Risk of Flooding from Surface Water Extent: 1 Percent Annual Chance

A GIS layer showing the extent of flooding from surface water with a 1% annual chance of occurrence. The dataset groups flood depth into six bands and is produced by the UK Environment Agency's Risk of Flooding from Surface Water mapping. It was last updated on 2026-07-06 and is not suitable for property-level assessment.

Use Cases

• Assess regional flood hazard exposure based on surface water flood extent.
• Model potential flood impact scenarios based on the 1% annual chance event.
• Inform high-level land-use planning and infrastructure siting based on indicative flood risk zones.
• Support public awareness and emergency preparedness initiatives based on broad flood risk areas.

Strengths

• Flood depth is categorized into six distinct bands for analysis.
• Based on the UK Environment Agency's authoritative Risk of Flooding from Surface Water mapping methodology.
• Last updated on 2026-07-06, indicating recent maintenance.

Limitations

• The record has been retired and superseded by another dataset.
• Explicitly not suitable for identifying flooding at an individual property level.
• Column-level documentation is absent; field semantics must be inferred after download.

Provenance

Source

Environment Agency (UK), incorporating data from Centre for Ecology & Hydrology (CEH), Defra, Met Office, DARD Rivers Agency, Cranfield University, James Hutton Institute, and Ordnance Survey.

Collection Method

Produced as part of the Risk of Flooding from Surface Water (RoFSW) mapping project.

Freshness

Last updated 2026-07-06 07:17:27.448720; freshness should be verified.

Geography

United Kingdom