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Thames Tideway Tunnels

Photo: Donaldson Associates

​Thames Tideway Tunnel is a major new sewer being constructed in London to intercept sewage overflow discharges that currently enter the river during storm events.

Ecology, environment, public health​

The storm water discharges result in pollution of the River Thames, and also contravene the European Urban Wastewater Treatment Directive.  The project will not only improve the environment, ecology, public health, appearance and reputation of London, but also give a much-needed and immediate boost to the economy by creating many thousands of skilled jobs and hundreds of apprenticeships.

Sewage treatment

The tunnel is 25km long, 7.2m diameter, and constructed at up to 65 metres depth below the River Thames.  The tunnel starts in West London and follows the route of the River Thames to Limehouse, and continues north-east to Abbey Mills Pumping Station near Stratford.  From there it connects to Lee Tunnel which transfers the sewage to Beckton Sewage Treatment Works.

Tender stage input

Donaldson Associates provided input to the Ferrovial Agroman, Laing O'Rourke Joint Venture during tender stage.  The FLO JV was subsequently awarded the Central contract on the project, the largest value of the three construction contracts on offer. 

Deep shafts

Working with Aecom and Arcadis to deliver the detailed design, Donaldson Associates' scope includes two deep shafts at existing discharge positions (8m and 9m internal diameter and up to 40m deep) and 10 No. connection tunnels (2.4m to 4.8m diameter) between intakes and shafts, and shafts and the main Thames Tideway Tunnel. 

SCL and segmental construction

The shafts include Sprayed Concrete Lining and segmental construction.
The design input is ongoing, and will run for approximately 18 months.  The works are expected to be constructed, and in use by 2023.

LAST UPDATED: 06.09.2017