Flood map for planning / development advice map

Development Advice Map

The Development Advice Map and associated planning policy TAN15: Development and Flood Risk is the current framework for assessing flood risk to and from new development.  

The Development Advice Map is used as a screening tool by Local Authorities to understand where further assessment of flooding may be needed.

We last updated the Development Advice Map in January 2020. No further updates are planned. Contact us for up-to-date information for your area.

View the Development Advice Map

(Right click on the map button to open it in a new tab)

 

Flood Map for Planning

The Welsh Government is due to implement a revised TAN15. This will be supported by the Flood Map for Planning, which shows how climate change will affect flood risk extents over the next century. The map shows the potential extent of flooding assuming no defences are in place.

The Flood Map for Planning has no official status until the Welsh Government implements the revised TAN15. However, it represents the best available information we have on flood risk and Natural Resources Wales will continue to use this to inform our planning advice. 

The Welsh Government has recently undertaken a consultation on proposed further amendments to the TAN15. This means the formal implementation of the TAN15 and Flood Map for Planning has been suspended. The consultation closed on 17 April 2023.

Local Planning Authorities were asked to review their Strategic Flood Consequences Assessments in line with the draft TAN15 published in September 2021 and the Flood Map for Planning.

More information on the formal implementation of the new TAN15 and Flood Map for Planning is set out in the Written Statement from the Welsh Government

The Flood Map for Planning has two views: 

  • Basic - this includes enough data for high level screening against TAN 15
  • Detailed - this includes extra detail that can be used for Flood Consequences Assessments
View the Flood Map for Planning

(Right click on the map button to open it in a new tab)

 

For present day, defended flood risk, view our Flood Risk Assessment Wales map. This map has no official status for planning purposes, as it does not consider the impact of climate change in the future. Together the two maps form the Wales Flood Map. 

What do the map layers mean? 

The Flood Map for Planning has the following layers, which show the potential extent of flooding, assuming no defences are in place:

Rivers – Flood Zone 2

Areas with 0.1% to 1% (1 in 1000 to 1 in 100) chance of flooding from rivers in a given year, including the effects of climate change. 

Rivers – Flood Zone 3

Areas with more than 1% (1 in 100) chance of flooding from rivers in a given year, including the effects of climate change. 

Rivers & Sea – Flood Zone 2

The combined 0.1% risk of flooding from rivers and the sea including climate change.

Rivers & Sea – Flood Zone 3

The combined 1% risk of flooding from rivers and the sea including climate change.

Sea – Flood Zone 2

Areas with 0.1% to 0.5% (1 in 1000 to 1 in 200) chance of flooding from the sea in a given year, including the effects of climate change.

Sea – Flood Zone 3

Areas with more than 0.5% (1 in 200) chance of flooding from the sea in a given year, including the effects of climate change.

Surface Water and Small Watercourses – Flood Zone 2

Areas with 0.1% to 1% (1 in 1000 to 1 in 100) chance of flooding from surface water and/or small watercourses in a given year, including the effects of climate change.

Surface Water and Small Watercourses – Flood Zone 3

Areas with more than 1% (1 in 100) chance of flooding from surface water and/or small watercourses in a given year, including the effects of climate change

TAN15 Defended Zones

Area that benefit from Risk Management Authority flood defences with the following minimum Standard of Protection:

  • 1 in 100 year (present day) for rivers
  • 1 in 200 year (present day) for the sea

For flood defences built from 2016 onwards there must be allowance for climate change and design freeboard. 

Recorded Flood Extents

Areas that are recorded as having flooded previously.

Flood defence location

More information about the location and standard of protection of formal flood risk defences.

Flood risk from reservoirs

More information about reservoir flood risk.

Main rivers

More information about main rivers. If a planning proposal is next to a main river, you may need a permit in addition to planning permission. 

NRW Local Model Manager

Areas where NRW holds detailed local flood models, which may be useful to help inform a flood consequences assessment to support a planning application. Contact datadistribution@naturalresourceswales.gov.uk to ask for access to this data. 

Shoreline Management Plans & coastal erosion

More information about Shoreline Management Plans and coastal erosion. You will need to consider these plans for coastal development proposals.

Challenging our flood maps 

Find out more about our flood risk mapping information, including guidance about:

Challenging our flood maps

Developing your own hydraulic models

Modelling for Flood Consequence Assessments

Map updates

We update the Flood Map for Planning on behalf of the Welsh Government every year in:

  • late May
  • late November

We list these updates below but only include changes to: 

  • Rivers Flood Zones
  • Sea Flood Zones
  • Rivers and Sea Flood Zones
  • TAN15 Defended Zones  

Contact us about about updates to other layers in the areas below.

November 2024 update

Published 28 November 2024

PDF Map books show the detail of the changes. These maps show the difference in flood extents between the May 2024 and November 2024 publication.

Updates to TAN15 Defended Zones:

1. A new Rivers TAN15 Defended Zone was created for Machen

Updates to Rivers Flood Zones:

1. River Cwm Dulyn at Nebo
2. River Elwy at Llanfair Talhaiarn
3. River Rhyd-hir at Pwllhei
4. River Rhymney at Ystrad Mynach

Updates to Sea Flood Zones:

1. Tidal areas North of Abersoch
2. Tidal areas South of Abersoch
3. Tidal area of Borth-y-Gest
4. Tidal area of Criccieth
5. Tidal area of Hafan-y-Mor
6. Tidal area of Morfa Bychan
7. Tidal area of Porthmadog
8. Tidal area of Pwllheli

May 2024 update

Published 23 May 2024

PDF Map books show the detail of the changes.  These maps show the difference in flood extents between the November 2023 and May 2024 publication.

Updates to TAN15 Defended Zones:

  1. A new Rivers TAN15 Defended Zone was created for Ruthin
  2. A new Rivers TAN15 Defended Zone was created for Llantrisant
  3. A new Sea TAN15 Defended Zone was created for Tywyn
  4. A Sea TAN15 Defended Zone was removed at Ogmore
  5. A Rivers TAN15 Defended Zone was removed at Ruthin
  6. A Rivers TAN15 Defended Zone was removed at Treherbert
  7. A Rivers TAN15 Defended Zone was removed at Pontyclun
  8. A Rivers TAN15 Defended Zone was removed at Machen
  9. A Rivers TAN15 Defended Zone was removed at Bedwas

Updates to Rivers Flood Zones:

  1. River Gwyrfai at Betws Garmon
  2. River Ogmore at Bridgend
  3. River Tawe at Clydach
  4. River Dulais at Crynant
  5. Guilsfield Brook at Guilsfield
  6. River Teme at Knighton
  7. River Severn at Llandinam
  8. River Dee at Llanuwchllyn
  9. Nant Morlais at Merthyr Tydfil
  10. Rhondda River upper catchment
  11. River Clwyd at Ruthin
  12. River Tawe at Swansea Vale
  13. River Tawe at Swansea
  14. River Rhymney from Ystrad Mynach to Machen

Updates to Sea Flood Zones:

  1. Tidal reaches from Barmouth to Fairbourne
  2. Tidal reaches from Llandanwg to Llanaber
  3. Tidal area of Llwyngwril
  4. Tidal areas of Pwllheli
  5. Tidal reaches from Tywyn to Borth

November 2023 update

Published 30 November 2023

PDF Map books show the detail of the changes.  These maps show the difference in flood extents between the May 2023 and November 2023 publication.

Updates to TAN15 Defended Zones:

  1. A new Rivers TAN15 Defended Zone was created at Bassaleg
  2. A new Sea TAN15 Defended Zone was created for Borth y Gest
  3. A new Sea TAN15 Defended Zone was created for Llanelli
  4. Three TAN15 Defended Zones removed at Pontarddulais

Updates to Rivers Flood Zones:

  1. River Severn at Caersws
  2. River Wye at Chepstow
  3. River Morlais at Ffos Las
  4. Ewyn Brook at Gaer, near Crickhowell
  5. River Cynffig at Margam
  6. River Ewenny at Pencoed
  7. River Avan at Port Talbot
  8. River Ebbw at Rogerstone
  9. River Tawe at Swansea
  10. River Ewenny at Waterton

Updates to Sea Flood Zones:

  1. Tidal reach of the River Wye at Chepstow
  2. Tidal areas of Llanelli
  3. Tidal areas of Margam
  4. Tidal area of Port Talbot
  5. Tidal areas of Swansea

May 2023 update

Published 26 May 2023

PDF Map books show the detail of the changes.  These maps show the difference in flood extents between the November 2022 and May 2023 publication.

Updates to TAN15 Defended Zones:

  1. A new Rivers TAN15 Defended Zone was created for Llanberis
  2. A Sea TAN15 Defended Zone was modified at Barmouth
  3. A Sea TAN15 Defended Zone was modified at Llanelli

Updates to Rivers Flood Zones:

  1. River Cynon from Hirwaun to Abercynon
  2. Nant Dowlais and Nant Myddlyn at Ystrad Barwig
  3. River Tawe at Clydach
  4. Nant Dyfatty at Burry Port
  5. Unnamed watercourse at Saundersfoot
  6. River Solva at Solva
  7. River Hwch and River Goch at Llanberis
  8. River Goch at Amlwch
  9. River Ceidiog at Llandrillo
  10. River Alyn at Mold

Updates to Sea Flood Zones:

  1. Barry Docks area
  2. Port Talbot frontage
  3. Tidal reaches of the River Neath at Neath
  4. Crofty frontage
  5. Llanelli frontage
  6. Llangennech frontage
  7. Tidal reaches of the River Towy at Carmarthen
  8. Tidal reaches of the River Cynin at St Clears
  9. Saundersfoot Bay
  10. Tidal reaches of the River Western Cleddau at Haverfordwest
  11. Tidal reach of the River Rheidol at Aberystwyth

November 2022 update

Published 28 November 2022.

PDF Map books show the detail of the changes.  These maps show the difference in flood extents between the May 2022 and November 2022 publication.

PDF Map book – Changes to TAN15 Defended Zones

PDF Map book – Changes to Flood Zone 3

PDF Map book – Changes to Flood Zone 2

Updates to TAN15 Defended Zones:

New TAN15 Defended Zones:

  1. A new Rivers TAN15 Defended Zone was created for Llangennech
  2. A new Sea TAN15 Defended Zone was created for Kidwelly
  3. A new Sea TAN15 Defended Zone was created for Tenby
  4. A new Sea TAN15 Defended Zone was created for Lougher
  5. A new Sea TAN15 Defended Zone was created for Porthcawl

Modified TAN15 Defended Zones:

  1. A Rivers TAN15 Defended Zone was modified at St Asaph
  2. A Rivers TAN15 Defended Zone was modified at Haverfordwest
  3. A Rivers TAN15 Defended Zone was modified at Pwll
  4. A Rivers TAN15 Defended Zone was modified at Pontarddulais
  5. A Rivers TAN15 Defended Zone was modified at Whitland
  6. A Rivers TAN15 Defended Zone was modified at Llandovery
  7. A Rivers TAN15 Defended Zone was modified at Swansea
  8. A Rivers TAN15 Defended Zone was modified at Port Talbot
  9. A Rivers TAN15 Defended Zone was modified at Resolven
  10. A Rivers TAN15 Defended Zone was modified at Cardigan
  11. A Rivers TAN15 Defended Zone was modified at Glynneath
  12. A Rivers TAN15 Defended Zone was modified at Beddgelert
  13. A Rivers TAN15 Defended Zone was modified at Aberystwyth
  14. A Rivers and Sea TAN15 Defended Zone was modified at Llanelli

Removed TAN15 Defended Zones:

  1. A Rivers TAN15 Defended Zone was removed at Cwmafan
  2. A Rivers TAN15 Defended Zone was removed at Dafen, north of Llanelli
  3. A Rivers TAN15 Defended Zone was removed at Pyle
  4. A Rivers TAN15 Defended Zone was removed at Gorseinon
  5. A Rivers TAN15 Defended Zone was removed at Johnstown
  6. A Rivers TAN15 Defended Zone was removed for Nantgarw
  7. A Rivers TAN15 Defended Zone was removed at Borth

There are a range of minor updates to the geographical extent of the TAN15 defended zones that aren’t listed above as part of this update. 

Updates to Rivers Flood Zones:

  1. River Rheidol at Aberystwyth
  2. River Amman at Ammanford
  3. River Glaslyn at Beddgelert
  4. Nant Gwrach at Blaengwrach
  5. Boverton Brook at Boverton
  6. River Ogmore at Bridgend
  7. River Dulais at Burry Port
  8. River Alyn at Caergwrle
  9. River Neath at Glyn-Neath
  10. River Elwy from St Asaph to Kinmel Bay
  11. Nant y Glasdwr at Cwmffwrdd
  12. River Twrch at Cwmtwrch
  13. River Taff at Abercanaid
  14. River Monnow at Monmouth
  15. Ewyn Brook at Gaer Crickhowell
  16. River Neath at Glynneath
  17. River Western Cleddau at Haverfordwest
  18. River Teifi at Lampeter
  19. River Wye South of Tintern
  20. River Dulais at Pwll
  21. River Towy at Llandeilo
  22. River Teifi at Llandysul
  23. River Rhymney at Llanederyn
  24. River Elwy at Llanfair Talhaiam
  25. River Usk at Llanfoist
  26. River Ewenni at Llanharan
  27. River Taff from Pontypridd to Cardiff
  28. River Llynfi at Maesteg
  29. River Ogwr at Ogmore Vale
  30. River Tawe at Pontardawe
  31. River Gwendraeth at Pontyates
  32. River Gwendraeth at Porthyrhyd
  33. River Cynffig at Pyle
  34. Bon Ville Stream at Saundersfoot
  35. River Monnow at Skenfrith
  36. Lledan Brook at Welshpool
  37. River Taf at Whitland
  38. River Tawe at Ystradgynlais

Updates to Sea Flood Zones:

  1. River Usk at Newport
  2. The Coastal frontage at Swansea
  3. River Wye South of Tintern

May 2022 update

Published 30 May 2022.

PDF Map books show the detail of the changes. These maps show the difference in flood extents between the March 2022 and May 2022 publication. 

Updates to TAN15 Defended Zones:

  1. A new Sea TAN15 Defended Zone was created for Aberaeron.
  2. A Sea TAN15 Defended Zone was removed at Marshes, Newport.

Updates to Rivers Flood Zones:

  1. River Daron at Aberdaron
  2. River Cresswell at Begelly
  3. River Hoddnant at Boverton
  4. River Wye at Builth Wells
  5. River Towy at Carmarthen
  6. Nant y Glasdwr at Cwmffrwd
  7. River Giedd at Cwmgiedd
  8. River Tawe at Cwmtwrch
  9. River Rhythalit at Cwm Y Glo
  10. River Aman at Glanamman
  11. River Western Cleddau at Haverfordwest
  12. River Ganol at Llandudno Junction
  13. River Towy at Llandeilo
  14. River Llanfairfechan at Llanfairfechan
  15. River Ceunant at Llanfihangel y Creuddyn
  16. River Morlais at Llangennech
  17. River Dulais at Llanwrda
  18. River Dovey at Machynlleth
  19. Melincourt Brook at Melincourt
  20. River Pennal at Pennal
  21. River Solva at Solva
  22. River Aeron at Tal Sarn
  23. Lledan Brook at Welshpool
  24. River Taf at Whitland

March 2022 Update

Published 17 March 2022. This was a delayed publication from November 2021.

Updates to TAN15 Defended Zones:

  1. A River TAN15 Defended Zone was removed at Llangennech
  2. A River TAN15 Defended Zone was removed at Ponthir
  3. A Sea TAN15 Defended Zone was created at Crofty

Updates to Rivers Flood Zones:

  1. River Adda at Bangor on Dee
  2. River Cadnant at Caernarfon
  3. River Severn at Caersws
  4. River Dee at Corwen
  5. River Wnion at Dolgellau
  6. River Henddol at Fairbourne
  7. River Cegidog at Ffrith
  8. River Cegidog at Llandrillo
  9. River Lliw at Llanuwchllyn
  10. River Rheidol at Aberystwyth
  11. River Loughor at Ammanford
  12. Nant Dyfatty at Burry Port
  13. River Cadoxton at Cadoxton
  14. Morlais River at Crofty
  15. River Towy at Llandovery
  16. River Teifi at Llandysul Pentre Cwrt
  17. River Rhymney at Llanederyn
  18. River Usk at Llanfoist
  19. River Llwyd at Pontypool, Cwmbran and Ponthir
  20. Ogwr Fawr at Ogmore Vale
  21. River Ewenny at Pencoed
  22. River Tawe at Pontardawe
  23. River Dutlais at Pontardulais
  24. River Avan at Port Talbort
  25. River Cynffig at Pyle
  26. River Neath at Resolven
  27. River Cynin at St Clears
  28. Rivers Ely and Taff at Cardiff
  29. River Rhymney at Ystrad Mynach
  30. Pant Basin at Merthyr Tydfil
  31. River Alyn at Rhydymwyn

GIS data

If you need to download GIS data, many of the map layers can be downloaded from DataMapWales.

Acknowledgements

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 r

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