UK Surface Water Flood Speed Risk Under Climate Change

United Kingdom flood speed risk maps assess the probability of surface water flooding at specific water velocity thresholds. The Environment Agency produced this dataset using national and local modelling, incorporating UKCP18 climate projections for the 2050s epoch. It was last updated in April 2026.

Use Cases

• Model flood hazard severity by analyzing speed likelihood layers for thresholds of 0.25m/s, 0.5m/s, 1m/s, and 2m/s.
• Prioritize mitigation investments by mapping areas with a 'High' likelihood band (>=3.3% annual chance) for dangerous flow speeds.
• Assess long-term climate impacts by evaluating risk projections for the 2040-2060 period under the RCP 8.5 scenario.
• Compare regional vulnerability by joining speed risk data with local flood authority (LLFA) modelling extents.

Strengths

• Provides five distinct risk layers for specific flood speed thresholds (0m/s, 0.25m/s, 0.5m/s, 1m/s, 2m/s).
• Integrates nationally consistent modelling with compatible local data from lead local flood authorities.
• Includes probabilistic risk bandings (High, Medium, Low, Very Low) with defined annual chance percentages.

Limitations

• Data is presented in PDF format, which is not readily machine-readable for analysis.
• The modelling is probabilistic, representing overall risk rather than specific event scenarios.
• Climate projection is limited to a single 'Central' allowance for the 2050s under RCP 8.5.

Provenance

Source

Environment Agency

Collection Method

Produced using national scale flood modelling enhanced with locally produced modelling from lead local flood authorities (LLFAs).

Time Range

Climate change projections for the 2050s epoch (2040-2060).

Freshness

Updated in April 2026.

Geography

United Kingdom