Sec. 304. (a) "Watercourse", for purposes of IC 14-25 through IC 14-30, means a channel that:
(1) has defined banks;
(2) is cut by erosion of running water through turf, soil, rock, or other material; and
(3) has a bottom over which water flows for substantial periods of the year.
(b) The term includes the following:
(1) The upstream and downstream parts of a watercourse that is lost in a swamp or a lake if the watercourse emerges from the swamp or lake in a well defined channel.
(2) A watercourse that has been improved by confining the watercourse in an artificial channel.