The new London Tideway Tunnel is now working. It intercepts, stores and ultimately transfers sewage waste away from the River Thames.
In May 2024, the new super sewer was connected to the Lee Tunnel, which has been in operation since 2016 – completing the full ‘London Tideway Tunnel’ network. The system now has a combined capacity of 1.6m m3 to protect the entire tidal Thames.
Stopping sewage reaching the thames
The map below shows Combined Sewer Overflows (CSO's) - points where rain and sewage used to spill into the Thames during heavy storms. Thanks to the super sewer, we're now capturing and diverting sewage from these sites to be properly treated, protecting the river and it's wildlife.
When sewage is captured, it travels down the tunnel which is 7.2 metres diameter wide, the equivalent of three London double decker buses, and the two connection tunnels are 5 metres in diameter and two metres in diameter respectively – 5 metres being roughly the size of a London Underground tunnel.
At Acton in West London where we start the tunnel, we are at our shallowest, 31 metres deep. It then falls away at a rate of 1 metre every 790 metres. Falling to 66 metres when we reach Abbey Mills Pumping Station in East London.
Watch how TBM Selina started her journey at Chambers Wharf:
TBM Selina is named after Dr Selina Fox, who founded the Bermondsey Medical Mission in 1904. The small clinic and eight-bed hospital provided medical and spiritual care to the most vulnerable women and children in the area and continues to this day as a local charity.
21 shafts were built across the project – some to launch tunnelling machines, most to channel sewage flows into the super sewer.
Watch how the shaft at Greenwich Pumping Station started excavation:
The London Tideway Tunnel has a storage capacity of 1.6m cubic metres, or around 600 Olympic-size swimming pools.
