The aqueduct carries the Slough Arm of the Grand Union Canal over Fray’s River.
The Slough Arm is a short branch from the Grand Union Main Line. It was opened in 1882 to serve the brick-making industry. The last commercial traffic was carried in 1960, but as the plans to fill it in were opposed locally, the stretch was re-opened in 1975 and has remained in use since.
Fray’s River is a man-made watercourse diverting some of the waters of the River Colne – effectively a long mill stream. It is named after John Fray a 15th century owner of Cowley Hall.