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, 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.

Identification

Identifier
NRW_DS125266
Alternative Title
  • Flood Defence Locations.lyr
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.
Dataset Reference Date (Publication)
2026-05-21
Owner
  Natural Resources Wales (NRW) -
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales
http://naturalresources.wales/?lang=en
Originator
  Natural Resources Wales (NRW) -
Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales
http://naturalresources.wales/?lang=en
 

Extent

Extent

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


 
 

Distribution

Distribution

Format Type and Description
  • Geographic Information System ( Unknown )

    Specification

    ArcGIS format

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

Quality

Data quality

Quality Scope
Dataset
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

Keywords

GEMET - INSPIRE themes, version 1.0
Type
Theme

Citation

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

Keywords

NRW Thesaurus
  • physical geography
  • flood defence
  • flood risk
  • flood risk management
Type
Theme

Citation

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

Keywords

IPSV Subjects List
  • Risk management
  • Risk assessment
Type
Theme

Citation

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

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)
Type
Theme

Citation

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

Spatial Reference System

Code
British National Grid (EPSG::27700)
 

Content

Content Information

NRW Profile

Custom Elements

 

Constraints

Constraints

Limitations on Public Access and Use

Restriction type
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

Use constraints type
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

File Identifier
4f4c4942-4343-5764-6473-313235323636 XML
Metadata Language
English
Resource type
Dataset
Metadata Date
2026-06-01T14:14:37.323Z
Metadata Standard Name
NRW
Metadata Standard Version

1.0

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

Publishing Body

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