Storm overflow register · 2025 annual return

Southern Water storm overflows, 2025

Southern Water reported 977 storm overflows in England for 2025. Together they recorded 15,554 spills over 114,868 hours, an average of 15.9 spills per overflow against 20.4 across England. That ranks 4 of 10 companies, where 1 is the fewest spills per overflow. Counting the same overflows in both years, spills were down 47% on 2024.

175 overflows did not spill · 42 spilled more than 60 times · 862 had monitors working for 90% of the year or more · 215 sewage treatment works with overflows

Hours spilling by month, 2025

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

All Southern Water 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
Wivelsfield WwTW Storm tank at sewage works Sewage works Wivelsfield Company site name WIVELSFIELD SSO - 116051 EA ID / permit SWS00963 · W00369 Outlet location TQ3386020250 (OS grid reference) · View on Apple Maps WFD catchment R. Adur East (GB107041012220) 2024 spills / hours 81 / 861 Long-term average 51.0 spills a year (monitored since 2019) High-spill reason (company) Performance - GW inundation Investigation Env Act (SODRP) investigation ongoing, UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 346 hours spilling →	Tributary of River Adur	42	346	down 48%	100%
Yalding Old Works Ceo Storm discharge at pumping station Company site name YALDING OLD WORKS CEO - 108764 EA ID / permit SWS00976 · A00268 Outlet location TQ6911050420 (OS grid reference) · View on Apple Maps WFD catchment Medway at Maidstone (GB106040018440) 2024 spills / hours 63 / 783 Long-term average 59.2 spills a year (monitored since 2019) High-spill reason (company) Not asset maintenance - Hydraulic capacity Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 342 hours spilling →	Trib of the River Medway	42	342	down 33%	100%
Porchfield Main Road PS CSO Storm discharge at pumping station Company site name MAIN ROAD PORCHFIELD CEO - 108550 EA ID / permit SWS00670 · A01047 Outlet location SZ4473091250 (OS grid reference) · View on Apple Maps WFD catchment NEWTOWN RIVER (GB520710101700) Shellfish water Cowes and Medina; Lepe Middle Bank; Lymington and Sowley; Newtown 2024 spills / hours 37 / 345 Long-term average 34.5 spills a year (monitored since 2019) High-spill reason (company) Not asset maintenance - Hydraulic capacity Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 342 hours spilling →	Rodge Brook	37	342	no change	100%
Bishops Waltham WwTW Storm tank at sewage works Sewage works Bishops Waltham Company site name BISHOPS WALTHAM SSO - 115716 EA ID / permit SWS00067 · W00006 Outlet location SU5414015990 (OS grid reference) · View on Apple Maps WFD catchment Main River Hamble (GB107042016250) 2024 spills / hours 88 / 984 Long-term average 19.3 spills a year (monitored since 2018) High-spill reason (company) Performance - GW inundation Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 336 hours spilling →	The River Hamble	36	336	down 59%	100%
Hambledon PS Storm discharge at pumping station Company site name FOREST ROAD DENMEAD NO 1 CSO - 100941 EA ID / permit SWS00392 · W00216 Outlet location SU6627011180 (OS grid reference) · View on Apple Maps WFD catchment Potwell Trib (GB107042016400) 2024 spills / hours 0 / 0.0 Long-term average 23.6 spills a year (monitored since 2016) High-spill reason (company) Performance - GW inundation Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 328 hours spilling →	Sheepwash Tributary	36	328	up from 0	100%
Henfield WwTW Storm tank at sewage works Sewage works Henfield Company site name HENFIELD SSO - 115743 EA ID / permit SWS00417 · W00015 Outlet location TQ2155017250 (OS grid reference) · View on Apple Maps WFD catchment Chess Stream (GB107041012110) 2024 spills / hours 111 / 1,358 Long-term average 65.5 spills a year (monitored since 2019) High-spill reason (company) Performance - GW inundation Investigation Env Act (SODRP) investigation ongoing, UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 327 hours spilling →	Chess Brook	36	327	down 68%	93%
Fernhurst WwTW Storm tank at sewage works Sewage works Fernhurst Company site name FERNHURST SSO - 115866 EA ID / permit SWS00308 · W00352 Outlet location SU8962027490 (OS grid reference) · View on Apple Maps WFD catchment R. Lod (GB107041012830) 2024 spills / hours 54 / 522 Long-term average 38.7 spills a year (monitored since 2019) High-spill reason (company) Not asset maintenance - Hydraulic capacity Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 323 hours spilling →	River Lod	34	323	down 37%	100%
Onslow Arms Pumping Station Storm discharge at pumping station Company site name BREWHURST MILL LOXWOOD CEO - 108302 EA ID / permit SWS00628 · S01018 Outlet location TQ0418031110 (OS grid reference) · View on Apple Maps WFD catchment Loxwood Stream (GB107041017970) 2024 spills / hours 57 / 803 Long-term average 43.6 spills a year (monitored since 2016) Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 321 hours spilling →	Loxwood Stream	30	321	down 47%	100%
St. John'S, Crowborough WwTW Storm tank at sewage works Sewage works St John S Crowborough Company site name ST JOHNS CROWBOROUGH SSO - 115785 EA ID / permit SWS00821 · W00037 Outlet location TQ4991033100 (OS grid reference) · View on Apple Maps WFD catchment Friars Gate Stream (GB106040018370) 2024 spills / hours 80 / 971 Long-term average 56.6 spills a year (monitored since 2018) High-spill reason (company) Not asset maintenance - Hydraulic capacity Investigation Env Act (SODRP) investigation ongoing, UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 316 hours spilling →	Pippingford Brook	38	316	down 53%	100%
South Ambersham WwTW Storm tank at sewage works Sewage works South Ambersham Company site name SOUTH AMBERSHAM SSO - 115439 EA ID / permit SWS00788 · W00383 Outlet location SU9201021220 (OS grid reference) · View on Apple Maps WFD catchment Western Rother (GB107041012810) 2024 spills / hours 58 / 718 Long-term average 50.6 spills a year (monitored since 2017) Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 316 hours spilling →	Tributary of the River Rother	28	316	down 52%	100%
Hartfield WwTW Storm tank at sewage works Sewage works Hartfield Company site name HARTFIELD SSO - 115775 EA ID / permit SWS00403 · W00120 Outlet location TQ4833036140 (OS grid reference) · View on Apple Maps WFD catchment Mid Medway from Hartfield to Eden Confluence (GB106040018181) 2024 spills / hours 71 / 927 Long-term average 42.3 spills a year (monitored since 2019) Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 312 hours spilling →	Tributary of the River Medway	30	312	down 58%	100%
Ashdene Road Ashurst CSO Overflow on sewer network Company site name ASHDENE ROAD ASHURST CSO - 108392 EA ID / permit SWS00024 · A01303 Outlet location SU3399011410 (OS grid reference) · View on Apple Maps WFD catchment Bartley Water (GB107042016730) 2024 spills / hours 27 / 168 Long-term average 40.0 spills a year (monitored since 2016) High-spill reason (company) Performance - GW inundation Monitor below 90% Sensor failure / issue · Resolved - Sep Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 312 hours spilling →	Bartley Water	48	312	up 78%	84%
Grayswood WwTW Inlet overflow at sewage works Sewage works Grayswood Company site name GRAYSWOOD CSO - 115984 EA ID / permit SWS00364 · A01480 Outlet location SU9235034430 (OS grid reference) · View on Apple Maps WFD catchment Loxwood/Chiddingfold Trib (GB107041017960) 2024 spills / hours 57 / 376 Long-term average 55.2 spills a year (monitored since 2016) High-spill reason (company) Not asset maintenance - Hydraulic capacity Investigation Env Act (SODRP) investigation ongoing, UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 309 hours spilling →	Two Tribs of River Chidd	52	309	down 9%	100%
Hamstreet WwTW Storm tank at sewage works Sewage works Hamstreet Company site name HAMSTREET SSO - 116015 EA ID / permit SWS00390 · W00021 Outlet location TQ9986033420 (OS grid reference) · View on Apple Maps WFD catchment Romney Marsh between Appledore and West Hythe (GB107040019700) 2024 spills / hours 66 / 798 Long-term average 48.3 spills a year (monitored since 2018) High-spill reason (company) Not asset maintenance - Hydraulic capacity Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 307 hours spilling →	Speringbrook Sewer	34	307	down 48%	100%
NO1 CSO Station Rd Robertsbridge Overflow on sewer network Company site name STATION ROAD ROBERTSBRIDGE NO 1 CSO - 103290 EA ID / permit SWS00605 · K02081 Outlet location TQ7364023540 (OS grid reference) · View on Apple Maps WFD catchment Glottenham Stream upstream of Robertsbridge (GB107040013430) 2024 spills / hours 100 / 792 Long-term average 72.3 spills a year (monitored since 2016) High-spill reason (company) Performance - GW inundation Investigation Env Act (SODRP) investigation ongoing, UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 304 hours spilling →	Freshwater River	71	304	down 29%	100%
Corporation St Rochester No 2 CSO Overflow on sewer network Company site name CORPORATION STREET ROCHESTER NO 2 CSO - 108620 EA ID / permit SWS00203 · A00967 Outlet location TQ7480068270 (OS grid reference) · View on Apple Maps WFD catchment MEDWAY (GB530604002300) 2024 spills / hours 0 / 0.0 Long-term average 6.0 spills a year (monitored since 2016) Monitor below 90% Sensor failure / issue · Resolved - Nov Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 296 hours spilling →	Tidal Estaury of River Medway	21	296	up from 0	69%
Partridge Place Turners Hill Ceo Storm discharge at pumping station Company site name PARTRIDGE PLACE TURNERS HILL CEO - 108304 EA ID / permit SWS00645 · A00297 Outlet location TQ3521036580 (OS grid reference) · View on Apple Maps WFD catchment Medway at Weir Wood (GB106040018070) 2024 spills / hours 61 / 467 Long-term average 39.8 spills a year (monitored since 2019) High-spill reason (company) Not asset maintenance - Hydraulic capacity Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 294 hours spilling →	Trib of the River Medway	34	294	down 44%	100%
Robertsbridge WwTW Storm tank at sewage works Sewage works Robertsbridge Company site name ROBERTSBRIDGE SSO - 115809 EA ID / permit SWS00711 · A00195 Outlet location TQ7432023510 (OS grid reference) · View on Apple Maps WFD catchment Lower Rother from Robertsbridge to Iden (GB107040013640) 2024 spills / hours 62 / 718 Long-term average 32.3 spills a year (monitored since 2016) Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 292 hours spilling →	Abbey Petty Sewer	30	292	down 52%	100%
Scaynes Hill WwTW Storm tank at sewage works Sewage works Scaynes Hill Company site name SCAYNES HILL SSO - 115742 EA ID / permit SWS00746 · W00008 Outlet location TQ3791024640 (OS grid reference) · View on Apple Maps WFD catchment Middle Ouse (GB107041012710) 2024 spills / hours 58 / 636 Long-term average 39.1 spills a year (monitored since 2016) High-spill reason (company) Not asset maintenance - Hydraulic capacity Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 291 hours spilling →	River Ouse	32	291	down 45%	100%
Rear of 35 Pelham Road Overflow on sewer network Company site name PELHAM ROAD LINDFIELD CSO - 108308 EA ID / permit SWS00698 · W00403 Outlet location TQ3411024670 (OS grid reference) · View on Apple Maps WFD catchment Scrase Bridge Stream at Haywards Heath (GB107041012680) 2024 spills / hours 96 / 988 Long-term average 72.0 spills a year (monitored since 2019) High-spill reason (company) Not asset maintenance - Hydraulic capacity Investigation Env Act (SODRP) investigation ongoing, UWWTR investigation ongoing Improvement Env Act (SODRP) improvement ongoing Volume & pollution Estimate from 287 hours spilling →	Freshwater River	50	287	down 48%	100%
Peel Common WwTW Storm tank at sewage works Sewage works Peel Common Company site name PEEL COMMON SSO - 115425 EA ID / permit SWS00651 · W00131 Outlet location SZ5810097700 (OS grid reference) · View on Apple Maps WFD catchment Solent (GB650705150000) Bathing water Lee-on-Solent; Stokes Bay Shellfish water Central Solent; Cowes and Medina; Ryde; Spithead and Stokes Bay 2024 spills / hours 78 / 995 Long-term average 58.3 spills a year (monitored since 2016) High-spill reason (company) Performance - GW inundation Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 283 hours spilling →	The Solent	37	283	down 53%	100%
Mill Lane Kennington Ceo Storm discharge at pumping station Company site name MILL LANE KENNINGTON CEO - 108684 EA ID / permit SWS00571 · A00738 Outlet location TR0319045370 (OS grid reference) · View on Apple Maps WFD catchment Great Stour between Ashford and Wye (GB107040019741) 2024 spills / hours 53 / 748 Long-term average 34.6 spills a year (monitored since 2018) Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 282 hours spilling →	Mill Stream	24	282	down 55%	100%
Calbourne WwTW Storm tank at sewage works Sewage works Calbourne Company site name CALBOURNE SSO - 115924 EA ID / permit SWS00133 · A00191 Outlet location SZ4201086740 (OS grid reference) · View on Apple Maps WFD catchment Caul Bourne (GB107101006020) Shellfish water Newtown 2024 spills / hours 112 / 1,954 Long-term average 63.1 spills a year (monitored since 2017) High-spill reason (company) Performance - GW inundation Investigation Env Act (SODRP) investigation ongoing, UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 280 hours spilling →	Caul Bourne	34	280	down 70%	100%
Wivelsfield Ceo Storm discharge at pumping station Company site name WIVELSFIELD CEO - 108387 EA ID / permit SWS00962 · A01041 Outlet location TQ3559019740 (OS grid reference) · View on Apple Maps WFD catchment Longford Stream (GB107041012960) 2024 spills / hours 27 / 239 Long-term average 13.0 spills a year (monitored since 2017) Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 279 hours spilling →	The Longford Ditch	28	279	up 4%	100%
Warnham Wwps Storm discharge at pumping station Company site name WARNHAM SSO - 115747 EA ID / permit SWS00910 · A01204 Outlet location TQ1671034050 (OS grid reference) · View on Apple Maps WFD catchment Boldings Brook (GB107041012910) 2024 spills / hours 41 / 383 Long-term average 49.2 spills a year (monitored since 2016) Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 276 hours spilling →	Boldings Brook, Trib of R.Arun	29	276	down 29%	100%
Liss Wastewater Treatment Works Storm tank at sewage works Sewage works Liss Company site name LISS SSO - 115920 EA ID / permit SWS00510 · W00401 Outlet location SU7720026990 (OS grid reference) · View on Apple Maps WFD catchment Western Rother (Upstream Petersfield) (GB107041012840) 2024 spills / hours 79 / 878 Long-term average 56.8 spills a year (monitored since 2019) Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 271 hours spilling →	River Rother & Batt'S Brook	25	271	down 68%	100%
Horsham WwTW Storm tank at sewage works Sewage works Horsham Company site name HORSHAM NEW SSO - 115826 EA ID / permit SWS00449 · A00152 Outlet location TQ1485029730 (OS grid reference) · View on Apple Maps WFD catchment R. Arun Horsham (GB107041012310) 2024 spills / hours 45 / 625 Long-term average 33.5 spills a year (monitored since 2017) Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 268 hours spilling →	Tributary of the River Arun	27	268	down 40%	100%
Frant S.T.W. Storm tank at sewage works Sewage works Frant S T W Company site name FRANT SSO - 115850 EA ID / permit SWS00332 · W00019 Outlet location TQ6035033650 (OS grid reference) · View on Apple Maps WFD catchment Bartley Mill Stream (GB106040018240) 2024 spills / hours 97 / 853 Long-term average 55.1 spills a year (monitored since 2016) High-spill reason (company) Performance - GW inundation Investigation Env Act (SODRP) investigation ongoing, UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 264 hours spilling →	The River Teise	45	264	down 54%	100%
Hawkhurst South WwTW Storm tank at sewage works Sewage works Hawkhurst South Company site name HAWKHURST SOUTH SSO - 115732 EA ID / permit SWS00409 · W00540 Outlet location TQ7688029340 (OS grid reference) · View on Apple Maps WFD catchment Kent Ditch (GB107040013600) 2024 spills / hours 74 / 713 Long-term average 57.7 spills a year (monitored since 2016) High-spill reason (company) Performance - GW inundation Investigation Env Act (SODRP) investigation ongoing, UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 259 hours spilling →	The Hawkhurst South Stream	41	259	down 45%	100%
Wisborough Green WwTW Storm tank at sewage works Sewage works Wisborough Green Company site name WISBOROUGH GREEN SSO - 115793 EA ID / permit SWS00958 · A01206 Outlet location TQ0535025390 (OS grid reference) · View on Apple Maps WFD catchment R. Kird (GB107041012300) 2024 spills / hours 40 / 457 Long-term average 18.1 spills a year (monitored since 2016) Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 259 hours spilling →	River Kird	25	259	down 38%	100%
Newhaven WwTW Inlet overflow at sewage works Sewage works Newhaven Company site name NEWHAVEN MAIN CSO - 116065 EA ID / permit SWS00600 · A00755 Outlet location TV4594097500 (OS grid reference) · View on Apple Maps WFD catchment Sussex (GB640704540003) Bathing water Seaford 2024 spills / hours 129 / 870 Long-term average 95.7 spills a year (monitored since 2016) High-spill reason (company) Not asset maintenance - Hydraulic capacity Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 257 hours spilling →	English Channel	72	257	down 44%	100%
Military Road Iden CSO Storm discharge at pumping station Company site name MILITARY ROAD IDEN CSO - 108286 EA ID / permit SWS00567 · A01064 Outlet location TQ9302021820 (OS grid reference) · View on Apple Maps WFD catchment ROTHER (GB540704016100) 2024 spills / hours 68 / 810 Long-term average 32.6 spills a year (monitored since 2018) High-spill reason (company) Not asset maintenance - Hydraulic capacity Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 256 hours spilling →	Tidal River Rother	43	256	down 37%	91%
Tinkers Lane PS, Ticehurst Storm discharge at pumping station Company site name TINKERS LANE TICEHURST CSO - 108363 EA ID / permit SWS00875 · A01141 Outlet location TQ6926031070 (OS grid reference) · View on Apple Maps WFD catchment Teise at Bewl (GB106040018500) 2024 spills / hours 68 / 777 Long-term average 51.6 spills a year (monitored since 2016) High-spill reason (company) Performance - GW inundation Investigation Env Act (SODRP) investigation ongoing, UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 255 hours spilling →	Unnamed Trib of Bewl Water	38	255	down 44%	100%
Hazelden PS CSO Storm discharge at pumping station Company site name HAZELDENE LANE NEWICK CEO - 108246 EA ID / permit SWS00413 · A01071 Outlet location TQ3988021320 (OS grid reference) · View on Apple Maps WFD catchment Middle Ouse (GB107041012710) 2024 spills / hours 71 / 627 Long-term average 35.9 spills a year (monitored since 2016) High-spill reason (company) Performance - GW inundation Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 255 hours spilling →	Freshwater River	35	255	down 51%	100%
Canadia CSO Storm discharge at pumping station Company site name CANADIA CSO - 108200 EA ID / permit SWS00136 · W00591 Outlet location TQ7445017680 (OS grid reference) · View on Apple Maps WFD catchment Line (GB107040013540) 2024 spills / hours 76 / 547 Long-term average 54.5 spills a year (monitored since 2019) High-spill reason (company) Not asset maintenance - Hydraulic capacity Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 254 hours spilling →	Trib of the River Line	40	254	down 47%	100%
Motney Hill WwTW Inlet overflow at sewage works Sewage works Motney Hill Company site name MOTNEY HILL NO.1 SSO - 115421 EA ID / permit SWS00586 · A00720 Outlet location TQ8315069000 (OS grid reference) · View on Apple Maps WFD catchment MEDWAY (GB530604002300) 2024 spills / hours 81 / 339 Long-term average 59.6 spills a year (monitored since 2016) High-spill reason (company) Not asset maintenance - Hydraulic capacity Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 254 hours spilling →	The Medway Estaury	62	254	down 23%	97%
Stubbs Lane Brede WwTW Storm tank at sewage works Sewage works Stubbs Lane Brede Company site name STUBBS LANE BREDE SSO - 115757 EA ID / permit SWS00838 · A00591 Outlet location TQ8297018820 (OS grid reference) · View on Apple Maps WFD catchment Brede between Battle and Winchelsea (GB107040013550) 2024 spills / hours 85 / 1,165 Long-term average 46.3 spills a year (monitored since 2016) Investigation Env Act (SODRP) investigation ongoing, UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 251 hours spilling →	Tributary of River Brede	29	251	down 66%	99%
Chequers Pumping Station Storm discharge at pumping station Company site name CHEQUERS LAMBERHURST CEO - 108604 EA ID / permit SWS00167 · A00598 Outlet location TQ6774036230 (OS grid reference) · View on Apple Maps WFD catchment Teise (GB106040018520) 2024 spills / hours 54 / 350 Long-term average 34.2 spills a year (monitored since 2019) High-spill reason (company) Not asset maintenance - Hydraulic capacity Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 244 hours spilling →	Freshwater River	34	244	down 37%	100%
Mill Corner Northiam WwTW Inlet overflow at sewage works Sewage works Mill Corner Northiam Company site name MILL CORNER NORTHIAM CSO - 116064 EA ID / permit SWS00568 · W00104 Outlet location TQ8280023710 (OS grid reference) · View on Apple Maps WFD catchment Lower Rother from Robertsbridge to Iden (GB107040013640) 2024 spills / hours 58 / 429 Long-term average 59.2 spills a year (monitored since 2016) High-spill reason (company) Not asset maintenance - Hydraulic capacity Investigation Env Act (SODRP) investigation ongoing, UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 242 hours spilling →	Tributary of River Rother	40	242	down 31%	100%
Headcorn Waste Water Station Storm discharge at pumping station Company site name MOAT ROAD HEADCORN SSO - 115965 EA ID / permit SWS00414 · A01116 Outlet location TQ8291044130 (OS grid reference) · View on Apple Maps WFD catchment Beult (GB106040018270) 2024 spills / hours 48 / 465 Long-term average 34.6 spills a year (monitored since 2016) Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 241 hours spilling →	Freshwater River	29	241	down 40%	100%
Willingdon Ceo Overflow on sewer network Company site name WILLINGDON NO 1 CSO - 108383 EA ID / permit SWS00950 · A01442B Outlet location TQ5952003930 (OS grid reference) · View on Apple Maps WFD catchment Langley Sewer at Eastbourne (GB107041006650) 2024 spills / hours 94 / 654 Long-term average 68.7 spills a year (monitored since 2018) High-spill reason (company) Not asset maintenance - Hydraulic capacity Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 241 hours spilling →	New Stream Ditch	52	241	down 45%	99%
Wellow Mill Wps Storm discharge at pumping station Company site name WELLOW MILL BLACKHILL CEO - 108499 EA ID / permit SWS00915 · A00641 Outlet location SU3116019560 (OS grid reference) · View on Apple Maps WFD catchment Blackwater (Test and Itchen) (GB107042016791) 2024 spills / hours 63 / 755 Long-term average 41.4 spills a year (monitored since 2016) Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 239 hours spilling →	River Blackwater	25	239	down 60%	100%
Thornham WwTW Storm tank at sewage works Sewage works Thornham Company site name THORNHAM SSO - 115369 EA ID / permit SWS00872 · W00354 Outlet location SU7582004730 (OS grid reference) · View on Apple Maps WFD catchment Great Deep (GB610070074000) Shellfish water Chichester Harbour (Chichester Channel); Chichester Harbour (Emsworth Channel); Chichester Harbour (Thornham Channel); Langstone Harbour 2024 spills / hours 52 / 602 Long-term average 33.8 spills a year (monitored since 2016) Investigation UWWTR investigation ongoing Improvement Env Act (SODRP) improvement ongoing, Bathing Water and/or Shellfish Water improvement ongoing Volume & pollution Estimate from 237 hours spilling →	Chichester Hbr via Little Deep	21	237	down 60%	100%
Forest Row WwTW Storm tank at sewage works Sewage works Forest Row Company site name FOREST ROW SSO - 115718 EA ID / permit SWS00324 · W00041 Outlet location TQ4555035580 (OS grid reference) · View on Apple Maps WFD catchment Medway at Weir Wood (GB106040018070) 2024 spills / hours 83 / 1,144 Long-term average 37.6 spills a year (monitored since 2016) Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 233 hours spilling →	River Medway	20	233	down 76%	97%
Coldharbour Lane CSO Overflow on sewer network Company site name COLDHARBOUR LANE HILDENBOROUGH REAR 30 CSO - 108612 EA ID / permit SWS00189 · A00415 Outlet location TQ5755049110 (OS grid reference) · View on Apple Maps WFD catchment Hilden Brook (GB106040018170) 2024 spills / hours 0 / 0.0 Long-term average 9.5 spills a year (monitored since 2023) Monitor below 90% Sensor failure / issue · Resolved - Nov Investigation Env Act (SODRP) investigation ongoing Improvement Env Act (SODRP) improvement ongoing Volume & pollution Estimate from 233 hours spilling →	The Hilden Brook	19	233	up from 0	86%
Chale WwTW Storm tank at sewage works Sewage works Chale Company site name CHALE SSO - 115937 EA ID / permit SWS00155 · W00155 Outlet location SZ4905080680 (OS grid reference) · View on Apple Maps WFD catchment R. Medina (GB107101005990) 2024 spills / hours 65 / 959 Long-term average 25.2 spills a year (monitored since 2016) Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 231 hours spilling →	River Medina	29	231	down 55%	100%
Slowhill Copse WwTW Storm tank at sewage works Sewage works Slowhill Copse Company site name SLOWHILL COPSE MARCHWOOD SSO - 115438 EA ID / permit SWS00782 · W00288 Outlet location SU3862011350 (OS grid reference) · View on Apple Maps WFD catchment SOUTHAMPTON WATER (GB520704202800) Shellfish water Southampton Water 2024 spills / hours 84 / 970 Long-term average 52.0 spills a year (monitored since 2016) Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 229 hours spilling →	Southampton Water	22	229	down 74%	100%
Eastbourne WwTW Inlet overflow at sewage works Sewage works Eastbourne Company site name EASTBOURNE CSO - 115457 EA ID / permit SWS00273 · A01106 Outlet location TQ6430000900 (OS grid reference) · View on Apple Maps WFD catchment Sussex East (GB640704540002) 2024 spills / hours 85 / 609 Long-term average 61.6 spills a year (monitored since 2017) High-spill reason (company) Not asset maintenance - Hydraulic capacity Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 229 hours spilling →	The English Channel	54	229	down 36%	100%
Romsey WwTW Storm tank at sewage works Sewage works Romsey Company site name ROMSEY SSO - 115431 EA ID / permit SWS00718 · W00219 Outlet location SU3495020620 (OS grid reference) · View on Apple Maps WFD catchment R. Test (GB107042016460) 2024 spills / hours 68 / 959 Long-term average 26.0 spills a year (monitored since 2016) Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 228 hours spilling →	The River Test	17	228	down 75%	90%
High Street Pumping Station Storm discharge at pumping station Company site name HIGH STREET COWES CEO - 108528 EA ID / permit SWS00428 · A00023 Outlet location SZ4968096220 (OS grid reference) · View on Apple Maps WFD catchment Solent (GB650705150000) Bathing water Cowes; Gurnard Shellfish water Central Solent; Cowes and Medina; Lepe Middle Bank; Stanswood Bay 2024 spills / hours 85 / 214 Long-term average 42.7 spills a year (monitored since 2019) High-spill reason (company) Data collection - Tidal / river inundation Investigation UWWTR investigation ongoing Improvement No improvement action in reporting period Volume & pollution Estimate from 226 hours spilling →	River Medina Estuary	61	226	down 28%	100%

Sewage treatment works

Storm tanks and inlet overflows at each Southern 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.