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Live data

It rains, and then the sewage flows

Every fifteen minutes, the Environment Agency measures the rain. Every few minutes, the water companies say which of their CSO Combined Sewage Overflow - a device that, when operating, pours combined rainwater & sewage into a waterway s are discharging. Put the two on the same map and move through time, and the relationship is not subtle.

The interesting days are not only the wettest ones. Sometimes it barely rains and the sewers give way anyway. Sometimes it does not rain at all.

 

Days worth watching
00:00
0 discharging now
00:0006:0012:0018:0024:00

No rainfall for this day yet. The Environment Agency archive lags behind — by 2 days at the moment — so the sewage is shown and the rain is not. The map is not saying it was dry. Rainfall is available up to 6 Oct 2026.
No sewage data for this day. The rainfall record goes back to December 2022, but the companies only began publishing overflows we can read in December 2024 — so this is the weather, with nothing yet to compare it against.

Each blue square is the rain measured across a patch of the country in that quarter of an hour; each dot is a storm overflow that was discharging at that moment, coloured by company and growing the longer it has been running.

Two different counts, and they are meant to differ. Most discharges are short — under two hours on an average day — so far more overflows run at some point in a day than are ever running together. On , were discharging in the same quarter of an hour at the worst point, but different overflows ran at some point during it. The map, the cards and the day buttons all show the first, so they agree with the dots you can count; “spilled today” is the second. Unlike the annual pages, which count only discharges lasting more than half an hour, this page counts every one.

Found by comparing each day's sewage against what a normal day with that much rain produces — nationally, and again for every constituency, because a national average hides a place that got no rain at all. 2435 local events turned up that way; these are the biggest of them, alongside the national ones. Pick one and watch it happen.

Dry spill 11 Jan - 17 Jan 2025
Newark
Sewage without rain

No rain fell anywhere in Newark for 4 days, and none on the day either. A storm overflow is for storms. There was no storm.

8
At once
0.0
mm of rain
886
Hours
Dry spill 27 Dec - 30 Dec 2025
West Dorset
Sewage without rain

No rain fell anywhere in West Dorset for 4 days, and none on the day either. A storm overflow is for storms. There was no storm.

11
At once
0.1
mm of rain
775
Hours
Dry spill 3 Mar - 9 Mar 2025
East Wiltshire
Sewage without rain

No rain fell anywhere in East Wiltshire for 4 days, and none on the day either. A storm overflow is for storms. There was no storm.

6
At once
0.2
mm of rain
689
Hours
Dry spill 16 Mar - 20 Mar 2025
Salisbury
Sewage without rain

No rain fell anywhere in Salisbury for 7 days, and none on the day either. A storm overflow is for storms. There was no storm.

6
At once
0.1
mm of rain
388
Hours
Dry spill 4 Mar - 7 Mar 2026
Newark
Sewage without rain

No rain fell anywhere in Newark for 4 days, and none on the day either. A storm overflow is for storms. There was no storm.

7
At once
0.0
mm of rain
360
Hours
Dry spill 26 Dec - 30 Dec 2025
South Cotswolds
Sewage without rain

No rain fell anywhere in South Cotswolds for 5 days, and none on the day either. A storm overflow is for storms. There was no storm.

5
At once
0.1
mm of rain
357
Hours
Dry spill 3 Mar - 9 Mar 2025
Newbury
Sewage without rain

No rain fell anywhere in Newbury for 4 days, and none on the day either. A storm overflow is for storms. There was no storm.

2
At once
0.1
mm of rain
333
Hours
Dry spill 3 Mar - 9 Mar 2025
South Northamptonshire
Sewage without rain

No rain fell anywhere in South Northamptonshire for 5 days, and none on the day either. A storm overflow is for storms. There was no storm.

2
At once
0.1
mm of rain
327
Hours
Dry spill 28 Dec - 31 Dec 2025
Truro and Falmouth
Sewage without rain

No rain fell anywhere in Truro and Falmouth for 4 days, and none on the day either. A storm overflow is for storms. There was no storm.

5
At once
0.0
mm of rain
307
Hours
Dry spill 26 Dec - 30 Dec 2025
Glastonbury and Somerton
Sewage without rain

No rain fell anywhere in Glastonbury and Somerton for 4 days, and none on the day either. A storm overflow is for storms. There was no storm.

5
At once
0.1
mm of rain
305
Hours
Dry spill 21 Mar - 23 Mar 2026
West Dorset
Sewage without rain

No rain fell anywhere in West Dorset for 4 days, and none on the day either. A storm overflow is for storms. There was no storm.

5
At once
0.1
mm of rain
279
Hours
Dry spill 3 Mar - 4 Mar 2025
Salisbury
Sewage without rain

No rain fell anywhere in Salisbury for 4 days, and none on the day either. A storm overflow is for storms. There was no storm.

8
At once
0.1
mm of rain
257
Hours
Dry spill 29 Dec - 31 Dec 2025
South Devon
Sewage without rain

No rain fell anywhere in South Devon for 5 days, and none on the day either. A storm overflow is for storms. There was no storm.

5
At once
0.1
mm of rain
253
Hours
Dry spill 3 Mar - 9 Mar 2025
Kettering
Sewage without rain

No rain fell anywhere in Kettering for 4 days, and none on the day either. A storm overflow is for storms. There was no storm.

3
At once
0.0
mm of rain
249
Hours
Dry spill 28 Dec - 30 Dec 2025
South East Cornwall
Sewage without rain

No rain fell anywhere in South East Cornwall for 4 days, and none on the day either. A storm overflow is for storms. There was no storm.

7
At once
0.0
mm of rain
237
Hours
Dry spill 4 Mar 2026
Daventry
Sewage without rain

No rain fell anywhere in Daventry for 4 days, and none on the day either. A storm overflow is for storms. There was no storm.

12
At once
0.0
mm of rain
226
Hours
Dry spill 21 Mar - 23 Mar 2026
South Devon
Sewage without rain

No rain fell anywhere in South Devon for 4 days, and none on the day either. A storm overflow is for storms. There was no storm.

4
At once
0.1
mm of rain
220
Hours
Dry spill 12 Jan - 18 Jan 2025
Mid Derbyshire
Sewage without rain

No rain fell anywhere in Mid Derbyshire for 4 days, and none on the day either. A storm overflow is for storms. There was no storm.

2
At once
0.0
mm of rain
205
Hours
Dry spill 16 Jan - 19 Jan 2025
St Ives
Sewage without rain

No rain fell anywhere in St Ives for 4 days, and none on the day either. A storm overflow is for storms. There was no storm.

3
At once
0.2
mm of rain
193
Hours
Dry spill 8 Mar - 9 Mar 2025
Salisbury
Sewage without rain

No rain fell anywhere in Salisbury for 7 days, and none on the day either. A storm overflow is for storms. There was no storm.

6
At once
0.1
mm of rain
191
Hours
Dry spill 15 Oct - 18 Oct 2025
Barrow and Furness
Sewage without rain

No rain fell anywhere in Barrow and Furness for 5 days, and none on the day either. A storm overflow is for storms. There was no storm.

2
At once
0.0
mm of rain
187
Hours
Dry spill 29 Dec 2025
Central Devon
Sewage without rain

No rain fell anywhere in Central Devon for 5 days, and none on the day either. A storm overflow is for storms. There was no storm.

9
At once
0.1
mm of rain
186
Hours
Dry spill 3 Mar - 9 Mar 2025
North East Hampshire
Sewage without rain

No rain fell anywhere in North East Hampshire for 4 days, and none on the day either. A storm overflow is for storms. There was no storm.

3
At once
0.1
mm of rain
183
Hours
Dry spill 12 Jan - 14 Jan 2025
Chichester
Sewage without rain

No rain fell anywhere in Chichester for 4 days, and none on the day either. A storm overflow is for storms. There was no storm.

3
At once
0.0
mm of rain
182
Hours
Dry spill 12 Jan - 18 Jan 2025
Rushcliffe
Sewage without rain

No rain fell anywhere in Rushcliffe for 4 days, and none on the day either. A storm overflow is for storms. There was no storm.

2
At once
0.0
mm of rain
178
Hours
Dry spill 16 Jan - 21 Jan 2025
Chichester
Sewage without rain

No rain fell anywhere in Chichester for 7 days, and none on the day either. A storm overflow is for storms. There was no storm.

2
At once
0.0
mm of rain
177
Hours
Dry spill 14 Jan - 19 Jan 2025
Rawmarsh and Conisbrough
Sewage without rain

No rain fell anywhere in Rawmarsh and Conisbrough for 6 days, and none on the day either. A storm overflow is for storms. There was no storm.

3
At once
0.0
mm of rain
177
Hours
Dry spill 2 Mar - 6 Mar 2025
North East Cambridgeshire
Sewage without rain

No rain fell anywhere in North East Cambridgeshire for 5 days, and none on the day either. A storm overflow is for storms. There was no storm.

3
At once
0.1
mm of rain
172
Hours
Dry spill 23 Apr - 29 Apr 2026
West Worcestershire
Sewage without rain

No rain fell anywhere in West Worcestershire for 4 days, and none on the day either. A storm overflow is for storms. There was no storm.

2
At once
0.0
mm of rain
172
Hours
Dry spill 27 Mar - 2 Apr 2025
Harpenden and Berkhamsted
Sewage without rain

No rain fell anywhere in Harpenden and Berkhamsted for 4 days, and none on the day either. A storm overflow is for storms. There was no storm.

2
At once
0.1
mm of rain
170
Hours
First flush 5 Jan - 7 Jan 2025
A little rain, a lot of sewage

It had been dry across the country for 4 days. Then a few millimetres of rain - and the sewers gave way anyway.

4,489
At once
22–49
mm of rain
177,206
Hours
First flush 26 Jan - 27 Jan 2025
A little rain, a lot of sewage

It had been dry across the country for 4 days. Then a few millimetres of rain - and the sewers gave way anyway.

3,025
At once
13–48
mm of rain
58,479
Hours
First flush 12 Mar - 13 Mar 2026
A little rain, a lot of sewage

It had been dry across the country for 4 days. Then a few millimetres of rain - and the sewers gave way anyway.

2,211
At once
10–52
mm of rain
41,995
Hours
First flush 27 Aug - 28 Aug 2026
A little rain, a lot of sewage

It had been dry across the country for 4 days. Then a few millimetres of rain - and the sewers gave way anyway.

1,314
At once
13–51
mm of rain
16,440
Hours
First flush 19 Jul 2025
A little rain, a lot of sewage

It had been dry across the country for 5 days. Then a few millimetres of rain - and the sewers gave way anyway.

810
At once
9–35
mm of rain
6,200
Hours
Deluge 5 Feb - 11 Feb 2026
The rain came, and so did the sewage

Heavy rain, and the overflows opened across the country. This is the case everybody agrees on.

3,198
At once
11–31
mm of rain
340,713
Hours
Deluge 4 Dec - 10 Dec 2025
Storm Bram

Winds over 69mph and up to 100mm of rain, falling on ground that was already saturated.

4,087
At once
14–58
mm of rain
305,393
Hours
Deluge 10 Nov - 16 Nov 2025
Storm Claudia

Named by AEMET in Spain. Extensive heavy rain across England and Wales - some areas had a month's rain in six days, with the worst of it in South Wales.

5,450
At once
24–69
mm of rain
289,489
Hours
Deluge 15 Dec - 19 Dec 2025
The rain came, and so did the sewage

Heavy rain, and the overflows opened across the country. This is the case everybody agrees on.

4,494
At once
16–46
mm of rain
229,709
Hours
Deluge 28 Nov - 2 Dec 2025
The rain came, and so did the sewage

Heavy rain, and the overflows opened across the country. This is the case everybody agrees on.

3,290
At once
15–71
mm of rain
196,554
Hours
Deluge 21 Jan - 23 Jan 2026
The rain came, and so did the sewage

Heavy rain, and the overflows opened across the country. This is the case everybody agrees on.

2,593
At once
10–30
mm of rain
116,983
Hours
Deluge 27 Jan - 28 Jan 2026
Storm Chandra

Exceptionally wet in south-west England - over 50mm of rain widely and up to 100mm on higher ground, with serious flooding in Devon, Cornwall and Dorset.

4,409
At once
18–48
mm of rain
114,906
Hours
Deluge 15 Feb - 16 Feb 2026
The rain came, and so did the sewage

Heavy rain, and the overflows opened across the country. This is the case everybody agrees on.

2,525
At once
11–24
mm of rain
80,964
Hours
Deluge 20 Sept - 21 Sept 2025
The rain came, and so did the sewage

Heavy rain, and the overflows opened across the country. This is the case everybody agrees on.

3,497
At once
14–69
mm of rain
58,419
Hours
Deluge 8 Jan - 9 Jan 2026
Storm Goretti

Named by Meteo-France. A 99mph gust at St Mary's Airport was the strongest on the Isles of Scilly in 47 years, and Colliford Dam recorded 61.8mm of rain.

1,723
At once
13–39
mm of rain
49,341
Hours
Deluge 4 Nov - 5 Nov 2025
The rain came, and so did the sewage

Heavy rain, and the overflows opened across the country. This is the case everybody agrees on.

1,898
At once
9–60
mm of rain
48,873
Hours
Deluge 11 Jan - 12 Jan 2026
The rain came, and so did the sewage

Heavy rain, and the overflows opened across the country. This is the case everybody agrees on.

1,571
At once
8–55
mm of rain
38,894
Hours
Deluge 1 Jan 2025
The rain came, and so did the sewage

Heavy rain, and the overflows opened across the country. This is the case everybody agrees on.

1,508
At once
14–41
mm of rain
28,084
Hours
Deluge 3 Oct 2025
Storm Amy

The first named storm of the season, and unusually severe for October. Gusts passed 92mph in exposed places, with widespread heavy rain.

2,441
At once
16–71
mm of rain
19,321
Hours
Deluge 23 Feb 2025
The rain came, and so did the sewage

Heavy rain, and the overflows opened across the country. This is the case everybody agrees on.

1,783
At once
10–56
mm of rain
18,497
Hours
Deluge 17 Sept 2025
The rain came, and so did the sewage

Heavy rain, and the overflows opened across the country. This is the case everybody agrees on.

1,864
At once
8–32
mm of rain
17,944
Hours
Deluge 3 Sept - 4 Sept 2025
The rain came, and so did the sewage

Heavy rain, and the overflows opened across the country. This is the case everybody agrees on.

661
At once
12–31
mm of rain
12,665
Hours
Deluge 14 Sept 2025
The rain came, and so did the sewage

Heavy rain, and the overflows opened across the country. This is the case everybody agrees on.

1,264
At once
8–29
mm of rain
9,532
Hours
Deluge 19 Oct 2025
The rain came, and so did the sewage

Heavy rain, and the overflows opened across the country. This is the case everybody agrees on.

1,108
At once
12–38
mm of rain
8,738
Hours
Still spilling 2 Feb 2026
Days after the rain stopped

The rain had stopped, and it was still spilling. The sewers were still emptying themselves into the rivers days later.

1,430
At once
1–12
mm of rain
27,689
Hours
Still spilling 17 Nov 2025
Days after the rain stopped

The rain had stopped, and it was still spilling. The sewers were still emptying themselves into the rivers days later.

1,221
At once
0–3
mm of rain
25,821
Hours
Still spilling 11 Dec 2025
Days after the rain stopped

The rain had stopped, and it was still spilling. The sewers were still emptying themselves into the rivers days later.

1,119
At once
0–9
mm of rain
21,643
Hours
Still spilling 21 Nov 2025
Days after the rain stopped

The rain had stopped, and it was still spilling. The sewers were still emptying themselves into the rivers days later.

967
At once
0–8
mm of rain
20,500
Hours
Wet spell 12 Feb - 14 Feb 2026
More sewage than the rain explains

Ordinary sustained rain, and far more sewage than a day like this usually produces.

2,566
At once
5–21
mm of rain
129,856
Hours
Wet spell 22 Nov - 25 Nov 2025
More sewage than the rain explains

Ordinary sustained rain, and far more sewage than a day like this usually produces.

2,022
At once
5–23
mm of rain
123,161
Hours
Wet spell 29 Jan - 31 Jan 2026
More sewage than the rain explains

Ordinary sustained rain, and far more sewage than a day like this usually produces.

1,960
At once
7–20
mm of rain
102,943
Hours
Wet spell 19 Feb - 21 Feb 2026
More sewage than the rain explains

Ordinary sustained rain, and far more sewage than a day like this usually produces.

1,802
At once
4–23
mm of rain
85,965
Hours
Wet spell 27 Feb - 28 Feb 2026
More sewage than the rain explains

Ordinary sustained rain, and far more sewage than a day like this usually produces.

1,595
At once
7–28
mm of rain
60,186
Hours
Wet spell 23 Feb - 24 Feb 2026
More sewage than the rain explains

Ordinary sustained rain, and far more sewage than a day like this usually produces.

987
At once
2–12
mm of rain
34,974
Hours
Wet spell 25 Jan 2026
More sewage than the rain explains

Ordinary sustained rain, and far more sewage than a day like this usually produces.

1,573
At once
3–16
mm of rain
32,432
Hours
Wet spell 18 Nov 2025
More sewage than the rain explains

Ordinary sustained rain, and far more sewage than a day like this usually produces.

1,484
At once
4–22
mm of rain
26,935
Hours
Wet spell 3 Feb 2026
More sewage than the rain explains

Ordinary sustained rain, and far more sewage than a day like this usually produces.

1,349
At once
3–16
mm of rain
26,041
Hours
Wet spell 16 Jan 2026
More sewage than the rain explains

Ordinary sustained rain, and far more sewage than a day like this usually produces.

1,297
At once
2–12
mm of rain
23,334
Hours
Wet spell 26 Feb 2025
More sewage than the rain explains

Ordinary sustained rain, and far more sewage than a day like this usually produces.

1,213
At once
7–20
mm of rain
20,595
Hours
Wet spell 12 Dec 2025
More sewage than the rain explains

Ordinary sustained rain, and far more sewage than a day like this usually produces.

1,017
At once
3–13
mm of rain
19,870
Hours
Wet spell 4 Sept 2026
More sewage than the rain explains

Ordinary sustained rain, and far more sewage than a day like this usually produces.

1,235
At once
5–20
mm of rain
7,092
Hours
Wet spell 30 Aug 2026
More sewage than the rain explains

Ordinary sustained rain, and far more sewage than a day like this usually produces.

693
At once
6–24
mm of rain
5,429
Hours
Wet spell 11 Sept 2025
More sewage than the rain explains

Ordinary sustained rain, and far more sewage than a day like this usually produces.

382
At once
6–29
mm of rain
4,455
Hours

The square is how much it rained; the drop is how much sewage followed.

Sewage data begins in December 2024; rainfall goes back to December 2022. Days before the sewage record starts show rain only.

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.

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Analysing sewage pollution by the Water Industry

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