Chelsea Waterworks Company Darenth Valley Main Sewerage Board East London Waterworks Company Grand Junction Waterworks Company Kent Waterworks Company Lambeth Waterworks Company Lee Conservancy Catchment Board Metropolitan Water Board New River Company Shadwell Waterworks Company Staines Reservoir Joint Committee Southwark and Vauxhall Water Company Thames Water Authority West Kent Main Sewerage Board West Middlesex Waterworks Company

Chelsea Waterworks Company Darenth Valley Main Sewerage Board East London Waterworks Company Grand Junction Waterworks Company Kent Waterworks Company Lambeth Waterworks Company Lee Conservancy Catchment Board Metropolitan Water Board New River Company Shadwell Waterworks Company Staines Reservoir Joint Committee Southwark and Vauxhall Water Company Thames Water Authority West Kent Main Sewerage Board West Middlesex Waterworks Company

Early water supply to the city of London came directly from wells and rivers. However, as early as 1236 the fresh water supply was dwindling as the number of residents in the city increased; and works began to bring in fresh water from outside the city. The water brought in by pipes and conduits was free to all, although trade use was taxed. Warders or Keepers were appointed to manage the conduits; financed by local taxes. On special occasions such as coronations the conduits were made to run with wine.

The era of free water gave way to the era of commercial supply with the foundation of the New River Company (1612) and the London Bridge Waterworks (1581). Chelsea Waterworks Company was founded in 1723, and in 1746 laid the first iron water main (pipes were previously made of wood or lead). The Southwark Water Company was founded in 1760, the Lambeth Water Works Company in 1785, the Vauxhall Water Company in 1805, the West Middlesex Waterworks Company in 1806, the East London Waterworks Company in 1807, the Kent Waterworks Company in 1809 and the Grand Junction Waterworks Company in 1811.

From the 1820's concern was expressed over the quality of the water supply, which was heavily polluted, leading the Chelsea Waterworks Company to introduce sand filtration. Others were slow to follow and London began to suffer the first of many cholera outbreaks. The Poor Law Commissioner's Sanitary Report of 1842 described the woeful sanitary conditions of London's poor, and recommended a constant water supply to every house. In 1849 Doctor John Snow published his pamphlet explaining that cholera was water-borne, and impetus was provided for reform and renewal of London's water supply, especially provision of clean water and a constant supply. However as many Members of Parliament were also shareholders of the water companies, it took a long time for reforming bills to be passed, and those that did get passed were either ignored or did not go far enough in their reforms.

It was not until 1902 that the Metropolis Water Act was passed, leading to the creation of the Metropolitan Water Board. This took over eight private water companies, taking over the New River Company headquarters on Rosebery Avenue, Clerkenwell. The board was made up of 66 delegated members, 14 from the London County Council, 31 from the Metropolitan Borough Councils and City Corporation, and 21 from the authorities of localities outside the water companies' areas. From 1907 widespread reservoir and waterworks building was carried out.

From 1974 the administration of the Metropolitan Water Board was transferred to the new Thames Water Authority. In 1989 Thames Water became a private company and set up a principal operating subsidiary, Thames Water Utilities Limited, to supply water and sewerage services.