• {'logoName' | translate} NRW Data Discovery

Flood Defence Structures
Lleoliadau Amddiffynfeydd rhag Llifogydd

  • English
  • wel
  • All

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.

  • Identification
  • Extent
  • Distribution
  • Quality
  • Keywords
  • Spatial Reference System
  • Content
  • Constraints
  • Maintenance
  • Metadata

Identification

Dynodydd
Identifier
NRW_DS125266
Teitl Amgen
Alternative Title
  • Flood Defence Locations.lyr
Laith Metadata
Metadata Language
English
Lineage

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.

Dyddiad cyfeirnod y set ddata (Cyhoeddiad)
Dataset Reference Date (Publication)
2026-05-21
Perchennog
Owner
  Natural Resources Wales (NRW) -
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales
http://naturalresources.wales/?lang=en
Cychwynnwr
Originator
  Natural Resources Wales (NRW) -
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales
http://naturalresources.wales/?lang=en
 

Extent

Extent

Hyd
Geographic Extent
Wales (WLS)
N
W
E
S
Map representing the geographic extent of the dataset


 
 

Distribution

Dosbarthiad
Distribution

Fformat - Math a Disgrifiad
Format Type and Description
  • Geographic Information System ( Unknown )

    Specification

    ArcGIS format

Lleolwr Adnoddau
Resource Locator
Web Service ( OGC:WMS )
Lleolwr Adnoddau
Resource Locator
Download Data and Web Services ( WWW:LINK-1.0-http--link )
 

Quality

Ansawdd Data
Data quality

Cwmpas Ansawdd
Quality Scope
Dataset
Dataset
Cydymffurfiad
Conformity
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
Explanation

This dataset has not been assessed for conformance to the referenced INSPIRE regulation.

Degree
false
Lineage

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.

 

Keywords

Allweddair
Keywords

GEMET - INSPIRE themes, version 1.0
  • Natural risk zones
Math
Type
Theme
Theme

Dyfyniad
Citation

Dyddiad (Cyhoeddiad)
Date (Publication)
2008-06-01
Code
geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme

Allweddair
Keywords

NRW Thesaurus

  • physical geography
  • flood defence
  • flood risk
  • flood risk management
Math
Type
Theme
Theme

Dyfyniad
Citation

Dyddiad (Cyhoeddiad)
Date (Publication)
2026-03-04
Code
geonetwork.thesaurus.local.theme.converted_nrw-keywords

Allweddair
Keywords

IPSV Subjects List

  • Risk management
  • Risk assessment
Math
Type
Theme
Theme

Dyfyniad
Citation

Dyddiad (Cyhoeddiad)
Date (Publication)
2020-11-18
Code
geonetwork.thesaurus.external.theme.subjects

Allweddair
Keywords

NRW SMNR Keywords

  • Management Areas (SMNR)
  • Coastal Margins (SMNR)
  • Ecosystem (SMNR)
  • Sea and Coast (SMNR)
  • Flooding (SMNR)
  • Hydrological Processes (SMNR)
  • Sustainable Management of Natural Resources (SMNR)
  • Soil and Land (SMNR)
  • Natural Resources (Incl. Features and Processes) (SMNR)
Math
Type
Theme
Theme

Dyfyniad
Citation

Dyddiad (Cyhoeddiad)
Date (Publication)
2024-06-26
Code
geonetwork.thesaurus.local.theme.converted_nrw-smnr-keywords
 

Spatial Reference System

Code
British National Grid (EPSG::27700)
 

Content

Gwybodaeth Cynnwys
Content Information

Proffil CNC
NRW Profile

Elfennau CNC
Custom Elements

 

Constraints

Constraints

Limitations on Public Access and Use

Math o Gyfyngiad
Restriction type
Other restrictions
Other restrictions
 

Access Constraints Directive

Limitations
no limitations
 

Access Constraints Text

Other constraints

There are no access restrictions on this data. NRW may release, publish or disseminate it freely.

 

Use Constraints

Cyfyngiadau Defnyddio
Use constraints type
Other restrictions
Other restrictions
Other constraints

© 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.

 

Attribution Statement

Other constraints

Contains Natural Resources Wales information © Natural Resources Wales and Database Right. All rights Reserved. © Welsh Local Authorities.

 

Licence

Other constraints
Open Government Licence
 
 
 

Metadata

Metadata

Dynodydd Ffeil
File Identifier
4f4c4942-4343-5764-6473-313235323636 XML
Laith Metadata
Metadata Language
English
Math o adnodd
Resource type
Dataset
Dataset
Dyddiad Metadata
Metadata Date
2026-06-01T14:14:37.323Z
Enw Safonol Metadata
Metadata Standard Name
NRW
Fersiwn Metadata
Metadata Standard Version

1.0

Pwynt Cyswllt
pointOfContact
  Natural Resources Wales (NRW) -
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales
http://naturalresources.wales/?lang=en
 
 

Publishing Body

Access the portal
Full access to the portal and metadata.


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