1, provided as a 3-digit ISO 639-2 code ('eng, 'cym', 'gla').

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Code List Name: languagevalue
• Max Length: 3

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

name2_text

The alternative language name assigned to identify the feature.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Max Length: 254

• OS NGD API – Features Filterable: Yes

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

name2_language

The language of name2, provided as a 3-digit ISO 639-2 code ('eng, 'cym', 'gla').

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Code List Name: languagevalue
• Max Length: 3

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

namesecondaryid

The identifier of the secondary name of the Water Link. Used to differentiate between features with the same name.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Max Length: 36

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

namesecondary1_text

The name of a sub-section of the feature, normally representing a named stretch of water or pool.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Max Length: 254

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

namesecondary1_language

The language of nameSecondary1, provided as a 3-digit ISO 639-2 code ('eng, 'cym', 'gla').

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Code List Name: languagevalue
• Max Length: 3

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

namesecondary2_text

The language alternative name of a sub-section of the feature.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Max Length: 254

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

namesecondary2_language

The language of nameSecondary2, provided as a 3-digit ISO 639-2 code ('eng, 'cym', 'gla').

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Code List Name: languagevalue
• Max Length: 3

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

nametertiaryid

The identifier of the tertiary name of the Water Link. Used to differentiate between features with the same name.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Max Length: 36

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

nametertiary1_text

The name of a smaller sub-section of the feature, normally representing a named stretch of water or pool.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Max Length: 254

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

nametertiary1_language

The language of nameTertiary1, provided as a 3-digit ISO 639-2 code ('eng, 'cym', 'gla').

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Code List Name: languagevalue
• Max Length: 3

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

nametertiary2_text

The language alternative name of the smaller sub-section of the feature.

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Max Length: 254

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0

nametertiary2_language

The language of nameTertiary2, provided as a 3-digit ISO 639-2 code ('eng, 'cym', 'gla').

• Data Types: String (GeoJSON), String (GPKG), String (CSV)

• Nullable: true

• Code List Name: languagevalue
• Max Length: 3

• OS NGD API – Features Filterable: No

• OS Select+Build Filterable: No

• Data Schema Version: 1.0