UK Surface Water Flood Flow Direction at 3.3% Annual Chance on 25m Grid

UK geospatial data showing the dominant flow direction of surface water flooding at maximum speed for a flood with a 3.3% annual chance. The dataset is part of the Risk of Flooding from Surface Water (RoFSW) mapping, previously known as the updated Flood Map for Surface Water. It was produced by the Environment Agency with contributions from other UK organizations and is based on data from 2015.

Use Cases

• Modeling regional surface water flood propagation based on dominant flow direction bands.
• Strategic land-use planning to avoid areas with high flood flow potential.
• Integrating with other flood risk layers for a composite hazard assessment.
• Creating educational or public awareness maps about surface water flood behavior.

Strengths

• Data is derived from a 2m resolution grid, suggesting a detailed source model.
• Flow directions are categorized into 8 compass bands, providing a structured classification.
• Explicitly defines the flood probability as a 3.3% chance in any given year.

Limitations

• The record has been retired and superseded by another dataset, indicating it is not the current version.
• Description metadata is limited; actual data quality requires manual inspection after download.
• Explicit warnings state it is not suitable for property-level assessment or as sole evidence for planning decisions.

Provenance

Source

Environment Agency, with spatial data licensed from Centre for Ecology & Hydrology (CEH) and other UK organizations.

Collection Method

Produced as part of the Risk of Flooding from Surface Water (RoFSW) mapping, resampled from a 2m grid.

Freshness

Last updated 2026-07-06 07:17:22.394224; freshness should be verified as the record is retired.

Geography

United Kingdom (implied by platform 'uk_data' and organization 'Environment Agency').