Risk of Flooding from Surface Water Hazard at 1% Annual Chance

Environment Agency data provides a GIS layer showing flood hazard ratings for surface water flooding with a 1% annual chance. The hazard rating is defined as a function of simultaneous depth and velocity, grouped into four bands. This dataset is part of the Risk of Flooding from Surface Water (RoFSW) mapping, previously known as the updated Flood Map for Surface Water.

Use Cases

• Regional flood risk modeling based on the 1% annual chance hazard rating.
• Strategic land-use planning based on the four-band hazard classification.
• Creating indicative flood hazard maps for public awareness at scales of 1:10,000 or less.

Strengths

• Hazard rating is defined by a specific function of simultaneous depth and velocity.
• Data is grouped into four distinct hazard bands for classification.
• Produced by the Environment Agency with contributions from multiple authoritative UK organizations.

Limitations

• Dataset has been retired and superseded by a newer version.
• Explicitly not suitable for property-level assessment or as sole evidence for planning decisions.
• Column-level documentation and sample data are unavailable.

Provenance

Source

Environment Agency, with data licensed from Centre for Ecology & Hydrology (CEH) and other UK government and research bodies.

Collection Method

Output of Risk of Flooding from Surface Water (RoFSW) mapping.

Time Range

Data copyright and database right is noted for 2015.

Freshness

Last update date is unknown; dataset is retired.

Geography

Likely covers England, given the source is the Environment Agency.