dataset · England
Statutory Main River Map
Statutory Main Rivers Map is a spatial (polyline) dataset that defines statutory watercourses in England designated as Main Rivers by the Environment Agency. Watercourses designated as ‘main river’ are generally the larger arterial watercourses. The Environment Agency has permissive powers, but not a duty, to carry out maintenance, improvement or construction work on designated main rivers. All other open water courses in England are determined by statute as an ‘ordinary watercourse’. On these w
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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
- statutory Main River watercourse lines (polyline) in England
- Coverage docs-verified
- England
- Update frequency docs-verified
- irregular
- Formats docs-verified
- Shapefile · GeoJSON · GeoPackage · File Geodatabase · OGC API - Features · WFS · WMS
- Access docs-verified
- Free and open; no public access constraints; Open Government Licence
Useful for
- Use cases llm-inferred
- FRA screening: check whether a site or reach lies on a designated Main River before scoping flood risk assessments · Identify whether the Environment Agency or the LLFA/Internal Drainage Board holds maintenance powers for a watercourse before scoping site works or consents · Map Main River reaches as a GIS constraint layer for drainage strategy and outfall siting
- Audience llm-inferred
- flood consultants · drainage engineers · hydrologists · planners · GIS analysts · civils engineers
Limitations
- Constraints llm-inferred
- Covers only statutory Main Rivers; other watercourses are ordinary watercourses and are not included · Designation does not imply a maintenance duty: the Environment Agency has permissive powers, not a duty · Update frequency is irregular, so check the Updated date before relying on it · Creation reference date is 2005-01-01, so geometry may not reflect recent changes
Evidence
- https://environment.data.gov.uk/api/file/download?fileDataSetId=9dabb220-deca-4d23-868a-4921ef245665&fileName=Data Version.txt
- https://www.data.gov.uk/dataset/4ae8ba46-f9a4-47d0-8d93-0f93eb494540/statutory-main-river-map
Check upstream coverage, uncertainty and licence before use. Station observations are not forecasts or design levels.