“Ordinary high water mark” on all lakes, streams, and tidal water is that mark that will be found by examining the bed and banks and ascertaining where the presence and action of waters are so common and usual, and so long continued in all ordinary years, as to mark upon the soil a character distinct from that of the abutting upland, in respect to vegetation as that condition exists on the effective date of this chapter or as it may naturally change thereafter: PROVIDED, that in any area where the ordinary high water mark cannot be found, the ordinary high water mark adjoining saltwater shall be the line of mean higher high tide and the ordinary high water mark adjoining fresh water shall be the line of mean high water. (Or, as shown by markings of water surface contaminants on rocks, bulkheads, pilings or other relatively permanent structure or natural feature.) (Ord. 583 §2.09(C) (part), 1980).