Wraysbury Reservoir

Wraysbury Reservoir
Aerial view of reservoir
Wraysbury Reservoir from the air, looking south
A map of Surrey with a mark indicating the location of Wraysbury Reservoir
A map of Surrey with a mark indicating the location of Wraysbury Reservoir
Wraysbury Reservoir
LocationSurrey
Coordinates51°27′39.7″N 0°31′25.2″W / 51.461028°N 0.523667°W / 51.461028; -0.523667
Typereservoir
Basin countriesUnited Kingdom
Surface area2.05 square kilometres (0.79 sq mi)
Water volume34 Gl (7.5×10^9 imp gal)
Wraysbury Reservoir
Site of Special Scientific Interest
LocationSurrey
Grid referenceTQ 025 745[1]
InterestBiological
Area205.6 hectares (508 acres)[1]
Notification1999[1]
Location mapMagic Map

Wraysbury Reservoir is a water supply reservoir for London, just west of the M25 near the village of Wraysbury, and directly under the western approach path of Heathrow Airport. Construction of the reservoir was begun in 1967 and completed by W. & C. French in 1970[2] with a capacity of 34,000 million litres (8,000 million gallons).[3]

Engineering design data for the Wraysbury reservoir is as follows.[4]

Parameter Value
Top water level above ordnance datum 31.1 m
Volume of water storage 35 million m3
Maximum depth of water 21 m
Water area 202 ha
Maximum height of bank above ground 17 m
Perimeter of bank 5,700 m

The reservoir is owned and operated by Thames Water; 400 million litres (100 million gallons) of water are pumped daily from an inlet at Datchet on the River Thames. A neighbouring reservoir is the King George VI Reservoir, opened in 1947, which is supplied from Hythe End. To keep the grass short and make inspections easier, Thames Water maintains a flock of sheep on the earthen banks.[5]

The reservoir is the site of the National Physical Laboratory's Open-Water Test Facility, used by the Ministry of Defence for test and calibration of sonar systems, as well as civilian commercial customers.[6]

It is a 205.6-hectare (508-acre) biological Site of Special Scientific Interest[1][7] and part of South West London Waterbodies Ramsar site[8] and Special Protection Area.[9] It has nationally important numbers of wintering cormorants, great crested grebe and shovelers. It also supports many gadwalls.[10]

  1. ^ a b c d "Designated Sites View: Wraysbury Reservoir". Sites of Special Scientific Interest. Natural England. Retrieved 21 November 2018.
  2. ^ "The Queen Mother Reservoir, Datchet" (PDF). Ground Engineering. October 1976. Retrieved 14 September 2015.
  3. ^ Spelthorne Borough Council - Three Rivers Ramble
  4. ^ Bell, F. G. (1979). Engineering Geology and Geotechnics. Butterworth-Heinemann Ltd. p. 270. ISBN 9780408003551.
  5. ^ "The real-life reservoir dogs (press release)". PR Newswire. Thames Water. Retrieved 4 December 2016.
  6. ^ "Calibration and characterisation of sonar transducers and systems | The UK Marine Science and Technology Compendium". naqbase.noc.ac.uk. Retrieved 2 October 2022.
  7. ^ "Map of Wraysbury Reservoir". Sites of Special Scientific Interest. Natural England. Retrieved 21 November 2018.
  8. ^ "Designated Sites View: South West London Waterbodies". Ramsar Site. Natural England. Retrieved 9 November 2018.
  9. ^ "Designated Sites View: South West London Waterbodies". Special Protection Areas. Natural England. Retrieved 9 November 2018.
  10. ^ "Wraysbury Reservoir citation" (PDF). Sites of Special Scientific Interest. Natural England. Retrieved 21 November 2018.