Tideway Tunnel

Tideway Tunnel in Fulham.

Built between 1859 and 1865, Sir Joseph Bazalgette's original London sewerage system was designed to capture both rainwater runoff and the sewage produced by four million people. As a failsafe, to prevent sewage backing up and flooding people's homes, Bazalgette's system had the ability to overflow into the Thames via 57 combined sewer overflows (CSO) along the banks of the river.

The Thames Tideway Tunnel will be a 25 km (16 mi) tunnel running mostly under the tidal section of the River Thames through central London to capture, store and convey almost all the raw sewage and rainwater that currently overflows into the river. Work started in November 2015 and is due to finish in 2025.

Once constructed, the main tunnel will have an internal diameter of 7.2 m (24 ft) and will run from Acton in the west of London to reach Abbey Mills in the east. It will connect 34 of the most polluting combined sewer overflows (CSOs) via transfer tunnels. The captured sewage will be transferred to the Stratford to East Ham section for onward delivery to Beckton Sewage Treatment Works for treatment. The recycled clean water will then be released into the River Thames.

There are 25 building sites along the river. Carnwath Road Riverside is one of the main drive sites from which the tunnel boring machines (TBMs) begin building the main tunnel. You can also see works on the Putney Embankment foreshore but this is a much smaller site. More information can be found on the Tideway website: https://www.tideway.london/locations/carnwath-road-riverside/

In 2017 the public voted on a short-list of 17 to name the six TBMs. They were named after inspirational women with a connection to the area where each individual machine started its journey. One began tunnelling from Fulham in 2018 and was named after Rachel Parsons, an engineer and advocate for women's employment rights, who set up the first women-only engineering company in Fulham.