Construction site in Rotherhithe underway on the Thames Tideway Tunnel or Super Sewer close to the City of London on 10th March 2020 in London, United Kingdom. The Thames Tideway Tunnel is an under-construction civil engineering project 25 km tunnel running mostly under the tidal section of the River Thames through central London, which will provide capture, storage and conveyance of almost all the combined raw sewage and rainwater discharges that currently overflow into the river.