High Maynard Reservoir is located in Walthamstow in the London Borough of Waltham Forest.

Construction of the High Maynard reservoir was completed in 1870 [2] by the East London Waterworks Company on former marshland and is now owned and managed by Thames Water.

In winter, cormorants roost on the island with their numbers reaching nationally important levels.

[3] The fringes of the reservoir contain many plant species that are uncommon to Greater London.

The water is open to the public and is popular with birdwatchers, walkers and anglers.