Storm overflow register · 2025 annual return

Dwr Cymru Welsh Water storm overflows, 2025

Dwr Cymru Welsh Water reported 122 storm overflows in England for 2025. Together they recorded 2,843 spills over 14,525 hours, an average of 23.3 spills per overflow against 20.4 across England. That ranks 7 of 10 companies, where 1 is the fewest spills per overflow. Counting the same overflows in both years, spills were down 46% on 2024.

9 overflows did not spill · 9 spilled more than 60 times · 117 had monitors working for 90% of the year or more · 26 sewage treatment works with overflows

Hours spilling by month, 2025

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

All Dwr Cymru Welsh 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
West of Wealstone Lane CSO Overflow on sewer network Company site name Wealstone Lane CSO EA ID / permit DCW00120 · CM0116401 Outlet location SJ4029168077 (OS grid reference) · View on Apple Maps WFD catchment Finchetts Gutter (GB111067056930) 2024 spills / hours 21 / 46 Long-term average 16.3 spills a year (monitored since 2017) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 51 hours spilling →	Bache Brook	27	51	up 29%	95%
Belmont Roundabout CSO Overflow on sewer network Company site name Hereford Belmont Roundabout EA ID / permit DCW00016 · AN0078601 Outlet location SO5072239508 (OS grid reference) · View on Apple Maps WFD catchment Wye - Bredwardine Br to Hampton Bishop (GB109055037113) 2024 spills / hours 28 / 223 Long-term average 18.3 spills a year (monitored since 2016) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 51 hours spilling →	River Wye	9	51	down 68%	94%
Bargates No 2174 CSO Overflow on sewer network Company site name Whitchurch (Shropshire) Park Avenue Mh38 EA ID / permit DCW00014 · CM0200301 Outlet location SJ5399141827 (OS grid reference) · View on Apple Maps WFD catchment Wych Upper (Worthenbury Upper) (GB111067052200) 2024 spills / hours 17 / 50 Long-term average 36.3 spills a year (monitored since 2017) High-spill reason (company) Not Applicable - Ongoing investigation Monitor below 90% Installation set-up/design issue · Resolved - Mar Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 49 hours spilling →	Tributary of Red Brook	46	49	up 171%	75%
Saughall Village CSO Overflow on sewer network Company site name Chester Saughall Village The Poplars Nra EA ID / permit DCW00102 · CM0059101 Outlet location SJ3610069257 (OS grid reference) · View on Apple Maps WFD catchment Garden City Drain (GB111067056960) 2024 spills / hours 31 / 117 Long-term average 18.4 spills a year (monitored since 2017) Monitor below 90% Comms failure / issue · Not Applicable - Ongoing investigation Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 41 hours spilling →	Tributary of the River Dee	9	41	down 71%	89%
Grosvenor Bridge CSO Overflow on sewer network Company site name Chester Grosvenor Bridge EA ID / permit DCW00056 · CG0355401 Outlet location SJ4001065463 (OS grid reference) · View on Apple Maps WFD catchment Dee (N. Wales) (GB531106708200) 2024 spills / hours 25 / 56 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 39 hours spilling →	River Dee	13	39	down 48%	100%
Chester Trooper Inn CSO Overflow on sewer network Company site name Pepper Street CSO EA ID / permit DCW00023 · CM0184601 Outlet location SJ4356365617 (OS grid reference) · View on Apple Maps WFD catchment Finchetts Gutter (GB111067056930) 2024 spills / hours 37 / 71 Long-term average 31.4 spills a year (monitored since 2017) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 36 hours spilling →	Bache Brook	14	36	down 62%	99%
Crane Street CSO Overflow on sewer network Company site name Chester Crane St Waste Ground Nr Manweb EA ID / permit DCW00030 · CM0167501 Outlet location SJ3980966444 (OS grid reference) · View on Apple Maps WFD catchment Dee (N. Wales) (GB531106708200) 2024 spills / hours 53 / 122 Long-term average 28.6 spills a year (monitored since 2017) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 35 hours spilling →	River Dee	20	35	down 62%	96%
Greyfriars Bridge CSO Overflow on sewer network Company site name Hereford Beneath Greyfriars Bridge EA ID / permit DCW00055 · AN0077101 Outlet location SO5073039570 (OS grid reference) · View on Apple Maps WFD catchment Wye - Bredwardine Br to Hampton Bishop (GB109055037113) 2024 spills / hours 41 / 245 Long-term average 47.1 spills a year (monitored since 2017) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 32 hours spilling →	River Wye	15	32	down 63%	93%
Kington Wastewater Treatment Works Storm tank at sewage works Sewage works Kington Company site name Kington EA ID / permit DCW00068 · AL1001501 Outlet location SO3068757081 (OS grid reference) · View on Apple Maps WFD catchment Arrow - conf Gilwern Bk to conf R Lugg (GB109055041840) 2024 spills / hours 37 / 78 Long-term average 28.2 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 31 hours spilling →	The Back Brook	17	31	down 54%	100%
Fownhope Sewage Treatment Works CSO Inlet overflow at sewage works Sewage works Fownhope Company site name Fownhope EA ID / permit DCW00048 · AN0390901 Outlet location SO5756534007 (OS grid reference) · View on Apple Maps WFD catchment Wye - Hampton Bishop to conf Kerne Br (GB109055037112) 2024 spills / hours 27 / 46 Long-term average 5.1 spills a year (monitored since 2016) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 30 hours spilling →	River Wye	10	30	down 63%	100%
Wyebank Rd CSO Overflow on sewer network Company site name Wyebank Road CSO, Chepstow EA ID / permit DCW00124 · AN0035401 Outlet location ST5406093701 (OS grid reference) · View on Apple Maps WFD catchment Wye (GB530905415406) 2024 spills / hours 32 / 26 Long-term average 26.0 spills a year (monitored since 2017) Monitor below 90% Comms failure / issue · Resolved - Aug Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 30 hours spilling →	River Wye	28	30	down 13%	79%
St.Martin'S Combined Sewer Overflow Overflow on sewer network Company site name St Martins B5069 Opp Village Hall Nra EA ID / permit DCW00111 · CM0081201 Outlet location SJ3127335740 (OS grid reference) · View on Apple Maps WFD catchment Perry - source to conf Common Bk (GB109054055010) 2024 spills / hours 18 / 3.5 Long-term average 11.0 spills a year (monitored since 2017) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 29 hours spilling →	Tributary of Morlais Brook	9	29	down 50%	100%
St Martins SPS Nefod Oswestry Storm discharge at pumping station Company site name St Martins EA ID / permit DCW00110 · CM0230701 Outlet location SJ3092036230 (OS grid reference) · View on Apple Maps WFD catchment Morlas Brook (GB111067051600) 2024 spills / hours 7 / 53 Long-term average 6.3 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 29 hours spilling →	Morlais Brook	5	29	down 29%	100%
Boathouse Inn CSO Overflow on sewer network Company site name The Boat House CSO, The Groves, Chester EA ID / permit DCW00017 · NPSWQD005835 Outlet location SJ4115666091 (OS grid reference) · View on Apple Maps WFD catchment Dee - Chester Weir to Ceiriog (GB111067057080) 2024 spills / hours 32 / 56 Long-term average 27.5 spills a year (monitored since 2017) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 29 hours spilling →	River Dee	23	29	down 28%	100%
Wilton Sewage Pumping Station Storm discharge at pumping station Company site name Wilton SPS EA ID / permit DCW00123 · AN0372801 Outlet location SO5844823796 (OS grid reference) · View on Apple Maps WFD catchment Wye - Hampton Bishop to conf Kerne Br (GB109055037112) 2024 spills / hours 49 / 322 Long-term average 8.8 spills a year (monitored since 2016) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 27 hours spilling →	River Wye	4	27	down 92%	100%
Jubilee Park No 3175 CSO Overflow on sewer network Company site name Whitchurch (Shropshire) Jubilee Park EA ID / permit DCW00065 · CG0342701 Outlet location SJ5398441480 (OS grid reference) · View on Apple Maps WFD catchment Wych Upper (Worthenbury Upper) (GB111067052200) 2024 spills / hours 17 / 47 Long-term average 14.8 spills a year (monitored since 2017) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 25 hours spilling →	Staggs Brook	14	25	down 18%	100%
Eign 1B Combined Sewer Overflow Inlet overflow at sewage works Sewage works Eign 1B Combined Sewer Company site name Hereford Eign EA ID / permit DCW00046 · AN0315201 Outlet location SO5213038850 (OS grid reference) · View on Apple Maps WFD catchment Wye - Bredwardine Br to Hampton Bishop (GB109055037113) 2024 spills / hours 25 / 82 Long-term average 12.1 spills a year (monitored since 2016) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 24 hours spilling →	River Wye	8	24	down 68%	100%
Saughall Seahill Road PS CSO Storm discharge at pumping station Company site name Chester Seahill EA ID / permit DCW00101 · NPSWQD005510 Outlet location SJ3560069649 (OS grid reference) · View on Apple Maps WFD catchment Garden City Drain (GB111067056960) 2024 spills / hours 15 / 63 Long-term average 11.0 spills a year (monitored since 2018) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 23 hours spilling →	Garden City Drain	11	23	down 27%	100%
Gladstone Road CSO Overflow on sewer network Company site name Gladstone Road Neston EA ID / permit DCW00051 · CG0359801 Outlet location SJ2940777342 (OS grid reference) · View on Apple Maps WFD catchment Tidal Dee (GB531106708200) Shellfish water Dee (East) 2024 spills / hours 17 / 25 Long-term average 8.0 spills a year (monitored since 2015) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 22 hours spilling →	Stanney Brook	8	22	down 53%	100%
Brampton Street CSO Overflow on sewer network Company site name Ross-On-Wye Brampton Street EA ID / permit DCW00018 · AN0014601 Outlet location SO6012124462 (OS grid reference) · View on Apple Maps WFD catchment Rudhall Bk - source to conf R Wye (GB109055029730) 2024 spills / hours 51 / 42 Long-term average 49.0 spills a year (monitored since 2018) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 22 hours spilling →	Rudhall Brook	27	22	down 47%	98%
CSO at Tilston Sewage Treatment Works Inlet overflow at sewage works Sewage works Tilston Company site name Tilston EA ID / permit DCW00039 · CM0021602 Outlet location SJ4547551688 (OS grid reference) · View on Apple Maps WFD catchment Aldford Brook (GB111067052120) 2024 spills / hours 35 / 103 Long-term average 35.4 spills a year (monitored since 2017) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 22 hours spilling →	Carden Brook	14	22	down 60%	100%
Manhole 50 Combined Sewer Overflow Overflow on sewer network Company site name Kington Bridge Street No 32 Garden Mh 50 EA ID / permit DCW00075 · AN0125801 Outlet location SO2993856480 (OS grid reference) · View on Apple Maps WFD catchment Arrow - conf Gladestry Bk to conf Gilwern Bk (GB109055036620) 2024 spills / hours 5 / 23 Long-term average 4.0 spills a year (monitored since 2017) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 20 hours spilling →	River Arrow	4	20	down 20%	100%
Unknown Overflow on sewer network Company site name Plough Lane Hereford CSO EA ID / permit DCW00031 · Unpermitted Outlet location SO4973939163 (OS grid reference) · View on Apple Maps WFD catchment Wye - Bredwardine Br to Hampton Bishop (GB109055037113) 2024 spills / hours 12 / 3.8 Long-term average 26.0 spills a year (monitored since 2024) High-spill reason (company) Not Applicable - Ongoing investigation Investigation UWWTR investigation completed Improvement No improvement action in reporting period Volume & pollution Estimate from 19 hours spilling →	River Wye	40	19	up 233%	99%
Christleton Whitchurch Road PS Storm discharge at pumping station Company site name Chester Whitchurch Road SPS EA ID / permit DCW00027 · CM0185501 Outlet location SJ4418065009 (OS grid reference) · View on Apple Maps WFD catchment Finchetts Gutter (GB111067056930) 2024 spills / hours 12 / 5.3 Long-term average 12.7 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 18 hours spilling →	Caldy Brook	10	18	down 17%	100%
5 Dee Cottages CSO Overflow on sewer network Company site name Neston Parkgate The Parade 5 Dee Cotts EA ID / permit DCW00011 · CM0170101 Outlet location SJ2760178628 (OS grid reference) · View on Apple Maps WFD catchment MERSEY (GB531206908100) Shellfish water Dee (East) 2024 spills / hours 16 / 26 Long-term average 7.0 spills a year (monitored since 2015) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 17 hours spilling →	Dee Estuary	6	17	down 63%	100%
Chirk Bank PS Storm discharge at pumping station Company site name Chirk Bank EA ID / permit DCW00125 · CM0230601 Outlet location SJ2944037370 (OS grid reference) · View on Apple Maps WFD catchment Ceiriog - confluence Dee to Teirw (GB111067051910) 2024 spills / hours 12 / 152 Long-term average 44.8 spills a year (monitored since 2018) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 17 hours spilling →	River Ceiriog	3	17	down 75%	100%
Heswall Storage Tank CSO Heswall Overflow on sewer network Company site name Heswall Gayton Riverbank Road Mh466 Nra EA ID / permit DCW00060 · CG0355101 Outlet location SJ2619080420 (OS grid reference) · View on Apple Maps WFD catchment MERSEY (GB531206908100) Shellfish water Dee (East) 2024 spills / hours 22 / 2.5 Long-term average 13.1 spills a year (monitored since 2015) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 17 hours spilling →	Estuarial Waters of the River Dee	6	17	down 73%	100%
Smallbrook No 2177 CSO Overflow on sewer network Company site name Whitchurch (Shropshire) Smallbrook Road EA ID / permit DCW00106 · CM0200601 Outlet location SJ5368841684 (OS grid reference) · View on Apple Maps WFD catchment Wych Upper (Worthenbury Upper) (GB111067052200) 2024 spills / hours 34 / 50 Long-term average 19.3 spills a year (monitored since 2017) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 15 hours spilling →	Staggs Brook	18	15	down 47%	99%
Great Hough Brook CSO Overflow on sewer network Company site name Lydbrook SPS EA ID / permit DCW00053 · AN0014901 Outlet location SO5955416816 (OS grid reference) · View on Apple Maps WFD catchment Wye - conf Walford Bk to Bigsweir Br (GB109055037111) 2024 spills / hours 23 / 83 Long-term average 21.6 spills a year (monitored since 2016) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 14 hours spilling →	Tributary of the River Wye	10	14	down 57%	100%
CSO at Newland STW Storm tank at sewage works Sewage works Newland Company site name Newland (Nr Coleford) EA ID / permit DCW00034 · AS1003301 Outlet location SO5511108949 (OS grid reference) · View on Apple Maps WFD catchment Valley Bk - source to conf R Wye (GB109055029670) 2024 spills / hours 17 / 49 Long-term average 36.0 spills a year (monitored since 2017) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 13 hours spilling →	Valley Brook	7	13	down 59%	97%
Malpas Sewage Treatment Works Inlet overflow at sewage works Sewage works Malpas Company site name Malpas Whitchurch Road EA ID / permit DCW00073 · CM0084901 Outlet location SJ4934446923 (OS grid reference) · View on Apple Maps WFD catchment Bradley Brook (GB111067052230) 2024 spills / hours 34 / 47 Long-term average 16.5 spills a year (monitored since 2017) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 13 hours spilling →	Unnamed Tributary of Wych Brook	16	13	down 53%	100%
3 Elms Road Combined Sewer Overflow Overflow on sewer network Company site name Hereford Three Elms Road/Ferndale Road EA ID / permit DCW00010 · AN0078801 Outlet location SO4948140832 (OS grid reference) · View on Apple Maps WFD catchment Yazor Bk - source to conf R Wye (GB109055037040) 2024 spills / hours 10 / 3.8 Long-term average 13.1 spills a year (monitored since 2017) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 12 hours spilling →	Yazor Brook	24	12	up 140%	98%
Cawdor Arch Combined Sewer Overflow Overflow on sewer network Company site name Ross-On-Wye Cawdor Arch EA ID / permit DCW00020 · AN0014501 Outlet location SO5993024610 (OS grid reference) · View on Apple Maps WFD catchment Rudhall Bk - source to conf R Wye (GB109055029730) 2024 spills / hours 54 / 31 Long-term average 23.9 spills a year (monitored since 2016) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 10 hours spilling →	Rudhall Brook	12	10	down 78%	100%
Cannop Road Sewage Pumping Station Storm discharge at pumping station Company site name Cannop Road (Nr Forest Of Dean) EA ID / permit DCW00019 · NPSWQD010007 Outlet location SO5934011362 (OS grid reference) · View on Apple Maps WFD catchment Cannop Bk - source to R Severn Estuary (GB109054032640) 2024 spills / hours 9 / 24 Long-term average 6.0 spills a year (monitored since 2017) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 7.8 hours spilling →	Cannop Brook	7	7.8	down 22%	100%
Unknown Overflow on sewer network Company site name Eign Road CSO, Hereford EA ID / permit DCW00004 · Unpermitted Outlet location SO5221739259 (OS grid reference) · View on Apple Maps WFD catchment Yazor Bk - source to conf R Wye (GB109055037040) 2024 spills / hours 23 / 91 Long-term average 22.8 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 6.5 hours spilling →	Yazor Brook	3	6.5	down 87%	100%
CSO at Bromyard WwTW Inlet overflow at sewage works Sewage works Bromyard Company site name Bromyard EA ID / permit DCW00032 · AL1000602 Outlet location SO6583954455 (OS grid reference) · View on Apple Maps WFD catchment Frome - conf Tedstone Bk to conf R Lugg (GB109055036780) 2024 spills / hours 9 / 17 Long-term average 10.5 spills a year (monitored since 2017) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 6.3 hours spilling →	River Frome	4	6.3	down 56%	93%
Saltney Sewerage Chester Street PS Storm discharge at pumping station Company site name Chester Chester Street EA ID / permit DCW00099 · CM0020201 Outlet location SJ3862265428 (OS grid reference) · View on Apple Maps WFD catchment MERSEY (GB531206908100) 2024 spills / hours 23 / 32 Long-term average 24.2 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 6.3 hours spilling →	River Dee	6	6.3	down 74%	100%
Three Elms Road CSO Overflow on sewer network Company site name Hereford Three Elms Road/Oatfield Close EA ID / permit DCW00118 · AN0078901 Outlet location SO4920040900 (OS grid reference) · View on Apple Maps WFD catchment Yazor Bk - source to conf R Wye (GB109055037040) 2024 spills / hours 24 / 19 Long-term average 14.3 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 6.0 hours spilling →	Yazor Brook	14	6.0	down 42%	100%
Unknown Overflow on sewer network Company site name Park West CSO Heswall EA ID / permit DCW00006 · Unpermitted Outlet location SJ2590880903 (OS grid reference) · View on Apple Maps WFD catchment Dee (N. Wales) (GB531106708200) Shellfish water Dee (East) 2024 spills / hours 11 / 5.3 Long-term average 8.2 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 6.0 hours spilling →	River Dee	6	6.0	down 45%	100%
Grandstand Road CSO Overflow on sewer network Company site name Hereford Grandstand Road EA ID / permit DCW00052 · AN0077701 Outlet location SO4936341329 (OS grid reference) · View on Apple Maps WFD catchment Yazor Bk - source to conf R Wye (GB109055037040) 2024 spills / hours 10 / 6.3 Long-term average 32.3 spills a year (monitored since 2017) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 4.3 hours spilling →	Yazor Brook	11	4.3	up 10%	99%
Barton Road Combined Sewer Overflow Overflow on sewer network Company site name Barton Road CSO, Hereford EA ID / permit DCW00015 · AN0266401 Outlet location SO5047939727 (OS grid reference) · View on Apple Maps WFD catchment Wye - Bredwardine Br to Hampton Bishop (GB109055037113) 2024 spills / hours 23 / 82 Long-term average 11.9 spills a year (monitored since 2018) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 4.0 hours spilling →	Yazor Brook	6	4.0	down 74%	100%
Edgar Park CSO Overflow on sewer network Company site name Chester Edgars Park EA ID / permit DCW00045 · CM0167601 Outlet location SJ4073565711 (OS grid reference) · View on Apple Maps WFD catchment Dee (N. Wales) (GB531106708200) 2024 spills / hours 16 / 9.8 Long-term average 9.3 spills a year (monitored since 2017) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 4.0 hours spilling →	River Dee	10	4.0	down 38%	99%
Unknown Overflow on sewer network Company site name Hereford Cycle Track CSO, Hereford EA ID / permit DCW00128 · Unpermitted Outlet location SO5050539622 (OS grid reference) · View on Apple Maps WFD catchment Wye - Bredwardine Br to Hampton Bishop (GB109055037113) 2024 spills / hours 2 / 1.8 Long-term average 6.0 spills a year (monitored since 2023) Investigation UWWTR investigation completed Improvement No improvement action in reporting period Volume & pollution Estimate from 4.0 hours spilling →	River Wye	1	4.0	down 50%	100%
Unknown Overflow on sewer network Company site name 72 Cheyney Rd CSO Chester EA ID / permit DCW00003 · Unpermitted Outlet location SJ3969167435 (OS grid reference) · View on Apple Maps WFD catchment Finchetts Gutter (GB111067056930) 2024 spills / hours 11 / 7.0 Long-term average 6.4 spills a year (monitored since 2020) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 2.5 hours spilling →	Finchetts Gutter	4	2.5	down 64%	100%
Seaton Avenue CSO Overflow on sewer network Company site name Hereford Seaton Avenue EA ID / permit DCW00103 · AN0078101 Outlet location SO5344740624 (OS grid reference) · View on Apple Maps WFD catchment Lugg - conf R Arrow to conf R Wye (GB109055036790) 2024 spills / hours 5 / 5.3 Long-term average 2.2 spills a year (monitored since 2016) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 2.0 hours spilling →	Lugg Rheay	6	2.0	up 20%	94%
Unknown Overflow on sewer network Company site name Chester Castle Drive EA ID / permit DCW00127 · Unpermitted Outlet location SJ4064065780 (OS grid reference) · View on Apple Maps WFD catchment Middle Dee (GB531106708200) 2024 spills / hours 27 / 16 Long-term average 22.7 spills a year (monitored since 2023) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 1.8 hours spilling →	River Dee	4	1.8	down 85%	97%
Unknown Overflow on sewer network Company site name No 1 Castlefields Leominster CSO EA ID / permit DCW00009 · Unpermitted Outlet location SO4999158465 (OS grid reference) · View on Apple Maps WFD catchment Arrow - conf Gilwern Bk to conf R Lugg (GB109055041840) 2024 spills / hours 10 / 14 Long-term average 5.4 spills a year (monitored since 2021) Investigation UWWTR investigation completed Improvement No improvement action in reporting period Volume & pollution Estimate from 1.3 hours spilling →	River Lugg	5	1.3	down 50%	100%
Station St Combined Sewer Overflow Overflow on sewer network Company site name Station Street Ross-On-Wye CSO EA ID / permit DCW00112 · AN0014701 Outlet location SO6034024308 (OS grid reference) · View on Apple Maps WFD catchment Rudhall Bk - source to conf R Wye (GB109055029730) 2024 spills / hours 5 / 1.3 Long-term average 1.6 spills a year (monitored since 2017) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.8 hours spilling →	Small Brook	3	0.8	down 40%	100%
Whitecross Road CSO Hereford Overflow on sewer network Company site name Whitecross Road CSO EA ID / permit DCW00122 · AN0078001 Outlet location SO5030239626 (OS grid reference) · View on Apple Maps WFD catchment Wye - Bredwardine Br to Hampton Bishop (GB109055037113) 2024 spills / hours 8 / 3.3 Long-term average 2.8 spills a year (monitored since 2015) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.8 hours spilling →	River Wye	2	0.8	down 75%	100%
Miss Chaves Combined Sewer Overflow Overflow on sewer network Company site name Widemarsh Common Road CSO, Hereford EA ID / permit DCW00081 · AN0266301 Outlet location SO5064940730 (OS grid reference) · View on Apple Maps WFD catchment Yazor Bk - source to conf R Wye (GB109055037040) 2024 spills / hours 4 / 1.0 Long-term average 5.5 spills a year (monitored since 2019) Investigation No investigation activity in reporting period Improvement No improvement action in reporting period Volume & pollution Estimate from 0.8 hours spilling →	Widemarsh Brook	2	0.8	down 50%	100%

Sewage treatment works

Storm tanks and inlet overflows at each Dwr Cymru Welsh 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.