Sewage spills per overflow in 2024
On average, every storm overflow in England discharged raw sewage nearly 32 times last year. Only 12.5% of overflows recorded zero spills.
Pollution incidents are surging
Water companies caused 2,801 pollution incidents in 2024 — the highest figure since records began. That’s a 47% jump from 2016, with serious incidents nearly doubling in a single year.
Serious pollution is getting worse
In 2024, water companies caused 75 serious pollution incidents — up from 47 the year before. These are Category 1 and 2 events: fish kills, river contamination, harm to drinking water.
Pollution per kilometre is climbing
Normalised for network size, pollution incidents rose 27% from 36.3 per 10,000km of sewer in 2019–20 to 45.9 in 2024–25. The system is getting dirtier, not cleaner.
Three billion litres lost every day
Water companies leak nearly 3,000 megalitres per day — enough to fill 1,200 Olympic swimming pools. After decades of slow improvement, leakage has flatlined and even crept back up.
The worst offenders
Thames Water alone leaks 580 megalitres per day. Several companies — Dŵr Cymru, Southern Water, South East Water — are actually leaking more than their baseline, missing their targets entirely.
Customers are paying the price
Customer satisfaction has fallen from 82.4 to 74.7 — a 9% decline. Supply interruptions are up 8%. People are getting a worse service while bills keep rising.
The league table of failure
Only one company — Portsmouth Water — is rated “leading”. Thames Water, Southern Water, Yorkshire Water, and Dŵr Cymru are all rated “lagging” by the regulator. The system is broken from top to bottom.