Above: Looking west while standing on the eastbound platform of Sloane Square Underground Station. The River Westbourne still flows through the large green box-section ‘tube’ above the two platforms.
Its a great shame that many of the tributaries of the Thames can no longer be seen above ground as they cross parts of Inner London. Due to the development of the land, most of the tiny streams are now buried in pipes or culverts. Many streams flow in sewer pipes and it is only with the aid of old maps showing their original course that it is possible to work out where the streams once flowed. Many of the deep underground lines run well below the level of London’s lost rivers. In the case of the underground lines that are ‘sub-surface’ – meaning that they run only a few feet below the surface of the ground – they posed a particular problem when they were constructed because they were at the level of some of the ancient streams.
One particular case is the River Westbourne. Today it is buried below ground level as it flows aross land that is now part of Paddington. Its course is seen above ground as The Serpentine, in Hyde Park. From there it once ran across land which became Sloane Square Underground Station, in Chelsea. To allow it to continue flowing, as ingenious solution was to construct a large rectangular ‘tube’ in which the water could flow just above platform level. It can easily be seen by passengers using either of the two platforms. This is the only known example where one of London’s streams actually crosses the site of a station.