Sewage flowed into London’s waterways for a whopping 12,000 hours last year

Thames Water dumped three times the amount of sewage in 2023 than in 2022

India Lawrence
Written by
India Lawrence
Contributing writer
Protestor with placard protesting sewage pollution in the Thames
Photograph: JessicaGirvan /

Londoners, we bring you disgusting news. Last year sewage was pumped into the capital’s waterways for more than 12,000 hours. That’s a lot of human waste going in to the city’s H2O supply. 

Despite this, just a few days ago mayor Sadiq Khan reaffirmed his manifesto promise to make all the capital’s waterways ‘swimmable’ by 2034. We can only hope.  

According to City Hall officers, sewage was released by Thames Water into the capital’s rivers for 12,105 hours and 38 minutes between March 2023 and March 2024. In contrast, this figure was only 3,361 hours and 17 minutes in the year prior, roughly a third of the sewage that was dumped in the water this year. For shame! 

Thames Water said ‘taking action to improve the health of rivers is a key focus’. While Sadiq Khan promised he wouldn’t allow the problem to continue. 

‘London’s rivers are the arteries of our city and should be a source of pride to us all but levels of sewage that water companies are pouring into our rivers is a scandal,’ Khan said. 

‘I will not stand by and allow this to continue. As well as demanding clear action from Thames Water, I will launch an ambitious plan to make London’s rivers and waterways so clean that they could be safe for swimming within 10 years.’

A Thames Water spokesperson responded: ‘We regard all discharges as unacceptable and taking action to improve the health of rivers is a key focus for us.

‘2023/24 has been the wettest winter in a decade, causing unprecedented levels of groundwater to enter the sewer system. The sewer system was historically designed to work in this way, relieving pressure caused by very wet weather to prevent sewage backing up into people’s homes.’

London’s newly completed ‘super sewer’ will divert 34 of the most polluting sewage outflows which flow into the Thames, but it’s not set to operate until 2025. On Time Out we’ve extensively covered the capital’s brand-new Thames Tideway tunnel: here are some pictures of it and here you can read more about the seven new Thames embankments that have resulted from the project

ICYMI: This beloved south London lido has reopened after a £4 million makeover.

Plus: A huge new curved bridge is coming to east London.

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