dataset · England
EA Hydrological Boundaries
The Hydrological Areas are a polygon dataset showing 139 hydrological units across England and parts of Wales, that have been defined by the Environment Agency. The units show areas that have broadly similar hydrological characteristics. Many of the hydrological areas are defined by surface water (river) catchments, which are areas of land from which all surface run-off flows through a series of streams, rivers and possibly lakes, to a particular point in the water course such as a river conflue
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Licence: ["There are no public access constraints to this data. Use of this data is subject to the licence identified.", "There are no public access constraints to this data. Use of this data is subject to the
Evidence quality: 57
Listed in data.gov.uk public catalogue API on 2026-10-16; relevance/value screened (haiku).
Metadata checked: 2026-10-14T13:20:00.000Z
What's in it
- Data offered docs-verified
- hydrological area boundaries (139 polygon units)
- Coverage docs-verified
- England and parts of Wales
- Update frequency docs-verified
- asNeeded
- Formats docs-verified
- OGC API - Features · WFS · WMS · SHP (zipped) · GPKG (zipped) · GeoJSON (zipped) · File Geodatabase (zipped)
- Access docs-verified
- Free, open access under Open Government Licence v3.0
Useful for
- Use cases llm-inferred
- Assigning FRA study sites to EA hydrological areas to select the appropriate flow or rainfall inputs · Screening groundwater recharge context for site investigations using the hydrogeologically defined units · Regional hydrological context maps for drainage strategy and water-quality assessments
- Audience llm-inferred
- flood risk consultants · hydrologists · hydrogeologists · drainage engineers · GIS analysts
Limitations
- Constraints llm-inferred
- Polygon unit boundaries only; not individual catchment or gauge data · Coverage is England and parts of Wales only, so no Scotland or Northern Ireland units · No spatial resolution or scale is stated in the docs · Update schedule is as-needed rather than fixed · Units mix surface-water and hydrogeological definitions, so they may not suit every analysis · Attribution statement required for reuse
Evidence
- https://environment.data.gov.uk/api/file/download?fileDataSetId=b9c2bc28-64b2-4120-a5ed-13fa58e0c471&fileName=EA_Hydrological_Boundaries.gdb.zip
- https://www.data.gov.uk/dataset/f3c13382-8558-4731-8eb0-b5f931a86f82/ea-hydrological-boundaries
Check upstream coverage, uncertainty and licence before use. Station observations are not forecasts or design levels.