Polluted by sewage 1,000 hours in 2026 so far..
What's a potential overflow? If the CSO goes 'Offline' while its Overflowing, we don't know if it stopped overflowing until we get a 'Stop' event.
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Donate Now| Company | Site Name | Receiving Waterway | Overflow Days | Total Duration (hours) | Offline/Potential Pollution |
|---|---|---|---|---|---|
| Dwr Cymru Welsh Water | Began Road Cardiff Storm Overflow No2 | River Rhymni | 58 | 573h 45m | - |
| Dwr Cymru Welsh Water | Tongwynlais Recreation Ground Storm Overflow | River Taff | 24 | 366h | - |
| Dwr Cymru Welsh Water | Ynys Bridge 2 Storm Overflow | River Taff | 10 | 35h 37m | - |
| Dwr Cymru Welsh Water | Parc Caedelyn Storm Overflow | Rhydwaedlyd Brook | 8 | 15h 25m | - |
| Dwr Cymru Welsh Water | Heathwood Road Storm Overflow | Nant Y Wedal | 5 | 7h 13m | - |
| Dwr Cymru Welsh Water | Westbourne Crescent Bottom Cardiff Storm Overflow | River Taff | 3 | 2h 28m | - |
| Dwr Cymru Welsh Water | Heol Amlwch Storm Overflow | River Taff via culverted watercourse | 1 | 0h 29m | - |
| Dwr Cymru Welsh Water | Began Road Cardiff Storm Overflow | Rhymney | 0 | 0h | - |
| Dwr Cymru Welsh Water | St. Mellons Bridge Road Storm Overflow | River Rhymni | 0 | 0h | - |
EDM (Event Duration Monitoring) data and Consented Discharges to Controlled Waters with Conditions from Environment Agency & Data Map Wales, and Scottish Water
Experimental derived data from Thames Water API, Some data may be missing or inaccurate. Live sewage data from Stream Water API
Uses Environment Agency rainfall data from the real-time data API (Beta) - Rainfall data is delayed by up to two days.
This website is intended to provide an accurate representation of the Environment Agency data. The data is hard to use, and thus some errors may have been made. If you find something that is incorrect, please raise an issue at the GitHub issues page and we'll endeavour to fix it quickly.
This project is not associated, approved or endorsed by any of the companies whose logos you see here.