Sunnyside Reservoir is a reservoir forming part of the Hampton

Hampton, London

Hampton is a suburban area, centred on an old village on the north bank of the River Thames, in the London Borough of Richmond upon Thames in England. Formerly it was in the county of Middlesex, which was formerly also its postal county. The population is about 9,500...

 waterworks complex within the London

London

London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...

 borough of Richmond-upon-Thames.

The reservoir was originally built by the Southwark and Vauxhall Waterworks Company

Southwark and Vauxhall Waterworks Company

The Southwark and Vauxhall Waterworks Company was a utility company supplying water to parts of south London in England. The company was formed by the merger of the Southwark and Vauxhall Water Companies in 1845 and became part of the publicly-owned Metropolitan Water Board in 1903.-Southwark Water...

 for pre-treatment water storage, but is now used as a settlement lagoon for washwater from the adjacent treatment works before the water is discharged back to the river Thames. The reservoir is now owned and managed by Thames Water

Thames Water

Thames Water Utilities Ltd, known as Thames Water, is the private utility company responsible for the public water supply and waste water treatment in large parts of Greater London, the Thames Valley, Surrey, Gloucestershire, Wiltshire, Kent, and some other areas of in the United Kingdom...

.

There was an idea to build a bridge for cyclist and pedestrians over the river adjacent to the reservoir in 2002, but this was very expensive and not progressed.