London water supply infrastructure

A crisis point was reached in the mid 19th century with the discovery that cholera arose from the extraction of water from the increasingly polluted Thames.

[1] The London area is classified as "seriously water stressed",[2] receiving less rain than Rome, Dallas, or Sydney,[3] and continued investment will be required to counteract the effects of climate change and a growing population in the 21st century.

This was a lead pipe which led via Charing Cross, Strand, Fleet Street and Ludgate to a large cistern or tank in Cheapside.

[6][7] The city authorities appointed "keepers of the conduits" who controlled access so that users such as brewers, cooks and fishmongers would pay for the water they used.

Wealthy Londoners living near the conduits could obtain permission for a connection to their homes, but this did not prevent their unauthorised tapping.

[9] Around 1593, another pumping station was built, again with the backing of the city, at Broken Wharf on Upper Thames Street by Bevis Bulmer.

[9] Initially proposed in 1602 by Edmund Colthurst, who had obtained a patent from King James I granting him the water rights, approximately 3 miles (5 km) of channel were dug before the project ran into financial difficulties.

In 1606, the City of London petitioned Parliament, which passed a series of acts overriding Colthurst's patent and transferred the water rights to Hugh Myddelton, who helped fund the project.

The Borough Waterworks Company was formed in 1770, originally supplying water to a brewery and the surrounds: between London and Southwark Bridges.

It was established on the south bank of the River Thames close to the present site of Hungerford Bridge where the Royal Festival Hall now stands.

[12] As London grew in the 19th century, facilities were needed to serve the increasing population in newly developed areas.

In 1832 the Lambeth Waterworks Company built a reservoir at Streatham Hill, and in 1834 obtained an Act of Parliament to extend its supplied zone.

[20] In 1833 the South London Waterworks Company was supplying 12,046 houses with approximately 12,000 imperial gallons (55,000 L) of water per day.

In 1829, the East London Waterworks Company moved their source of water further up river to Lea Bridge as a result of pollution caused by population growth.

[16] In 1845 the limits of supply of the company were "all those portions of the Metropolis, and its suburbs, which lie to the east of the city, Shoreditch, the Kingsland Road, and Dalston; extending their mains even across the river Lea into Essex, as far as West Ham.

[22] On 10 January 1845 the Southwark and Vauxhall waterworks companies submitted a memorandum to the Health of Towns Commissioners proposing amalgamation.

The Grand Junction, West Middlesex and Southwark and Vauxhall Waterworks Companies built the works above Molesey Lock at Hampton designed by Joseph Quick.

[17] In the mid 19th century the East London Waterworks Company purchased the Coppermill at Walthamstow and modified it to drive a water pump to assist in the building of reservoirs on nearby marshland in the Lea Valley .

A series of arbitration hearings was held to determine the amount that the shareholders of the nine private water companies were paid, which resulted in a total payout of £47 million (equivalent to £6.37 billion in 2023).

[28] Over the next 70 years, the MWB significantly invested in London's water supply, constructing many large reservoirs in the Thames and Lea valley areas.

Designed by consulting engineers Sir William Halcrow & Partners, and constructed between 1955 and 1959, it is a 19-mile (31 km), 102-inch (2.6 m) diameter concrete-lined tunnel running from the non-tidal Thames at Hampton Water Works to Lockwood pumping station at the Lee Valley Reservoir Chain.

Another pump was originally installed at the Stoke Newington shaft to supply up to 12.5 million imperial gallons (57 megalitres) per day to the reservoirs there.

By the 1980s, the ageing system of surface-level trunk mains, which transported treated water in bulk around London, was becoming overloaded and suffering an increasing number of leaks.

A deep-level system of 80 kilometres (50 mi) of concrete tunnels, the Ring Main connected the large water works in the west of London with pumping stations in the centre, close to the areas of highest demand.

This rising groundwater raised the risk of damage to tunnels and structures with deep foundations, but also the opportunity to use the aquifer itself as a reservoir.

[34] The North London Artificial Recharge (NLAR) scheme, licensed by the Environment Agency in 1995, consists of a network of boreholes in the Enfield, Haringey, and Lee Valley areas.

The nearly 400-year-old New River took on a new role as a convenient method of transporting raw water from the Enfield and Haringey boreholes to the treatment works at Hornsey and Coppermills (via the Amhurst Main running from Stoke Newington to the Lee Valley).

[40][41] This facility, the Thames Gateway Water Treatment Works, is rarely used due to the high cost of operation, and in 2022 the capacity was downgraded to 100 Ml/day.

[42] The Thames Water Ring Main was extended between 2007 and 2010, with the construction of two new tunnels: a northern leg from New River Head to Stoke Newington, connecting the treatment plant at Coppermills to the ring main, and a southern leg from Brixton to the pumping station and reservoirs at Honor Oak.

Thames Water negotiated with the project to enhance the specification of these boreholes, and a new treatment plant was built at East Ham.