SDCL § 43-17-23: Natural factors given precedence in water marks--When man-made influences considered.

In determining the ordinary high water mark, natural factors take precedence. Man-made influences, either those that have been constructed to lower the mark or those constructed to raise the mark, shall be disregarded unless the influences have been lawfully constructed or have existed and been accepted for a period of time determined by the Water Management Board to be the equivalent of natural conditions.