Closure
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).
A short way downstream of the confluence with the Mersey, the ship canal followed a more southerly course than the old navigation, which remained in use as late as 1950 from Rixton Junction downstream.
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. The Woolston New Cut, excavated in 1821, is still visible although completely dry. Woolston Old Cut, built in 1755, still exists although the lock is gone.
Read more about this topic: Mersey And Irwell Navigation