Southern Water

was responsible for at least 29,355 sewage overflows in 2024
On average 80.4 times a day

These lasted for 304,536 hours (That's 35.25 years!) - in 830 different locations across their service area

Southern Water has 17 CSOs dumping sewage right now

Here are the ones that have been overflowing for the longest, without interruption

We are getting more data collated for each of the CSOs... right now we just have the Constituency. Unfortunately, the water companies use different names for the CSOs in their live data than in the annual returns, so it will take a bit of time to link all the data up....

1. SRN0006

Brighton Kemptown and Peacehaven

Started 2 months ago

2. SRN0144

Bexhill and Battle

Started 4 hours ago

3. SRN0332

Hastings and Rye

Started 4 hours ago

4. SRN0364

Hastings and Rye

Started 4 hours ago

5. SRN0367

Sussex Weald

Started 2 hours ago

6. SRN0372

Lewes

Started 1 hour ago

7. SRN0458

Romsey and Southampton North

Started 4 months ago

8. SRN0474

Chichester

Started 4 days ago

9. SRN0592

Lewes

Started 1 hour ago

How many Sewage Overflows are dumping sewage?

We have live data for Southern Water so we can track what happens every day - given that overflows are supposed to happen on an 'exceptional' basis only - does the chart indicate that?

The red line indicates the number of CSOs that overflowed for at least 30mins, the grey, the number of CSOs that were offline for at least 30mins, and the blue line is the total number of CSOs that we can get information for.

There is daily updated information on all constituencies covered by Southern Water

2024 - 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.

2024 - 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.

Southern Water is highlighted in the plot below

2024 - Worst Locations Southern Water

1. LAVANT WWTW

Chichester polluted for 6,829 hours, into River Lavant

287 incidents

That's 9.48 months.

5.5 times a week, on average

2. KINGS SOMBORNE WWTW

Romsey and Southampton North polluted for 5,481 hours, into River Test

252 incidents

That's 7.61 months.

4.8 times a week, on average

3. HAM LANE LEWES SETTLES STORM TANK

Lewes polluted for 4,824 hours, into Tidal River Ouse

259 incidents

That's 6.7 months.

5 times a week, on average

4. HAMMERWOOD ROAD ASHURST WOOD WPS

Sussex Weald polluted for 4,130 hours, into Shovelstrode Stream

193 incidents

That's 5.74 months.

3.7 times a week, on average

5. HAWKHURST NORTH WWTW

Tunbridge Wells polluted for 4,084 hours, into Hexden Channel

213 incidents

That's 5.67 months.

4.1 times a week, on average

6. SANDOWN WWTW

Isle of Wight East polluted for 4,081 hours, into English Channel

283 incidents

That's 5.67 months.

5.4 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.