UK Surface Water Flood Hazard Ratings Under Climate Change

RoFSW hazard maps model the probability of dangerous surface water flooding across England, using depth and speed to calculate hazard ratings. The dataset presents risk for the 2050s epoch under a high-emissions climate scenario (RCP 8.5). It is produced by the UK Environment Agency using national and local flood models, with data current as of 2026.

Use Cases

• Classify land parcels into High, Medium, Low, or Very Low annual flood likelihood bands for zoning and insurance pricing.
• Model flood hazard severity by analyzing combined flood depth and speed features to assign ratings of 0, 0.25, 0.5, 0.75, 1.25, or 2.
• Assess future climate impact by applying the Central 2050s allowance from UKCP18 projections to surface water flood risk.
• Identify flood extents and likelihoods for hazard ratings at or above specific thresholds (e.g., 0.5) for emergency response planning.

Strengths

• Probabilistic risk assessment provides three explicit annual likelihood bands (High >=3.3%, Medium 1-3.3%, Low 0.1-1%).
• Integrates national-scale modelling with compatible local data from Lead Local Flood Authorities.
• Models future conditions using the latest UK Climate Projections (UKCP18) for the 2040-2060 epoch.

Limitations

• Spatial resolution and specific row/column counts are not provided in the description.
• Risk is presented only for a single climate scenario (RCP 8.5) and a single future epoch (2050s).
• Primary file format is PDF, which may complicate direct computational analysis compared to raster or vector formats.

Provenance

Source

Environment Agency (UK)

Collection Method

Produced using national scale flood modelling enhanced with locally produced modelling from Lead Local Flood Authorities.

Time Range

Future projection for the 2050s epoch (2040-2060).

Freshness

Last updated in April 2026.

Geography

United Kingdom (England, based on the authority).