I havent seen my pond over flow, but I have only had the place for a year and a half, it does look like it has had some heavy overflow in the past.But I dont think that it has in a long time.
I think that it may seep around the over flow at about a foot from the overflow pipe It maybe had a inch of ice last year off and on through the winter, it was a mild winter here last year.

A little snow, Please!