Georgia Code Title 36. Local Government § 36-35-2

(a) No municipal corporation shall be incorporated, dissolved, merged, or consolidated with any other municipal corporation, or have its municipal boundaries changed except by local Act of the General Assembly or by such methods as may be provided by general law.

(b) Whenever any local Act of the General Assembly deannexes property lying within the boundaries of a municipal corporation, such property shall not be subject to annexation under Chapter 36 of this title by the municipal corporation from which the property was deannexed for a period of three years from such deannexation.