Identification

Identifier

NRW_DS124841

Alternative Title

• Flood Risk from Surface Water and Small Watercourses
• Flood Risk from the Sea
• Flood Risk from Rivers

Metadata Language

English

Lineage

For Rivers and Surface Water and Small Watercourses: ‘High’ risk means that each year, this area has a chance of flooding of greater than 1 in 30 (3.3%) ‘Medium’ risk means that each year, an area has a chance of flooding of between 1 in 100 (1%) and 1 in 30 (3.3%). ‘Low’ risk means that each year, an area has a chance of flooding of between 1 in 1000 (0.1%) and 1 in 100 (1%). For the Sea: ‘High’ risk means that each year, this area has a chance of flooding of greater than 1 in 30 (3.3%) ‘Medium’ risk means that each year, an area has a chance of flooding of between 1 in 200 (0.5%) and 1 in 30 (3.3%). ‘Low’ risk means that each year, an area has a chance of flooding of between 1 in 1000 (0.1%) and 1 in 200 (0.5%) The risk assessment takes into account the effect of flood defences where we have information. Flood defences reduce, but do not completely stop the chance of flooding as they can be overtopped or fail. Flood risk information for each source has been created as ‘onion-skins’, i.e. with no overlapping data between individual risk bands. These risk bands should be combined and displayed a single layer for each flood source. If data is displayed in map form to others, appropriate map scales should be used given the indicative nature of the modelling. It should be shown with a maximum zoom scale of 1:5,000 and that base mapping of 1:10,000 is used to give context. The flood mapping is based on areas at risk of flooding and is not specific to individual properties. NRW doesn’t hold information about an individual property’s construction that might affect whether flooding of a certain depth could enter a property and cause damage. As such, our information has been produced to identify general areas potentially at risk of flooding for further investigation. Spatial resolution of the data: National scale modelling undertaken at 2m grid resolution. Local scale modelling undertaken at different resolutions, typically between 2m – 10m.

Additional Information

More information is available in the FRAW (2019) project report and NRWs Understanding your flood risk results webpage ( https://naturalresources.wales/flooding/managing-flood-risk/understanding-your-flood-risk-results?lang=en ) for more information on our flood risk data and how it should be used.

Dataset Reference Date (Publication)

2023-11-30

Extent

Extent

Geographic Extent

Wales (WLS)

N

W

E

S

 

Distribution

Quality

Keywords

Spatial Reference System

Content

Constraints