For questions about river water quality data, CSO spill figures, methodology, partnership opportunities, or to report an error in our data, please email us at the address above. We aim to respond within 2 working days.
—Rivers
—CSO Spills 2025
—Poor-quality reaches
—Excellent reaches
—No-swim zones
Last sync: 7 Jul 2026 · EA / SEPA / NRW / EPA / EEA
🏊 Swimable
💧 Drinkable
⚠ CSOs
☣ Pollution
🌍 All
🇬🇧 British Isles
🇫🇷 W. Europe
🇩🇪 C. Europe
🇮🇹 S. Europe
🇵🇱 E. Europe
🇸🇪 N. Europe
Water Quality
Excellent<250 CFU/100ml🏊 Swim 💧 Drink
Good250–500 CFU/100ml🏊 Generally safe ⚠ Treat
Sufficient500–900 CFU/100ml⚠ Caution 🚫 No drink
Poor>900 CFU/100ml🚫 No swim 🚫 No drink
CSO — active / recent
CSO — elevated risk
Pollution source
Select a river reach
Click any coloured line on the map
Click any river reach on the map to see water quality data, swim & drink advisories, CSO spill counts, and pollution sources.