The cottage beside the bridge over the Allt Arder (Allt means 'burn' so saying 'Allt Arder Burn' is tautological) is (or was) called Cally Cottage, which seems to support your hypothesis.
As for the 1829 floods, I suggest you have a look at 'The Great Moray Floods of 1829' by Sir Thomas Dick Lauder, who compiled information about all the places affected by the Great Flood. I do have a copy, but I am not at home just now and I don't take my library on holiday with me

The book might be online somewhere - a lot of old books have been digitised and made available online.