(a) No landowner or other person shall, except as provided in this chapter, encourage, procure, cause or aid in the cutting or injury of any tree or vegetation within 30 feet of the center of any natural watercourse, or within 25 feet of the edge of such watercourse, whichever is greater.
(b) For purposes of this chapter a natural watercourse means any stream with a reasonable well-defined channel, and includes streams which have a permanent flow, as well as those which result from the accumulation of water after rainfalls and which regularly flow through channels formed by the force of the waters.