A. The zoning district boundary lines shall be: the centerline of either a street, alley or railroad right-of-way; the centerline of an easement; the thread of a stream, slough or river; or the boundary lines of sections, divisions of sections, tracts, blocks or lots; or such lines extended as otherwise indicated.

B. Where a zoning district boundary line is indicated as approximately following the centerline of either a street, alley or railroad right-of-way; the centerline of an easement; the thread of a stream, slough or river; or the boundary lines of sections, divisions of sections, tracts, blocks or lots; then said line shall be construed to be the zoning district boundary.

C. Where a zoning district boundary line is indicated as being approximately parallel to the centerline of either a street, alley or railroad right-of-way; the centerline of an easement; the thread of a stream, slough or river; or the boundary lines of sections, divisions of sections, tracts, blocks or lots; then the zoning district boundary line shall be construed as being parallel thereto and at a distance determined by the use of the scale shown on the official zoning map.

D. Where a zoning district boundary line is not indicated as provided herein, and where a zoning district boundary line divides a piece of property that may later be subdivided into new tracts, blocks and/or lots, the zoning district boundary line shall be construed to include the new tract, block and/or lot in their entirety if they have more than 50 percent of their land area within that zoning district boundary line.

E. Whenever any street, alley or railroad right-of-way, or easement is vacated as provided by law, then the zoning district adjoining each side of such street, alley or railroad right-of-way, or easement shall be automatically extended to the center of such vacation, and the area included in the vacation shall be subject to the regulations of the extended zoning districts.

F. A zoning district boundary line indicated as approximately following the thread of a stream, slough or river shall automatically move as the stream, slough or river changes its water course. (Ord. 88-010 § 2, 1988. 2004 Code § 18.08.030.)