The Lee Tunnel, also known as the Stratford to East Ham deep tunnel, is an overflow sewer in East

London London is the Capital city, capital and List of urban areas in the United Kingdom, largest city of both England and the United Kingdom, with a population of in . London metropolitan area, Its wider metropolitan area is the largest in Wester ...

for storage and conveyance of foul

sewage Sewage (or domestic sewage, domestic wastewater, municipal wastewater) is a type of wastewater that is produced by a community of people. It is typically transported through a sewerage, sewer system. Sewage consists of wastewater discharged fro ...

mixed with

rainwater Rain is a form of precipitation where water droplets that have condensed from atmospheric water vapor fall under gravity. Rain is a major component of the water cycle and is responsible for depositing most of the fresh water on the Eart ...

. It was built as part of the Thames Tideway Scheme and runs from Abbey Mills Pumping Station down to pumps and storage tanks at Jenkins Lane, Beckton Sewage Treatment Works. It is wholly under the

London Borough of Newham The London Borough of Newham () is a London borough created in 1965 by the London Government Act 1963. It covers an area previously administered by the Essex county boroughs of West Ham and East Ham, authorities that were both abolished by ...

. This tunnel, of diameter, laid at between deep, at start, to at finish, captures , or 16 million tonnes, of sewage annually from the single largest polluting CSO in London - the amount varies with rainfall. This sewage overflow had flowed untreated into the

River Lea The River Lea ( ) is in the East of England and Greater London. It originates in Bedfordshire, in the Chiltern Hills, and flows southeast through Hertfordshire, along the Essex border and into Greater London, to meet the River Thames at Bow Cr ...

, after which it diluted gradually in the

Thames Tideway The Tideway is the part of the River Thames in England which is subject to tides. This stretch of water is downstream from Teddington Lock. The Tideway comprises the upper Thames Estuary including the Pool of London. Tidal activity Depending o ...

(the narrowest parts of the

Thames Estuary The Thames Estuary is where the River Thames meets the waters of the North Sea, in the south-east of Great Britain. Limits An estuary can be defined according to different criteria (e.g. tidal, geographical, navigational or in terms of salinit ...

). It can take 30 days for effluent to reach the sea from the Tideway. From its terminus, pumps send the effluent into the adjacent Beckton Sewage Treatment Works – the largest such works in Europe. From that works the resultant water (treated sewage), with solids removed and the most harmful chemicals treated, empties into the (Thames's) Tideway, its upper estuary. Lying at AOD means a second source of London's old-style combined sewers' effluent can be caught, that from the

Thames Tideway Tunnel The Thames Tideway Tunnel is a deep-level sewer along the tidal section of the River Thames in London, running from Acton in the west to Abbey Mills in the east, where it joins the Lee Tunnel which connects to Beckton Sewage Treatment Wor ...

, which is due to open in 2025.

Construction

Thames Water awarded the construction contract to the MVB JV consortium, comprising Morgan Sindall, VINCI Construction Grands Projets and Bachy Soletanche, in January 2010. The contract price, combined with Thames Water's own improvements was estimated at £635 million. Construction began with sinking of vertical shafts in 2010. In February 2012, the TBM, built by Herrenknecht and named Busy Lizzie, started work at the east end. In 2013, a UK record concrete slipform pour was achieved: 29 days of continual pouring. The tunnel is the deepest bored in London. The TBM reached the west end in January 2014. The tunnel was completed, and opened by

Mayor of London The mayor of London is the chief executive of the Greater London Authority. The role was created in 2000 after the Greater London devolution referendum in 1998, and was the first directly elected mayor in the United Kingdom. The current ...

Boris Johnson Alexander Boris de Pfeffel Johnson (born 19 June 1964) is a British politician and writer who served as Prime Minister of the United Kingdom and Leader of the Conservative Party (UK), Leader of the Conservative Party from 2019 to 2022. He wa ...

, in January 2016.

References

{{authority control London water infrastructure Tunnels in London Geography of the River Thames River Lea Thames Water