Anyone who has read Ben Aaronovitch’s darkly funny, somewhat addictive fantasy thriller Rivers of London, would know that the Thames is not the only river that traverses the capital.
Rising in Hampstead, the River Westbourne – which has also been called the Kilburn, the Bayswater, and the Serpentine River, among other names – flows south through Bayswater, and enters Hyde Park at what is now the Serpentine, which was formed in 1730 by building a dam across the Westbourne at the instigation of Queen Caroline to beautify the royal park.
It then crosses through Knightsbridge, which was originally a bridge over the Westbourne itself (where the citizens of London met Queen Matilda of England in 1141), and runs south under Bourne Street, SW1, through Sloane Square and on through Chelsea to join the River Thames near the Chelsea Hospital.
The waters of the Westbourne were originally pure and in 1437 and 1439 conduits were laid to carry its water into the City of London for drinking. In the 19th Century, however, the water became filthy and impure by its use as a sewer, and the rise of the water closet as the prevailing form of sanitation. It ceased to provide the water for the Serpentine in 1834.
When Belgravia, Chelsea and Paddington were developed in the early 19th Century, it became necessary to drive the river Westbourne underground to build over it. The river was therefore directed into pipes in the early part of the nineteenth century and the Westbourne became one of the lost rivers of London.
The original pipe can still be seen running above the platform of Sloane Square tube station. It is located just below the ceiling towards the end of the platforms closest to the exits. Although the station was badly bombed during the Battle of Britain in November 1940, the old iron pipe was not damaged.