Bathing Waters ZOI Catchments: UK Surface Runoff Risk Areas

United Kingdom zones of influence (ZOI) for designated bathing waters, representing areas where heavy rainfall may lead to surface runoff and reduced water quality. The polygons were derived from digital elevation models and manual digitization for use in bathing water profiles under the 2006/7/EC directive. The dataset is updated annually by the Environment Agency to reflect changes in the designated bathing water inventory.

Use Cases

• Modeling surface water runoff pollution risk based on catchment boundaries.
• Assessing bathing water quality impacts from upstream land use based on zones of influence.
• Supporting regulatory compliance and reporting under the Bathing Water Directive based on defined catchment areas.
• Identifying potential sources of contamination for bathing waters based on connected streams and rivers.

Strengths

• Data is updated annually to reflect changes in the official bathing water inventory.
• Polygons are derived from authoritative sources including digital elevation models.
• Dataset is produced and maintained by the UK Environment Agency.

Limitations

• Description metadata is limited; actual data quality requires manual inspection after download.
• Column-level documentation is absent; field semantics must be inferred after download.
• The polygons were originally designed for low-resolution PDF maps in 2012, which may affect spatial precision.

Provenance

Source

Environment Agency

Collection Method

Derived from digital elevation models and manual digitization.

Freshness

Last updated 2026-07-06 07:09:06.514583; freshness should be verified.

Geography

United Kingdom