4f4c4942-4343-5764-6473-313235323636 English Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en 2026-05-20T09:02:06.427Z NRW 1.0 wel British National Grid (EPSG::27700) Flood Defence Structures Flood Defence Structures Lleoliadau Amddiffynfeydd rhag Llifogydd Flood Defence Locations.lyr 2026-05-20 NRW_DS125266 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: 1. 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). 2. 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. 3. 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. 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: 1. 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). 2. 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. 3. 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. Mae'r Gronfa Ddata Asedau Llifogydd Genedlaethol yn cofnodi'r seilwaith llifogydd yng Nghymru a reolir gan Awdurdodau Llifogydd Lleol Arweiniol a Cyfoeth Naturiol Cymru (CNC). Mae'n cynnwys llawer o argloddiau, waliau, giatiau llifogydd, cwlferi, a sgriniau mewnfeydd (sy'n dal malurion), ond nid pob seilwaith llifogydd sy'n cael ei gynnal neu sy'n eiddo i'r partïon hyn. Mae'r seilwaith yma wedi'i lunio i helpu i reoli'r risg o lifogydd o afonydd a'r môr. Dydyn nhw ddim yn cael gwared ar y risg o lifogydd a gallant fethu mewn tywydd eithafol. Mae tair set ddata ar gael fel data agored. Lleoliadau'r amddiffynfeydd rhag llifogydd. Mae'r rhain yn dangos aliniad llinellol asedau atal llifogydd sydd wedi'u hadeiladu i amddiffyn rhag llifogydd o afonydd a'r môr. Mae'n cynnwys y math, yr hyd, y sawl sy’n eu cynnal, a manylion adnabod. Mae'r lleoliadau amddiffynfeydd hyn i'w gweld hefyd yn Asesiad Perygl Llifogydd Cymru, y Map Llifogydd ar gyfer Cynllunio a mapiau Gweld strwythurau atal llifogydd yn agos atoch chi. Efallai y byddant yn ymwneud ag Ardal sy'n Elwa o Amddiffynfa rhag Llifogydd a pharth TAN15. Cwlferi (Polylinell); Mae'r rhain yn dangos lleoliad dangosol cwlferi tanddaearol ar gyfer arweiniad cyffredinol yn unig. Mae'r priodoleddau'n cynnwys y sawl sy’n eu cynnal, y perchennog, yr hyd a manylion adnabod. Oherwydd natur a hanes tanddaearol llawer o gwlferi, efallai na fydd y lleoliadau'n gywir, yn gyflawn, neu’n gyfredol. Agoriadau a Sgriniau Cwlferi (Pwyntiau). Mae'r rhain yn dangos lleoliad dangosol agoriadau a sgriniau cwlferi (y cyfeirir atynt yn aml fel Sgriniau Malurion). Mae'r priodoleddau'n cynnwys y sawl sy’n eu cynnal, y perchennog a manylion adnabod. Efallai na fydd y lleoliadau a’r manylion yn gywir, yn gyflawn neu’n gyfredol. Byddwn yn diweddaru'r wybodaeth yn rheolaidd pan fydd data newydd a gwell ar gael. Os oes gennych unrhyw ymholiadau neu bryderon am leoliad, cyflwr, neu gofnodion o asedau llifogydd, gwiriwch gyda'r perchennog neu'r sawl sy’n eu cynnal. Mae'r set ddata hon yn seiliedig ar leoliad daearyddol asedau llifogydd yng Nghymru ac mae'n deillio o fesurau 6, 7 ac 8 y Strategaeth Llifogydd Genedlaethol sy'n ceisio dod â'r data hwn at ei gilydd a'i wneud yn hygyrch i'r cyhoedd. Mae'r data'n cael ei gymryd o systemau rheoli asedau a reolir gan Cyfoeth Naturiol Cymru a'r Awdurdodau Llifogydd Lleol Arweiniol canlynol. Cyngor Bwrdeistref Sirol Blaenau Gwent Cyngor Bwrdeistref Sirol Bridgend Cyngor Bwrdeistref Sirol Caerphilly Cyngor Caerdydd Cyngor Sir Caerfyrddin Cyngor Sir Ceredigion Cyngor Dinas Casnewydd Dinas a Sir Abertawe Cyngor Bwrdeistref Sirol Conwy Cyngor Bwrdeistref Sirol Sir Ddinbych Cyngor Gwynedd Cyngor Sir Ynys Môn Cyngor Bwrdeistref Sirol Merthyr Tudful Cyngor Sir y Fflint Cyngor Sir Fynwy Cyngor Bwrdeistref Sirol Castell-nedd Port Talbot Cyngor Sir Penfro Cyngor Sir Powys Cyngor Bwrdeistref Sirol Rhondda Cynon Taf Cyngor Bwrdeistref Sirol Torfaen Cyngor Bro Morgannwg Cyngor Bwrdeistref Sirol Wrecsam Mae lleoliad asedau llifogydd ar gyfer arweiniad cyffredinol yn unig. Nid yw'n dangos pob ased llifogydd nac unrhyw erydiad / amddiffyniad arfordirol a reolir gan y cyrff hyn. Gall rhywfaint o'r data fod yn anghywir neu'n hen. Efallai na fyddai rhai o'r asedau tanddaearol yn hysbys neu wedi eu cofnodi'n gywir. Os oes gennych unrhyw ymholiadau neu bryderon am leoliad, cyflwr neu gofnodion o asedau llifogydd, gwiriwch gyda'r perchennog neu'r sawl sy'n eu cynnal. Cydnabyddiaeth Yn cynnwys gwybodaeth Cyfoeth Naturiol Cymru © Cyfoeth Naturiol Cymru a hawl cronfa ddata. Cedwir pob hawl. © Awdurdodau Lleol Cymru. Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Natural risk zones GEMET - INSPIRE themes, version 1.0 2008-06-01 geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme physical geography flood defence flood risk management flood risk NRW Thesaurus 2026-03-04 geonetwork.thesaurus.local.theme.converted_nrw-keywords Risk assessment Risk management IPSV Subjects List 2020-11-18 geonetwork.thesaurus.external.theme.subjects Coastal Margins (SMNR) Ecosystem (SMNR) Management Areas (SMNR) Sea and Coast (SMNR) Flooding (SMNR) Sustainable Management of Natural Resources (SMNR) Hydrological Processes (SMNR) Natural Resources (Incl. Features and Processes) (SMNR) Soil and Land (SMNR) NRW SMNR Keywords 2024-06-26 geonetwork.thesaurus.local.theme.converted_nrw-smnr-keywords There are no access restrictions on this data. NRW may release, publish or disseminate it freely. no limitations © CNC/NRW & © Welsh Local Authorities. Data may be re-used under the terms of the Open Government Licence providing it is done so, acknowledging both the source and NRW's copyright. It is the recipient's responsibility to ensure the data is fit for the intended purpose. Contains Natural Resources Wales information © Natural Resources Wales and Database Right. All rights Reserved. © Welsh Local Authorities. Open Government Licence English inlandWaters location SeaVoX Vertical Co-ordinate Coverages 2021-01-06 Wales (WLS) -5.777741 -2.608865 51.240829 53.513067 1900-01-31 Geographic Information System Unknown ArcGIS format https://datamap.gov.wales/capabilities/layergroup/4126/?ows_service=wms OGC:WMS Web Service https://datamap.gov.wales/layergroups/geonode:nrw_flood_defence_structures WWW:LINK-1.0-http--link Download Data and Web Services Commission Regulation (EU) No 1089/2010 of 23 November 2010 implementing Directive 2007/2/EC of the European Parliament and of the Council as regards interoperability of spatial data sets and services 2010-12-08 This dataset has not been assessed for conformance to the referenced INSPIRE regulation. false This dataset is based on the geographical location of flood assets in Wales and stems from measures 6, 7 and 8 of the National Flood Strategy that aims to bring this data together and make it publicly accessible. The data is taken from asset management systems managed by Natural Resources Wales and the following Lead Local Flood Authorities: Blaenau Gwent CBC Bridgend CBC Caerphilly CBC Cardiff Council Carmarthenshire CC Ceredigion CC City & County of Swansea Conwy CBC Denbighshire CBC Flintshire CC Gwynedd Council Isle of Anglesey CC Merthyr Tydfil CBC Monmouthshire CC Neath-Port Talbot CBC Newport CC Pembrokeshire CC Powys CC Rhondda Cynon Taff CBC Torfaen CBC Vale of Glamorgan Council Wrexham CBC The position of flood assets is for general guidance only. It does not show all flood assets or any coastal erosion/ protection managed by these bodies. Some of the data may be inaccurate or out-of-date. Some of the underground assets might not be known or recorded accurately. This dataset is based on the geographical location of flood assets in Wales and stems from measures 6, 7 and 8 of the National Flood Strategy that aims to bring this data together and make it publicly accessible. The data is taken from asset management systems managed by Natural Resources Wales and the following Lead Local Flood Authorities: Blaenau Gwent CBC Bridgend CBC Caerphilly CBC Cardiff Council Carmarthenshire CC Ceredigion CC City & County of Swansea Conwy CBC Denbighshire CBC Flintshire CC Gwynedd Council Isle of Anglesey CC Merthyr Tydfil CBC Monmouthshire CC Neath-Port Talbot CBC Newport CC Pembrokeshire CC Powys CC Rhondda Cynon Taff CBC Torfaen CBC Vale of Glamorgan Council Wrexham CBC The position of flood assets is for general guidance only. It does not show all flood assets or any coastal erosion/ protection managed by these bodies. Some of the data may be inaccurate or out-of-date. Some of the underground assets might not be known or recorded accurately.