I often go by the new large drainage pond at Conservation Drive and Dixie Road in Brampton. On Friday evening and this evening, I saw a very large solitary swan there.
I studied it hard through my binoculars, and I am confident that it is a Trumpeter Swan rather than a Tundra due to the size and the absence of any marking on the beak.
From ebird, I see these are not common sightings around here, particularly at this time of year, so perhaps worth a look.