Under what circumstances would a vote of the people be required when setting up districts and at-large versus rotating Mayor?

Article IV, Section 2 of the Charter provides that “all elections to fill public offices and elections on measures shall be made, held and conducted in the manner provided by law.”  Thus, Staff has concluded that under this provision, a vote of the people is not required to change to district-based elections for the four Councilmember seats.  It is staff’s opinion, however, that converting the office of Mayor to a fifth district-based seat would require a charter amendment, that would require a vote of the electorate.