Flood Map for Planning – Climate Change Extents (defended and undefended)

The Flood Map for Planning includes several layers of information, which includes data created to support the use of Flood Zones in the planning process. These datasets show the extent of land at risk of flooding to a defined annual exceedance probability (AEP) or chance of flooding each year, taking into account the possible effects of climate change (detailed below).

These datasets include the following scenarios:

● Undefended: 0.1% AEP (1 in 1000) Rivers/Sea ● Undefended: 1% AEP (1 in 100) Rivers/ 0.5% AEP (1 in 200) Sea ● Defended: 0.1% AEP (1 in 1000) Rivers/Sea ● Defended: 1% AEP (1 in 100) Rivers/ 0.5% AEP (1 in 200) Sea

The undefended products show flood extents that ignore the presence and condition of flood defences.

The defended products take into account the presence of flood defences and assume that they operate in the way they were intended (or designed) to function. This does not include any asset failure (or removal) scenarios.

Climate change scenarios have been produced to indicate the possible impacts of climate change on future risk. The climate change allowances are based on the latest UK Climate Projections (UKCP18) from the Met Office, using the Representative Concentration Pathway (RCP) 8.5. The specific climate change scenarios shown are as follows:

● the ‘Central’ allowance for the 2080s epoch (2070-2125) for risk of flooding from rivers
● the ‘Upper End’ allowance for risk of flooding from the sea, accounting for cumulative sea level rise to 2125

For climate change scenarios, it is assumed that existing flood defences continue to function in the same way as present day. No allowance is made for any future changes to flood defence design or operation.

These datasets are designed to only give an indication of flood risk to an area of land and are not suitable for showing whether an individual property is at risk of flooding. This is because we cannot know all the details about each property.

Information on flood depth, speed or volume of flow is not included.