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Data Provider: Welsh Government Properties at Risk of Flooding
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Year[Filtered]
Measure1
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[Collapse]Risk 1
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Risk 2
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Local Authority 1
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[Collapse]Wales21,62939,47961,108146,1061,336208,550
WalesIsle of Anglesey6014951,096521481,665
Gwynedd1,7311,7063,4375,460768,973
Conwy6621,4602,12214,36944016,931
Denbighshire1,2401,7683,00812,50411115,623
Flintshire1,2271,1432,3709,3771811,765
Wrexham4135419541,263672,284
Powys2,7644,3727,1365,23220112,569
Ceredigion1,2199552,1743,12945,307
Pembrokeshire5263388641,51312,378
Carmarthenshire4,0153,2347,2497,5223414,805
Swansea1,8491,2873,1362,48445,624
Neath Port Talbot9472,6133,56010,1962713,783
Bridgend1,0011,5812,5822,342294,953
Vale of Glamorgan4111,0171,4281,39702,825
Cardiff5822,1982,78032,32021635,316
Rhondda Cynon Taf5194,0394,5585,7951010,363
Merthyr Tydfil579491,0061,16222,170
Caerphilly1981,9952,1934,86367,062
Blaenau Gwent1441,4341,57879402,372
Torfaen742,2212,2951,381193,695
Monmouthshire7619891,7505,54397,302
Newport6883,1443,83216,9391420,785

Metadata

Title
Properties at Risk of Flooding in Wales

Last update
January 2017 January 2017

Next update
2019

Publishing organisation
Welsh Government

Source 1
National Flood Risk Assessment data, Natural Resources Wales

Contact email
stats.environment@gov.wales

Designation
None

Lowest level of geographical disaggregation
Local authorities

Geographical coverage
Wales

Languages covered
English only

Data licensing
You may use and re-use this data free of charge in any format or medium, under the terms of the Open Government License - see http://www.nationalarchives.gov.uk/doc/open-government-licence

General description
The National Flood Risk Assessment (NaFRA) together with the National Property Dataset (NPD) are used to determine the number of properties (residential and non-residential) at risk of flooding from rivers and sea in Wales.

Data collection and calculation
The chance of flooding is set out in four risk categories:

High Risk; Greater than or equal to 1 in 30 (3.3%) chance in any given year
Medium Risk; Less than 1 in 30 (3.3%) but greater than or equal to 1 in 100 (1%) chance in any given year
Low Risk; Less than 1 in 100 (1%) but greater than or equal to 1 in 1,000 (0.1%) chance in any given year
Very Low Risk; Less than 1 in 1,000 (0.1%) chance in any given year

The NaFRA includes flooding from all rivers with a catchment size greater than 3 square kilometres, and all flooding from the sea (both along the open coast and tidal estuaries). Smaller rivers are included in the assessment where they fall within the area that could be affected by an extreme flood (0.1% chance in any year).
The assessment takes into account the type, location and condition of flood defences, and the chance of these defences being overtopped or breached during major floods. The likelihood of flooding and the consequent costs (economic damages) are assessed for each 50m square impact zone.
It does not include other forms of flooding such as highway drains, sewers, overland flow or rising groundwater.

Frequency of publication
Annual

Data reference periods
2014 onwards

Rounding applied
None.

Statistical quality
The NaFRA includes flooding from all rivers with a catchment size greater than 3 square kilometres, and all flooding from the sea (both along the open coast and tidal estuaries). Smaller rivers are included in the assessment where they fall within the area that could be affected by an extreme flood (0.1% chance in any year).
The assessment takes into account the type, location and condition of flood defences, and the chance of these defences being overtopped or breached during major floods. The likelihood of flooding and the consequent costs (economic damages) are assessed for each 50m square impact zone.
It does not include other forms of flooding such as highway drains, sewers, overland flow or rising groundwater.

Keywords
Flooding