| Queen Mother Reservoir | |
| Coords: | 51.4819°N -0.5489°W |
| Pushpin Map: | Berkshire |
| Area: | 475acres |
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 475acres 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.
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.
| 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 |