Whenever there shall be a change in the population in any of the seven districts heretofore established following a decennial federal census beginning in 1990, there shall be a reapportionment of the council districts in the following manner:
(1) The mayor shall within six months after the publication of the 1990 federal census, and each decennial federal census thereafter, file with the council a report containing a recommended plan for the reapportionment of the council district boundaries to comply with the following specifications:
a. Each district shall be formed of contiguous, and to the extent reasonably possible, compact territory, and its boundary lines shall be the centerlines of streets or other well-defined boundaries.
b. Each district shall contain as nearly as is reasonable the same population.
The report shall include a map and description of the districts recommended and shall be drafted as a proposed ordinance and considered by the council as other ordinances are considered. Once filed with the clerk, the report shall be treated as an ordinance introduced by a council member.
(2) The council shall enact a redistricting ordinance within six months after receiving such report. If the council fails to enact the redistricting ordinance within the said six months, the redistricting plan submitted by the mayor shall become effective without enactment by the council, as if it were a duly enacted ordinance.
(3) Such redistricting ordinance shall apply to the first regular election held more than six months after its becoming effective and to all municipal elections, regular or special, held after the first regular election. No incumbent council member shall be deprived of his or her unexpired term of office because of such redistricting.