High Maynard Reservoir is located in Walthamstow

Walthamstow

Walthamstow is a district of northeast London, England, located in the London Borough of Waltham Forest. It is situated north-east of Charing Cross...

 in the London Borough of Waltham Forest

London Borough of Waltham Forest

The London Borough of Waltham Forest is in northeast London, England. Officially, it forms part of Outer London as it borders Essex. However, it can be seen that the NE London boundary does not extend far compared to elsewhere in the city...

. The storage reservoir

Reservoir

A reservoir , artificial lake or dam is used to store water.Reservoirs may be created in river valleys by the construction of a dam or may be built by excavation in the ground or by conventional construction techniques such as brickwork or cast concrete.The term reservoir may also be used to...

 is one of the Lee Valley Reservoir Chain

Lee Valley Reservoir Chain

The Lee Valley Reservoir Chain is located in the Lee Valley, and comprises 13 reservoirs that supply drinking water to London.- Reservoirs :The following waters are located in the London Borough of Enfield and are known collectively as the Chingford Reservoirs, which are a Site of Special...

 and supplies drinking water to London

London

London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...

.

History

The reservoir was built in the mid 19th century by the East London Waterworks Company

East London Waterworks Company

The East London Waterworks Company was one of eight private water companies in London absorbed by the Metropolitan Water Board in 1904.The company was founded by Act of Parliament in 1806, and in 1845 the limits of supply were described as "all those portions of the Metropolis, and its suburbs,...

 on former marshland and is now owned and managed by Thames Water

Thames Water

Thames Water Utilities Ltd, known as Thames Water, is the private utility company responsible for the public water supply and waste water treatment in large parts of Greater London, the Thames Valley, Surrey, Gloucestershire, Wiltshire, Kent, and some other areas of in the United Kingdom...

.

Ecology

The water is a Site of Special Scientific Interest

Site of Special Scientific Interest

A Site of Special Scientific Interest is a conservation designation denoting a protected area in the United Kingdom. SSSIs are the basic building block of site-based nature conservation legislation and most other legal nature/geological conservation designations in Great Britain are based upon...

 (SSSI). In winter, cormorants

Great Cormorant

The Great Cormorant , known as the Great Black Cormorant across the Northern Hemisphere, the Black Cormorant in Australia and the Black Shag further south in New Zealand, is a widespread member of the cormorant family of seabirds...

 roost on the island with their numbers reaching nationally important levels. The fringes of the reservoir contain many plant species that are uncommon to Greater London

Greater London

Greater London is the top-level administrative division of England covering London. It was created in 1965 and spans the City of London, including Middle Temple and Inner Temple, and the 32 London boroughs. This territory is coterminate with the London Government Office Region and the London...

.

Recreation

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

Walking

Walking is one of the main gaits of locomotion among legged animals, and is typically slower than running and other gaits. Walking is defined by an 'inverted pendulum' gait in which the body vaults over the stiff limb or limbs with each step...

 and anglers.