Another of London’s now hidden rivers also rises in the Hampstead area. It is the River Westbourne and it is believed its source is situated at Whitestone Pond on Hampstead Heath. It has not always been called by its present name. In fact, over the years, it has been known by up to ten other names including the River Serpentine, River Kilburn, River Bayswater and the River Ranelagh. If we follow the course of the river from its source we find that it flows through Kilburn under such roads as Kilburn Park Road, Craven Terrace and Gloucester Terrace.
Hyde Park is a very large area of greenery right in the centre of London. And one of the best-known features of the park is the Serpentine. This is a lake which was created in 1730 when the River Westbourne was dammed on the instructions of the wife of George II, Queen Caroline. Today the Serpentine is used for boating and in parts for swimming. In fact, in 2012, it formed the swimming section of the Olympic Games Triathlon.
However, although the lake is still here it is no longer supplied by the Westbourne. This ceased in 1834 when it was incorporated into the London sewer system. Today the Serpentine relies on three bore holes for its water supply.
From Hyde Park the Westbourne flows under Knightsbridge whose name apparently refers to a real bridge which crossed over the river. We have reports that this bridge was in existence as far back as the twelfth century. In the early part of the eighteenth century the river was redirected into pipes in order that the ground could be built upon. There is a point on the river’s course where these pipes which still carries the river, can be observed. Go to Sloane Square Tube Station and stand on the platform. Above, you will see a green metal conduit. This carries the pipes of river water.
The Westbourne next reaches Bourne Street before passing under Chelsea where it finally outfalls into the Thames. You can still see a part of this outfall about 300 metres to the west of Chelsea Bridge. It takes the form of a pipe called the Ranelagh Sewer and can be observed at low tide.