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

The Story of London’s Sewer System

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

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 nineteenth century and included magnificent cathedral-like sewage pumping stations.

View of decorative ironwork inside Crossness Pumping Station
The restored Crossness pumping station today. Its Romanesque-style architecture features spectacular ornamental cast ironwork. Listed Grade I. © Historic England DP060324.

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.

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.

Cartoon of a robed skeleton travelling down the Thames in a wooden boat
Punch cartoon 10 July 1858: ‘The Silent Highwayman’ – Death rows on the Thames at the time of the ‘Great Stink’, July/August 1858. Public Domain.

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

Tons of lime was 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.

Punch Cartoon
Punch cartoon showing a workman spreading lime, watched by Old Father Thames, 31 July 1858. Public Domain.

Sir Joseph Bazalgette

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

Portrait of Sir Joseph Bazalgette
Sir Joseph Bazalgette (1819-1891). Public Domain.

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.

Sketch showing people constructing sewage tunnels
Construction of sewage tunnels near Old Ford, Bow, East London. © Wellcome Images.

Parliament gave full responsibility for cleaning up the Thames to the MBW – favouring Bazalgette’s plans – along with 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 both 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 that he had been vindicated.

BLOG crossness group of workers & officials archive HE OP04614
Group of workers and officials – Joseph Bazalgette possibly among them – outside the unfinished Crossness pumping station, Abbey Wood, London. Designed by Joseph Bazalgette and architect Charles Driver. © Historic England 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 south of the river up 12 metres into a reservoir using four enormous powerful beam engines, 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.

Archive image of one of the four beam engines.
Archive image of one of four beam engines at Crossness, London. © Historic England OP04623.

Effluent from north of the river was pumped by Abbey Mills pumping station – another temple of engineering in elaborate Italianate Gothic style – for similar discharge into the Thames, well beyond the city limits.

Decorative exterior of Abbey Mills pumping station, London.
Abbey Mills pumping station, Stratford, London, 1868, designed by Joseph Bazalgette, Edmund Cooper and architect Charles Driver. Listed Grade II*. © 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 to create the vast Albert (1869) Victoria (1870) and Chelsea (1874) Embankments to accommodate his low lying sewers.

BLOG victoria embankment 1890 postcard public domain
Postcard of the Victoria Embankment, 1890. Public Domain.

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

BLOG memorial joseph bazalgette creative commons
Memorial to Sir Joseph Bazalgette (knighted in 1874), Victoria Embankment, London. Listed Grade II. Creative Commons.

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

One of the super sewer’s six giant Tunnel Boring Machine
One of the super sewer’s six giant Tunnel Boring Machine © Thames Tideway

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

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 of 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.

13 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.

  3. Susan Conway

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

  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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