While the Tideway super sewer project, following the River Thames through the heart of London, is a British endeavor, the contracting team is very multinational. Even though the United Kingdom is preparing to leave the European Union, contractors from France, Spain and the Netherlands, backed by European Union financing, are helping to drive the U.K.’s biggest water project, being built to comply with EU law.

The first of five German and French-made tunnel boring machines set off on its stretch of the super sewer in November. With its diameter varying from 6.5 meters to 7.2 m, the Tideway Tunnel will run from Acton in the west to Abbey Mills, sloping down at a 1:800 incline and reaching about 65 m below ground at its deepest point.