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.

Sir Joseph Bazalgette was the Victorian engineering mastermind and public health visionary behind the vast sewage system that Londoners still rely on today.

Contemporary image of a street sewer - egg shapes with a narrow walkway ath the bottom. A person can be seen wearing a head torch
An egg-shaped street sewer – narrower at the bottom than the top to encourage the flow. © Tim Newbury

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. Much was engineered in the middle of the nineteenth century and includes magnificent cathedral-like sewage pumping stations.

A sketched cartoon of 'Father Thames' introducing his children to the female embodyment of the City of London. Three sickly children shown represent diptheria, scrofula and cholera
Satirical Punch cartoon by John Leech, 3 July 1858: ‘Father Thames introducing his offspring to the fair City of London.’ The three children represent diptheria, scrofula and cholera. 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 wide use of the new flushing toilets exacerbated the problem, overwhelming cesspits and causing more waste to flow into the river.

Cartoon of a woman spinning a wheel filled with sea creatures and bugs, representing the Thames Water.
Cartoon by William Heath: ‘Monster soup commonly called Thames Water.’ Public Domain.

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 disease 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 10th 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 completely overwhelming to those nearby, including Parliament whose legislative business was disrupted.

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

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

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

Joseph Bazalgette was chief engineer of the Metropolitan Board of Works (MBW), having began his career in public health engineering in 1849. He spent several frustrating years drawing up various 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.

The Great Stink was the catalyst for radical change. 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, and one 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
Sketch of The Prince of Wales opening Crossness pumping station
HRH The Prince of Wales opening Crossness pumping station, 4 April 1865.  Public Domain.

Integral to Bazalgette’s plans was the construction of four major pumping stations to lift sewage up from low lying sewers for discharge eastwards.

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

The magnificent Crossness pumping station raised the effluent from south of the river up 12 metres into a reservoir by means of 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.

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

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.

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

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. 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.

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

Upgrading Sir Joseph Bazalgette’s sewer system – a 21st Century Super Sewer

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 spills untreated into the Thames each year, especially after extreme weather.  Tideway is in the process of 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 embankment 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:

11 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.

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