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.

Cardiff North

Polluted by sewage 280 times in 2025 lasting 1,893 hours

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

Select Another Constituency

Select the constituency from the drop-down
โœ” means we have live data (๐‘ฅ if not)

Live data for Cardiff North in 2026

So far this year (as of 18 May 2026, 12:00) there has been 1,000 hours of sewage overflows, from 9 CSO Combined Sewage Overflow - a device that, when operating, pours combined rainwater & sewage into a waterway s

Totals for Cardiff North in 2025

9 Sites polluted by Dwr Cymru Welsh Water
280 sewage dumps
1,893 hours duration
That's 2.63 months. 5.4 times a week, on average

Change Over Time

Take Action

Your local MP is Anna McMorrin (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
We need your support!

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

Donate Now

Pollution Summary 2025

Here are all the reported sewage overflow totals for Cardiff North in 2025. Sometimes sewage can be being dumped for months at a time.

Reporting refers to how much of the time the monitoring was active. In this constituency all the declared CSO Combined Sewage Overflow - a device that, when operating, pours combined rainwater & sewage into a waterway s appeared to have monitoring enabled for more than 50% of the year

Company Waterway Site Sewage Dumps Duration (Hours) Reporting %
Dwr Cymru Welsh Water River Taff Tongwynlais CSO 69 1,222 99.9
Dwr Cymru Welsh Water River Rhymney Storm Water Overflow at Began, St Mellons 93 412 96.7
Dwr Cymru Welsh Water River Taff Ynys Bridge CSO 32 155 98.6
Dwr Cymru Welsh Water Nant-Y-Wedal HEATHWOOD ROAD CSO, HEATHWOOD JUNCTION 27 27 92.8
Dwr Cymru Welsh Water Rhydwaedlyd Brook Caedelyn Park Boundary CSO 26 26 99.8
Dwr Cymru Welsh Water Rhymney River Began Road CSO 10 24 99.5
Dwr Cymru Welsh Water River Taff Via Culverted Watercourse ABERPORTH RD CSO 9 17 91.9
Dwr Cymru Welsh Water Taff Bottom of Westbourne Crescent CSO, Cardiff 13 8 99.6
Dwr Cymru Welsh Water River Rhymney CSO at Bridge Road, St Mellons, Cardiff 1 0 97.2

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.