The National Flood Hazard and Risk Maps 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 and 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 Risk Maps 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 Risk to a range of receptors, grouped in categories of People, Economic and Environment. Risk information is aggregated and displayed at a community scale.
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.