Mill ponds were often created through the construction of a mill dam or weir (and mill stream) across a waterway.
In many places, the common proper name Mill Pond has remained even though the mill has long since gone. It may be fed by a man-made stream, known by several terms including leat and 'mill stream'. The channel or stream leading from the mill pond is the mill race, which together with weirs, dams, channels and the terrain establishing the mill pond, is the power producing purpose of the civil engineering hydraulic system.
The term mill pond is often used colloquially and in literature to refer to a very flat body of water. Witnesses of the loss of RMS Titanic reported that the sea was "like a mill pond".