1. Except as provided in subsection 2 of this section, property of a municipality which abuts another municipality may be concurrently detached from one municipality and annexed by the other municipality by the enactment by the governing bodies of each municipality of an ordinance describing by metes and bounds the property, declaring the property so described to be concurrently detached and annexed, and stating the reasons for and the purposes to be accomplished by the detachment and annexation. One certified copy of each ordinance shall be filed with the county clerk, with the county assessor, with the county recorder of deeds, and with the clerk of the circuit court of the county in which the property is located, whereupon the concurrent detachment and annexation shall be complete and final. Thereafter all courts of this state shall take notice of the limits of both municipalities as changed by the ordinances. No declaratory judgment or election shall be required for any concurrent detachment and annexation permitted by this section if there are no residents living in the area or if there are residents in the area and they be notified of the annexation and do not object within sixty days.

2. In a county of the first classification with a charter form of government containing all or a portion of a city with a population of at least three hundred thousand inhabitants:

(1) Unimproved property of a municipality which overlaps another municipality may be concurrently detached from one municipality and annexed by the other municipality by the enactment by the governing body of the receiving municipality of an ordinance describing by metes and bounds the property, declaring the property so described to be detached and annexed, and stating the reasons for and the purposes to be accomplished by the detachment and annexation. A copy of said ordinance shall be mailed to the city clerk of the contributing municipality, which shall have thirty days from receipt of said notice to pass an ordinance disapproving the change of boundary. If such ordinance is not passed within thirty days, the change shall be effective and one certified copy of the ordinance shall be filed with the county clerk, with the county assessor, with the county recorder of deeds, and with the clerk of the circuit court of the county in which the property is located, whereupon the concurrent detachment and annexation shall be complete and final. Thereafter all courts of this state shall take notice of the limits of both municipalities as changed by the ordinances. No declaratory judgment or election shall be required for any concurrent detachment and annexation permitted by this section if the landowners in the area are notified and do not object within sixty days; or

(2) An island of unincorporated area within a municipality, which is contiguous to more than one municipality or contiguous to the Missouri River and the Blue River, may be annexed by an abutting municipality by the enactment by the governing body of the municipality of an ordinance describing the metes and bounds of the property, declaring the property so described to be annexed, and stating the reasons for and the purposes to be accomplished by the annexation. All recording shall be accomplished in the same manner as set out in subdivision (1) of this subsection and shall be effective unless the governing body of the county passes an ordinance within thirty days disapproving the annexation. No declaratory judgment or election shall be required for any annexation permitted by this subdivision. Any annexation permitted by this subdivision shall exclude any property within the unincorporated area when such property has been owned by the same family for at least sixty consecutive years and consists of ten acres or more. The line of ownership from the original settler or buyer may be through children, grandchildren, siblings, nephews, or nieces, including through marriage or adoption.