Working with Natural Processes in Wales: Runoff Attenuation Features for 3.3% AEP

The Working with Natural Processes (WWNP) in Wales: Runoff Attenuation Features 3.3% AEP dataset is a geospatial layer identifying potential locations for temporary water storage to attenuate flooding. It is produced by the Government Digital Service and is based on Risk of Flooding from Surface Water data, highlighting areas of high flow accumulation for a 3.3% annual exceedance probability event. The data constrains potential features to non-urban areas, excluding roads, rails, and canals.

Use Cases

• Identifying potential sites for gully blocking based on areas of ponding on slopes steeper than 6%.
• Prioritizing locations for enhanced water storage to mitigate surface water flooding.
• Supporting land-use planning by mapping high flow accumulation zones outside urban infrastructure.
• Modeling flood attenuation potential for specific annual exceedance probability scenarios.

Strengths

• Dataset is constrained to exclude urban areas, roads, rails, and canals, focusing on feasible natural intervention sites.
• Identifies ponding areas between 100 and 5000 square meters, providing a scale for potential features.
• Tags specific opportunities for gully blocking on slopes steeper than 6%.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count and file size are unknown, which may limit suitability assessment.
• Last update date is unknown; freshness unverified.

Provenance

Source

Government Digital Service

Collection Method

Derived from the Risk of Flooding from Surface Water datasets.

Time Range

null

Freshness

unknown

Geography

Wales