WWNP Runoff Attenuation Features 1% AEP

Runoff Attenuation Features Potential identifies between 100 and 5000 square metre areas of high surface water flow accumulation for the 1% Annual Exceedance Probability flood scenario across England. The dataset, part of the Environment Agency's Working with Natural Processes toolbox, pinpoints locations where temporary water storage could attenuate flooding, excluding urban areas, roads, rails, and canals. It is designed to signpost opportunities for interventions like gully blocking on slopes steeper than 6% but does not consider land ownership, design specifics, or recent land-use changes.

Use Cases

• Prioritizing sites for gully blocking based on slope and flow accumulation data.
• Screening landscapes for potential runoff attenuation feature placement outside of built infrastructure.
• Supporting strategic planning for Natural Flood Management (NFM) interventions at a catchment scale.
• Informing feasibility studies for Working with Natural Processes projects by highlighting initial opportunity areas.

Strengths

• Dataset is based on the authoritative Risk of Flooding from Surface Water datasets from the Environment Agency.
• Features are constrained by specific, documented criteria (e.g., area 100-5000 m², slope >6%, exclusion of urban/transport areas).
• Cross-platform presence on UK and EU open data portals indicates established use and official provenance.

Limitations

• Key metadata such as row count, specific columns, file size, and license are not provided by any source.
• Data does not account for land ownership, detailed engineering design, or recent changes in land use or building.
• A last updated date of '2026-04-07' appears to be a future date, casting doubt on the accuracy of this metadata field.

Provenance

Source

Environment Agency (UK) as part of the Mapping Potential for Working with Natural Processes project (SC150005).

Collection Method

Derived from Risk of Flooding from Surface Water datasets; identifies high flow accumulations for a 1% Annual Exceedance Probability event.

Freshness

2026-04-07 14:35:50.702361 (Note: This is a future date, suggesting potential metadata error)

Geography

England