There were at least 537,886 "sewage spills" into rivers in 2023, lasting an almost unbelievable 4,292,989 hours

An image showing the river network in England and Wales, highlighting those polluted with sewage

Rivers Ranked for 2023

Here are the top rivers in England and Wales that had sewage overflows in 2023. As the list is grouped by company, some rivers may feature more than once, being polluted by different companies along their length.

The full list is quite long. You can access that

As there are different rivers with the same name in different parts of the country, it didn't seem sensible to group by river name alone.

The category of "river" is made by the water companies in their "Consent to Discharge with Conditions" - so although there are a number of Seas in this list, that's what they are reporting

Rank River Company Sewage Dumps Change Duration (Hours) Change
1 River Calder Yorkshire Water 4,177 1,209 32,732 14,653
2 River Avon Wessex Water 4,719 2,060 32,577 23,486
3 River Severn Severn Trent Water 3,057 789 30,236 12,741
4 River Aire Yorkshire Water 4,888 1,317 29,458 15,648
5 River Teifi Dwr Cymru Welsh Water 2,579 690 28,371 14,292
6 Unknown South West Water 3,351 1,306 28,279 8,883
7 River Ouse Yorkshire Water 2,774 1,118 27,386 17,630
8 River Tame United Utilities 3,180 1,116 25,484 14,472
9 River Wharfe Yorkshire Water 2,456 769 23,120 12,322
10 River Tawe Dwr Cymru Welsh Water 2,592 774 22,776 8,795
11 River Trent Severn Trent Water 2,939 1,026 21,776 12,668
12 River Irwell United Utilities 3,457 1,072 20,904 7,965
13 River Tamar South West Water 1,999 476 20,372 4,826
14 River Don Yorkshire Water 2,231 739 18,312 10,562
15 Solent Southern Water 1,550 537 16,942 8,279
16 River Eden United Utilities 2,021 329 16,645 4,865
17 River Derwent Severn Trent Water 2,732 755 16,576 7,634
18 River Rother Southern Water 1,237 453 15,730 5,764
19 River Torridge South West Water 1,406 465 15,610 8,428
20 River Usk Dwr Cymru Welsh Water 1,864 304 15,439 4,398

Data Sources & Accuracy

EDM (Event Duration Monitoring) data and Consented Discharges to Controlled Waters with Conditions from Environment Agency & Data Map Wales

Experimental derived data from Thames Water API, Some data may be missing or inaccurate. This 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.