The River Fleet – London’s second tidal waterway

By , June 20, 2009 2:58 pm

London’s tidal river? Easy one, it’s the River Thames.

But the Thames isn’t the only one. The River Fleet, now mostly running underground, was a navigable, tidal river, which joins the Thames next to Blackfriars Bridge, and marks the historic boundary between the cities of London and Westminster.

The Fleet’s course isn’t a long one; it rises as  springs in Hampstead, a posh, hilly and leafy area of north London. After about half a mile, it goes underground, and is buried the rest of the way.

An extract from Greenwood's 1830 Map of London, showing the River Fleet and two bridges over it, near St. Pancras and Bloomsbury

An extract from Greenwood's 1830 Map of London, showing the River Fleet and two bridges over it, near St. Pancras and Bloomsbury


Historically, pirates operated on the River Fleet, barges went up and down, watermills were powered by it, and sewage gases exploded.

Visitors to the Royal Courts of Justice or the Temple are likely to walk along Fleet Street, and the newspaper industry as a whole is still known as “Fleet Street”, although the papers mostly moved east out of central London towards Wapping and Canary Wharf in the 1980s.

This article is about the course, history and current state of the River Fleet.

The Course and Geography of the River Fleet

The River Fleet starts life as a  number of springs on Hampstead Heath, an impressive 800-acre area of common land north of central London.  There are two main sources, one on either side of Parliament Hill, both about 350 feet above sea level.

Highgate model boat pond, created in the 1700s by damming the River Fleet

Highgate model boat pond, created in the 1700s by damming the River Fleet


The streams are dammed into a series of ponds, the Highgate Ponds and the Hampstead Ponds. Three are run as year-round swimming pools, one for men, one for women, and one mixed-sex (warning, it’s not that warm on Hampstead Heath in the winter….) The City of London Corporation runs the bathing ponds, and the relevant page on its website can be found here.

From Hampstead, the two streams run downhill, mostly underground in culverts and pipes, through Kentish Town and Camden, joining together south of Camden Town. There are memories of the Fleet River before it went underground, including Fleet Road and Fleet Primary School.

The River Fleet continues south, going under King’s Cross Station in a sewer / pipe, and southwards towards St. Pancras and Bloomsbury. A tributary of the Fleet enters from the west, having started life near Tottenham Court Road, and come past University College, London, and University College Hospital.

The mouth of the River Fleet at low tide, under Blackfriars Bridge

The mouth of the River Fleet at low tide, under Blackfriars Bridge

South of Camden, the first St. Pancras Church was built on the banks of the River Fleet in about 380 AD, and Old St. Pancras Church is still above the current course of the Fleet today.

The Fleet then wriggles its way south, west of Clerkenwell, and along the Farringdon Road.  Another tributary runs underground from near the Barbican, through Smithfield Market (meat and butchery) to join the Fleet at the south of Farringdon Road.

The Fleet’s river valley is quite deep here, a real descent from Snow Hill in the east and Holborn in the west. The Victorian Holborn Viaduct crosses the river valley.  At  the bottom of the valley, over the now-buried river, is the main road going south to Blackfriars.

Samuel Scott's 1750 painting of the River Thames and the mouth of the River Fleet

Samuel Scott's 1750 painting of the River Thames and the mouth of the River Fleet

Fleet Street, originally a road from Westminster to the City of London via Aldwych, is just to the west of the Fleet, near the River Thames. Until the first bridge was built over the River Fleet here in about 1180 AD, the Fleet could be forded at the easterly end of Fleet Street.

The River Fleet emerges today, as it has done for centuries, near Blackfriars.

There is a great website featuring photographs from all along the River Fleet’s course (overground) which can be found here.



History of the River Fleet

The Roman River Fleet

In Roman times, the River Fleet marked the westerly edge of City of London, and was outside the city walls. It was a navigable, strongly-running river, and powerful enough to run a tidal mill on one of the two small islands on the east side of the Fleet estuary. For a detailed academic article on the archaeological remains of the Roman Fleet, see here.

The Anglo-Saxon River Fleet

In 900 AD, the estuary of the River Fleet, where it joined the River Thames, was approximately 100 yards wide, and shallow and marshy at the edges. It was possible to ford the Fleet here, with care, and at low tide only. The name “Fleet” comes from an Anglo-Saxon word, fl?ot, meaning  “tidal inlet”.

The Medieval Fleet

Fleet Prison, built on the east bank of the River Fleet in 1197, and open until 1844

Fleet Prison, built on the east bank of the River Fleet in 1197, and open until 1844

As London grew after the Norman Conquest in 1066 AD, the River Fleet became very useful for boats and barges.  During the reign of King John, the Knights Hospitaller and St. Batholomew’s Hospital shared a wharf on Fleet Lane, allowing goods and people to be ferried up the Fleet from the Thames.

Further up the Fleet, near Farringdon Road today, there are road names which recall the Fleet’s barges unloading coal from Newcastle, such as Newcastle Lane, Newcastle Close, and Old Seacoal Lane.

Stone for building Old St. Paul’s Cathedral was also ferried up the Fleet.

By the 12th century, people were already complaining that the River Fleet was smelly and polluted. Several tanneries were next to the Fleet, and discharging a nasty cocktail of offal, skin scraps and dog faeces into the river.  Butchers threw unwanted and rotten animal parts in the Fleet, and human sewage and other industry by-products joined them.

In the early 13th century, the Whitefriars (Camelites) who had their base next to the mouth of the Fleet, were complaining that the stench overpowered their incense, even during Mass when there was a lot of incense being burned.

Edward I was attacked by pirates who sailed up the River Fleet – the pirates came second in the fight which followed.

The River Fleet got ever nastier, and became a slum area over time.

The River Fleet in Tudor and Stuart times

The Royal opening of the Holborn Viaduct, which passes over the Fleet River Valley, in 1869

The Royal opening of the Holborn Viaduct, which passes over the Fleet River Valley, in 1869

In 1598, John Stow wrote in his Survey of London that there were five bridges over the Fleet, and said it was, “impassable for boats, by reason of the many encroachments thereon made, by the throwing of offal and other garbage by butchers, saucemen and others, and by reason of the many houses of office standing upon it” (A “house of office” was a toilet or lavatory, here emptying directly into the river).

After the Great Fire of London in 1666, Sir Christopher Wren turned the River Fleet into the wider, straighter New Canal, with docks on both side of the river; it was about 30 feet wide. But it stayed horribly smelly, contaminated still with rubbish and sewage, and was pretty unpopular.

Higher up the Fleet, a number of fashionable wells and spas were established, as the water here was clean and uncontaminated. The most popular were Clerk’s Well, Bagnigge Well, and St. Bride’s Well. Although the wells have long-gone, Clerkenwell and Brideswell are places in London to this day.

The Covering of the River Fleet

A sarcastic drawing of the heavily-polluted New Canal / River Fleet in 1728. The bathers are a comment on the river's cleanliness

A sarcastic drawing of the heavily-polluted New Canal / River Fleet in 1728. The bathers are a comment on the river's cleanliness

Unloved, smelly, and in the way, the Fleet started to be covered over.  In 1733, the part from Fleet Bridge to Holborn Bridge was covered over, and in 1739, the stretch from Holborn to Ludgate Circus was covered over, and the Fleet Market and the Mansion House built over it.

When the Regent’s Canal was constructed in 1810 – 1815, the Fleet was buried northwards, to Camden Town, and by 1880 the whole river, apart from the few hundred yards from the source springs, was underground in pipes, conduits and the New Canal bed.

In 1846, a build up of sewage and associated gasses caused a massive explosion, and the pipes near King’s Cross blew up, sending a tidal wave of sewage through the streets, demolishing buildings, flooding houses, and ramming a boat on the Thames, near the mouth of the Fleet, into Blackfriars Bridge.

The River Fleet today

Most of the Fleet remains underground. The mouth can be seen near Blackfriars Bridge, at low tide, and the streams and ponds are popular spots on Hampstead Heath.

The truly intrepid (I am not among their number) can, if the proper arrangements are made, explore the pipes and conduits underground through which the River Fleet now flows. An article about people doing just that, underground, can be found here.



13 Responses to “The River Fleet – London’s second tidal waterway”

  1. Paraglider says:

    Fascinating article. I lived and worked in Farringdon for a year or so and became quite interested in Fleet ‘memorabilia’ around Smithfields area. The idea of the underground river is haunting.

  2. Jondoe says:

    Nice handling of a topic that has the potential to completely run away from you. Having started and stopped writing similar articles on many occasions I know all too well how that can go.

  3. Spencer Greystrong says:

    A very interesting article. The Fleet River gave a lot of trouble when the Metropolitan Railway was being built in the 1860′s. They were using the ‘cut and cover’ method at Farringdon in 1862 when the Fleet undermined the embankment ‘filling the tunnel with sewage for a great distance’.

    I can recommend a book called ‘The Lost Rivers of London’ by Nicholas Barton, first published in 1962 and revised and reprinted several times since. He lists 14 such rivers with another 5 ‘dubious’.

  4. Matthew Wright says:

    Thank you very much, maybe I’ll explore the those tunnels one day…

  5. [...] was much wider, shallower, and more marshy than it is today. (For more about the now underground River Fleet’s history and geography, click [...]

  6. Mick says:

    I have “played” underground at the Fleet. from about 9 to 13 years old during the forties and fifties.
    I am the son of a caretaker and was brought up in Charterhouse site of an old Barbican monastry and I know some of the places mentioned here.
    During the bombing of the old City, openings that had been closed for years were revealed and as a boy I spent all my free time exploring the tunnels, sewers and underground cellars that interconnected with the Fleet under the City of London.
    I explored alone using candles and pilfered bike lights.
    I had hundreds of adventures and no-one ever knew I was there.
    This included ways into St Paul’s catacombs from deep below ground. One of the tunnels connected to my old school Hugh Myddleton Secondary’s cellars. During my adventures I found an old crypt with dozens of stone coffins and cellars full of old cloth, rotten furs and barrels of what may have been flour or seeds. I also found a room full of old muskets and arms from about the 17th century. The room was knee deep in water and everything was moldy and rusty.
    Unfortunately I could never tell anyone because I would have been punished, my father was very strict. When I was 14 or so I discovered girls and never bothered ‘adventuring’ again and at 16 I emigrated to Canada and have never been back.

    Now in my old age I realize just how lucky I was to have been brought up in Charterhouse, which at the time was a secluded acreage of old buildings, cloisters, and gardens, completely enclosed with high walls and only one way in, that was locked at 9pm. Later they made another entrance at the north end of Charterhouse and I can see from the Google map that it’s now opened onto Clerkenwell road.
    Thank you for the article it brought back many memories of exciting (for me) adventures that most kids can only dream about. As a sideline – I now enjoy dungeon crawling role playing games.

  7. Alan says:

    Very interesting I also have seen the River Fleet underground.I worked in Fleetway House on Farringdon Street and this building had what we called dungeons these were used as air raid shelters in the war and still had writing on the walls showing hospital exit etc. The River also was here and occasionally used to flood part of the dungeons. The building has since been demolished and Barclays Bank is there. Great memories for me and one of London’d hidden treasures>

  8. p.e.owen says:

    I worked for Westminster City Council in the late 50′s 60′s and rember going down the sewer from Dury Lane (I worked in Engineers drawing office) it was part of the job to know how the sewers worked the Fleet river at that time ran above our heads in a culvert, we walked in the sewer below it, also we had a tour from Argil St. to Regent St, that was very inpressive

  9. p.e.owen says:

    I worked for Westminster City Council in the late 50′s 60′s and remember going down the sewer from Dury Lane (I worked in Engineers drawing office) it was part of the job to know how the sewers worked the Fleet river at that time ran above our heads in a culvert, we walked in the sewer below it, also we had a tour from Argil St. to Regent St, that was very inpressive

  10. Rayna Zink says:

    I simply found your blog unexpectedly from the search engine. 1st time I saw it, I recognize it’s a terribly informative blog. I got therefore many something new from here. Good work and thanks for that!

  11. Jenny Bergner says:

    Thank you. I found this very informative. I am reading The Fields Beneath, about Kentish Town where I grew up. I walked over Parliament Hill Fields and Hampstead so many times and my school was close by. I nearly dipped in the ponds but my mother told stories of people being drowned, caught in the weeds.

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