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.
The Reservoir Chain is a major geographic constraint; together with the Thames it is one of the two significant topographic features that divide the capital and define the communities on either side. The Lower Lea Valley, downstream of the reservoirs, is more integrated, with better east-west transport connectivity.

Geographic significance

The Chain separates the London Boroughs of Haringey and Enfield to the west, from Waltham Forest and Essex in the east. The corridor includes 13 reservoirs, two to three channels of the Lee, as well as marshes and parkland, up to a mile wide.
During WWI, the settlements on both sides of the Upper Lea were badly hit by Germany Army and Navy airship raids. It is believed the crews mistook the Reservoir Chain for the Thames and released their bombs on what they took to be central London.
The Boundary Commission treats the Thames and Lea as natural barriers within London. When reviewing the boundaries of London’s parliamentary constituencies, it concludes that any constituency spanning either river would be artificial and not reflect local communities or identities. The 2018 review compromised on this, allowing a cross-Lea constituency further south, in the Lower Lea where the communities on each side are more integrated due to greater quantity and quality of the road and rail links across the valley.
The corridor is part of the Metropolitan Green Belt and its national and international significance for wildlife is reflected by SSSI, Ramsar and SPA designations. Lying between some of Londons’s most densely populated areas, the Reservoir Chain and associated open land provides a highly valued ecological, landscape and recreational resource for the people of north and east 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 Scientific Interest:
The following waters, together known as the Walthamstow Reservoirs, are located in the London Borough of Waltham Forest and, with the exception of one, form a Site of Special Scientific Interest:
The reservoirs have the following characteristics:
ReservoirWater Source Water SupplyDepth, metresCapacity, Ml
King George VRiver Lea, New River, Lea DiversionPumped7.512,500
William GirlingLea DiversionPumped12.516,500
BanburyLea Diversion & Thames-Lee tunnelPumped8.52,950
LockwoodLea Diversion & Thames-Lee tunnelPumped10.42,500
High MaynardLee Diversion, Walthamstow No. 4, East WarwickGravity-fed5.8680
Low MaynardHigh MaynardGravity-fed3.0150
East WarwickHigh Maynard, West WarwickGravity-fed5.8960
West WarwickEast WarwickGravity-fed5.8800
Walthamstow No. 4High Maynard, Walthamstow No. 5Gravity-fed5.8590
Walthamstow No. 5Walthamstow No. 4Gravity-fed5.8770

Water supply

The reservoirs are fed by the following waters:
After being stored in the above reservoirs the water is piped to the Coppermills Water Treatment Works.