Heavy rainfall in the autumn and winter is thought to be behind the huge increase in raw sewage discharges just announced by the Environment Agency. Latest figures show more than 4m hours of discharges were poured into rivers and seas last year, a 129% increase on the previous 12 months.

Total discharges from the 14,000 storm overflows owned by English water companies that release untreated sewage into rivers and coastal waters increased by 54%, making 2023 the worst year for sewage spills.

The data also shows that in 2023:

• The average number of spills per overflow was 33 compared to 23 in 2022 and 32.6 in 2020;
• 40% of storm overflows spilled less than 10 times in 2023 compared to 48% in 2022 and 40% in 2020;
• 9% of storm overflows did not spill at all in 2023 compared to 18% in 2022 and 13% in 2020.

The Guardian reports that senior industry sources were preparing for the government to turn its guns on water companies after the record year of discharges.

The Environment Agency is setting up a whistleblowing hotline for people who work in the industry to report any activity that concerns them.

Sewage discharges are also thought to be behind the discovery of E coli in the River Thames, leading Boat Race organisers to warn rowers not to enter water.