thames tideway tunnel, united kingdom

The Thames Tideway Tunnel is a major new sewer that will help tackle the problem of overflows from the capital's Victorian sewers and protect the river from pollution. 

The scheme includes a 25km-long bored interception tunnel and associated shafts, connecting tunnels and pumping stations. 

COWI is designing two 45m-deep vertical shafts - involving piled, segmental and sprayed concrete lining methods - and 14 connecting tunnels with segmental or sprayed concrete linings at depths ranging from 15m to 60m below ground. 

Construction of the project is expected to complete in 2023.