Risk of Flooding from Rivers and Sea

Risk of Flooding from Rivers and the Sea (RoFRS) shows the chance of flooding from rivers and the sea taking into account the presence and condition of flood defences. It is our main way of communicating flood risk from rivers and sea to the public through our ‘Check Your Long Term Flood Risk’ service on gov.uk.

While flood defences reduce the level of risk they do not completely remove it. For example, water can flow over the top of the defence, or they can fail in extreme weather conditions or if they are in poor condition. As a result, the RoFRS maps may show that there is risk to areas behind some flood defences.

RoFRS is a probabilistic product, meaning that it shows the overall risk, rather than the risk associated with a specific event or scenario. This risk is displayed as one of four likelihood bandings:

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

This data also presents the likelihood of flooding for the following depths:

0.2m 
0.3m 
0.6m 
0.9m 
1.2m

NB. This is a complex dataset, with preview available only on certain zoom levels. The Web Mapping service has been set to 1:50 000 in the <MaxScaleDenominator> attribute. The services are set to be visible from the 1:50 000 scale range. There may be some variation, since end client software may interpret the request differently.