South West Water storm overflows in 2025
What the official annual return shows for South West Water’s storm overflows in England, compared with 2024 and with the other water companies.
Summary
The 2025 annual return lists 1,365 storm overflows run by South West Water in England. 1,357 have a usable spill count. Together they recorded 46,164 spills and 407,006 hours of discharge. The median outlet recorded 21 spills and 39.4 hours.
For a fair comparison with 2024, we use only the 1,241 outlets with a count in both years and a monitor that worked at least 90% of each year. Their spills went from 51,535 to 41,873, a fall of 19%. 680 recorded fewer spills and 398 recorded more.
178 outlets (13.1%) recorded no spills in 2025. 282 (20.8%) recorded 60 or more.
South West Water’s median of 21 spills per outlet is the highest of the 10 companies in the return. The England median is 11.
45 outlets had a monitor that worked for less than 90% of the year, and 7 gave no operation figure. Counts from those outlets may be low.
- 1,365
- Outlets listed
- 46,164
- Spills in 2025
- 21
- Median per outlet
- 407,006
- Recorded hours
How many spills each outlet recorded
Outlets with a usable 2025 count, grouped by the number of spills. The longest bar is the largest group.
- 0
- 178 13.1%
- 1 to 9
- 300 22.1%
- 10 to 19
- 171 12.6%
- 20 to 39
- 266 19.6%
- 40 to 59
- 160 11.8%
- 60 or more
- 282 20.8%
Spills over time
The median outlet run by South West Water recorded 21 spills in 2025, against 11 across England.
1,241 outlets have a comparable count for both 2024 and 2025, with the monitor working at least 90% of each year. 398 recorded more spills, 680 fewer and 163 the same. Together they went from 51,535 to 41,873 spills, a fall of 19%.
Largest rises from 2024 to 2025
- Merton STW So Merton64 → 144
- Love Ln CSO Marldon0 → 63
- North Fal STW So St Stevens12 → 72
| Year | Outlets with a count | Total spills | Median per outlet | England median |
|---|---|---|---|---|
| 2025 | 1,357 | 46,164 | 21 | 11 |
| 2024 | 1,359 | 56,165 | 23 | 19 |
| 2023 | 1,276 | 56,288 | 26 | 20 |
| 2022 | 1,194 | 34,465 | 12 | 13 |
| 2021 | 974 | 38,305 | 20 | 19 |
Earlier returns list fewer of these outlets, so totals are not comparable between years. The median per outlet and the like-for-like change are fairer comparisons. Counts are events, not volume.
Largest falls from 2024 to 2025
Only outlets with a count in both years and at least 90% monitor operation in each. Counts depend on rainfall as well as on the sewer network, so a fall does not show on its own that an overflow improved.
- Roborough STW SSO Roborough327 → 143
- Dulford Spst Pscsoeo Dulford283 → 132
- Honiton STW SSO Honiton219 → 75
- Abbotsham STW So Abbotsham329 → 196
- Chilsworthy STW So Gunnislake174 → 41
- Salcombe Regis STW So Salcombe Regis366 → 235
- Lime Kiln PS CSO Budleigh Salterton212 → 83
- Yeoford STW SSO Crediton123 → 31
- Lerryn Spst Pscsoeo Lerryn101 → 19
- Feniton STW SSO Feniton114 → 33
Most spills in 2025
- 1Croyde STW So Croyde253spills
Croyde Bay (Coastal)
- 2Shop STW So Shop243spills
Tributary of Coombe Valley Stream
- 3Salcombe Regis STW So Salcombe Regis235spills
Salcombe Regis Stream
- 4Horns Cross STW So Horns Cross230spills
Tributary of River Yeo
- 5Town Quay Spst Pscsoeo Fowey198spills
River Fowey Estuary (E)
- 6Abbotsham STW So Abbotsham196spills
Kenwith Stream
- 7Tatworth STW SSO Tatworth189spills
Forton Brook
- 8Rewe STW SSO Rewe175spills
River Culm
- 9High Bickington STW So High Bickington173spills
Tributary of Langham Lake(S)
- 10Brayford STW So Brayford172spills
River Bray(S)
Most hours in 2025
- 1Salcombe Regis STW So Salcombe Regis5,446hours
Salcombe Regis Stream
- 2Shop STW So Shop4,967hours
Tributary of Coombe Valley Stream
- 3Tatworth STW SSO Tatworth4,141hours
Forton Brook
- 4Brayford STW So Brayford3,763hours
River Bray(S)
- 5Chacewater STW SSO Chacewater3,542hours
(S) River Carnon
- 6Altarnun STW SSO Altarnun3,295hours
Penpont Water
- 7Praze An Beeble STW SSO Praze An Beeble3,153hours
(S) Praze River
- 8Tiverton STW SSO Tiverton3,152hours
River Exe
- 9Pyworthy STW SSO Pyworthy2,919hours
Derril Water(S)
- 10Delabole STW SSO Delabole2,903hours
River Allen
Waterbodies with the most spills
Total 2025 spills from outlets the return links to each waterbody. A waterbody with more outlets will usually have a higher total.
| Waterbody | Outlets | Spills | Spills per outlet |
|---|---|---|---|
| Teign (Lower) | 11 | 528 | 48 |
| Dart | 6 | 482 | 80.3 |
| Lower Culm | 12 | 474 | 39.5 |
| Lower River Tavy | 11 | 457 | 41.5 |
| Meavy | 7 | 457 | 65.3 |
| Upper River Yeo (Bideford) | 5 | 434 | 86.8 |
| Lower Axe | 8 | 430 | 53.8 |
| Seaton | 10 | 416 | 41.6 |
| Lower River Otter | 18 | 408 | 22.7 |
| Lower Little River Dart | 4 | 394 | 98.5 |
How to read this report
- A spill is a counted event under the 12/24-hour method. It is not a volume, and it does not measure harm or water quality.
- Missing counts are left out, not treated as zero. Low monitor operation can make a count too low.
- Rankings compare counts only. They do not show whether an overflow broke its permit or the law.
- Earlier years list fewer outlets, so compare medians or like-for-like groups, not totals.
Data: Environment Agency event duration monitoring annual returns, Open Government Licence v3.0. How spills are counted · How the data works · Sources