4f4c4942-4343-5764-6473-313234373930 English Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en 2026-04-07T11:06:50.008Z NRW 1.0 wel British National Grid (EPSG::27700) National Flood Hazard Maps - Present Day National Flood Hazard Maps - Present Day Mapiau Perygl Llifogydd Cenedlaethol - Y Presennol Mapiau Perygl Llifogydd Cenedlaethol National Flood Hazard Maps Present Day.lyr 2020-10-01 NRW_DS124790 The National Flood Hazard Maps for Present day, are based on generalised modelling only. The maps have been published to comply with the Flood Risk Regulations (2009) and the EU Directive (2007/60/EC), and used to inform the creation of Flood Risk Management plans across Wales. These maps have no official status for Planning or Insurance purposes, therefore the public and professionals are advised to use the information contained within the Flood Risk Assessment Wales Map, the Development Advice Map/ Flood Map for Planning (as appropriate) for these purposes as these will be more up-to-date and incorporate improved modelling information. The National Flood Hazard Maps for Present Day have been created for 3 sources of flooding, namely, 1. Flooding from Rivers 2. Flooding from the Sea 3. Flooding from Surface Water & Small Watercourse The Maps show flood depth, velocity (speed and direction), hazard and extent for High, Medium and Low risk scenarios without raised flood defences. For Rivers and Surface Water & Small Watercourses, High risk is up to 1 in 30year; Medium risk is between 1 in 30 and 1 in 100year; and Low risk is between 1 in 100year and 1 in 1,000year Annual Exceedance Probability (AEP). For the Sea, High risk is up to 1 in 30 year; Medium risk is between 1 in 30 to 1 in 200 year; and Low risk 1 in 200 year to 1 in 1000 year. The Flooding from Surface Water & Small Watercourses dataset is a direct replacement for the earlier Updated Flood Map for Surface Water (uFMfSW), 2013 and is based on the modelling of Surface Water Catchments. Details of the modelling work to produce the new National Flood Hazard Maps are available in the supporting Information sheets. The National Flood Hazard Maps for Present day, are based on generalised modelling only. The maps have been published to comply with the Flood Risk Regulations (2009) and the EU Directive (2007/60/EC), and used to inform the creation of Flood Risk Management plans across Wales. These maps have no official status for Planning or Insurance purposes, therefore the public and professionals are advised to use the information contained within the Flood Risk Assessment Wales Map, the Development Advice Map/ Flood Map for Planning (as appropriate) for these purposes as these will be more up-to-date and incorporate improved modelling information. The National Flood Hazard Maps for Present Day have been created for 3 sources of flooding, namely, 1. Flooding from Rivers 2. Flooding from the Sea 3. Flooding from Surface Water & Small Watercourse The Maps show flood depth, velocity (speed and direction), hazard and extent for High, Medium and Low risk scenarios without raised flood defences. For Rivers and Surface Water & Small Watercourses, High risk is up to 1 in 30year; Medium risk is between 1 in 30 and 1 in 100year; and Low risk is between 1 in 100year and 1 in 1,000year Annual Exceedance Probability (AEP). For the Sea, High risk is up to 1 in 30 year; Medium risk is between 1 in 30 to 1 in 200 year; and Low risk 1 in 200 year to 1 in 1000 year. The Flooding from Surface Water & Small Watercourses dataset is a direct replacement for the earlier Updated Flood Map for Surface Water (uFMfSW), 2013 and is based on the modelling of Surface Water Catchments. Details of the modelling work to produce the new National Flood Hazard Maps are available in the supporting Information sheets. Mae'r Mapiau Perygl Llifogydd Cenedlaethol ar gyfer y Presennol yn seiliedig ar fodelu cyffredinol yn unig. Cyhoeddwyd y mapiau i gydymffurfio â Rheoliadau Perygl Llifogydd (2009) a Chyfarwyddeb yr UE (2007/60/EC) a chawsant eu defnyddio i gyfarwyddo’r gwaith o greu cynlluniau Rheoli Perygl Llifogydd ledled Cymru. Nid oes gan y mapiau hyn unrhyw statws swyddogol at ddibenion cynllunio neu yswiriant, felly cynghorir y cyhoedd a gweithwyr proffesiynol i ddefnyddio'r wybodaeth sydd i’w chael yn Map Asesu Perygl Llifogydd Cymru, y Map Cyngor Datblygu/Map Llifogydd ar gyfer Cynllunio (fel y bo'n briodol) at y dibenion hyn gan y bydd y rhain yn fwy diweddar ac yn cynnwys gwybodaeth fodelu well. Mae'r Mapiau Perygl Llifogydd Cenedlaethol ar gyfer y Presennol wedi cael eu creu ar gyfer tair ffynhonnell o lifogydd, sef: Llifogydd o afonydd Llifogydd o'r môr Llifogydd o ddŵr wyneb a chyrsiau dŵr bychain Mae'r mapiau'n dangos dyfnder y llifogydd, cyflymder (cyflymder a chyfeiriad), peryglon ac ehangder ar gyfer sefyllfaoedd perygl uchel, canolig ac isel heb amddiffynfeydd rhag llifogydd uwch. Ar gyfer afonydd a dŵr wyneb a chyrsiau dŵr bychain, risg uchel yw Tebygolrwydd Gormodiant Blynyddol (AEP) o hyd at 1 mewn 30 o flynyddoedd, risg ganolig yw AEP o rhwng 1 a 30 ac 1 mewn 100 o flynyddoedd, a risg isel yw AEP o rhwng 1 mewn 100 o flynyddoedd ac 1 mewn 1,000 o flynyddoedd. Ar gyfer y môr, risg uchel yw AEP o hyd at 1 mewn 30 o flynyddoedd, risg ganolig yw AEP o rhwng 1 mewn 30 ac 1 mewn 200 o flynyddoedd, a risg isel yw AEP o rhwng 1 mewn 200 o flynyddoedd ac 1 mewn 1,000 o flynyddoedd. Mae'r set ddata Llifogydd o Ddŵr Wyneb a Chyrsiau Dŵr Bychain wedi disodli set ddata gynharach, y Map Llifogydd Diweddaredig ar gyfer Dŵr Wyneb (2013), yn uniongyrchol ac mae'n seiliedig ar fodelu dalgylchoedd dŵr wyneb. Mae manylion y gwaith modelu i lunio’r Mapiau Peryglon Llifogydd Cenedlaethol newydd ar gael yn y taflenni gwybodaeth ategol. Cydnabyddiaethau Yn cynnwys gwybodaeth Cyfoeth Naturiol Cymru gwybodaeth © Cyfoeth Naturiol Cymru a hawl cronfa ddata. Cedwir pob hawl. Mae rhai nodweddion o'r wybodaeth hon yn seiliedig ar ddata gofodol digidol wedi'i drwyddedu gan Ganolfan Ecoleg a Hydroleg y DU © UKCEH, Asiantaeth yr Amgylchedd © EA a Getmapping Plc a Bluesky International Limited [2015]. DEFRA, y Swyddfa Dywydd ac Asiantaeth Afonydd yr Adran Amaethyddiaeth a Datblygu Gwledig © Hawlfraint y Goron. © Prifysgol Cranfield. © Sefydliad James Hutton. Yn cynnwys data'r AO © Hawlfraint y Goron a hawl cronfa ddata. Gwasanaethau Tir ac Eiddo © Hawlfraint y Goron a hawl cronfa ddata. Darllenwch y drwydded i ddeall amodau defnyddio'r data. 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 JBA Consultancy JBA Consulting, 1 Belle Vue Square, Broughton Road, Skipton, BD23 1FJ andrew.gubbin@jbaconsulting.com https://www.jbaconsulting.com/ Natural Resources Wales (NRW) Maes-y-Ffynnon, Penrhosgarnedd, Bangor, Gwynedd, LL57 2DW, Wales enquiries@naturalresourceswales.gov.uk http://naturalresources.wales/?lang=en Area management/restriction/regulation zones and reporting units GEMET - INSPIRE themes, version 1.0 2008-06-01 geonetwork.thesaurus.external.theme.httpinspireeceuropaeutheme-theme flood risk flood hazard floods (flooding) NRW Thesaurus 2026-03-04 geonetwork.thesaurus.local.theme.converted_nrw-keywords SeaDataNet Parameter Discovery Vocabulary 2024-06-19 geonetwork.thesaurus.external.theme.rdf+xml IPSV Subjects List 2020-11-18 geonetwork.thesaurus.external.theme.subjects 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. Some features of this information are based on digital spatial data licensed from the UK Centre for Ecology and Hydrology © UKCEH, © EA and Getmapping Plc and Bluesky International Limited (2015). Defra, Met Office and DARD Rivers Agency © Crown copyright. © Cranfield University. © James Hutton Institute. Contains OS data © Crown copyright and database right. Land and Property Services © Crown copyright and database right. Data may be re-used under the terms of the Open Government Licence providing it is done so, acknowledging both the source and copyright of the owners. 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. Some features of this information are based on digital spatial data licensed from the UK Centre for Ecology & Hydrology © UKCEH, the Environment Agency © EA and Getmapping Plc and Bluesky International Limited [2015]. Defra, Met Office and DARD Rivers Agency © Crown copyright. © Cranfield University. © James Hutton Institute. Contains OS data © Crown copyright and database right. Land & Property Services © Crown copyright and database right. Open Government Licence English inlandWaters SeaVoX Vertical Co-ordinate Coverages 2021-01-06 Wales (WLS) -5.777741 -2.608865 51.240829 53.513067 2019-01-01 2019-12-31 More information on the FRAW 2018 project can be found in the final project report. JBA Consulting 2019. Flood Risk Assessment Wales Project Report. Unpublished report commissioned by Natural Resources Wales. 363 pp, Natural Resources Wales, Cardiff. Risk of Flooding from Surface Water Geographic Information System Unknown WMS and WMTS data feeds from JBA consulting. Feed doesn’t have feature information enabled. https://datamap.gov.wales/documents/2649 WWW:LINK-1.0-http--link View and Download Data 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 The datasets have been created as part of the Flood Risk Assessment Wales (FRAW) 2018 project. The modelling has been undertaken on the Environment Agency Integrated Height Model (EA IHM) 2016, with input rainfall and flow estimates from the Centre for Ecology & Hydrology (CEH). Sea level estimates have been taken from the Coastal Flood Boundary Project (CFB) 2018. The datasets have been created as part of the Flood Risk Assessment Wales (FRAW) 2018 project. The modelling has been undertaken on the Environment Agency Integrated Height Model (EA IHM) 2016, with input rainfall and flow estimates from the Centre for Ecology & Hydrology (CEH). Sea level estimates have been taken from the Coastal Flood Boundary Project (CFB) 2018.