There was such a bad smell coming from the river that Londoners started gasping. Those who could afford to flee the city. Those left behind soaked their curtains in chloride of lime to avoid the smell and placed handkerchiefs over their noses whenever they went out. The local press wrote, “He who once breathes the funk can never forget it, and may consider himself lucky if he lives to remember it.”
It was 1858. Temperatures remained above 30 °C (86 °F) for several weeks. Not a drop of rain fell to cool the city or wash away the filth that was sinking into the River Thames. London’s lifeline became an open sewer: a dirty, sludge-filled mixture of human and animal waste, garbage and industrial pollution. The persistent heat caused the river to reach unusually low levels, leaving sewage and rotting garbage visible on its banks. Scorching in the summer sun, the rotting waste fermented, creating a suffocating smog over the city.
‘A deadly sewer’
Between 1800 and 1850, London’s population doubled to 2.5 million, making the capital of the British Empire the largest city in the world.
But its old, hopelessly decrepit sewer system could not keep up. Waste from homes and businesses flowed directly into the Thames.
The increasing popularity of indoor flush toilets in wealthy homes has made matters worse. Human waste was discharged directly into the river. In past centuries, cesspools were emptied at night by so-called “night soil men”.
Now, at high tide, the polluted water came back into the streets. Londoners were used to the foul smell from the Thames. But the Great Stink surpasses everything they ever knew.
Charles Dickens wrote in Little Dorrit, “In the heart of the town instead of a fine fresh river there bubbled and flowed a deadly sewer.”
Still people kept bathing in the river and drinking its water.
A fatal misconception: Bad air causes disease
During the Summer of the Great Stink, outbreaks of dysentery, typhoid, and the dreaded cholera spread rapidly. At the time, most people believed that diseases were caused by breathing in foul-smelling air – poisonous “miasma”, a theory dating back to ancient Greece.
During the first cholera epidemic between 1831 and 1854, which killed more than 30,000 people, physician John Snow noticed a pattern. In the poor Soho district of London, about 500 people died when overflowing sumps contaminated the neighborhood’s water supply.
Snow became convinced that the disease was spread not by bad air but by polluted drinking water.
He famously removed the handle from the neighboring Broad Street water pump, ending the outbreak.
He later mapped cholera deaths near other public pumps and found the same pattern.
But few politicians were ready to accept his theory. Snow died in June 1858 – just before the Great Stink reached its peak.
a new sewer system
For years, London’s Metropolitan Board of Works had urged lawmakers to modernize the city’s sewer system. Parliament repeatedly refused to fund the project. The grand monuments attracted far more attention than the underground infrastructure.
That changed when lawmakers experienced the terrible stench themselves.
The recently completed Palace of Westminster, home of Parliament, is located right next to the Thames. During the Great Stink, the smell became so strong that people abandoned the building and fled to the countryside. Ultimately, he approved a decision he had delayed for years: London would finally be free of the river’s “noxious breaths”. Within just 18 days, Parliament passed legislation allocating £3 million for the construction of a new sewer system.
Engineer Joseph Bazalgette was chosen to solve the crisis.
He designed approximately 1,800 kilometers (1,100 mi) of underground sewers, which intercepted waste from streets and buildings before it could flow into the Thames. They also built embankments and riverside promenades that hid the main sewer lines, protecting the city from flooding. Finally, they built two giant pumping stations that lifted the waste water so it could be continued through the system.
Completed in 1868, the Abbey Mills Pumping Station became known as the “Cathedral of Sewage” for its magnificent architecture – but above all, it stood as a triumph over filth, disease and polluted streets.
A system that lasted into the 21st century
By 1875, the project was completed. Bazalgette built the world’s most advanced sewer system at the time. Notably, he planned for the future of London, designing it to serve a population 50% larger than that of the city at the time – approximately 4.5 million people. Since then, cholera became history.
More than 150 years later, almost 9 million people live in the city, and Bazalgette’s Victorian pipes are struggling with the demands of modern life – clogged with everything from sanitary pads and diapers to condoms and food waste.
Despite subsequent expansions, their system remained the backbone of London’s wastewater network until 2025, when the 25-kilometre Thames Tideway Tunnel was opened to relieve pressure on the historic sewers. Because no one in London wants to experience the Great Stink again.
This article was originally written in German.