Hey, english is not my first language, therefore I'm not familiar with all expressions and idioms in the language, so I wonder what does it mean to see a river clean? Is it a common expression and what does it mean? Normally rivers have clean water so it's transparent, but maybe the rivers in Manchester during Morrisseys childhood was polluted and unclear, due to e.g. industry? And that this sentence symbolises a presence in those times, seeing at first his current poor state (dirty river), but then visualising his future unfold as a popstar and the river becoming clean? Something like that?