Lands below the applicable natural or ordinary water mark, or the applicable artificial high water mark, of any lake, river, stream, channel or other body of public water shall not be counted in the calculations for determining the maximum density for a subdivision. For example, if a forty (40) acre parcel in the R-5 zoning district contains thirty (30) acres submerged under Lake Pend Oreille's artificial high water mark, then the parcel contains ten (10) "usable" acres for the purpose of determining the maximum density in a subdivision. (Ord. 501, 11-18-2008)