dataset · Wales
Flood Defence Structures
The National Flood Asset Database records flood infrastructure in Wales managed by Lead Local Flood Authorities (LLFAs) and Natural Resources Wales (NRW). It includes many embankments, walls, flood gates, culverts, and inlet screens (which catch debris), but not all flood infrastructure maintained or owned by these parties. This infrastructure has been constructed to help manage the risk of flooding from rivers and the sea. They do not remove the risk of flooding and can be overtopped, blocked,
Visit source ↗Source details
Licence: ["There are no access restrictions on this data. NRW may release, publish or disseminate it freely.", "\u00a9 CNC/NRW & \u00a9 Welsh Local Authorities. Data may be re-used under the terms of the Open
Evidence quality: 43.4
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
- Flood defence locations (linear alignment, type, length, maintainer, ID) · Culvert locations (polyline, indicative only, maintainer, owner, length, ID) · Culvert openings and screens (points, indicative only, maintainer, owner, ID)
- Coverage docs-verified
- Wales
- Update frequency docs-verified
- biannually
- Formats docs-verified
- Web Service (file format not specified)
- Access docs-verified
- Free/open. No access restrictions; data may be re-used under the Open Government Licence v3.0 (per data.gov.uk).
Useful for
- Use cases llm-inferred
- FRA baseline: mapping flood defence alignments and their maintainers near a site in Wales · Preliminary culvert and screen constraints for drainage or civils design (indicative only, verify on site) · Identifying the owner or maintainer of flood assets before enquiries or works
- Audience llm-inferred
- flood consultants · drainage engineers · GIS analysts · civils engineers · hydrologists
Limitations
- Constraints llm-inferred
- Covers Wales only · Not all flood infrastructure maintained or owned by LLFAs and NRW is included · Culvert locations are indicative and may not be accurate, complete or up to date · Culvert openings and screen locations and details may not be accurate, complete or up to date · Updated biannually, so recent changes may be missing · Defences can be overtopped, blocked or fail, so the data does not remove flood risk
Evidence
- https://datamap.gov.wales/capabilities/layergroup/4126/?ows_service=wms
- https://www.data.gov.uk/dataset/b01b7ee4-f6de-46d2-b57e-4c11c13b1585/flood-defence-structures1
Check upstream coverage, uncertainty and licence before use. Station observations are not forecasts or design levels.