The Wraysbury Reservoir is a water supply reservoir for 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...

 lying just west of the M25

M25 motorway

The M25 motorway, or London Orbital, is a orbital motorway that almost encircles Greater London, England, in the United Kingdom. The motorway was first mooted early in the 20th century. A few sections, based on the now abandoned London Ringways plan, were constructed in the early 1970s and it ...

 near the village of Wraysbury

Wraysbury

Wraysbury, traditionally spelt Wyrardisbury, is a village and civil parish in Berkshire, England. It is located in the very east of the county, in the part that was in Buckinghamshire until 1974...

 and Heathrow airport. The reservoir was begun in 1967 and completed in 1970 with a capacity of 34,000 million litres.

The reservoir is owned and operated 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...

 and 400 million litres of water are pumped daily from an inlet at Datchet

Datchet

Datchet is an English Thameside village and civil parish situated in the unitary authority of Windsor and Maidenhead in the county of Berkshire. It was transferred to Berkshire from Buckinghamshire in 1974....

 on the River Thames

River Thames

The River Thames flows through southern England. It is the longest river entirely in England and the second longest in the United Kingdom. While it is best known because its lower reaches flow through central London, the river flows alongside several other towns and cities, including Oxford,...

. A neighbouring reservoir is the King George VI Reservoir

King George VI Reservoir

The King George VI Reservoir in England lies to the south of Stanwellmoor near Stanwell and Heathrow. The reservoir was opened in November 1947 and named after the then reigning monarch King George VI. It is owned by Thames Water....

, opened in 1947, which is supplied from Hythe End

Hythe End

Hythe End is a place in Berkshire between Wraysbury and Staines, England on the northern bank of the River Thames close to Bell Weir Lock.Hythe End consists of several riverside homes, mainly on The Island, Hythe End. There are gravel pits to the north which make up a Site of Special Scientific...

.

Wraysbury Reservoir is within a Site of Special Scientific Interest

Site of Special Scientific Interest

A Site of Special Scientific Interest is a conservation designation denoting a protected area in the United Kingdom. SSSIs are the basic building block of site-based nature conservation legislation and most other legal nature/geological conservation designations in Great Britain are based upon...

which also includes gravel pits at Wraysbury.