First Thames Tideway Tunnel connections go live
Dubbed “London's super sewer”, the first connections of the UK's Thames Tideway Tunnel are now operational.
Launched in 2016, this project aims to improve and preserve the waters of the River Thames by storing and transferring wastewater and stormwater to prevent them from flowing into the river during periods of rain. Teams from the Costain, VINCI Construction Grands Projets and Bachy Soletanche (VINCI Construction) joint venture, built 10km of the project's 25km of tunnels.
In May 2024 the Thames Tideway Tunnel was connected to the Lee Tunnel, a project our teams previously built between 2010 and 2016. This system, with a combined capacity of 1.6 million cubic metres, will contribute to the ecological health of the river. In October, four of the system's 21 locations had the valves activated, making the system operational. As a result, 589,000 cubic metres of wastewater was captured in a single day, preventing the discharge of 219,000 cubic metres into the River Thames. When fully open, the tunnel will be able to treat the equivalent of 640 Olympic-sized wastewater swimming pools, reducing discharges into the river by almost 95%. The other sites in the network will be activated progressively throughout 2025.