Prescott Channel

From the more extensive Wikipedia page

The Prescott Channel was built in 1930–35 as part of a flood relief scheme for the River Lee Navigation in the East End of London, and was named after Sir William Prescott, the then chairman of the Lee Conservancy Board.] Rubble from the demolished Euston Arch was used in 1962 to improve the channel, which forms part of the Bow Back Rivers.