London’s super sewer has been successfully connected to the existing network following a two-week programme of vital work from Tideway and Thames Water.

London’s super sewer has been successfully connected to the existing network following a two-week programme of vital work from Tideway and Thames Water.

Yesterday marked the end of work to break down the thick wall connecting London’s new 25km super sewer, the Thames Tideway Tunnel, to the existing 6.9km Lee Tunnel which links Abbey Mills Pumping Station to Beckton Sewage Treatment Works.

While the Tideway team undertook the removal of the 1.5m-thick wall at Abbey Mills Pumping Station, a team from Thames Water was working at the eastern end at Beckton constructing a new weir wall.

Now the two tunnels are connected for the first time, creating the London Tideway Tunnels network and paving the way for the new system to begin its protection of the River Thames.

The wall was constructed from concrete and steel and was one metre thick, spanning approximately eight metres in both height and width. It was positioned 66 metres below ground level and until yesterday separated the two systems. In order to remove it, the Lee Tunnel was taken out of service.

Yesterday the penstocks were opened at Abbey Mills, bringing the Lee Tunnel back into service and marking the beginning of the new combined system.

Nevil Muncaster, Thames Water’s Engineering and Asset Director, commented:

“Connecting the Thames Tideway Tunnel to the Lee Tunnel is a major step in this project. I’d like to recognise our teams at Abbey Mills and Beckton and the Tideway Integration Group for their work to manage the system while the connection works have taken place & CVB and Tideway London for their work to achieve this milestone. This major piece of infrastructure will give us extra capacity and help our system cope with our region’s growing population, impact of climate change and helping us further protect our environment for the future. It’s a great step forward for London.”

In the coming weeks and months, the entire system will be carefully brought online with individual combined sewage overflows being connected to the new tunnel.

This commissioning and testing phase will take place over several months, with the project expected to be fully operational in 2025.

Roger Bailey, Tideway Chief Technical Officer, said:

“The Tideway and Thames Water teams have worked brilliantly over the past fortnight to get these jobs done and I’d like to offer my sincere thanks for their collaboration and professionalism in getting us to this stage without incident.

“Our focus is now on bringing this newly-live asset into full operation – and looking forward to a cleaner, healthier river environment for generations to come.”