Environment Agency
Event Duration Monitoring — storm overflow spills
Annual return of storm overflow discharge events in England: the number of spill events and total duration recorded by event duration monitors at each combined sewer overflow, by water company and site.
Rights
- Licence
- Open Government Licence v3.0
- Commercial reuse
- Yes
- Redistribution
- Yes
- Derivative use
- Yes
- Attribution required
- YesContains public sector information licensed under the Open Government Licence v3.0.
- Terms last checked
- 23 August 2026
Access and coverage
- Publisher
- Environment Agency
- Geographic coverage
- England — by overflow site and water company
- Temporal coverage
- 2016 onwards
- Update frequency
- annual
- Formats
- csv, xlsx
- Bulk download
- Available
- Registration required
- No
- Cost to Hydrionis
- Free
- Domains
- wastewater, quality, enforcement
Notes
Monitoring coverage rose from a small minority of overflows in 2016 to effectively complete coverage by 2023. Rising spill counts therefore partly reflect rising measurement, and Hydrionis annotates the series accordingly rather than presenting the increase as purely physical.
What Hydrionis uses it for
5 observations across 1 metrics currently reference this source.