(1) Any person who obstructs the navigation of the main channel of any navigable river or other stream, by building mills, erecting dams or locks, in or across the same, unless authorized by law, or by any other means whatever, shall be liable to a penalty of two hundred fifty dollars ($250), one half (½) to the use of the person who sues for it and the other one half (½) to the use of the state.
(2) In addition to the civil penalty in subsection (a), such obstruction of the main channel of any navigable river or other stream is a Class C misdemeanor.