Storm overflow register · 2025 annual return

United Utilities storm overflows, 2025

United Utilities reported 2,270 storm overflows in England for 2025. Together they recorded 60,843 spills over 327,452 hours, an average of 26.8 spills per overflow against 20.4 across England. That ranks 9 of 10 companies, where 1 is the fewest spills per overflow. Counting the same overflows in both years, spills were down 23% on 2024.

295 overflows did not spill · 313 spilled more than 60 times · 2,076 had monitors working for 90% of the year or more · 289 sewage treatment works with overflows

Hours spilling by month, 2025

Hours spilling, all United Utilities overflows, from the start/stop records. Spills running across a month end are split between the months.

All United Utilities storm overflows

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

Overflow	Discharges to	Spills 2025	Hours 2025	Spills vs 2024	Monitor uptime
Waggon Road CSO Overflow on sewer network EA ID / permit UUP02004 · 01TAM0091 Outlet location SD9753001970 (OS grid reference) · View on Apple Maps WFD catchment Tame (Chew Brook to Swineshaw Brook) (GB112069061111) 2024 spills / hours 3 / 0.6 Long-term average 3.6 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.6 hours spilling →	River Tame	2	1.6	down 33%	93%
Church Street West CSO 091KB Overflow on sewer network Company site name Church Street West CSO EA ID / permit UUP00487 · 01BRY0029 Outlet location SD7878007090 (OS grid reference) · View on Apple Maps WFD catchment Irwell (Roch to Croal) (GB112069060840) 2024 spills / hours 4 / 2.3 Long-term average 3.7 spills a year (monitored since 2019) Monitor below 90% Sensor failure / issue · Resolved - Apr Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.6 hours spilling →	River Irwell	3	1.6	down 25%	77%
Bromborough Pool Village PS 51026 Storm discharge at pumping station Company site name Bromborough Pool Village PS EA ID / permit UUP00334 · 016881615 Outlet location SJ3541084411 (OS grid reference) · View on Apple Maps WFD catchment MERSEY - Transitional (GB531206908100) Bathing water Wallasey Shellfish water North Wirral (East) 2024 spills / hours 5 / 9.4 Long-term average 4.4 spills a year (monitored since 2018) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.6 hours spilling →	River Mersey Estuary	1	1.6	down 80%	100%
Near Butts Beck CSO (321H7) Overflow on sewer network Company site name Near Butts Beck Footpath CSO EA ID / permit UUP01369 · 01PEN0025 Outlet location SD8756046820 (OS grid reference) · View on Apple Maps WFD catchment Stock Beck (GB112071065540) 2024 spills / hours 15 / 239 Long-term average 9.4 spills a year (monitored since 2021) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.6 hours spilling →	Butts Beck	5	1.6	down 67%	100%
Leach Lane St Helens CSO Overflow on sewer network Company site name Leach Lane (St. Helens) CSO EA ID / permit UUP01125 · 016982980 Outlet location SJ5265092360 (OS grid reference) · View on Apple Maps WFD catchment Sutton Brook (GB112069061170) 2024 spills / hours 13 / 7.9 Long-term average 20.2 spills a year (monitored since 2020) Monitor below 90% Sensor failure / issue · Resolved - Aug Investigation No investigation activity in reporting period Improvement Env Act (SODRP) improvement ongoing Volume & pollution Estimate from 1.6 hours spilling →	Sutton Mill Brook	1	1.6	down 92%	84%
Alton Street No 2 CSO 161BP Overflow on sewer network Company site name Alton Street No.2 CSO EA ID / permit UUP00109 · 01CRE0035 Outlet location SJ6996055310 (OS grid reference) · View on Apple Maps WFD catchment Valley Brook (Englesea Brook to Weaver) (GB112068055310) 2024 spills / hours 42 / 947 Long-term average 21.2 spills a year (monitored since 2020) Investigation Operational investigation completed Improvement Operational improvement completed Volume & pollution Estimate from 1.6 hours spilling →	Valley Brook	5	1.6	down 88%	100%
Waste Lane CSO Site Id 472W0 Overflow on sewer network Company site name WASTE LANE CSO EA ID / permit UUP02035 · 01VRY0055 Outlet location SJ5944071600 (OS grid reference) · View on Apple Maps WFD catchment Cuddington Brook (Source to Crowton Brook) (GB112068060480) 2024 spills / hours 25 / 37 Long-term average 13.6 spills a year (monitored since 2021) Investigation Operational investigation completed Improvement Operational improvement completed Volume & pollution Estimate from 1.6 hours spilling →	Cuddington Brook	4	1.6	down 84%	99%
Barlow Moor Rd/Palatine Rd CSO Overflow on sewer network Company site name Barlow Moor Road/Palatine Road CSO EA ID / permit UUP00187 · 01MAN0236 Outlet location SJ8346091620 (OS grid reference) · View on Apple Maps WFD catchment Mersey (upstream of Manchester Ship Canal) (GB112069061030) 2024 spills / hours 0 / 0.0 Long-term average 0.5 spills a year (monitored since 2024) Monitor below 90% Sensor failure / issue · Resolved - Nov Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 1.5 hours spilling →	River Mersey	1	1.5	up from 0	59%
9 Turton Road CSO (BRY0138) Overflow on sewer network Company site name 9 Turton Road EA ID / permit UUP02244 · EPRJB3890WT Outlet location SD7743313232 (OS grid reference) · View on Apple Maps WFD catchment Kirklees Brook (GB112069064610) 2024 spills / hours 1 / 0.4 Long-term average 1.5 spills a year (monitored since 2024) Monitor below 90% Sensor failure / issue · Resolved - Oct Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.5 hours spilling →	Unnamed tributary of Kirklees Brook	2	1.5	up 100%	88%
Bradfield Avenue CSO 318FN Overflow on sewer network Company site name BRADFIELD AVENUE CSO EA ID / permit UUP00294 · 01SEF0011 Outlet location SJ3718099520 (OS grid reference) · View on Apple Maps WFD catchment Alt US Bull Bridge (GB112069061441) 2024 spills / hours 2 / 0.3 Long-term average 4.3 spills a year (monitored since 2019) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 1.5 hours spilling →	Moor Hey Brook tributary of the River Alt	2	1.5	no change	93%
Prestwich Clough CSO 09034 Overflow on sewer network Company site name Prestwich Clough CSO EA ID / permit UUP01575 · 016983247 Outlet location SD8117003530 (OS grid reference) · View on Apple Maps WFD catchment Irwell (Croal to Irk) (GB112069061451) 2024 spills / hours 9 / 2.8 Long-term average 12.1 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.5 hours spilling →	Prestwich Clough Brook	5	1.5	down 44%	100%
Manor Street Bow Street CSO 072ES Overflow on sewer network Company site name MANOR STREET / BOW STREET CSO EA ID / permit UUP01249 · 01BOL0122 Outlet location SD7187009410 (OS grid reference) · View on Apple Maps WFD catchment Middle Brook (GB112069064540) 2024 spills / hours 0 / 0.0 Long-term average 1.2 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.5 hours spilling →	Croal Minor	1	1.5	up from 0	100%
Reedyford Rd CSO (32020) Overflow on sewer network Company site name Reedyford Road CSO EA ID / permit UUP01643 · 017180619 Outlet location SD8634038560 (OS grid reference) · View on Apple Maps WFD catchment Walverden Water (GB112071065130) 2024 spills / hours 7 / 5.8 Long-term average 7.6 spills a year (monitored since 2021) Investigation Operational investigation completed Improvement Operational improvement completed Volume & pollution Estimate from 1.5 hours spilling →	Culvrtd Trib of Walverden Wtr	1	1.5	down 86%	100%
Fir Tree Avenue Pumping Station Storm discharge at pumping station Company site name Fir Tree Avenue PS EA ID / permit UUP00736 · 01SAL0001 Outlet location SD7247000210 (OS grid reference) · View on Apple Maps WFD catchment Shaw Brook (GB112069061090) 2024 spills / hours 3 / 1.2 Long-term average 9.5 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.5 hours spilling →	Sniggley Ditch	2	1.5	down 33%	100%
Western Road CSO Overflow on sewer network EA ID / permit UUP02083 · 01TRA0002 Outlet location SJ7419094330 (OS grid reference) · View on Apple Maps WFD catchment Mersey (upstream of Manchester Ship Canal) (GB112069061030) 2024 spills / hours 0 / 0.0 Long-term average 13.0 spills a year (monitored since 2019) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 1.5 hours spilling →	Carrs Ditech (Culvert)	3	1.5	up from 0	100%
Ullgill Moresby (MH65) CSO Overflow on sewer network Company site name Ullgill Moresby (MH65) CSO EA ID / permit UUP01977 · 017580419 Outlet location NX9903021260 (OS grid reference) · View on Apple Maps WFD catchment Lowca Beck (GB112074070040) 2024 spills / hours 2 / 0.7 Long-term average 4.2 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.4 hours spilling →	Trib of Lowca Beck	2	1.4	no change	100%
Manc' Road (Chapel-En-Le-Frith) CSO Overflow on sewer network Company site name Manchester Road EA ID / permit UUP01225 · EPRQB3590EV Outlet location SK0504080460 (OS grid reference) · View on Apple Maps WFD catchment Randall Carr Brook (GB112069060860) 2024 spills / hours 24 / 30 Long-term average 25.3 spills a year (monitored since 2020) Monitor below 90% Sensor failure / issue · Resolved - Jun Investigation No investigation activity in reporting period Improvement Env Act (SODRP) improvement ongoing Volume & pollution Estimate from 1.4 hours spilling →	Combs Reservoir	5	1.4	down 79%	58%
Whitby Road Combined Sewer Overflow Overflow on sewer network Company site name Whitby Road CSO EA ID / permit UUP02109 · 016881598 Outlet location SJ4097077103 (OS grid reference) · View on Apple Maps WFD catchment Manchester Ship Canal (GB71210004) 2024 spills / hours 1 / 0.4 Long-term average 3.5 spills a year (monitored since 2020) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 1.4 hours spilling →	Manchester Ship Canal	4	1.4	up 300%	97%
Victoria Avenue/Glenbrook CSO Overflow on sewer network Company site name Victoria Avenue/Glenbrook CSO EA ID / permit UUP01995 · 016993670 Outlet location SD8404004060 (OS grid reference) · View on Apple Maps WFD catchment Irk (Wince to Irwell) (GB112069061131) 2024 spills / hours 0 / 0.0 Long-term average 4.3 spills a year (monitored since 2020) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 1.4 hours spilling →	River Irk via SWS	9	1.4	up from 0	100%
Boundary Park Road CSO Overflow on sewer network EA ID / permit UUP00288 · 01OLD0033 Outlet location SD9063006910 (OS grid reference) · View on Apple Maps WFD catchment Irk (Sourtce to Wince Brook) (GB112069061161) 2024 spills / hours 7 / 1.5 Long-term average 9.7 spills a year (monitored since 2020) Investigation Env Act (SODRP) investigation ongoing Improvement Env Act (SODRP) improvement ongoing Volume & pollution Estimate from 1.4 hours spilling →	Plumpton Clough	3	1.4	down 57%	100%
Bolton Road CSO Overflow on sewer network Company site name Bolton Road CSO EA ID / permit UUP00271 · 01BBN0105 Outlet location SD6952021260 (OS grid reference) · View on Apple Maps WFD catchment Darwen - headwaters to conf Davy Field Bk (GB112071065240) 2024 spills / hours 13 / 6.3 Long-term average 9.0 spills a year (monitored since 2024) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.4 hours spilling →	Unnamed Trib of River Darwen	5	1.4	down 62%	99%
Oakwood Drive Croftlands CSO Overflow on sewer network Company site name Oakwood Drive (Croftlands) Combined Sewer Overflow EA ID / permit UUP01435 · 017380296 Outlet location SD2907277209 (OS grid reference) · View on Apple Maps WFD catchment Dragley Beck (GB112073071160) Shellfish water Morecambe Bay (Leven) 2024 spills / hours 3 / 14 Long-term average 1.0 spills a year (monitored since 2017) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.4 hours spilling →	Dragley Beck	2	1.4	down 33%	100%
Valley Road Pumping Station Storm discharge at pumping station Company site name Valley Road PS EA ID / permit UUP01987 · 017160300 Outlet location SD5281028450 (OS grid reference) · View on Apple Maps WFD catchment RIBBLE - transitional (GB531207112400) Bathing water Southport; St Annes; St. Annes North; Blackpool South Shellfish water Ribble 2024 spills / hours 4 / 3.7 Long-term average 14.1 spills a year (monitored since 2017) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.3 hours spilling →	River Ribble Estuarine Waters	3	1.3	down 25%	100%
Sandhills Lane CSO Overflow on sewer network Company site name Sandhills Lane CSO EA ID / permit UUP01714 · 016930970 Outlet location SJ3320093101 (OS grid reference) · View on Apple Maps WFD catchment MERSEY - Transitional (GB531206908100) Bathing water Wallasey Shellfish water North Wirral (East) 2024 spills / hours 7 / 8.4 Long-term average 13.4 spills a year (monitored since 2018) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.3 hours spilling →	Mersey Estuary	3	1.3	down 57%	100%
Allen St/Lord St CSO Overflow on sewer network Company site name Allen Street/Lord Street CSO EA ID / permit UUP00102 · EPRSB3793EM Outlet location SJ9374077640 (OS grid reference) · View on Apple Maps WFD catchment Dean (Bollington to Bollin) (GB112069061360) 2024 spills / hours 3 / 0.6 Long-term average 3.4 spills a year (monitored since 2021) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.3 hours spilling →	River Dean	2	1.3	down 33%	92%
Hartshead Close/Manshaw Road CSO Overflow on sewer network Company site name HARTSHEAD CLOSE / MANSHAW ROAD CSO EA ID / permit UUP00908 · 01MAN0203 Outlet location SJ9013897264 (OS grid reference) · View on Apple Maps WFD catchment Platt Brook (Source to Fallowfield Bk) (GB112069061060) 2024 spills / hours 1 / 0.3 Long-term average 3.5 spills a year (monitored since 2020) Investigation Operational investigation completed Improvement Operational improvement completed Volume & pollution Estimate from 1.3 hours spilling →	Culverted Section Moss Brook	1	1.3	no change	99%
Acton Bridge STW Inlet overflow at sewage works Sewage works Acton Bridge Company site name Acton Bridge WwTW EA ID / permit UUP02258 · Unpermitted Outlet location SJ5927474401 (OS grid reference) · View on Apple Maps WFD catchment Trout Beck (Cairn Beck) (GB102076073900) 2024 spills / hours 61 / 88 Long-term average 34.0 spills a year (monitored since 2024) Monitor below 90% Access - Unable to retrieve data from non-telemetry data logger · Resolved - Nov Investigation Operational investigation completed Improvement Operational improvement completed Volume & pollution Estimate from 1.3 hours spilling →	Trib Trout Beck	7	1.3	down 89%	82%
Bankhall CSO 99007 LIV0038 Overflow on sewer network Company site name Bankhall CSO EA ID / permit UUP00182 · 016930969 Outlet location SJ3320093500 (OS grid reference) · View on Apple Maps WFD catchment MERSEY - Transitional (GB531206908100) Bathing water Wallasey Shellfish water North Wirral (East) 2024 spills / hours 9 / 1.5 Long-term average 7.0 spills a year (monitored since 2017) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.3 hours spilling →	Mersey Estuary	6	1.3	down 33%	100%
Clifton Rd Leach St CSO 091KQ Overflow on sewer network Company site name Clifton Road/Leach Street CSO EA ID / permit UUP00509 · 01BRY0039 Outlet location SD8056003980 (OS grid reference) · View on Apple Maps WFD catchment Irwell (Croal to Irk) (GB112069061451) 2024 spills / hours 10 / 1.7 Long-term average 9.7 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.3 hours spilling →	Trib Prestwich Clough via SWS	6	1.3	down 40%	100%
Strand Road Storm Sewer Overflow Overflow on sewer network Company site name Strand Road CSO EA ID / permit UUP01878 · 016931014 Outlet location SJ3250094300 (OS grid reference) · View on Apple Maps WFD catchment MERSEY - Transitional (GB531206908100) Bathing water Wallasey Shellfish water North Wirral (East) 2024 spills / hours 3 / 5.0 Long-term average 19.7 spills a year (monitored since 2021) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.3 hours spilling →	River Mersey	2	1.3	down 33%	100%
Hampden Road CSO 091XV BRY0041 Overflow on sewer network Company site name Hampden Road CSO EA ID / permit UUP00892 · 016993787 Outlet location SD8191003930 (OS grid reference) · View on Apple Maps WFD catchment Irwell (Croal to Irk) (GB112069061451) 2024 spills / hours 8 / 3.9 Long-term average 20.0 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.3 hours spilling →	Prestwich Clough via Clvrt	4	1.3	down 50%	100%
South of Blackley New Road CSO Overflow on sewer network Company site name Blackley New Road CSO EA ID / permit UUP01784 · 016993799 Outlet location SD8390003150 (OS grid reference) · View on Apple Maps WFD catchment Irk (Wince to Irwell) (GB112069061131) 2024 spills / hours 8 / 3.9 Long-term average 29.5 spills a year (monitored since 2020) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 1.3 hours spilling →	River Irk	3	1.3	down 63%	99%
Sandside Pumping Station Storm discharge at pumping station Company site name Sandside PS EA ID / permit UUP01716 · 017370202 Outlet location SD4779080770 (OS grid reference) · View on Apple Maps WFD catchment KENT - transitional (GB531207312000) 2024 spills / hours 0 / 0.0 Long-term average 1.2 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.2 hours spilling →	River Bela	1	1.2	up from 0	100%
Abbeyhills Combined Sewer Overflow Overflow on sewer network Company site name Abbeyhills Combined Sewer Overflow (31028) (OLD0124) EA ID / permit UUP00070 · 01OLD0124 Outlet location SD9482203177 (OS grid reference) · View on Apple Maps WFD catchment Medlock (Source to Lumb Brook) (GB112069061151) 2024 spills / hours 2 / 0.3 Long-term average 1.1 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.2 hours spilling →	Culvert Glodwick Brook	2	1.2	no change	100%
Long Street Combined Sewer Overflow Overflow on sewer network Company site name Long Street CSO (near the Market Place) EA ID / permit UUP01176 · 016993581 Outlet location SD8704006010 (OS grid reference) · View on Apple Maps WFD catchment Irk (Sourtce to Wince Brook) (GB112069061161) 2024 spills / hours 3 / 0.9 Long-term average 3.8 spills a year (monitored since 2020) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 1.2 hours spilling →	Clvrt'D Section the River Irk	3	1.2	no change	100%
Lord North Street/Clifton St CSO Overflow on sewer network Company site name LORD NORTH STREET / CLIFTON STREET CSO EA ID / permit UUP01185 · 01MAN0069 Outlet location SJ8662099660 (OS grid reference) · View on Apple Maps WFD catchment Medlock (Lumb Brook to Irwell) (GB112069061152) 2024 spills / hours 8 / 1.1 Long-term average 11.0 spills a year (monitored since 2020) Monitor below 90% Sensor failure / issue · Resolved - Sep Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.2 hours spilling →	Shooters Brook	4	1.2	down 50%	89%
Dyehouse Lane CSO Overflow on sewer network Company site name Dyehouse Lane CSO EA ID / permit UUP00671 · 016982937 Outlet location SD9131015060 (OS grid reference) · View on Apple Maps WFD catchment Roch (Source to Spodden) (GB112069064720) 2024 spills / hours 5 / 0.9 Long-term average 16.7 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.2 hours spilling →	Ash Brook	11	1.2	up 120%	99%
Lee Road CSO (369BA) Overflow on sewer network Company site name Lee Road CSO EA ID / permit UUP01128 · 016982935 Outlet location SD8625021810 (OS grid reference) · View on Apple Maps WFD catchment Irwell (Source to Whitewell Brook) (GB112069064660) 2024 spills / hours 2 / 2.0 Long-term average 1.2 spills a year (monitored since 2021) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.2 hours spilling →	River Irwell	1	1.2	down 50%	100%
O/S 50 Bispham Ave Overflow on sewer network Company site name Outside No. 50 Bispham Avenue EA ID / permit UUP01423 · 017081264 Outlet location SD5335023700 (OS grid reference) · View on Apple Maps WFD catchment Lostock US Farington Weir (GB112070064911) 2024 spills / hours 0 / 0.0 Long-term average 0.5 spills a year (monitored since 2024) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 1.1 hours spilling →	River Lostock	1	1.1	up from 0	94%
Opposite No 7 Cromer Road CSO Overflow on sewer network Company site name Opposite No.7 Cromer Road CSO EA ID / permit UUP01471 · 01SEF0056 Outlet location SD3302013222 (OS grid reference) · View on Apple Maps WFD catchment Three Pool's Waterway (GB112070064830) Bathing water St Annes; St Annes North; Blackpool South; Blackpool Central; Blackpool North; Southport; Ainsdale 2024 spills / hours 5 / 1.8 Long-term average 5.6 spills a year (monitored since 2017) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 1.1 hours spilling →	Sandy Brook	4	1.1	down 20%	100%
Altrincham Rd Westend Ave CSO 431BS Overflow on sewer network Company site name ALTRINCHAM ROAD / WEST END AVENUE CSO EA ID / permit UUP00110 · 01MAN0226 Outlet location SJ8431088730 (OS grid reference) · View on Apple Maps WFD catchment Mersey (upstream of Manchester Ship Canal) (GB112069061030) 2024 spills / hours 6 / 1.9 Long-term average 10.9 spills a year (monitored since 2018) Investigation Env Act (SODRP) investigation ongoing, Operational investigation completed Improvement Operational improvement completed Volume & pollution Estimate from 1.1 hours spilling →	Gatley Brook via SWS	3	1.1	down 50%	95%
Snebra Whitehaven CSO 023B2 Overflow on sewer network Company site name Snebra Whitehaven CSO EA ID / permit UUP01776 · 01COP0039 Outlet location NX9831016730 (OS grid reference) · View on Apple Maps WFD catchment Solway Outer South (GB641211630003) 2024 spills / hours 1 / 0.3 Long-term average 2.0 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.1 hours spilling →	Trib of Pow Beck	2	1.1	up 100%	100%
181 London Road CSO Overflow on sewer network Company site name 181 London Road CSO EA ID / permit UUP00011 · 016892203 Outlet location SJ6594072970 (OS grid reference) · View on Apple Maps WFD catchment Dane (Wheelock to Weaver) (GB112068060470) 2024 spills / hours 32 / 37 Long-term average 56.2 spills a year (monitored since 2021) Investigation No investigation activity in reporting period Improvement Env Act (SODRP) improvement ongoing Volume & pollution Estimate from 1.1 hours spilling →	River Dane via SWS	5	1.1	down 84%	97%
Alton St Combined Sewer Overflow Overflow on sewer network Company site name Alton Street CSO EA ID / permit UUP00108 · 016892334 Outlet location SJ6984055350 (OS grid reference) · View on Apple Maps WFD catchment Valley Brook (Englesea Brook to Weaver) (GB112068055310) 2024 spills / hours 1 / 0.2 Long-term average 3.2 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.1 hours spilling →	Valley Brook	5	1.1	up 400%	97%
Trinity Street/Dean Street CSO Overflow on sewer network Company site name Trinity Street/Dean Street CSO EA ID / permit UUP01967 · 016993730 Outlet location SJ9636098530 (OS grid reference) · View on Apple Maps WFD catchment Tame (Chew Brook to Swineshaw Brook) (GB112069061111) 2024 spills / hours 5 / 1.3 Long-term average 4.0 spills a year (monitored since 2021) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.1 hours spilling →	The River Tame	3	1.1	down 40%	100%
Apple Street CSO Overflow on sewer network EA ID / permit UUP00121 · 01BBN0040 Outlet location SD6709027610 (OS grid reference) · View on Apple Maps WFD catchment Blakewater (GB112071065310) 2024 spills / hours 6 / 0.9 Long-term average 22.5 spills a year (monitored since 2020) Investigation Env Act (SODRP) investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 1.1 hours spilling →	River Blakewater	5	1.1	down 17%	100%
Langley Rd North CSO Overflow on sewer network Company site name Langley Road North CSO EA ID / permit UUP01107 · 016982973 Outlet location SD8081001070 (OS grid reference) · View on Apple Maps WFD catchment Irwell (Croal to Irk) (GB112069061451) 2024 spills / hours 4 / 2.3 Long-term average 4.5 spills a year (monitored since 2024) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.1 hours spilling →	River Irwell	5	1.1	up 25%	96%
Dean Road CSO 278A2 Overflow on sewer network Company site name Dean Road CSO EA ID / permit UUP00621 · EPRJB3299AW Outlet location SJ8630082781 (OS grid reference) · View on Apple Maps WFD catchment Dean (Bollington to Bollin) (GB112069061360) 2024 spills / hours 1 / 0.1 Long-term average 2.2 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.0 hours spilling →	River Dean	2	1.0	up 100%	100%
Watery Lane CSO Shaft C1 PRE0093 Overflow on sewer network Company site name Watery Lane CSO (Shaft C1) EA ID / permit UUP02057 · 017180497 Outlet location SD5240429937 (OS grid reference) · View on Apple Maps WFD catchment RIBBLE_Transitional (GB531207112400) Bathing water St Annes 2024 spills / hours 0 / 0.0 Long-term average 9.0 spills a year (monitored since 2018) Monitor below 90% Sensor failure / issue · Resolved - Jul Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.0 hours spilling →	Moorbrook Culvert	1	1.0	up from 0	78%
Castle Carrok CSO Overflow on sewer network Company site name Castle Carrok CSO (Adjacent Donlea House) EA ID / permit UUP00419 · 017680315 Outlet location NY5422055720 (OS grid reference) · View on Apple Maps WFD catchment Gelt (GB102076074040) 2024 spills / hours 5 / 6.7 Long-term average 11.8 spills a year (monitored since 2021) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.0 hours spilling →	Castle Carrock Beck	7	1.0	up 40%	100%

Sewage treatment works

Storm tanks and inlet overflows at each United Utilities 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.