View of decorative ironwork inside Crossness Pumping Station
A brief introduction to Architecture Historic photography

The Story of London’s Sewer System

Hidden beneath London's streets lie incredible tunnels and sewers that take waste from our homes.

Hidden beneath the city streets of London lie 2,000 kilometres of brick tunnels that take raw sewage from our homes, along with 130 kilometres of interconnecting main sewers the size of railway tunnels.

Much was engineered in the middle of the 19th century, including magnificent cathedral-like sewage pumping stations.

The Great Stink

In the 19th century, London’s population numbered around 2 million. The city suffered fatal epidemics of cholera when thousands died. The Victorians had no known cure.

A cartoon of a robed skeleton travelling down the Thames in a wooden boat.
This punch cartoon from 10 July 1858, called ‘The Silent Highwayman’, shows Death rowing on the Thames at the time of the ‘Great Stink’.

It was widely believed breathing in ‘miasma’, foul contaminated air, caused disease and death.

London-based physician Dr John Snow put forward the theory that the condition was water-borne, but his ideas received little attention. The year 1853-54 saw cholera claim a further 10,738 victims.

In the scorching summer of 1858, temperatures averaged 35 degrees Celcius. The stench from the Thames, the ‘Great Stink’, became overwhelming for those nearby, including Parliament, whose legislative business was disrupted.

A Punch cartoon.
A Punch cartoon showing a workman spreading lime, watched by Old Father Thames. Published 31 July 1858.

Tons of lime were spread on the Thames foreshore and near the mouths of sewers discharging into the river to try and dissolve the toxic effluent, with little effect.

Parliament was forced to legislate to create a new unified sewage system for London. The Bill became law on 2 August 1858.

Sir Joseph Bazalgette

The Great Stink was the catalyst for radical change. Sir Joseph Bazalgette was the Victorian engineering mastermind and public health visionary behind the vast sewage system that Londoners still rely on today.

A portrait of Sir Joseph Bazalgette.
A portrait of Sir Joseph Bazalgette.

Before Bazalgette’s designs, raw sewage seeped from inadequate sewers into the River Thames, turning it into a stinking open sewer, its foreshore thick with untreated human waste, industrial discharge and slaughterhouse effluent.

The increasingly widespread use of the new flushing toilets exacerbated the problem, overwhelming cesspits and causing more waste to flow into the river.

Bazalgette was chief engineer of the Metropolitan Board of Works (MBW), having begun his career in public health engineering in 1849.

He spent several frustrating years drawing up plans for a revolutionary rethink of the city’s sewers, only to see them repeatedly shelved as Parliament and others argued about the system’s merits.

A sketch showing people constructing sewage tunnels.
This illustration shows the construction of sewage tunnels near Old Ford in Bow, East London. © Wellcome Images.

Parliament gave full responsibility for cleaning up the Thames to the MBW, favouring Bazalgette’s plans and the ability to borrow £3 million. This was a colossal sum then, which had more than doubled by the end of the project.

When completed in the mid-1870s, the new sewage network’s enclosed design, which captured sewage and rainwater, virtually eliminated cholera.

Dr John Snow’s theory about cholera being a water-borne disease was correct, although he died at the height of the Great Stink without knowing he had been vindicated.

A photograph of a large group of workers standing outside a historic building surrounded by scaffolding.
A group of workers and officials, Joseph Bazalgette possibly among them, outside the unfinished Crossness Pumping Station in London. © Historic England Archive. OP04614.

Integral to Bazalgette’s plans was constructing four major pumping stations to lift sewage from low-lying sewers for discharge eastwards.

Beautiful Victorian pumping stations

The magnificent Crossness Pumping Station raised the effluent from the south of the river up 12 metres into a reservoir using four enormous powerful beam engines.

A photograph of the decorative ironwork inside Crossness Pumping Station
The Grade I listed Crossness Pumping Station in London. Its Romanesque-style architecture features spectacular ornamental cast ironwork. © Historic England Archive. DP060324.

It was designed by James Watt & Co and named Victoria, Prince Consort, Albert Edward and Alexandra.

From here, it was released into the Thames well beyond London, swept out to sea on the ebbing tide.

A black and white photograph of one of the old four beam engines.
One of four beam engines at Crossness Pumping Station in London. © Historic England Archive. OP04623.

Abbey Mills pumping station pumped effluent from the north of the river. Completed in 1868, it’s another temple of engineering in elaborate Italianate Gothic style, for similar discharge into the Thames, well beyond the city limits.

A photograph of the decorative exterior of Abbey Mills pumping station, London.
The Grade II* listed Abbey Mills Pumping Station in Stratford, London. © Look Up London.

London’s embankments

Bazalgette, who remained Chief Engineer of the MBW for 33 years, also changed the face of London by reclaiming 7 kilometres of riverside land and muddy foreshore.

A postcard showing the Victoria Embankment in 1890.
A postcard of the Victoria Embankment in 1890.

Here, he created the vast Albert (1869), Victoria (1870) and Chelsea (1874) Embankments to accommodate his low-lying sewers.

He also laid out new city thoroughfares, including Shaftesbury Avenue, Northumberland Avenue and Charing Cross Road, and built bridges across the Thames, including Hammersmith and Battersea.

A photograph of the stone memorial to Joseph Bazalgette.
The Grade II listed memorial to Sir Joseph Bazalgette on Victoria Embankment in London.

Joseph Bazalgette’s enlightened public health legacy is largely unsung today, with his sewer network hidden deep beneath the city. This small wall-mounted bust is Bazalgette’s only public memorial.

Upgrading Bazalgette’s sewer system

London’s 150-year-old sewage system is today struggling under the strain of the city’s ever-increasing population, which is now nearly 9 million.

A photograph of one of the super sewer’s giant Tunnel Boring Machines.
One of the Thames Tideway Tunnel’s six giant Tunnel Boring Machines. © Thames Tideway.

Millions of tons of raw sewage still spill untreated into the Thames each year, especially after extreme weather.

Tideway is building a ‘super sewer’, the Thames Tideway Tunnel, to relieve the pressure on the old system. It will run under London for 25 kilometres, from Acton in the west to Beckton in the east, at depths between 30 and 60 metres, using gravity to transfer the waste eastwards for treatment. It is due for completion in 2024.

As part of the super sewer project, a new barrier is planned for the river by Blackfriars Bridge. The public open space will be named Bazalgette Embankment in honour of Sir Joseph Bazalgette.

Written by Nicky Hughes.

Further reading

16 comments on “The Story of London’s Sewer System

  1. I find Victorian pumping stations fascinating, I’m not far from Papplewick in Nottinghamshire & love to see it ‘in steam.’ Is it possible to visit Crossness & Abbey Mills at all?

  2. Lancastrian

    Today we have much to thank the Victorians for throughout out Britain their achievement’s are amazing mainly through vision, innovation man power and sacrifice.

    • Or greed.

      • Yes we have a lot to thank them for – of course Parliament should have done something earlier, but thank goodness that a brilliant Englishman like Joseph Bazalgette, from Enfield. Most of the Victorian structures and buildings stand today.

      • Reply to Robbie – not sure where ‘greed’ comes in to this. The building of the sewage system was essential and well done by Bazelgette. A master of engineering.

  3. Susan Conway

    Nothing we build today will work for as long as theirs has. We should be very thankful for their amazing workmanship.

    • maggiemoo2015

      Im thankful as my family come from the mills on both my sides. My Great Grandad owned his mill and was a proud man but kindly. We were not rich but lived in a very happy environment. I so wish we had more of that now. Every day new perversions are discovered and i find society generally a no go area.
      Can i put a picture in here ?

  4. 2,000 kilometres is a great achievement, pity that we are unable to achieve such a result these days. It takes years to do just a few metres!

  5. A truly great man; also Dr. Snow. They persevered in the face of continuing scepticism and obfuscation by poiiticans. As motorways are extended and new airport runways planned have our rulers yet learned any lessons in the face of climate change and plastic polution?

  6. Rashid Makhdum

    Inverted egg shaped sewers also exist in Walled City of Lahore, Pakistan. Those were probably laid by the Victorian Government in 1870s just after the introduction of piped water supply. Some of these mains are still in use. I happened to witness one of these lines in 2010 when it was replaced with a concrete sewer in one of the southern bazaars of the Walled City. Amazing how quickly the technology traveled in those days.

    • maggiemoo2015

      Hi , this is interesting. Im slowly searching for underground reservoir pictures, not for any reason except i love finding the beauty carved and moulded into the spaces. Im doing continent by continent and so many created in the desert areas of course. I will search re the walled city and its restructuring , id have thought it would have been protected . You are blessed to have been there whatever your belief. I am a collager 2D and 3d and collect images for my art. Respect Amanda

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