Risk of Flooding from Surface Water

Defra Network WMS server provided by the Environment Agency. "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 1 in 30 (3.3%) chance of flooding in any year  Medium – Less than 1 in 30 (3.3%) but greater than or equal to 1 in 100 (1%) chance of flooding in any given year  Low – Less than 1 in 100 (1%) but greater than or equal to 1 in 1000 (0.1%) chance of flooding in any given year  Very low – less than 1 in 1000 (0.1%) chance of flooding in any given year 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 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.  RoFRS is created using a combination of local flood model information and national flood modelling. These are used to generate the probabilities of flood risk for each 2m grid square of land, with the aim of using the best available flood risk information in any one location. For particular areas, sections of a previous (50m resolution) RoFRS dataset have been retained and used. These are due to be replaced with new data in the future." - Defra Data Services Platform

Defra Network WMS server provided by the Environment Agency. This record is for Approval for Access product AfA055. Flood Alert Areas are geographical areas where it is possible for flooding of low-lying land and roads to occur from rivers, sea and in some locations groundwater. A single Flood Alert Area may cover the floodplain within the Flood Warning Service Limit of multiple catchments of similar characteristics. A Flood Alert Area may contain one or more Flood Warning Areas. In some coastal locations a Flood Alert may be issued for spray or overtopping and be defined by a stretch of coastline. A Flood Alert is issued to warn people of the possibility of flooding and encourage them to be alert, stay vigilant and make early / low impact preparations for flooding. Flood Alerts are issued earlier than Flood Warnings to provide advance notice of the possibility of flooding and may be issued when there is less confidence that flooding will occur in a Food Warning Area. Flood Warnings Areas (established to apply to discrete communities) are available in AfA054. INFORMATION WARNING: The groundwater flood alert areas are either at a community/local scale, or where this is not possible are more generalised and based on other factors, such as geology and counties. In general, specialists used the national groundwater dataset to make a comparison with historical maps and bedrock geology to create the groundwater flood alert areas. Additional data sources, including groundwater susceptibility maps, borehole data, local modelling and LiDAR may also have been used depending on the location of the area. More information available on: Defra Data Services Platform

Defra Network WMS server provided by the Environment Agency. The majority of records began in 1946 when predecessor bodies to the Environment Agency started collecting detailed information about flooding incidents, although we hold limited details about flooding incidents prior to this date. If an area is not covered by the Historic Flood Map it does not mean that the area has never flooded, only that we do not currently have records of flooding in this area that meet the criteria for inclusion. It is also possible that the pattern of flooding in this area has changed and that this area would now flood or not flood under different circumstances. Outlines that don’t meet this criteria are stored in the Recorded Flood Outlines dataset. The Historic Flood Map takes into account the presence of defences, structures, and other infrastructure where they existed at the time of flooding. It will include flood extents that may have been affected by overtopping, breaches or blockages. Flooding is shown to the land and does not necessarily indicate that properties were flooded internally. Flood outlines are digitised in ArcGIS from a number of sources including surveyed flood events. More information available on: Defra Data Services Platform

Defra Network WMS server provided by the Environment Agency. Records began in 1946 when predecessor bodies to the Environment Agency started collecting detailed information about flooding incidents, although we may hold limited details about flooding incidents prior to this date. The absence of coverage by Recorded Flood Outlines for an area does not mean that the area has never flooded, only that we do not currently have records of flooding in this area. It is also possible that the pattern of flooding in this area has changed and that this area would now flood or not flood under different circumstances. The Recorded Flood Outlines take into account the presence of defences, structures, and other infrastructure where they existed at the time of flooding. It includes flood extents that may have been affected by overtopping, breaches or blockages. Any flood extents shown do not necessarily indicate that properties were flooded internally. A companion dataset Historic Flood Map contains a subset of these Recorded Flood Outlines which satisfy a certain criteria. More infromation available on: Defra Data Services Platform

Flood Hazard Mapping is an important part of the U.S. National Flood Insurance Program. The Federal Emergency Management Agency publishes Flood Insurance Rate Maps that show areas where the annual likelihood of a flood is 1% or greater (Special Flood Hazard Areas). Because standard homeowners insurance does not cover flood damage the congress created the National Flood Insurance Program in 1968. In participating communities homeowners and renters are able to by federally-backed flood insurance. Dataset Summary This layer's data represents Federal Emergency Management Agency's (FEMA) Flood Insurance Rate Map (FIRM) data. This data is based upon the original vector data from FIRM. These data are important for floodplain management, mitigation, and insurance activities for the National Flood Insurance Program (NFIP). The National Flood Hazard Layer (NFHL) data present the flood risk information depicted on the FIRM in a digital format suitable for use in electronic mapping applications. The NFHL database is a subset of the information created for the Flood Insurance Studies (FIS) and serves as a means to archive a portion of the information collected during the FIS. The NFHL data incorporates Digital Flood Insurance Rate Map (DFIRM) databases published by Federal Emergency Management Agency (FEMA).  This layer initially shows the flood zones by FEMA Flood Zone Designations with this symbology: The layer covers the continental U.S. Link to source metadata (Metadata is specific to each locale.) What can you do with this layer? The vector features for this layer can be used for visualization and analysis in ArcGIS. The features in this layer are only visible at scales larger than 1:1,155,582. The features can also be downloaded for use with ArcGIS desktop by with the Extract Landscape Source Data tool. This layer is part of a larger collection of landscape layers that you can use to perform a wide variety of mapping and analysis tasks. This collection includes a raster layer that was derived from this data representing the locations of wetlands. Important Note: This layer is available for users with an ArcGIS Organizational subscription. To access this layer, you'll need to sign in with an account that is a member of an organizational subscription.  If you don't have an organizational subscription, you can create a new account and then sign up for a 30 day trial of ArcGIS Online. This service is currently in beta. For more information, see the Landscape Layers group on ArcGIS Online.

Flood Hazard Mapping is an important part of the U.S. National Flood Insurance Program. The Federal Emergency Management Agency publishes Flood Insurance Rate Maps that show areas where the annual likelihood of a flood is 1% or greater (Special Flood Hazard Areas). Because standard homeowners insurance does not cover flood damage the congress created the National Flood Insurance Program in 1968. In participating communities homeowners and renters are able to by federally-backed flood insurance. Dataset Summary This layer's data represents Federal Emergency Management Agency's (FEMA) Flood Insurance Rate Map (FIRM) data. This data is based upon the original vector data from FIRM. These data are important for floodplain management, mitigation, and insurance activities for the National Flood Insurance Program (NFIP). The National Flood Hazard Layer (NFHL) data present the flood risk information depicted on the FIRM in a digital format suitable for use in electronic mapping applications. The NFHL database is a subset of the information created for the Flood Insurance Studies (FIS) and serves as a means to archive a portion of the information collected during the FIS. The NFHL data incorporates Digital Flood Insurance Rate Map (DFIRM) databases published by Federal Emergency Management Agency (FEMA).  This layer initially shows the flood zones by FEMA Flood Zone Designations with this symbology: The layer covers the continental U.S. Link to source metadata What can you do with this layer? The vector features for this layer can be used for visualization and analysis in ArcGIS. The features in this layer are only visible at scales larger than 1:1,155,582. The features can also be downloaded for use with ArcGIS desktop by with the Extract Landscape Source Data tool. This layer is part of a larger collection of landscape layers that you can use to perform a wide variety of mapping and analysis tasks. This collection includes a raster layer that was derived from these data.