Lockwood Reservoir is located in Walthamstow in the London Borough of Waltham Forest. It is one of the ten Walthamstow Reservoirs, which are part of the Lee Valley Reservoir Chain. The reservoirs supply drinking water to London and are owned by Thames Water.
The reservoir is a Site of Special Scientific Interest (SSSI).
The reservoir was completed in 1903 and constructed by the East London Waterworks Company, which was then taken over by the Metropolitan Water Board in 1904.