The Queen Mother Reservoir is a public water supply reservoir that lies between the M4 and the M25 to the west of London, close to Datchet. It is 475 acres (1.92 km2) in size or about 1 km in diameter - making it one of the largest inland areas of water in Southern England.[1] It is managed by Thames Water.
| Queen Mother Reservoir | |
|---|---|
 Reservoir and sailing club | |
  Queen Mother Reservoir | |
| Location | Berkshire, England |
| Coordinates | 51°28′55″N 0°32′56″W / 51.48194°N 0.54889°W |
| Type | Bank side reservoir |
| Basin countries | United Kingdom |
| Surface area | 475 acres (1.92 km2) |
| Water volume | 38,000 megalitres (1,300×106 cu ft) |
This is one of a number of reservoirs to the west of London and was completed in 1976. It was inaugurated on 9 July that year by Queen Elizabeth The Queen Mother, after whom it is named.[2] Its water is pumped from the River Thames nearby.[3] The water improves in quality during its retention in the reservoir as solids settle and organic contaminants are adsorbed and degraded through a combination of natural biological processes aided by sunlight and oxygenation. Water from the reservoir is treated (often using slow sand filters) before being put into supply as London tap water.[4] The reservoir contains a limnological tower.[5]
During the design and early construction it was called the Datchet reservoir due to its closeness to the town.[6]
Engineering design data for the Queen Mother reservoir is as follows.[6]
| Parameter | Value |
|---|---|
| Top water level above ordnance datum | 35 m |
| Volume of water storage | 37 million m3 |
| Maximum depth of water | 23 m |
| Water area | 192 ha |
| Maximum height of bank above ground | 20 m |
| Perimeter of bank | 5,350 m |
The reservoir lies within the Colne Valley regional park and like other local reservoirs is popular for sailing and bird-watching. Petrels have been spotted at this reservoir.[7]