What Is the Thames Tideway Tunnel? Londonist » Whatever the problem in London, the engineers’ solution is usually a tunnel. That’s why the Thames Tideway Tunnel (aka ‘super sewer’) is London’s proposed solution to sewage overflows into the River Thames. Michelle2018-03-07T10:18:26-08:00November 23rd, 2017|England, Public-Private Partnerships, Thames Tideway Tunnel, Wastewater|