dataset · England
Reservoir Flood Extents - Wet Day (National)
This data shows the individual flood extents for all large raised reservoirs in the event that they were to fail and release the water held on a “wet day” when local rivers had already overflowed their banks. It represents a prediction of a credible worst case scenario, however it’s unlikely that any actual flood would be this large. The data gives no indication of likelihood or probability of reservoir flooding. Flood extents are not included for smaller reservoirs or for reservoirs commissione
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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: 67.7
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
- reservoir flood extents for large raised reservoirs (wet-day failure scenario)
- Coverage llm-inferred
- England
- Update frequency docs-verified
- quarterly
- Formats docs-verified
- OGC API - Features · WFS · WMS · GeoPackage · GeoJSON · Shapefile · File Geodatabase · LYR
- Access docs-verified
- Free and open download; no public access constraints; Open Government Licence v3.0; attribution required (© Environment Agency)
Useful for
- Use cases llm-inferred
- Reservoir failure flood extent screening for a development site near a large raised reservoir · Flood risk assessment (FRA) constraint layer for reservoir breach scenarios · Emergency planning and site-selection overlay around large reservoirs
- Audience llm-inferred
- flood risk consultants · planners · GIS analysts · civils engineers
Limitations
- Constraints docs-verified
- Represents a credible worst-case wet-day scenario; an actual flood is unlikely to be this large · Gives no indication of likelihood or probability of reservoir flooding · Excludes smaller reservoirs and reservoirs commissioned after October 2016
Evidence
- https://environment.data.gov.uk/api/file/download?fileDataSetId=17af618d-1be0-44b6-bf91-199460a534ac&fileName=Data Version.txt
- https://www.data.gov.uk/dataset/8a385f2f-c1ca-4037-b851-11662114b9e1/reservoir-flood-extents-wet-day-national
Check upstream coverage, uncertainty and licence before use. Station observations are not forecasts or design levels.