Thames Water Cleaning the Thames: Amey’s role as Systems Integrator on Thames Tideway

River Thames - showing the London Eye
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The London sewage system designed by Bazalgette has served the capital for over 150 years. The system was designed to server four million people, but today the population is nearer nine million. The combined system funnels sewage and rainwater to the treatment works at Beckton, but when it rains heavily the untreated (albeit diluted) sewage spills into the river Thames. A new sewer system is needed that serves modern London and that can cope with further increases in population.

At a glance

  • A new super sewer system to ensure the River Thames remains clean for use for another 100 years
  • The project aims to reduce the amount of overflows to four per year, down from 50
  • Amey is responsible for the design, construction, installation and test of the system which controls the operation of the Tideway Tunnel
  • Amey is implementing cyber security policies to ensure that the asset is as secure as possible
  • Handover of the completed system is expected to be in 2025

Key metrics

  • £4.3

    billon project

  • 7.2m

    in diameter

  • 25km

    long tunnel

A new “super sewer” that is 7.2m in diameter is being built along a 25km length of the river Thames at an estimated cost of £4.3 billion. The sewer runs from Acton in the West connecting to Beckton Sewage Works in the East via the existing Lee Tunnel. Excess surface water run-off during periods of heavy rainfall will no longer result in raw sewage flowing into river, instead the Victorian sewers will over-flow into the Tideway Tunnel and channelled to the Beckton Sewage Treatment Works at a rate that can be processed.

Currently there is an overflow of sewage into the river roughly fifty times each year. The Tideway project aims is to reduce this to a maximum of four times per year. The additional capacity provided by this super-sewer should ensure that London, and the River Thames, remain clean for use for another 100 years.

Amey has been the Systems Integration Contractor on the Thames Tideway Tunnel Project since 2015, working alongside of some of Europe's biggest contractors including Balfour Beatty, BAM, Costain and Ferrovial. Handover of the completed system is expected to be in 2025.



Amey is responsible for the design, construction, installation and test of the system which controls the operation of the Tideway Tunnel.

Thames Tideway

Amey is responsible for the design, construction, installation and test of the system which controls the operation of the Tideway Tunnel. The SCADA system regulates the gravity feed of effluent from West to East at a rate that can be processed by the plant at Beckton. Sensors measure the levels in each section and the system controls the flow by opening and controlling penstocks (sluice gates) at 21 locations along the length of the sewer to regulate the flow of effluent.

Amey is managing the installation of a telemetry panel, 3G antenna and BT Openreach telecommunications equipment at each of the sites: the work is carried out by specialist contractors under Amey supervision. Amey is responsible for the design of each installation and post installation testing at each site. Risk assessments, method statements and test protocols must be approved by the client prior to installation. Where SCADA equipment is being installed on existing Thames Water sites, their approval must also be obtained to ensure continued functionality of existing systems is maintained. Control and monitoring of the 21 sites is effected by a control centre at Beckton consisting of two servers, one of which operates in “hot standby” mode. Systems resilience is achieved using two hardwired BT Openreach connections: 3G antennas provide further redundancy. Control and monitoring of the Beckton site can be achieved from four further sites that connect to the system. In all Amey is installing equipment at 26 worksites.

As a high-profile infrastructure asset, it must be anticipated that the system will, at some stage, come under cyber-attack. Amey is implementing appropriate cyber security policies to ensure that the asset is as secure as possible. Cyber security within a process controls environment is not the norm but by considering these aspects from the outset, Amey is ensuring that the IT infrastructure and its management is suitable for the challenges of the 21st century where digital security is as important, if not more so, than the physical security of assets.

Amey brings a wealth of experience in this area of cyber security; building upon knowledge gained through providing highways infrastructure and implementing secure communications networks that meet ISO27001 requirements, CPNI guidelines and best practice for process controls networks. The use of automated failover network paths and dual-redundant server and PLC architectures, ensures the fully-integrated system is highly-resilient and highly-available.

Achievements to Date

By January 2024, Amey had completed the design, installation, and test at 14 of the 21 worksites along the Thames.

The control centre at Beckton and three other sites had also been installed. Amey expects to complete the remainder of the installations by mid-2024.

The Amey Tideway Team includes professionals specialising in planning, development and design, testing and commissioning, maintenance, supplier engagement, training, HSWEQ, and commercial management. Collectively, these interdisciplinary teams are contributing to the overarching objectives of improving water quality, enhancing public health, fostering community well-being, ensuring long-term sustainability, and environmental compliance along the River Thames. Amey is proud of its ongoing involvement in the project, which it expects to complete in 2025.


Speaking on the impact of the project, Alex Gilbert, Managing Director, Amey Consulting has said:

“The river Thames is one of the world’s most iconic rivers and the lifeblood in making London the global city it is today. However, London currently relies on a 150-year-old sewer system built for a population less than half its current size. Amey is incredibly proud to be playing a leading role alongside our alliance partners in upgrading Bazalgette’s Victorian sewage system and providing a cleaner Thames for the people of London and the South-East. This project demonstrates the true value of investing in infrastructure, by cleaning and enhancing our natural world, for people to enjoy and wildlife to thrive in, for generations to come.”

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