(1) In case an unincorporated area is within the potential jurisdiction of more than one planning board, then the boundary between the conflicting areas shall be determined by agreement between the planning boards involved with the approval of their respective governing bodies. Any map showing the boundary line so agreed upon and approved shall be filed as provided in 76-1-502 and thereafter shall fix the limit of territorial jurisdiction with respect to planning boards.
(2) In case the jurisdictional area of a city-county planning board, which is established subsequent to the establishment of a county planning board, is potentially within the jurisdiction of the county planning board, then the property outside any incorporated city between the conflicting areas shall be determined by agreement between the planning boards involved with the approval of the respective governing bodies, and a map showing the boundary lines so agreed upon shall be filed as provided in 76-1-502 and thereafter shall fix the limits of the territorial jurisdiction of the respective planning boards.