(a) Subject to the limitations provided by this Code section, the governing authority of any municipal corporation is authorized to reapportion the election districts from which members of the municipal governing authority are elected following publication of the United States decennial census of 1980 or any future such census. Such reapportionment of districts shall be effective for the election of members to the municipal governing authority at the next regular general municipal election following the publication of the decennial census.

(b) The municipal governing authority shall by ordinance amend its charter pursuant to paragraph (1) of subsection (b) of Code Section 36-35-3 to reapportion the districts in accordance with the following specifications:

(1) Each reapportioned district shall be formed of contiguous territory; and the boundary lines of such district shall be the center lines of streets or other well-defined boundaries;

(2) Variations in population among such districts shall comply with the one person-one vote requirements of the United States Constitution; and

(3) The reapportionment shall be limited to adjusting the boundary lines of the existing districts only to the extent reasonably necessary to comply with the requirements of paragraph (2) of this subsection; and the number of members of the municipal governing body and the manner of electing such members, except for the adjustment of district boundary lines, shall not be changed by the municipal governing authority.

(c) In addition to reapportionment following publication of the decennial census, a municipal governing authority shall reapportion districts pursuant to this Code section if the annexation of additional territory to the corporate boundaries of the municipality has the effect of denying electors residing within the newly annexed territory the right to vote for members of the municipal governing authority on substantially the same basis as the other electors of the municipality vote for members of the municipal governing authority. The reapportionment provided for in this subsection shall meet the criteria specified in subsection (b) of this Code section and shall be further limited to making only those adjustments in district boundary lines as may be reasonably necessary to include the newly annexed territory within such districts. Reapportionment under this subsection shall be effective for the next regular general municipal election following the annexation.

(d) This Code section shall not prohibit the General Assembly from enacting a local law at any time to amend the charter of a municipality to reapportion or otherwise change election districts from which members of the municipal governing authority are elected. If such action is taken by the General Assembly following publication of a decennial census, but before the first regular general municipal election following the publication of such census, the local Act of the General Assembly shall nullify the power given to the municipal governing authority by subsections (a) and (b) of this Code section to reapportion districts following publication of that decennial census. If such action is taken by the General Assembly in conjunction with the annexation, by local Act of the General Assembly, of additional territory to the corporate boundaries of the municipality, the local Act of the General Assembly shall nullify the power and duty given to the municipal governing authority by subsection (c) of this Code section to reapportion districts as a result of that annexation.

(e) In addition to reapportionment following publication of the decennial census, the governing authority of any municipal corporation with a population of 40,000 or more according to the latest United States decennial census is authorized not more than one time during the ten-year period between the publication of consecutive decennial censuses to reapportion or modify the election districts from which members of the municipal governing authority are elected; provided, however, that (1) no such reapportionment shall result in the redistricting of more than 600 persons, (2) no such reapportionment shall occur within 180 days of a general or special municipal election or primary, and (3) a map reflecting any changes and copies of any communications to or from the United States Department of Justice relating to such changes are furnished to the Secretary of State and the Legislative Reapportionment Office within 30 days after such change or communication. Such reapportionment of districts shall be effective for the election of one or more members to the municipal governing authority at the next regular general municipal election or special municipal election following such reapportionment.