(A) A municipality may exercise the powers granted under the provisions of this chapter in the total area within its corporate limits. A county may exercise the powers granted under the provisions of this chapter in the total unincorporated area or specific parts of the unincorporated area. Unincorporated areas of the county or counties adjacent to incorporated municipalities may be added to and included in the area under municipal jurisdiction for the purposes of this chapter provided that the municipality and county councils involved adopt ordinances establishing the boundaries of the additional areas, the limitations of the authority to be exercised by the municipality, and representation on the boards and commissions provided under this chapter. The agreement must be formally approved and executed by the municipal council and the county councils involved.
(B) The governing body of a municipality may designate by ordinance the county planning commission as the official planning commission of the municipality. In the event of the designation, and acceptance by the county, the county planning commission may exercise the powers and duties as provided in this chapter for municipal planning commissions as are specified in the agreement reached by the governing authorities. The agreement must specify the procedures for the exercise of powers granted in the chapter and shall address the issue of equitable representation of the municipality and the county on the boards and commissions authorized by this chapter. This agreement must be formally stated in appropriate ordinances by the governing authorities involved.