This is the Torrente Bitto (roughly translated, Bitto Stream), which I suspect may form the border between the two locations described above. It flows north into the Adda river, which is flowing roughly west (with quite a few twists and turns) before it dumps itself into Lake Como.

Unfortunately I had no chance of getting a really clear shot of it and wouldn't unless I could get off at the next station and spend a couple of days there, along with every other station on the line.

Yeah, chance would be a fine thing.