London Underground is a damp place at the best of times. Every day, according to Transport for London, 30 million litres of water are pumped out of the system. To put that figure in familiar, boozy terms, this is the equivalent of around six pints for every Londoner, every 24 hours. With modern pumping equipment, the challenge is surmountable. But it wasn't always routine. And when the rains fall, or the tide swells, or pipes burst, things can still go very badly wrong.
Flooding on the tube network is surprisingly common. In the early days of the network, any heavy storm would close down the cut-and-cover lines, with notable incidents in 1899, 1901, 1904, 1906 and 1915. The line from King's Cross to Farringdon was particularly prone, with steep banks and the underlying River Fleet always threatening to break from its sewer. Large-scale flooding is now a reduced threat, but localised incidents sill occur, such as the inundation of Stratford just before the Olympics.
We've picked out 10 examples of floods from the archives, many of which you won't have heard of before.
1862: King's Cross to Farringdon
The first section of the London Underground was flooded at least twice before it even opened. In June 1862, a heavy downpour caused the Fleet Sewer to burst its containment, flooding the works and destroying a large section of wall (see image, top). It was inundated for a second time a month later when another storm flooded the works near Acton Street. The waters came so rapidly that surprised workers were forced to 'leave a portion of their clothes and their tools behind them' (Kentish Chronicle). The Fleet once again intruded into the rail channel, to a depth of 15 feet.
1885: Sloane Square
Like the River Fleet, the River Westbourne was long ago covered over and converted into a sewer. It's a well-known bit of London trivia that the sewer can be spotted from the platforms of Sloane Square station, where it passes overhead in a steel pipe. A decrepit precursor to this conduit burst open in June 1885 following a heavy downpour. Fortunately, nobody was injured, but the tracks were flooded to a depth of three feet while the sewage was pumped back out. The replacement pipe was made of sterner stuff, and held firm when a direct hit on the station in 1940 claimed many lives.
1901: King's Cross to Farringdon
This troublesome stretch was often flooded, but was particularly stricken following continuous heavy rain in July this year. The tracks were closed for several days while workmen pumped with futility against the ongoing downpour. Elsewhere, Crouch Hill station was said to be submerged under seven feet of water. 'Business men are only able to reach town with much difficulty,' noted the Manchester Evening News.
1911: Piccadilly Circus
A freak storm unleashed such quantities of rain on the capital that coster carts in Ludgate were washed a considerable distance down the road. In Piccadilly Circus, a drainage pipe burst, flooding the Bakerloo pedestrian tunnels to a depth of a foot. Remarkably, the trains kept running throughout, though two lifts were put out of action. The storm is also notable for an account of ball lightening appearing outside the Foreign Office in Whitehall. 'Its descent was accompanied by a loud cackling [sic] sound, which caused some alarm, but no damage was done,' reported the Dundee Courier.
1928: Thames Flood
The last major river flooding in central London occurred in January of this year. Large tracts of riverside were submerged and 14 people died. (In one forgotten incident, a pyjama-clad, off-shift policeman dived into the basement of the Tate gallery to rescue a trapped man, before spending the entire evening rescuing others, and then reporting for duty for his morning shift. What a hero.) The Underground was, of course, also affected. Many stations were inundated, including some upriver such as Putney. Meanwhile, the Blackwall and Rotherhithe tunnels were completely flooded.
1930: Tottenham Court Road
The morning rush hour traffic was disrupted on 15 December, when a 24 inch water main burst on Oxford Street. But considerably more damage was done down in Tottenham Court Road tube station. Water crept in through the roof, flooding the main ticket hall and sending an ankle-deep torrent down the escalators. The situation was just about under control, when a second flood occurred. Those in the booking hall had to run for their lives. Large amounts of sand and cement were washed into the concourse, and many tiles fell off the buckled walls. Yet the Central Line was only down for a few hours and the station itself reopened the same day. A similar incident occurred the year before at Aldwych station.
1939: IRA Attacks
In a little-remembered incident just before the Second World War, two suitcase bombs were detonated at Leicester Square and Tottenham Court Road by IRA sympathisers. Five people were injured, one seriously, and the stations were badly damaged. At Tottenham Court Road, the blast ruptured a major water pipe, leading to the station's second flooding in a decade.
1939: Planning for War
In the run-up to the Second World War, a devastating aerial bombardment of London was feared and anticipated. Several tube stations close to the river and major water mains were closed down between September and December 1939 to allow the installation of flood gates. If a tunnel was bombed, these could be closed to prevent the inundation spreading through the network. Notably, Charing Cross and Waterloo were fitted with ten steel gates, each weighing six tons. As it happened, the gates were never needed. However, an earlier concrete plug saved the day after an old section of tunnel loop at Charing Cross was hit.
Although enemy action never caused the Thames to flood into working tunnels, a direct hit on Balham station in 1940 broke a water main. A torrent of water and mud gushed down into the station tunnels, killing at least 65 people. More photographs of this horrific incident are collected here.
Today, the greatest risk of flooding comes from heavy downpours and burst water mains. One incident just before the 2012 Olympics saw Stratford Central Line station closed for a day, when a water pipe burst, flooding the track with 2 million litres. It's not just an issue for the tube. In 2021, Pudding Mill Lane DLR station and Hackney Wick Overground station (both adjacent to Stratford) both saw heavy flooding at concourse level. Such incidents are only likely to get more common as climate change affects weather patterns further.
See also: London Reconnections also has an article covering some of the more famous flood incidents in more detail.