Same; notice to other units of government

(a) Before any city adopts a comprehensive plan or part thereof, subdivision regulations, zoning regulations or building or setback lines affecting property located outside the corporate limits of such city, written notice of such proposed action shall be given to the board of county commissioners of the county in which such property is located. Such notice also shall be given to the township board of the township in which such property is located if the township is located in a county not operating under the county unit road system. Such notice shall be given at least 20 days prior to the proposed action. (b) Before any county adopts a comprehensive plan or part thereof, subdivision regulations, zoning regulations or building or setback lines affecting property located within three miles of the corporate limits of a city, written notice of such proposed action shall be given to the governing body of such city. In any county not operating under the county unit road system, before any county adopts a comprehensive plan or part thereof, subdivision regulations or building or setback lines, written notice of such proposed action shall be given to the township board of such township in which the affected property is located. The notice required by this subsection shall be given at least 20 days prior to the proposed action. (c) The provisions of this section shall become effective on and after January 1, 1992.