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, or fail in extreme weather conditions.
Three datasets are available as open data:
Flood defence Locations. These show the linear alignment of flood defence asset that have been built to protect against flooding from rivers and the sea. It includes the type, length, maintainer, and an ID. These defence locations are also shown in Flood Risk Assessment Wales (FRAW), Flood Map for Planning (FMfP) and Find flood defence structures near you maps. They may relate to an Area Benefiting from Flood Defence (FRAW) and TAN15 zone (FMfP).
Culverts (Polyline); These show an indicative location of underground culverts for general guidance only. Attributes include maintainer, owner, length and ID. Due to the underground nature and history of many culverts, the locations may not be accurate, complete, or up to date.
Culvert openings and Screens (Points). These show an indicative location of culvert openings and screens (often referred to as Trash or Debris Screens). Attributes include maintainer, owner and ID. Locations and details may not be accurate, complete or up to date.
We will regularly update the information when new and improved data becomes available. If you have any queries or concerns about location, maintenance, condition, or records of flood assets, check with the owner or maintainer.
