Media Queries
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Here are all the Senedd constituencies in Wales that had sewage overflows in 2025
Click on the constituency name to see more details...
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Donate Now| Rank | Constituency | Sewage Dumps | Change | Duration (Hours) | Duration | Change |
| 1 | Ceredigion Penfro | 13,615 | -758 | 149,973 | 17.36 years | -3,012 |
| 2 | Sir Gaerfyrddin | 13,675 | 128 | 128,942 | 14.92 years | 8,869 |
| 3 | Gwynedd Maldwyn | 12,099 | 36 | 103,501 | 11.98 years | 3,113 |
| 4 | Bangor Conwy Môn | 7,821 | 101 | 74,355 | 8.61 years | 3,066 |
| 5 | Brycheiniog Tawe Nedd | 8,306 | -1,649 | 60,658 | 7.02 years | -17,208 |
| 6 | Afan Ogwr Rhondda | 7,377 | -947 | 45,980 | 5.32 years | -11,308 |
| 7 | Pontypridd Cynon Merthyr | 5,561 | -867 | 31,396 | 3.63 years | -9,956 |
| 8 | Sir Fynwy Torfaen | 3,813 | -1,061 | 29,040 | 3.36 years | -11,754 |
| 9 | Blaenau Gwent Caerffili Rhymni | 4,311 | -837 | 20,476 | 2.37 years | -2,920 |
| 10 | Gŵyr Abertawe | 3,103 | -41 | 20,179 | 2.34 years | -3,696 |
| 11 | Casnewydd Islwyn | 2,641 | -1,212 | 20,138 | 2.33 years | -11,725 |
| 12 | Pen-y-bont Bro Morgannwg | 1,757 | -543 | 15,654 | 1.81 years | -7,087 |
| 13 | Clwyd | 1,982 | -1,037 | 10,415 | 1.21 years | -5,943 |
| 14 | Fflint Wrecsam | 1,705 | -1,408 | 7,913 | 10.99 months | -10,258 |
| 15 | Caerdydd Penarth | 1,089 | -422 | 6,377 | 8.86 months | -5,293 |
| 16 | Caerdydd Ffynnon Taf | 456 | -138 | 4,099 | 5.69 months | -104 |
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.
Get in touch if you have queries or want to discuss our data.
press [at] top-of-the-poops.org