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Cardiff North - 2025 Sewage

Polluted by sewage 1,725 hours in 2025

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

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View Annual Sewage Data

You're looking at the totals that we have calculated for sewage in Cardiff North 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.

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Daily Data

Jan - 0 hours
Feb - 68 hours
Mar - 1 hours
Apr - 15 hours
May - 10 hours
Jun - 21 hours
Jul - 0 hours
Aug - 6 hours
Sept - 175 hours
Oct - 91 hours
Nov - 491 hours
Dec - 842 hours
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Totals so far

Company Site Name Receiving Waterway Overflow Days Total Duration (hours) Offline/Potential Pollution
Dwr Cymru Welsh Water Tongwynlais Recreation Ground Storm Overflow River Taff 65 1,161h 2m -
Dwr Cymru Welsh Water Began Road Cardiff Storm Overflow No2 River Rhymni 69 379h 59m -
Dwr Cymru Welsh Water Ynys Bridge 2 Storm Overflow River Taff 21 111h 40m -
Dwr Cymru Welsh Water Parc Caedelyn Storm Overflow Rhydwaedlyd Brook 19 21h 39m -
Dwr Cymru Welsh Water Began Road Cardiff Storm Overflow Rhymney 5 18h 41m -
Dwr Cymru Welsh Water Heathwood Road Storm Overflow Nant Y Wedal 17 17h 44m -
Dwr Cymru Welsh Water Westbourne Crescent Bottom Cardiff Storm Overflow River Taff 9 11h 9m -
Dwr Cymru Welsh Water Heol Amlwch Storm Overflow River Taff via culverted watercourse 5 2h 56m -
Dwr Cymru Welsh Water St. Mellons Bridge Road Storm Overflow River Rhymni 1 0h 30m -

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

Annual figures up to and including 2025 come from official water company returns. The 2026 figure is our own estimate, derived continuously from the companies' live data feeds.

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.