“The first annual Tideway Benefits Report has revealed significant improvement in river health following the opening of the super sewer in 2025.

Storm overflows to the tidal Thames have been successfully reduced by 86%, compared to pre-Tideway levels, as the operation of this significant asset is transferred to Thames Water from Tideway, the company set up to deliver the project.

The findings mark a new chapter for the River Thames and signals that London’s principal waterway, which was once declared biologically dead in the late 1950s, is firmly on the road to recovery.”

From Thames Water.