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.

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): 2025-04-22

Temporal Extent

Begin date: 1900-01-31

Topic category

Inland waters
Location

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

Geographic Extent: Wales (WLS)

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 )

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

GEMET - INSPIRE themes, version 1.0

Natural risk zones

Type: Theme

Citation

Date (Publication): 2008-06-01

Code: geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme

Keywords

NRW Thesaurus

physical geography
flood risk management
flood risk
flood defence

Type: Theme

Citation

Date (Publication): 2025-01-08

Code: geonetwork.thesaurus.local.theme.converted_nrw-keywords

Keywords

IPSV Subjects List

Risk assessment
Risk management

Type: Theme

Citation

Date (Publication): 2020-11-18

Code: geonetwork.thesaurus.external.theme.subjects

Keywords

NRW SMNR Keywords

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

Type: Theme

Citation

Date (Publication): 2024-06-26

Code: geonetwork.thesaurus.local.theme.converted_nrw-smnr-keywords

Code: British National Grid (EPSG::27700)

Content Information

NRW Profile

Custom Elements

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

Licence

Other constraints: Open Government Licence

Metadata

File Identifier: 4f4c4942-4343-5764-6473-313235323636 XML

Metadata Language: English

Resource type: Dataset

Metadata Date: 2025-04-24T09:53:31.822Z

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

Access the portal

Full access to the portal and metadata.

Flood Defence Structures

Identification

Temporal Extent

Extent

Extent

Distribution

Distribution

Quality

Data quality

Keywords

Keywords

Citation

Keywords

Citation

Keywords

Citation

Keywords

Citation

Spatial Reference System

Content

Content Information

NRW Profile

Custom Elements

Constraints

Constraints

Limitations on Public Access and Use

Access Constraints Directive

Access Constraints Text

Use Constraints

Attribution Statement

Licence

Metadata

Metadata

Publishing Body