South West Water

was responsible for at least 58,249 sewage overflows in 2023
On average 159.6 times a day

These lasted for 530,736 hours (That's 61.43 years!) - in 1,117 different locations across their service area

2023 - By Water Company

How does each water company compare? These are the totals by company for each. The totals are really high, counting things in hours doesn't make it very easy to think about. Here we show how many years of continuous sewage dumps happened in a single year, by water company.

2023 - Asset Spill Duration Comparison

It isn't like there are just a few outliers... the problem exists across the entire estate of water assets. Here we show a 'cumulative frequency diagram' - where the number of CSOs that dumped sewage for a time, or longer, is shown. You can see that many CSOs dumped sewage into a river for months and months.

South West Water is highlighted in the plot below

2023 - Worst Locations South West Water

1. PRINCETOWN SEWAGE TREATMENT WORKS

Torridge and Tavistock polluted for 5,244 hours, into Blackbrook River

253 incidents

That's 7.28 months.

4.9 times a week, on average

2. DULFORD PSCSO/EO

Honiton and Sidmouth polluted for 5,212 hours, into Weaver

258 incidents

That's 7.24 months.

5 times a week, on average

3. STOKE HILL WWTW

South West Devon polluted for 5,177 hours, into Milton Stream

294 incidents

That's 7.19 months.

5.7 times a week, on average

4. BEALS MILL NO 2 CSO

North Cornwall polluted for 5,050 hours, into River Inny

346 incidents

That's 7.01 months.

6.7 times a week, on average

5. SALCOMBE REGIS WWTW CSO

Honiton and Sidmouth polluted for 4,827 hours, into Salcombe Regis Stream

223 incidents

That's 6.7 months.

4.3 times a week, on average

6. DELABOLE WASTEWATER TREATMENT WORKS

North Cornwall polluted for 4,771 hours, into River Allen

343 incidents

That's 6.63 months.

6.6 times a week, on average

Water Companies

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. This 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.