Supervisors shall be elected by Supervisorial District. Each candidate for the office of County Supervisor shall be an elector in the District which the candidate seeks to represent and shall be elected by the electors of such District. Except as otherwise provided in this Charter, candidates shall be nominated and elected pursuant to the general law. The five Supervisorial Districts shall be apportioned by ordinance pursuant to the general law and this Charter. A County Supervisor must reside in his or her District during the Supervisor's incumbency.