The construction of the Manchester Ship Canal obliterated large parts of the earlier navigation, including almost the whole of the Irwell part of the course (except for a short length upstream of Pomona Docks, which is the only surviving part of the navigation today).
The lower reaches of the ship canal from Eastham to Latchford obliterated a large section of the Runcorn to Latchford Canal, leaving just a short stub joining the navigation to the Canal near Stockton Heath.