 The canal was originally supplied by the River Irwell in Bury , at the Weddell Brook tributary . This proved insufficient for local industry and in 1842 Elton Reservoir at Bury was built to become the canal 's principal supply . Although the Bury and Bolton arms are on one level , the Salford arm used seventeen broad locks , including some in staircases ( Nob End , for example ) , to descend 190 feet ( 58 m ) over 8 miles ( 13 km ) from the summit level to the lowest point at Salford . Robert Fulton had proposed an inclined plane at Nob End , but this design was rejected . The connection with Fletcher 's Canal near Clifton Aqueduct was made by a single lock 90 feet ( 27 m ) long by 21 feet ( 6 m ) wide , with a drop of 18 inches ( 46 cm ) . 
