It's a Dirty Business

Watch Channel 4's documentary about the state of the water industry, then sign the petition to bring water back to public ownership.

Rhondda and Ogmore - 2025 Sewage

Polluted by sewage 27,281 hours in 2025 - That's 3.16 years

© OpenStreetMap contributors
Contains OS Data © Crown copyright & database right 2021-2024
© Top of the Poops 2021-2024

Which Year?

Select Another Constituency

Select the constituency from the drop-down
✔ means we have live data (𝑥 if not)

View Annual Sewage Data

You're looking at the totals that we have calculated for sewage in Rhondda and Ogmore for 2025. It is an estimate, based on very poor quality live data from the Water Companies. This may not align with the 'official' reported sewage values from the water companies, which is reported in April following then end of the year - so 2025 numbers are reported in April 2026.

What's a potential overflow? If the CSO goes 'Offline' while its Overflowing, we don't know if it stopped overflowing until we get a 'Stop' event.

Take Action

Your local MP is Chris Bryant (Labour) - Find out more about their interests, donors, and voting at They Work For You

Share this page, post a message, and tell others about the huge problem of sewage pollution across the UK
Post
Post

Constituencies near Rhondda and Ogmore

Daily Data

Jan - 0 hours
Feb - 1,731 hours
Mar - 63 hours
Apr - 542 hours
May - 392 hours
Jun - 1,274 hours
Jul - 255 hours
Aug - 333 hours
Sept - 4,903 hours
Oct - 1,757 hours
Nov - 7,366 hours
Dec - 8,660 hours
Daily data is experimental and data is not guaranteed to be accurate. Please inform us of any issue, we will fix.
Please note: We don't have rainfall data for Wales. If you know where to source it please let us know!
We need your support!

Please consider a one-off or small recurring donation. We need your help to keep this site going.

Donate Now

Totals so far

Company Site Name Receiving Waterway Overflow Days Total Duration (hours) Offline/Potential Pollution
Dwr Cymru Welsh Water Hermon Street Treorchy Storm Overflow Rhondda Fawr River 137 1,958h 13m -
Dwr Cymru Welsh Water Llangeinor Bettws Street Storm Overflow River Garw 113 1,811h 33m -
Dwr Cymru Welsh Water Craig Tal Y Fan Blackmill Storm Overflow River Ogmore 80 1,715h 29m -
Dwr Cymru Welsh Water Dimbath Avenue Storm Overflow Ogwr Fach River 106 1,704h 45m -
Dwr Cymru Welsh Water Cemetery Road Ogmore Vale Storm Overflow Ogwr Fawr 106 1,644h 30m -
Dwr Cymru Welsh Water Station Row Storm Overflow River Garw 86 1,022h 59m -
Dwr Cymru Welsh Water Ely Valley Road Storm Overflow River Ely 97 965h -
Dwr Cymru Welsh Water Ferndale Road Tylorstown Storm Overflow Rhondda Fach River 74 956h 2m -
Dwr Cymru Welsh Water Pontycymmer Fenton Place Storm Overflow River Garw 105 904h 51m -
Dwr Cymru Welsh Water Brook Street Porth Storm Overflow River Rhondda 114 887h 2m -
Dwr Cymru Welsh Water Park View Tylorstown Storm Overflow Rhondda Fach River 102 800h 45m -
Dwr Cymru Welsh Water Gwendoline Street Sports Ground Storm Overflow Ogwr Fach River 108 772h 7m -
Dwr Cymru Welsh Water Fir Street Rear Ferndale Storm Overflow Rhondda Fach River 99 721h 50m -
Dwr Cymru Welsh Water St John Street Ogmore Vale Storm Overflow Ogwr Fach River 89 658h 47m -
Dwr Cymru Welsh Water Davies Street Tonypandy Storm Overflow River Clydach 106 644h 9m -
Dwr Cymru Welsh Water Ynyscrug Roundabout Storm Overflow Rhondda Fawr River 47 575h 57m -
Dwr Cymru Welsh Water Pant Yr Awel Lewistown Storm Overflow Nany-Y-Ci 54 571h 15m -
Dwr Cymru Welsh Water Pen Dinas Road Dinas Storm Overflow Rhondda Fawr 92 558h 37m -
Dwr Cymru Welsh Water Rear of Elm Street Gilfach Goch Storm Overflow Ogwr Fach River 59 531h 45m -
Dwr Cymru Welsh Water Greenwood Park Storm Overflow Rhondda Fach River 67 511h 57m -
Dwr Cymru Welsh Water Ystrad Road Church Road Junction Storm Overflow Rhondda Fawr River 147 374h 48m -
Dwr Cymru Welsh Water Ynys Park Storm Overflow Rhondda Fawr River 72 366h 40m -
Dwr Cymru Welsh Water Glynfach Road Porth Storm Overflow Rhondda Fawr River 86 360h 30m -
Dwr Cymru Welsh Water Edmonedes Street Courts Storm Overflow Rhondda Fach River 49 341h 47m -
Dwr Cymru Welsh Water Vicarage Road Penycraig Storm Overflow Culvert To Rhondda Fawr River 66 314h 58m -
Dwr Cymru Welsh Water Cross Street Ynyshir Storm Overflow Rhondda Fach River 77 310h -
Dwr Cymru Welsh Water Oak Street Treherbert Storm Overflow Rhondda Fawr 69 289h 57m -
Dwr Cymru Welsh Water Trealaw Road Tonypandy Overflow River Rhondda 75 282h 24m -
Dwr Cymru Welsh Water Blake Street Storm Overflow Rhondda Fach River 59 268h 19m -
Dwr Cymru Welsh Water Station Road Ferndale Storm Overflow Rhondda Fach River 79 262h 11m -
Dwr Cymru Welsh Water Ferndale Banana Tip No. 1 Storm Overflow Rhondda Fach River 21 255h 15m -
Dwr Cymru Welsh Water Treherbert Blaencwm Road Storm Overflow Rhondda Fawr 56 251h 31m -
Dwr Cymru Welsh Water Ferndale Banana Tip No. 3 Storm Overflow Rhondda Fach River 64 239h 32m -
Dwr Cymru Welsh Water Aberrhondda Road Storm Overflow Rhondda Fach River 45 239h 11m -
Dwr Cymru Welsh Water Mountain Row Storm Overflow Rhondda Fach River 52 198h 16m -
Dwr Cymru Welsh Water Tylacelyn Road Hughes Street Storm Overflow Rhondda Fawr River 66 194h 41m -
Dwr Cymru Welsh Water Commercial Street Nant Y Moel Storm Overflow Ogwr Fawr River 69 187h 15m -
Dwr Cymru Welsh Water Highfield Industrial Estate Storm Overflow Rhondda Fach River 42 148h 51m -
Dwr Cymru Welsh Water Railway Terrace Clydach Vale Storm Overflow River Clydach 48 143h 4m -
Dwr Cymru Welsh Water Dan-Y-Bryn Gilfach Goch Storm Overflow Ogwr Fach 45 135h 53m -
Dwr Cymru Welsh Water Gelligaled Park Tyntyla Road Storm Overflow Rhondda River Fawr 42 133h -
Dwr Cymru Welsh Water Waunrhydd Road Storm Overflow River Ely 29 128h 8m -
Dwr Cymru Welsh Water Pontygwaith Bridge Storm Overflow Rhondda Fach River 40 123h 41m -
Dwr Cymru Welsh Water Llwynypia Road Storm Overflow River Rhondda 56 123h 4m -
Dwr Cymru Welsh Water Penycraig Roundabout Storm Overflow River Rhondda 45 119h 17m -
Dwr Cymru Welsh Water Ogmore Valley Water Street Storm Overflow Ogwr Fawr River 14 113h 58m -
Dwr Cymru Welsh Water Mill Street West Tonyrefail Storm Overflow River Ely 38 106h 27m -
Dwr Cymru Welsh Water Commercial Street Blaenllechau Storm Overflow River Rhondda Fach 20 102h 12m -
Dwr Cymru Welsh Water Station Road Maerdy Storm Overflow Rhondda Fach 32 99h -
Dwr Cymru Welsh Water Clarence Street Pentre Storm Overflow Rhondda Fawr River 9 98h 45m -
Dwr Cymru Welsh Water Commercial Place Pontycymer Overflow Garw 39 87h 16m -
Dwr Cymru Welsh Water Trehafod Storm Tank Storm Overflow River Rhondda 7 72h 58m -
Dwr Cymru Welsh Water School Street Ton Pentre Overflow Rhondda River 25 71h 28m -
Dwr Cymru Welsh Water Ferndale Banana Tip Additional Tank Storm Overflow Rhondda Fach River 18 68h 22m -
Dwr Cymru Welsh Water Rees Street West Storm Overflow River Rhondda 44 67h 21m -
Dwr Cymru Welsh Water Cwrt Gwalia Storm Overflow Ogwr Fawr River 16 66h 6m -
Dwr Cymru Welsh Water Long Row Blaenllechau Storm Overflow Rhondda Fach River 25 58h 33m -
Dwr Cymru Welsh Water De Winton Street Rear Storm Overflow Nant Clydach 12 45h 11m -
Dwr Cymru Welsh Water Cadwgan Terrace Storm Overflow River Rhondda 14 43h 15m -
Dwr Cymru Welsh Water Wattstown Bailey Street Land reclam Site Storm Overflow Rhondda River Fawr 8 37h 55m -
Dwr Cymru Welsh Water Sherwood Street Llwynypia Storm Overflow Rhondda River Fawr 30 37h 53m -
Dwr Cymru Welsh Water Old Brithweunydd Road Storm Overflow River Rhondda 31 34h 9m -
Dwr Cymru Welsh Water Rees Street Gelli Storm Overflow Rhondda River Fawr 23 30h 30m -
Dwr Cymru Welsh Water Griffin Park Pentre Storm Overflow Rhondda Fawr River 7 25h 30m -
Dwr Cymru Welsh Water Tylacelyn Road Rugby Club Storm Overflow River Rhondda 24 25h 21m -
Dwr Cymru Welsh Water Trehafod Storm Overflow River Rhondda 35 25h 15m -
Dwr Cymru Welsh Water Ynyscynon Road Storm Overflow Rhondda Fawr River 9 24h 43m -
Dwr Cymru Welsh Water George Street Treherbert Storm Overflow River Rhondda 10 23h 41m -
Dwr Cymru Welsh Water Blaen Y Cwm Road Blaencwm Overflow River Rhondda 12 22h 14m -
Dwr Cymru Welsh Water River Street Ogmore Vale Storm Overflow Ogwr Fawr River 7 21h 45m -
Dwr Cymru Welsh Water Herbert Street Storm Overflow River Rhondda 11 20h 38m -
Dwr Cymru Welsh Water Bute Street Treherbert Storm Overflow Rhondda Fawr 5 16h 43m -
Dwr Cymru Welsh Water James Terrace Storm Overflow Rhondda Fach River 7 15h 33m -
Dwr Cymru Welsh Water South of River Street Ystrad Rhondda Overflow Rhondda Fach River 7 15h 28m -
Dwr Cymru Welsh Water Railway Terrace Cwmparc Storm Overflow Nant Cwm Parc/Afon Rhondda Fach 8 14h 44m -
Dwr Cymru Welsh Water Dolgwilym River Bridge Storm Overflow Rhondda Fach River 11 10h 24m -
Dwr Cymru Welsh Water Tynybryn Road Storm Overflow River Ely 9 9h 35m -
Dwr Cymru Welsh Water Victoria Street Storm Overflow River Afan 9 7h 40m -
Dwr Cymru Welsh Water David Street Treherbert Storm Overflow Rhondda Fawr River 6 6h 45m -
Dwr Cymru Welsh Water Ashdale Road Storm Overflow River Ely 3 5h 30m -
Dwr Cymru Welsh Water Oxford Street Pontycymer Overflow River Garw 10 5h 16m -
Dwr Cymru Welsh Water Crichton Street Storm Overflow River Rhondda 11 4h 52m -
Dwr Cymru Welsh Water Hill Street Storm Overflow Rhondda Fawr River 14 4h 13m -
Dwr Cymru Welsh Water William Street Ystrad 1 Storm Overflow River Rhondda Fawr 3 3h 27m -
Dwr Cymru Welsh Water Ynyswen Rd Overflow Rhondda River 5 2h 45m -
Dwr Cymru Welsh Water Llewellyn Street Pentre Storm Overflow River Cynon 5 2h 10m -
Dwr Cymru Welsh Water Elizabeth Close Pentre Storm Overflow Rhondda Fawr 5 2h -
Dwr Cymru Welsh Water Furnace Road Pontygwaith Storm Overflow River Rhondda Fach 6 1h 32m -
Dwr Cymru Welsh Water Maple Court Storm Overflow Nant Muchydd 2 1h 30m -
Dwr Cymru Welsh Water Blaen-Y-Cwm Terrace Storm Overflow Nant Ystradffernol 2 1h 29m -
Dwr Cymru Welsh Water Railway Terrace Ogmore Vale Storm Overflow Ogwr Fawr River 2 1h 28m -
Dwr Cymru Welsh Water Oakfield Terrace Storm Overflow Nant Y Ffosp 4 1h 15m -
Dwr Cymru Welsh Water Unknown Unknown 1 1h 14m -
Dwr Cymru Welsh Water Mill Street Tonyrefail Storm Overflow River Ely 3 1h -
Dwr Cymru Welsh Water Penrhys Road Storm Overflow Rhondda Fach River 2 0h 58m -
Dwr Cymru Welsh Water Park Road Cwmparc Storm Overflow Tributary of Nant Cwmparc 3 0h 44m -
Dwr Cymru Welsh Water Lewis Street Pentre Storm Overflow Rhondda Fawr River 1 0h 30m -
Dwr Cymru Welsh Water High Street Pontycymer Overflow River Garw 1 0h 29m -
Dwr Cymru Welsh Water Cymmer Road Porth Storm Overflow Rhondda Fawr 1 0h 29m -
Dwr Cymru Welsh Water Treherbert Storm Overflow River Rhondda Fawr 1 0h 15m -
Dwr Cymru Welsh Water Taff Street Storm Overflow Rhondda Fach River 1 0h 14m -
Dwr Cymru Welsh Water Glannant Road Storm Overflow Nant Abercerdin 1 0h 14m -
Dwr Cymru Welsh Water Unknown Unknown 0 0h -
Dwr Cymru Welsh Water Fern Street Storm Overflow Ogwr Fawr River 0 0h -
Dwr Cymru Welsh Water Unknown Unknown 0 0h -
Dwr Cymru Welsh Water Tyntyla Road Tonypandy Storm Overflow Rhondda Fawr River 0 0h -
Dwr Cymru Welsh Water Dunraven Street Storm Overflow River Rhondda Fawr 0 0h -
Dwr Cymru Welsh Water St John Street Overflow Ogwr Fawr River 0 0h -
Dwr Cymru Welsh Water Llewellyn Street Storm Overflow River Rhondda Fawr 0 0h -
Dwr Cymru Welsh Water East of Dyfodwg Street Junction with Station Road Storm Overflow Rhondda River Fawr 0 0h -
Dwr Cymru Welsh Water Cuckoo Street Pontycymer Overflow River Garw 0 0h -
Dwr Cymru Welsh Water Taff Street Rear Storm Overflow Rhondda Fach River 0 0h -
Dwr Cymru Welsh Water Pontycymmer Richard Street Storm Overflow Tributary of Afon Cynon 0 0h -
Dwr Cymru Welsh Water Gwendoline Street Storm Overflow River Garw 0 0h -
Dwr Cymru Welsh Water Tonyrefail Police Station Storm Overflow River Ely 0 0h -
Dwr Cymru Welsh Water Rheidol Close Rail Bridge Storm Overflow Rhondda Fawr 0 0h -

Data Sources & Accuracy

EDM (Event Duration Monitoring) data and Consented Discharges to Controlled Waters with Conditions from Environment Agency & Data Map Wales, and Scottish Water

Experimental derived data from Thames Water API, Some data may be missing or inaccurate. Live sewage data from Stream Water API

Uses Environment Agency rainfall data from the real-time data API (Beta) - Rainfall data is delayed by up to two days.

This website is intended to provide an accurate representation of the Environment Agency data. The data is hard to use, and thus some errors may have been made. If you find something that is incorrect, please raise an issue at the GitHub issues page and we'll endeavour to fix it quickly.

This project is not associated, approved or endorsed by any of the companies whose logos you see here.

Top of the Poops

Analysing sewage pollution by the Water Industry

Follow on Instagram

Media Queries

Get in touch if you have queries or want to discuss our data.

press [at] top-of-the-poops.org

Please Support Us

We rely on donations to fund our work. Please support us if you can
Yes! Support TOTP!

© 2020-2025 Top-Of-The-Poops CC-BY-SA 4.0,
© Openstreetmap contributors, Contains OS data © Crown copyright and database right 2021-2025,
Contains Water UK National Storm Overflow Hub Data CC-BY-SA 4.0 and analysis © 2025 Top-Of-The-Poops

Some data reproduced under Open Government Licence

Please don't scrape these pages - we can maybe share our data with you

Full Copyright information available at: our GitHub page