Storm overflow register · 2025 annual return

South West Water storm overflows, 2025

South West Water reported 1,365 storm overflows in England for 2025. Together they recorded 46,164 spills over 407,006 hours, an average of 33.8 spills per overflow against 20.4 across England. That ranks 10 of 10 companies, where 1 is the fewest spills per overflow. Counting the same overflows in both years, spills were down 18% on 2024.

178 overflows did not spill · 275 spilled more than 60 times · 1,313 had monitors working for 90% of the year or more · 334 sewage treatment works with overflows

Hours spilling by month, 2025

050k100k150k200kJan 2025: 84,216 hours spillingJanFeb 2025: 45,207 hours spillingFebMar 2025: 9,740 hours spillingMarApr 2025: 21,006 hours spillingAprMay 2025: 2,363 hours spillingMayJun 2025: 8,257 hours spillingJunJul 2025: 1,289 hours spillingJulAug 2025: 2,570 hours spillingAugSep 2025: 11,756 hours spillingSepOct 2025: 9,772 hours spillingOctNov 2025: 60,065 hours spillingNovDec 2025: 150,480 hours spillingDec
Hours spilling, all South West Water overflows, from the start/stop records. Spills running across a month end are split between the months.

All South West Water storm overflows

Sorted by hours spilling. Open an overflow for its permit, location, reasons for high spills and improvement status.

OverflowDischarges toSpills 2025Hours 2025Spills vs 2024Monitor uptime
Whiddon Down STW
Inlet overflow at sewage works
Sewage works
Whiddon Down
Company site name
WHIDDON DOWN STW_SO_WHIDDON DOWN
EA ID / permit
SBB01355 · 203600
Outlet location
SX69299244 (OS grid reference) · View on Apple Maps
WFD catchment
Fingle Brook (GB108046008570)
2024 spills / hours
23 / 244
Long-term average
15.0 spills a year (monitored since 2021)
Investigation
UWWTR investigation completed
Improvement
No improvement action in reporting period
Fingle Brook(S) 0 0.0 down 100% 100%
Uffculme WwTW
Storm tank at sewage works
Sewage works
Uffculme
Company site name
UFFCULME STW_SSO_UFFCULME
EA ID / permit
SBB01293 · SWWA 6
Outlet location
ST06221186 (OS grid reference) · View on Apple Maps
WFD catchment
Lower Culm (GB108045014970)
2024 spills / hours
6 / 54
Long-term average
27.0 spills a year (monitored since 2018)
Investigation
UWWTR investigation completed
Improvement
UWWTR improvement completed
River Culm 0 0.0 down 100% 100%
Upton Cross Combined Sewer Overflow
Overflow on sewer network
Company site name
UPTON CROSS_CSO_RILLA MILL
EA ID / permit
SBB01297 · 301891
Outlet location
SX28617266 (OS grid reference) · View on Apple Maps
WFD catchment
Lower River Lynher (GB108047007670)
2024 spills / hours
0 / 0.0
Long-term average
0.0 spills a year (monitored since 2020)
Investigation
No investigation activity in reporting period
Improvement
No improvement action in reporting period
Trib of River Lyner 0 0.0 no change 95%
West Alvington CSO
Overflow on sewer network
Company site name
WEST ALVINGTON_CSO_W ALVINGTON
EA ID / permit
SBB01332 · 203417
Outlet location
SX72654357 (OS grid reference) · View on Apple Maps
WFD catchment
Not part of a WFD catchment
Shellfish water
Salcombe
2024 spills / hours
21 / 8.7
Long-term average
11.4 spills a year (monitored since 2010)
Investigation
UWWTR investigation completed
Improvement
No improvement action in reporting period
Kingsbridge Estuary(S) 0 0.0 down 100% 100%
11 High Street CSO
Overflow on sewer network
Company site name
11 HIGH STREET_CSO_HATHERLEIGH
EA ID / permit
SBB00005 · 201777
Outlet location
SS54050422 (OS grid reference) · View on Apple Maps
WFD catchment
Lower River Lew (Torridge) (GB108050008220)
2024 spills / hours
48 / 109
Long-term average
12.2 spills a year (monitored since 2016)
Investigation
UWWTR investigation completed
Improvement
No improvement action in reporting period
River Lew 0 0.0 down 100% 100%
Ashprington WwTW
Inlet overflow at sewage works
Sewage works
Ashprington
Company site name
ASHPRINGTON STW_SO_ASHPRINGTON
EA ID / permit
SBB00052 · NRA-SW-3983
Outlet location
SX81485636 (OS grid reference) · View on Apple Maps
WFD catchment
Not part of a WFD catchment
2024 spills / hours
11 / 20
Long-term average
52.1 spills a year (monitored since 2016)
Investigation
UWWTR investigation completed
Improvement
No improvement action in reporting period
River Harbourne (Estuarine) 0 0.0 down 100% 97%
Spreyton STW
Inlet overflow at sewage works
Sewage works
Spreyton
Company site name
SPREYTON STW_SO_SPREYTON
EA ID / permit
SBB01115 · 203380
Outlet location
SX69859752 (OS grid reference) · View on Apple Maps
WFD catchment
Upper River Yeo (Lapford) (GB108050008270)
2024 spills / hours
0 / 0.0
Long-term average
0.0 spills a year (monitored since 2021)
Investigation
No investigation activity in reporting period
Improvement
No improvement action in reporting period
Coombe Stream(S) 0 0.0 no change 93%
Tolskithey Lane CSO
Overflow on sewer network
Company site name
TOLSKITHY LANE_CSO_REDRUTH
EA ID / permit
SBB01248 · 301685
Outlet location
SW68124249 (OS grid reference) · View on Apple Maps
WFD catchment
Portreath Stream (GB108049000620)
2024 spills / hours
– / –
Long-term average
3.3 spills a year (monitored since 2020)
Monitor below 90%
Installation set-up/design issue · Resolved - February after reporting year
Investigation
No investigation activity in reporting period
Improvement
No improvement action in reporting period
Trib of Portreath Stream – – 0%
Beals Mill No 2 CSO
Overflow on sewer network
Company site name
BEALS MILL NO 2_CSO_TREBURLEY
EA ID / permit
SBB00090 · 301890
Outlet location
SX35967707 (OS grid reference) · View on Apple Maps
WFD catchment
Lower River Inny (GB108047007890)
2024 spills / hours
87 / 1,953
Long-term average
302.8 spills a year (monitored since 2018)
Monitor below 90%
No longer operational as an overflow - permit revoked or to be revoked · Overflow no longer spilling to environment - from Jan
Investigation
No investigation activity in reporting period
Improvement
No improvement action in reporting period
River Inny – – –
Beals Mill No 1 CSO
Overflow on sewer network
Company site name
BEALS MILL NO 1_CSO_TREBURLEY
EA ID / permit
SBB00089 · 301889
Outlet location
SX35967707 (OS grid reference) · View on Apple Maps
WFD catchment
Lower River Inny (GB108047007890)
2024 spills / hours
64 / 716
Long-term average
113.2 spills a year (monitored since 2018)
Monitor below 90%
No longer operational as an overflow - permit revoked or to be revoked · Overflow no longer spilling to environment - from Jan
Investigation
No investigation activity in reporting period
Improvement
No improvement action in reporting period
River Inny – – –
O/S 8 Callenick Street CSO
Overflow on sewer network
Company site name
CALENICK ST NO8_CSO_TRURO
EA ID / permit
SBB00861 · 301799
Outlet location
SW82514480 (OS grid reference) · View on Apple Maps
WFD catchment
Zelah Brook (GB108048002360)
2024 spills / hours
– / –
Monitor below 90%
No longer operational as an overflow - permit revoked or to be revoked · Overflow no longer spilling to environment - from Jan
Investigation
No investigation activity in reporting period
Improvement
No improvement action in reporting period
Kenwyn River (E) – – –
Playing Fields CSO
Overflow on sewer network
Company site name
BRIDESTOW_CSO_BRIDESTOW
EA ID / permit
SBB00943 · 301828
Outlet location
SX51318943 (OS grid reference) · View on Apple Maps
WFD catchment
Lew (Tamar) (GB108047007770)
2024 spills / hours
– / –
Long-term average
0.0 spills a year (monitored since 2022)
Monitor below 90%
No longer operational as an overflow - permit revoked or to be revoked · Overflow no longer spilling to environment - from Jan
Investigation
No investigation activity in reporting period
Improvement
No improvement action in reporting period
River Lyd (S) – – –
Topsham Road Jct Robers Road CSO
Overflow on sewer network
Company site name
TOPSHAM RD/ROBERTS RD_CSO_EXETER
EA ID / permit
SBB01250 · 201926
Outlet location
SX92239189 (OS grid reference) · View on Apple Maps
WFD catchment
Exe (Creedy to Estuary) (GB108045009040)
Shellfish water
Exe Estuary
2024 spills / hours
– / –
Long-term average
0.8 spills a year (monitored since 2018)
Monitor below 90%
No longer operational as an overflow - permit revoked or to be revoked · Overflow no longer spilling to environment - from Jan
Investigation
No investigation activity in reporting period
Improvement
No improvement action in reporting period
River Exe via SWS – – –
Jubilee Buildings
Overflow on sewer network
Company site name
185 OUTLAND RD CSO PLYMOUTH
EA ID / permit
SBB01402 · 301714/CS/01
Outlet location
SX46225441 (OS grid reference) · View on Apple Maps
WFD catchment
PLYMOUTH TAMAR (GB520804714300)
2024 spills / hours
– / –
Monitor below 90%
No longer operational as an overflow - permit revoked or to be revoked · Overflow no longer spilling to environment - from Jan
Investigation
No investigation activity in reporting period
Improvement
No improvement action in reporting period
Stonehouse Creek – – –
Industrial Estate CSO
Overflow on sewer network
Company site name
DOBLES LANE IND EST CSO HOLSWORTHY
EA ID / permit
SBB01404 · 302155/CS/01
Outlet location
SS34320483 (OS grid reference) · View on Apple Maps
WFD catchment
River Deer (GB108047013880)
2024 spills / hours
– / –
Monitor below 90%
No longer operational as an overflow - permit revoked or to be revoked · Overflow no longer spilling to environment - from Jan
Investigation
No investigation activity in reporting period
Improvement
No improvement action in reporting period
Trib of River Deer – – –

Sewage treatment works

Storm tanks and inlet overflows at each South West Water sewage works. The figures are 2025 spills.

← All water companies · Contains Environment Agency data licensed under the Open Government Licence v3.0. How to read the data.