Thames Water dumps tonnes of sewage on parliament’s doorstep

Over the last five years, both Tory and Labour ministers have stood at the despatch box to denounce the sewage scandal.

But Good Law Project can reveal that Thames Water has been steadily dumping sewage on parliament’s doorstep. Between 2020 and 2024, the five storm overflows located within a half a mile of Downing Street have poured sewage out into the river for a total of almost 900 hours.

Two of these sewer overflows operate next to a bust of Sir Joseph Balzagette – the engineer who built the Victorian sewer network that London still relies on.

“Sewage is being dumped right under MPs’ noses and still there’s been no meaningful action to tackle the root cause of the problem: the greed of water companies’ owners”, said Good Law’s Project’s executive director, Jo Maugham.

“We’re in an absurd situation where Thames Water can dump on the government’s doorstep for almost 900 hours, and still Steve Reed is too frightened to trigger the only real fix: a debt haircut for owners,” Maugham added.

Last month the Court of Appeal ruled that Thames Water can borrow £3bn more, a plan which many observers think means customers will face even higher bills.

Over its entire sewer network, Thames Water discharged raw sewage over 23,000 times for almost 300,000 hours last year – figures that are up 35% and 51% from 2023. But, remarkably, it was still one of the least polluting water firms in 2024. 

The worst offender was South West Water, which dumped sewage into the sea, rivers, and waterways on a whopping 56,000 occasions, over a duration of 544,000 hours. 

The total number of spills across the industry reduced in 2024 by 2%, but the severity of those spills has increased. The total duration has surpassed 2023’s record, rising to 3.62m hours.

Thames Water is counting on a new super sewer to cut pollution in London’s rivers and waterways. But four of the five overflows near parliament are not connected to the tideway tunnel, so will carry on pouring raw sewage into the Thames for the foreseeable future.

It’s the latest example of mismanagement that will see the firm’s debt soar to a massive £22bn.

When we put these figures to Thames Water, it insisted the company would “deliver a record amount of investment to address our ageing infrastructure” over the next five years.

“This includes £1.8 billion to improve river health in London,” the firm said. “In addition, the newly completed tideway tunnel will reduce the volume of discharges entering the tidal Thames in a typical year by 95%.”

“We are continuing to execute our plans to upgrade over 250 of our sites across the region to lower the number of storm discharges.”

When we approached the environment department for comment, they referred us to Environment Secretary Steve Reed’s statement, in which he called the latest sewage dumping figures “disgraceful” and pledged to take “further and faster” action.

MPs may carry on debating our broken water industry, but customers will be paying for Thames Water’s failures for years to come.