The Queen Mother Reservoir is a public water supply reservoir lying to the west of London, beyond the M25 and south of the M4. Built in 1976, it has an area of 192 hectares (475 acres) and a circumference of about 5.2km (3.25 miles), making it one of the largest inland bodies of water in southern England. It is managed by Thames Water.
The reservoir is on the westernmost border of the London Natural History Society recording area. About 1.2km (0.7 miles) of its western shore lies outside this area, along with a narrow strip (up to 200m wide) of its water surface area. See map, right.
Directions: By car: From the M4, take the A4 towards Colnbrook and and take a right fork toward the village. Instead of going into Colnbrook village follow the road round the right bend. This is Horton Road. The reservoir is just along past the bend on the right hand side.
Access: The reservoir is only open to members of the Berkshire Ornithological Club. For information on joining the club and how to get a permit see here.