Thames Tideway Tunnel

Running underneath the River Thames, is a 150-year-old sewer system, which was initially built for a population less than half its current size. The new tunnel will ensure the capital’s sewerage system is fit to support its projected population for at least the next 100 years. It will also tackle the issue of discharges of untreated sewage that currently enter the River Thames on a regular basis. 

We are working in a three-way equal joint venture alongside Morgan Sindall and BAM Nuttall, to deliver the £416 million, seven kilometre ‘West’ section of the overall 25km long Thames Tideway Tunnel. 

Spanning from Acton in West London to Wandsworth in South West London, the West section of the project will incorporate seven separate work sites along the route. This unique infrastructure project, which is the largest ever undertaken by the UK water industry, is another example of the part we are playing in 21st Century engineering. 

Scope of works  

Construction works began in 2016 with tunnelling starting two years later in 2018. All six of the tunnelling boring machines finished their drives in 2022, marking the end of the tunnelling phase of the project.  

When the final works are completed in 2025, the new super sewer will dramatically reduce sewage pollution, creating a cleaner, healthier River Thames and enabling the capital’s sewer system to continue to serve London. 

Thinking locally 

Using Building Information Modelling (BIM), we tested and simulated construction before works started on site to ensure the safe and efficient delivery of the project and to minimise disruption to local residents. A large percentage of the project materials were also transported down the river to ease road congestion and reduce emissions and disruption throughout the duration of the project. 

The overall Thames Tideway Tunnel scheme has created more than 4,000 sustainable jobs on the project. Throughout the project, we have engaged with local businesses and SMEs to provide job opportunities for local people. Tideway has also provided more than 100 apprentices with employment, demonstrating our commitment to inspire and upskill a new generation of infrastructure experts.