COULD THE THAMES FLOOD?

Night after night, we watch the scenes from around the country: motorboats going up and down main streets, helicopters lifting people off rooves, church towers poking defiantly above the water, businesses destroyed, homes ruined. It hasn’t happened in London – yet. Could it?

It has. In 1928, heavy snowfall at Christmas in the Cotstwolds near the source of the Thames was followed at New Year by a sudden thaw, heavy rain, a high tide and a storm surge in the North Sea, raising levels in the Thames Estuary to 1.5 metres above normal. The situation was made worse by the recent dredging of the Thames, designed to deepen the river channel and allow bigger boats into the port, but having the unintended consequence of speeding the surge of water. In the early hours of January 7^th 1928, the river burst its banks from the City all the way to Hammersmith. Fourteen people were drowned in basement flats in Lambeth. The ground floor of the Tate Gallery (now Tate Britain) was flooded, damaging several Turner paintings. Water swept onto the terrace of the House of Commons, forming a pool at the base of Big Ben. The old Lambeth Bridge was destroyed. The dilapidated area around Millbank was particularly badly affected, and the flood prompted an extensive new build, including the construction of Thames House, now headquarters of MI5.  

In 1953, catastrophic floods which killed over 300 people down the east coast of England reached London, but got no further than Canning Town in the east, and claimed only one life: a night watchman who inhaled the fumes of a broken gas pipe. It was enough, though, to speed up work on a flood barrier.

The Thames Flood Barrier was opened in 1984. When closed, it shuts off the inland river, protecting it from what is happening out at sea, containing surges caused by heavy rain, stormy conditions and high tides. It’s worked so far; we ought to be safe. But the fear of flooding is still there in the folk memory. One colleague at the school I teach at recalls the pre-Thames Barrier flood drill. When the waters rose, the air raid sirens would be sounded all over Hammersmith. Her task was to seize a mop and go round all the toilets cleaning up the waste that would back up from the sewers (she must have been very junior). Though the Barrier is supposed to last till 2070, some say the effects of climate change mean it will be unfit for purpose long before that. The river made our city, and the river could destroy it. The prosperity of the city in the form of its carbon footprint could yet be its downfall. Another reason to get on your bike.